The false promise of “renewable natural gas”
February 20, 2020 1:40 PM Subscribe
It’s no substitute for shifting to clean electricity. To stay in line with the targets laid out in the Paris climate agreement, the US needs to reach net-zero carbon emissions by 2050, known as “deep decarbonization.” Virtually every credible study on deep decarbonization agrees on the basics of a strategy to get there...This strategy — for which I use the shorthand “electrify everything!” — is beginning to catch on, especially in California, which is always something of a preview of broader trends to come. In a relatively short span of time, a robust “all-electric movement” has emerged, as dozens of towns and cities take steps to encourage all-electric construction in new buildings...Natural gas utilities do not like this movement one bit. The more all-electric buildings there are, the fewer natural gas ratepayers there are. An all-electric future inevitably involves the obsolescence, or at least the substantial diminution, of natural gas utilities. Naturally, they are fighting back furiously, with astroturf groups, PR campaigns, and lobbying at the local level.
My FIL was looking at rebuilding a geothermal loop heat pump (heat and cool through forced air) for a house he was prepping for sale a couple of years ago. The cost of the system was in the 10s of thousands with cost returns equaling gas nearing the 25 year mark. Which was the expected lifetime of the system.
posted by bonehead at 2:02 PM on February 20, 2020 [1 favorite]
posted by bonehead at 2:02 PM on February 20, 2020 [1 favorite]
Thing I like about natgas is I’ve never had an outage in my life.
Also2, making toasted marshmallows on an induction cooktop is . . . difficult.
posted by Heywood Mogroot III at 2:13 PM on February 20, 2020 [1 favorite]
Also2, making toasted marshmallows on an induction cooktop is . . . difficult.
posted by Heywood Mogroot III at 2:13 PM on February 20, 2020 [1 favorite]
There's a lot of practical difficulties. There really are.
I agree the frack-til-you-cack paradigm is a false hope, but unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to. I'm not psyched about that, either. A true dilemma.
I recommend this free online book to get a sense of the gap between where we are and where we ought to be.
posted by Glomar response at 2:17 PM on February 20, 2020 [4 favorites]
I agree the frack-til-you-cack paradigm is a false hope, but unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to. I'm not psyched about that, either. A true dilemma.
I recommend this free online book to get a sense of the gap between where we are and where we ought to be.
posted by Glomar response at 2:17 PM on February 20, 2020 [4 favorites]
Biogas is natural gas for all practical purposes, but the extent to which it's produced, mostly as an agricultural byproduct from waste digestion, is really only barely enough to cover the uses to which farmer's can make of it. It certainly has a place in powering seed corn drying mills but there is no where near enough produced to power a significant fraction of the residential or commercial requirements.
There are theoretical CO2 to CH4 pathways for solar production, which edge closer to reality all the time. There's a company in BC that's nearing the engineering scale, indeed turning sunlight into longer-chain hydrocarbons. They're still several times the cost of petro-methane though.
posted by bonehead at 2:26 PM on February 20, 2020
There are theoretical CO2 to CH4 pathways for solar production, which edge closer to reality all the time. There's a company in BC that's nearing the engineering scale, indeed turning sunlight into longer-chain hydrocarbons. They're still several times the cost of petro-methane though.
posted by bonehead at 2:26 PM on February 20, 2020
My understanding is that a lot of builders and contractors in CA are getting ready for a future where new gas runs are against code. It's definitely partially a sales technique but there is mounting pressure to get your fancy gas ranges in before they're banned. This is destined to be an extraordinarily unpopular measure in the pretty substantial parts of the state who don't have utility natural gas and instead have propane gas appliances. It's kind of a punch in the gut when your alternative is hugely expensive electricity provided by PG&E.
posted by feloniousmonk at 2:29 PM on February 20, 2020
posted by feloniousmonk at 2:29 PM on February 20, 2020
"Natural" gas is still methane, currently touted as essential to any "feasible" transition, and its "renewable" country-side cousin really just helps a subtler lock-in to the fossil fuel paradigm for another generation or so. And no end of "unknown knowns" (here's a summary) ready to take our remaining carbon budget out quite by surprise...
posted by progosk at 2:40 PM on February 20, 2020 [2 favorites]
posted by progosk at 2:40 PM on February 20, 2020 [2 favorites]
rossmessi, the upcoming version of the Vermont codes has provisions for allowing electric back-up in situations like yours, substantially reducing the redundancy costs. They don't officially take effect until September, but you may find leeway to cite them in your approach. Worth looking into depending on the stage of your project.
Mostly, which is to say that this is a recognized problem and there are active efforts to find the best regulatory formula.
posted by meinvt at 2:40 PM on February 20, 2020 [1 favorite]
Mostly, which is to say that this is a recognized problem and there are active efforts to find the best regulatory formula.
posted by meinvt at 2:40 PM on February 20, 2020 [1 favorite]
I live in the frozen north. The only homes I have ever had experience of, that used electric heat, had ruinously expensive utility bills. Of course, all of them were rentals, which means no one had invested in efficiency; they just shrug and pass the cost on to the tenant.
Is it actually possible to heat a northern home, with electric, in a way that isn't cost prohibitive? As a homeowner I have been very willing to invest in energy conservation, so when given the chance over the years I have installed high efficiency furnaces, insulation, upgraded windows, etc. But my electric heat experiences during my renting days were so incredibly dismal that I never have considered electric heat again. If I bought the right things, could electric now do better?
posted by elizilla at 2:52 PM on February 20, 2020 [2 favorites]
Is it actually possible to heat a northern home, with electric, in a way that isn't cost prohibitive? As a homeowner I have been very willing to invest in energy conservation, so when given the chance over the years I have installed high efficiency furnaces, insulation, upgraded windows, etc. But my electric heat experiences during my renting days were so incredibly dismal that I never have considered electric heat again. If I bought the right things, could electric now do better?
posted by elizilla at 2:52 PM on February 20, 2020 [2 favorites]
You will run into prohibitive electrical expenses heating a home in merely the mountainous not-north in California. Our house has 2x6 construction in order to accommodate extra insulation, has been examined and winterized and sealed and so on, and we still got eye watering bills from our electric heat this winter. You find things like PG&E says the rate is $X but that's actually the off-peak rate, where the peak rate is $X+50% and peak times run from 4-9 PM. You can get bumped into a higher pricing tier, etc. They break out all of the techniques.
Here's where this gets really terrible: if you're in a forested rural area chances are good it's cheaper (maybe substantially) to heat your house primarily with wood burning stoves or fireplaces and only to use utility heat as a supplement, if at all. Of course, these fires produce more pollution and have a worse impact on air quality than their natural gas or electric equivalents.
posted by feloniousmonk at 3:00 PM on February 20, 2020 [1 favorite]
Here's where this gets really terrible: if you're in a forested rural area chances are good it's cheaper (maybe substantially) to heat your house primarily with wood burning stoves or fireplaces and only to use utility heat as a supplement, if at all. Of course, these fires produce more pollution and have a worse impact on air quality than their natural gas or electric equivalents.
posted by feloniousmonk at 3:00 PM on February 20, 2020 [1 favorite]
I saw the NYT article about Bellingham going gas free and I do wonder if it will really do anything to improve the world or if it is just a classist rearranging of the deck chairs. That sounds awfully sour so to qualify it I should say that I am not opposed at all to mandating the use of the best sort of heating but it seems like a very complex issue. There is so much confusion about what electric heat is and the capacity for natural gas appliances to be efficient that the debate, such as it is, is pretty inchoate. Does anyone else remember when we were on the cusp of getting individual fuel cells that would generate our electricity and use the waste heat to heat our houses or hot water?
posted by Pembquist at 3:04 PM on February 20, 2020
posted by Pembquist at 3:04 PM on February 20, 2020
If you’re in an area where the bulk of the electric comes from natural gas, you’re better off using natural gas at home for heating and cooking. We have a long way to come on cleaner energy before that’s not the case. For example, our water heater and stove are natural gas. We can get the water warmed or food cooked with a gas flame doing the work quickly. Or... we can get electricity from the utility that’s generated from natural gas, with a lot of the energy potential in gas lost in the generating process, and even more lost due to inefficiency in transmission. The utility’s generators would burn several times more gas than we would to accomplish the same thing.
I’m not saying this as “rah rah natural gas” by a long shot. It’s just the current reality. More and more renewables are coming online, and if we can get large scale storage figured out, that’s the real game changer since we’ll have much much less wasted generated power (if generated power isn’t used, it gets caught by batteries and the resource used to generate the power isn’t wasted.) I do say this as someone who has solar on the roof, since we’re fortunate enough to be able to do so. As a side note, it’s absurd that Arizona building codes don’t require solar on all new residential construction as well as compatible commercial buildings. Nuclear sounds fine and good, but it costs a LOT to build a plant that will operate safely, plus there’s going to be a multiple year lead time before that plant generates any return on investment. If you’re looking at $5 billion plus and 5-7 years before you sell a single kilowatt, that’s a hard sell for any investor. You could buy a metric farkton of solar and wind for that same money and be selling power within a few months.
posted by azpenguin at 3:11 PM on February 20, 2020 [1 favorite]
I’m not saying this as “rah rah natural gas” by a long shot. It’s just the current reality. More and more renewables are coming online, and if we can get large scale storage figured out, that’s the real game changer since we’ll have much much less wasted generated power (if generated power isn’t used, it gets caught by batteries and the resource used to generate the power isn’t wasted.) I do say this as someone who has solar on the roof, since we’re fortunate enough to be able to do so. As a side note, it’s absurd that Arizona building codes don’t require solar on all new residential construction as well as compatible commercial buildings. Nuclear sounds fine and good, but it costs a LOT to build a plant that will operate safely, plus there’s going to be a multiple year lead time before that plant generates any return on investment. If you’re looking at $5 billion plus and 5-7 years before you sell a single kilowatt, that’s a hard sell for any investor. You could buy a metric farkton of solar and wind for that same money and be selling power within a few months.
posted by azpenguin at 3:11 PM on February 20, 2020 [1 favorite]
Thing I like about natgas is I’ve never had an outage in my life.
On the other hand, electric heat almost never causes your house to explode.
It's kind of a punch in the gut when your alternative is hugely expensive electricity provided by PG&E.
California is a great place to put in PV solar. It's a terrific investment; the more the power company charges, the better solar looks. Even up here in New England, I make out like a bandit. My panels went up in 2010, and paid for themselves in about 7 years. Most years, I only pay one electric bill during the year, because of snow on the roof. I just got this year's bill, for $35.
I'm assuming that a progressive state like CA would mandate balance-billing and offer tax rebates on solar installations. My best advice is to not buy into the schemes where somebody owns the panels on your roof and promises you'll pay them less than the power company charges. Buy and own your panels, even if you have to take out a loan to do it. The leased- panel companies get all the benefits of the panels on their customers' roofs, and the customers get crumbs. Also, if you want to sell your house, they effectively have a lien on it, and you have to pay them off before you can sell it.
posted by Kirth Gerson at 3:15 PM on February 20, 2020 [5 favorites]
On the other hand, electric heat almost never causes your house to explode.
It's kind of a punch in the gut when your alternative is hugely expensive electricity provided by PG&E.
California is a great place to put in PV solar. It's a terrific investment; the more the power company charges, the better solar looks. Even up here in New England, I make out like a bandit. My panels went up in 2010, and paid for themselves in about 7 years. Most years, I only pay one electric bill during the year, because of snow on the roof. I just got this year's bill, for $35.
I'm assuming that a progressive state like CA would mandate balance-billing and offer tax rebates on solar installations. My best advice is to not buy into the schemes where somebody owns the panels on your roof and promises you'll pay them less than the power company charges. Buy and own your panels, even if you have to take out a loan to do it. The leased- panel companies get all the benefits of the panels on their customers' roofs, and the customers get crumbs. Also, if you want to sell your house, they effectively have a lien on it, and you have to pay them off before you can sell it.
posted by Kirth Gerson at 3:15 PM on February 20, 2020 [5 favorites]
Is it actually possible to heat a northern home, with electric, in a way that isn't cost prohibitive?
You are probably talking about direct heating with electricity? When people talk about electrification of heat that tech is included but they are also talking about heat pumps. Heat pumps basically use a unit of electricity to drive a mechanism which is similar to what's in your fridge to take heat from the environment into your home. There are different kinds of heat pump: ground, water and air source and depending on the type, plus local geology and other factors for each unit of electricity in you get more units of heat for your building. So a decently efficient Ground Source HP might have Co-efficient of Performance (CoP) of 4, which means for each unit of electricity in, you end up with a total of 4 units of heat in your house. So its a lot more efficient than just using electricity directly. If you live somewhere that gets hot in the summer you can run them in reverse too and they will cool and at the same time this can improve the CoP for the winter by dumping summer heat into the soil.
posted by biffa at 3:16 PM on February 20, 2020 [7 favorites]
You are probably talking about direct heating with electricity? When people talk about electrification of heat that tech is included but they are also talking about heat pumps. Heat pumps basically use a unit of electricity to drive a mechanism which is similar to what's in your fridge to take heat from the environment into your home. There are different kinds of heat pump: ground, water and air source and depending on the type, plus local geology and other factors for each unit of electricity in you get more units of heat for your building. So a decently efficient Ground Source HP might have Co-efficient of Performance (CoP) of 4, which means for each unit of electricity in, you end up with a total of 4 units of heat in your house. So its a lot more efficient than just using electricity directly. If you live somewhere that gets hot in the summer you can run them in reverse too and they will cool and at the same time this can improve the CoP for the winter by dumping summer heat into the soil.
posted by biffa at 3:16 PM on February 20, 2020 [7 favorites]
I just wish I'd had the foresight to replace my gas-fired heater with something electric when I replaced the old one, as it's the only gas appliance left in the house, and is the only reason I have utility bills at anything above the cost of a grid connection (presently $15/mo for me).
Meanwhile, my solar array had a 9 year ROI horizon when installed, and with pricing going the way it is I think I'm gonna bet it'll be less than that. I used to be a gas partisan back in Chicago (gas range, gas heater, gas dryer), but now I just grimace when I see my winter heating bill ($115) and compare it to my summer cooling bill of $15. Given my energy balance I could probably offset the electric heat by adding a panel, maayybe two, to my system.
The only real drawback is the same one faced by everyone out here: PGE outages. Goddamn, will batteries hurry the hell up?
posted by aramaic at 3:17 PM on February 20, 2020 [1 favorite]
Meanwhile, my solar array had a 9 year ROI horizon when installed, and with pricing going the way it is I think I'm gonna bet it'll be less than that. I used to be a gas partisan back in Chicago (gas range, gas heater, gas dryer), but now I just grimace when I see my winter heating bill ($115) and compare it to my summer cooling bill of $15. Given my energy balance I could probably offset the electric heat by adding a panel, maayybe two, to my system.
The only real drawback is the same one faced by everyone out here: PGE outages. Goddamn, will batteries hurry the hell up?
posted by aramaic at 3:17 PM on February 20, 2020 [1 favorite]
Where is the information about the carbon generated TO PRODUCE ELECTRICITY????
posted by amtho at 3:25 PM on February 20, 2020 [2 favorites]
posted by amtho at 3:25 PM on February 20, 2020 [2 favorites]
So its a lot more efficient than just using electricity directly.
Yeah just to elaborate on what biffa is saying... direct electric heating through heating coils has been a fairly stagnant technology for years. It's fairly easy to convert electricity to heat through the use of a resistor at near 100% efficiency and the only gains you can get are from more efficient distribution of that heat in your home (but distribution also uses more power in the shape of fans or pumps).
But heat pumps don't make heat, they move heat energy around. Through compression cycles you can steal heat even from things that are colder than your home, in the same way that you can get your refrigerator colder than your home. So when biffa says a factor of 4, that's 4x the efficiency of a resistive heater.
posted by JauntyFedora at 3:26 PM on February 20, 2020 [1 favorite]
Yeah just to elaborate on what biffa is saying... direct electric heating through heating coils has been a fairly stagnant technology for years. It's fairly easy to convert electricity to heat through the use of a resistor at near 100% efficiency and the only gains you can get are from more efficient distribution of that heat in your home (but distribution also uses more power in the shape of fans or pumps).
But heat pumps don't make heat, they move heat energy around. Through compression cycles you can steal heat even from things that are colder than your home, in the same way that you can get your refrigerator colder than your home. So when biffa says a factor of 4, that's 4x the efficiency of a resistive heater.
posted by JauntyFedora at 3:26 PM on February 20, 2020 [1 favorite]
The argument for electrification of heat and transport in the UK has been going on for about 12, maybe 15 years. It has had a resurgence in recent years and we are also seeing the pushback by the gas people. There is a general assumption that we will see more electrification in the UK as EV sales go up, but we've seen only very limited expansion of heat pumps.
If you go to any heat events in the UK then there will be gas people there playing up the benefits of biogas, but I would say, more significantly playing up hydrogen, produced from either fossil fuels (so dirty and less efficient than just burning methane) or from renewables, basically using electrolysis to mitigate variable renewable generation like wind and solar. The problem with this is that the process of electrolysis, transport, combustion gives an efficiency of 50-60% while a battery can do up to 80%.
There is already some hydrogen going into UK grids, they can mix about 20% H2 in with natural gas without any issues, but anything above that and it becomes a safety issue that will require substantial infrastructure investment. The UK, along with some other EU Member States, has said it will stop connection to the gas grid for new build from some near future date, so the push is on to put in the most viable alternatives. Of course, one can argue this should have happened back in 2016 when we were supposed to have regs requiring zero carbon homes. So that'll be anther million plus gas connected homes in the meantime, all chugging out carbon dioxide until the net zero date in 2050.
This is the big issue of course, how to decarbonise existing homes? Most countries have already built 60-80% of the houses they will have in 2050. Heat in most EU countries is about a third of national energy demand.
posted by biffa at 3:30 PM on February 20, 2020
If you go to any heat events in the UK then there will be gas people there playing up the benefits of biogas, but I would say, more significantly playing up hydrogen, produced from either fossil fuels (so dirty and less efficient than just burning methane) or from renewables, basically using electrolysis to mitigate variable renewable generation like wind and solar. The problem with this is that the process of electrolysis, transport, combustion gives an efficiency of 50-60% while a battery can do up to 80%.
There is already some hydrogen going into UK grids, they can mix about 20% H2 in with natural gas without any issues, but anything above that and it becomes a safety issue that will require substantial infrastructure investment. The UK, along with some other EU Member States, has said it will stop connection to the gas grid for new build from some near future date, so the push is on to put in the most viable alternatives. Of course, one can argue this should have happened back in 2016 when we were supposed to have regs requiring zero carbon homes. So that'll be anther million plus gas connected homes in the meantime, all chugging out carbon dioxide until the net zero date in 2050.
This is the big issue of course, how to decarbonise existing homes? Most countries have already built 60-80% of the houses they will have in 2050. Heat in most EU countries is about a third of national energy demand.
posted by biffa at 3:30 PM on February 20, 2020
elizilla, it depends on what you mean by northern. Modern air source heat pumps, as found in the decent mini-split systems, can heat a space more efficiently than resistance heating down to around 0F. If you have a well insulated home, occasional dips below 0F won't cost you much, but if you often see subzero temperatures for days or weeks at a time, that's when the expense of the backup heat becomes an issue.
That said, I used to live in a place with an air source heat pump that used a natural gas/propane backup rather than electric. I'm not sure if such things still exist in the time of 90%+ efficiency furnaces, but if they do it would be a pretty good option if you have gas access. You shouldn't normally use much anyway, so even relatively expensive propane could make a reasonable backup.
Heat pumps are far better than most people give them credit for, even the relatively crappy units from the 80s.
More broadly, it's pretty interesting to see people touting all electric houses again. My grandma lived in the same house from around 1964 until she died in the 2010s, all electric the entire time. It even had the little all electric medallion on the door bell. Being in Arkansas and having very cheap rates, the electric bill never got out of hand even without a heat pump.
Ironically, my SO and I spent a lot more and had much less predictable bills than grandma did late in her life thanks to us living in a poorly insulated house built in 1930 and the before-fracking price volatility of natural gas. Not that electric resistance heat would have been any cheaper for the same BTUs, even at only a few cents a kWh.
The point of the anecdote is that what is most economical and environmentally sound will vary drastically depending on climate zone and even more local factors like tree canopy, surrounding topography, and many other factors. There is little specific advice on the subject that can, even in principle, be applicable to most people. Only general principles like "use as little of the least carbon intensive energy you can in your circumstances" that are of little practical use apply across the board.
posted by wierdo at 3:32 PM on February 20, 2020 [2 favorites]
That said, I used to live in a place with an air source heat pump that used a natural gas/propane backup rather than electric. I'm not sure if such things still exist in the time of 90%+ efficiency furnaces, but if they do it would be a pretty good option if you have gas access. You shouldn't normally use much anyway, so even relatively expensive propane could make a reasonable backup.
Heat pumps are far better than most people give them credit for, even the relatively crappy units from the 80s.
More broadly, it's pretty interesting to see people touting all electric houses again. My grandma lived in the same house from around 1964 until she died in the 2010s, all electric the entire time. It even had the little all electric medallion on the door bell. Being in Arkansas and having very cheap rates, the electric bill never got out of hand even without a heat pump.
Ironically, my SO and I spent a lot more and had much less predictable bills than grandma did late in her life thanks to us living in a poorly insulated house built in 1930 and the before-fracking price volatility of natural gas. Not that electric resistance heat would have been any cheaper for the same BTUs, even at only a few cents a kWh.
The point of the anecdote is that what is most economical and environmentally sound will vary drastically depending on climate zone and even more local factors like tree canopy, surrounding topography, and many other factors. There is little specific advice on the subject that can, even in principle, be applicable to most people. Only general principles like "use as little of the least carbon intensive energy you can in your circumstances" that are of little practical use apply across the board.
posted by wierdo at 3:32 PM on February 20, 2020 [2 favorites]
I have some bad news about the electric grid in California.
California is much bigger than SF and the 10 miles around its border. Here in Orange County I only hear about California's power issues on MeFi, honestly. The last time I experienced a power outage that wasn't because of a tree in my own yard was during the Clinton Administration. Even during Enron, I lived in the LADWP service area and I read about those power issues on the news as well.
But, I can't believe for a second that there is a big constituency in CA that wants to throw away their gas stoves, gas dryers, and gas furnaces for electric. At least by a group of people that pays their own utility bills. Electricity is so much more expensive.
posted by sideshow at 3:34 PM on February 20, 2020 [1 favorite]
California is much bigger than SF and the 10 miles around its border. Here in Orange County I only hear about California's power issues on MeFi, honestly. The last time I experienced a power outage that wasn't because of a tree in my own yard was during the Clinton Administration. Even during Enron, I lived in the LADWP service area and I read about those power issues on the news as well.
But, I can't believe for a second that there is a big constituency in CA that wants to throw away their gas stoves, gas dryers, and gas furnaces for electric. At least by a group of people that pays their own utility bills. Electricity is so much more expensive.
posted by sideshow at 3:34 PM on February 20, 2020 [1 favorite]
Where is the information about the carbon generated TO PRODUCE ELECTRICITY????
Its in lots of places. Its not a secret. Here is a live map showing current carbon intensity from electrical generation in each European country and in some of the US regions (largely CA and eastern electrical regions). Based on your profile your local supply is pretty dirty right now, even accounting for it being a peak demand time.
posted by biffa at 3:38 PM on February 20, 2020 [3 favorites]
Its in lots of places. Its not a secret. Here is a live map showing current carbon intensity from electrical generation in each European country and in some of the US regions (largely CA and eastern electrical regions). Based on your profile your local supply is pretty dirty right now, even accounting for it being a peak demand time.
posted by biffa at 3:38 PM on February 20, 2020 [3 favorites]
Electricity is so much more expensive.
Its difficult to compete with fossil fuels when the climate change it causes is passed on as costs to the commons. Dumping CO2 and other pollutants into the atmosphere and letting the grandkids worry about the costs down the line is baked in to our model for delivering energy and it will be hard to persuade people to pony up for the damage we all cause.
posted by biffa at 3:42 PM on February 20, 2020 [13 favorites]
Its difficult to compete with fossil fuels when the climate change it causes is passed on as costs to the commons. Dumping CO2 and other pollutants into the atmosphere and letting the grandkids worry about the costs down the line is baked in to our model for delivering energy and it will be hard to persuade people to pony up for the damage we all cause.
posted by biffa at 3:42 PM on February 20, 2020 [13 favorites]
For my new reasonably eco-friendly build I had full double glazing, proper window and eave design to maximize winter sun and minimize summer sun, and extra insulation put into the walls and roof, waffle pod foundation, I run heat pumps for cooling and heating, and thermal solar hot water with an electric backup, induction cooking instead of gas and explicitly refused the natural gas connection... my electricity usage over the last 100 days of summer has been 5kwh per day, which is the lowest I've ever had in my life.
I have a personal hate for natural gas. The pilot lights on many legacy appliances burn so much gas - as much as 50% of the total gas usage over low demand periods like summer - and you pay a daily supply charge that works out to be $360 per year even if you use zero gas.
Insulation is probably the best thing you can spend on. There was one summer day where we came home from the movies and the air temperature was about 45°C, we just got home and had a nap and didn't even need to turn on any fans or AC that day or night because inside was a comfortable 25°C.
We have an efficient AC unit in our room that's rated at a Cooling EER of 6.45 and Heating COP of 5.75 ... at max power, it uses 470 watts of electricity to generate 2.7 kilowatts of heat.
posted by xdvesper at 3:42 PM on February 20, 2020 [7 favorites]
I have a personal hate for natural gas. The pilot lights on many legacy appliances burn so much gas - as much as 50% of the total gas usage over low demand periods like summer - and you pay a daily supply charge that works out to be $360 per year even if you use zero gas.
Insulation is probably the best thing you can spend on. There was one summer day where we came home from the movies and the air temperature was about 45°C, we just got home and had a nap and didn't even need to turn on any fans or AC that day or night because inside was a comfortable 25°C.
We have an efficient AC unit in our room that's rated at a Cooling EER of 6.45 and Heating COP of 5.75 ... at max power, it uses 470 watts of electricity to generate 2.7 kilowatts of heat.
posted by xdvesper at 3:42 PM on February 20, 2020 [7 favorites]
I think PGE covers a little bit more area than a ten mile radius around SF?!... It covers a massive portion of the state's territory. I think Orange County residents hearing about California power issues only on MeFi says more about their own provincialism than it does about the seriousness or magnitude of the issue?
posted by flamk at 3:42 PM on February 20, 2020 [1 favorite]
posted by flamk at 3:42 PM on February 20, 2020 [1 favorite]
Is it actually possible to heat a northern home, with electric, in a way that isn't cost prohibitive?
Depends how expensive electricity is. Quebec has a lot of cheap hydroelectricity. About 85% of Quebec households use electricity for heating, mostly baseboard heaters.
Where is the information about the carbon generated TO PRODUCE ELECTRICITY????
Mark Jaccard suggests that climate policy should focus on decarbonizing two key sectors: electricity and transport. Together they account for more than half of future greenhouse gas emissions.
posted by russilwvong at 4:07 PM on February 20, 2020 [2 favorites]
Depends how expensive electricity is. Quebec has a lot of cheap hydroelectricity. About 85% of Quebec households use electricity for heating, mostly baseboard heaters.
Where is the information about the carbon generated TO PRODUCE ELECTRICITY????
Mark Jaccard suggests that climate policy should focus on decarbonizing two key sectors: electricity and transport. Together they account for more than half of future greenhouse gas emissions.
posted by russilwvong at 4:07 PM on February 20, 2020 [2 favorites]
Its difficult to compete with fossil fuels when the climate change it causes is passed on as costs to the commons. Dumping CO2 and other pollutants into the atmosphere and letting the grandkids worry about the costs down the line is baked in to our model for delivering energy and it will be hard to persuade people to pony up for the damage we all cause.
To me it's like unleaded vs. leaded gasoline. We know that lead has terrible effects on children's brains, so it makes sense to use unleaded gas, even though leaded is cheaper.
Same thing with carbon-free vs. fossil-fuel energy: we know that burning fossil fuels is destabilizing the climate, so it makes sense to switch to carbon-free energy, even though that means energy will be more expensive.
As you say, that's arguably an illusion, because you're not paying for the cost of climate damage caused by burning fossil fuels.
posted by russilwvong at 4:13 PM on February 20, 2020 [2 favorites]
To me it's like unleaded vs. leaded gasoline. We know that lead has terrible effects on children's brains, so it makes sense to use unleaded gas, even though leaded is cheaper.
Same thing with carbon-free vs. fossil-fuel energy: we know that burning fossil fuels is destabilizing the climate, so it makes sense to switch to carbon-free energy, even though that means energy will be more expensive.
As you say, that's arguably an illusion, because you're not paying for the cost of climate damage caused by burning fossil fuels.
posted by russilwvong at 4:13 PM on February 20, 2020 [2 favorites]
Thing I like about natgas is I’ve never had an outage in my life.
On the other hand, electric heat almost never causes your house to explode.
Explode, no. Burn... tens of thousands of homes per year get torched in electrical fires.
posted by azpenguin at 5:52 PM on February 20, 2020 [1 favorite]
On the other hand, electric heat almost never causes your house to explode.
Explode, no. Burn... tens of thousands of homes per year get torched in electrical fires.
posted by azpenguin at 5:52 PM on February 20, 2020 [1 favorite]
Cooking on a gas range is much easier and can lead to better results.
posted by SoberHighland at 5:54 PM on February 20, 2020
posted by SoberHighland at 5:54 PM on February 20, 2020
Cooking on a gas range is much easier and can lead to better results
I felt the same way, until I used an induction range; mine can boil a pot of water in two minutes and has an ultra low “melt” setting that can hold something at a melted temp (eg: chocolate) more reliably for any length of time I want than any gas range I’ve ever used (including one that cost $30K and required a commercial vent system). The only thing it can’t do is wok hei, but unless you’ve got a wok burner you’re not getting that on a home gas range either.
Keeping the induction range clean is also hilariously easy compared to my old gas maintenance routine. Wipe, and I’m done.
Seriously, a decent induction cooktop was a total game-changer for me. Not for everyone, probably, but oh my god I’m never going back it’s amazing.
posted by aramaic at 6:09 PM on February 20, 2020 [6 favorites]
I felt the same way, until I used an induction range; mine can boil a pot of water in two minutes and has an ultra low “melt” setting that can hold something at a melted temp (eg: chocolate) more reliably for any length of time I want than any gas range I’ve ever used (including one that cost $30K and required a commercial vent system). The only thing it can’t do is wok hei, but unless you’ve got a wok burner you’re not getting that on a home gas range either.
Keeping the induction range clean is also hilariously easy compared to my old gas maintenance routine. Wipe, and I’m done.
Seriously, a decent induction cooktop was a total game-changer for me. Not for everyone, probably, but oh my god I’m never going back it’s amazing.
posted by aramaic at 6:09 PM on February 20, 2020 [6 favorites]
^ seconding the fact that induction cooking is a real game changer. From an efficiency point of view it's actually just the same as an electric element stove.... but for me the main advantage is that the glass doesn't get very hot as the energy is transferred direct to the pot, so spillages don't harden on the cooking surface the way they do on gas stoves. Spray on some detergent after you're done and wipe and you have a beautiful mirror finish on the black glass, like the surface of a new smartphone. Induction does transfer heat at a ferocious rate - at max it boils water faster than my old gas stove, and on the low end you just pick a specific power level to simmer soups.
It even helpfully has temperature sensors in the glass to tell you if the glass is hot from contact with the pot so you don't scorch yourself while cleaning it!
posted by xdvesper at 7:33 PM on February 20, 2020 [3 favorites]
It even helpfully has temperature sensors in the glass to tell you if the glass is hot from contact with the pot so you don't scorch yourself while cleaning it!
posted by xdvesper at 7:33 PM on February 20, 2020 [3 favorites]
Agreed on induction, I was a diehard gas fan, until I got induction and now I'll never go back. Gets hotter, goes lower, easier to clean, and as an added bonus, I'm not filling my house up with airborne pollutants (people underestimate just how many VOCs etc gas cooktops put out).
I agree the frack-til-you-cack paradigm is a false hope, but unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to
Baseload power is a myth, even intermittent renewables are enough. Here's another article, and another.
These articles are written by professors, energy analysts, and the people running the Chinese power grid.
When you talk about the need for baseload power and renewables inability to supply it - wittingly or not - you are parroting talking points that were devised and promoted by climate deniers. The claims have no factual basis (much like nuclear, for that matter).
We have the technology and capability for a 100% renewable electricity grid today. The only barriers are political, not technical.
posted by smoke at 7:44 PM on February 20, 2020 [12 favorites]
I agree the frack-til-you-cack paradigm is a false hope, but unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to
Baseload power is a myth, even intermittent renewables are enough. Here's another article, and another.
These articles are written by professors, energy analysts, and the people running the Chinese power grid.
When you talk about the need for baseload power and renewables inability to supply it - wittingly or not - you are parroting talking points that were devised and promoted by climate deniers. The claims have no factual basis (much like nuclear, for that matter).
We have the technology and capability for a 100% renewable electricity grid today. The only barriers are political, not technical.
posted by smoke at 7:44 PM on February 20, 2020 [12 favorites]
Is it actually possible to heat a northern home, with electric, in a way that isn't cost prohibitive?
Depends on what you mean by "heat a northern home". Our house in NE Washington about 100 miles from Canada was built in 1952 and wasn't built to accommodate central heat of any sort. The old heaters, in-wall coil heaters that I believe the British would call something like "the electric fire" are in many rooms, and baseboard heaters that I believe are a later installation are in some rooms, sometimes the same room. We've been using local radiant free-standing heaters, the micathermic type like this, for several years now. They work pretty well for maintaining keep-an-extra-layer-on levels of warmth, and they aren't eye-wateringly costly to run.
(They can be a bit hard to find the right temp balance on, but once you do the fine tuning of the thermostat knob to your liking, they function quite well)
We had been using the free-standing electric oil-filled radiators for a long time because, well, thermal mass and all that... but one day i came home from work early due to a scheduling fluke and found one of those units dripping flaming oil onto the carpet of our living room (which wasn't itself on fire, thank goodness!), and we move away from that technology pretty quickly after that.
We like the free-standing better than wall-mounted because you can move them around if you need warm close to where you are NOW sitting, plus better air circulation (which is entire passive, so no fan noise).
YMMV, but we've used this kind of heat for years and it is cheaper than running baseboard heaters. I do run the fire in my bathroom on cold days, while I shower, and turn it off when I emerge and bask in its glow while I towel off. Glorious!
posted by hippybear at 8:49 PM on February 20, 2020 [1 favorite]
Depends on what you mean by "heat a northern home". Our house in NE Washington about 100 miles from Canada was built in 1952 and wasn't built to accommodate central heat of any sort. The old heaters, in-wall coil heaters that I believe the British would call something like "the electric fire" are in many rooms, and baseboard heaters that I believe are a later installation are in some rooms, sometimes the same room. We've been using local radiant free-standing heaters, the micathermic type like this, for several years now. They work pretty well for maintaining keep-an-extra-layer-on levels of warmth, and they aren't eye-wateringly costly to run.
(They can be a bit hard to find the right temp balance on, but once you do the fine tuning of the thermostat knob to your liking, they function quite well)
We had been using the free-standing electric oil-filled radiators for a long time because, well, thermal mass and all that... but one day i came home from work early due to a scheduling fluke and found one of those units dripping flaming oil onto the carpet of our living room (which wasn't itself on fire, thank goodness!), and we move away from that technology pretty quickly after that.
We like the free-standing better than wall-mounted because you can move them around if you need warm close to where you are NOW sitting, plus better air circulation (which is entire passive, so no fan noise).
YMMV, but we've used this kind of heat for years and it is cheaper than running baseboard heaters. I do run the fire in my bathroom on cold days, while I shower, and turn it off when I emerge and bask in its glow while I towel off. Glorious!
posted by hippybear at 8:49 PM on February 20, 2020 [1 favorite]
unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to
"Generation at levels we are accustomed to" inherently builds in wasting energy at levels we are accustomed to.
End-use energy efficiency remains the single biggest untapped energy reserve on the planet. Dollar for dollar, it outperfoms nukes by at least a factor of ten. It also starts delivering benefits right away, not twenty years down the line when the plant finally starts producing.
Plus everything smoke said.
None of this stuff is new, and neither is the dinosaur squeezings industry's FUD around it. If you're interested in learning more, Amory Lovins has made a career out of doggedly and persistently refuting Big Energy propaganda, with footnotes.
posted by flabdablet at 9:04 PM on February 20, 2020 [2 favorites]
"Generation at levels we are accustomed to" inherently builds in wasting energy at levels we are accustomed to.
End-use energy efficiency remains the single biggest untapped energy reserve on the planet. Dollar for dollar, it outperfoms nukes by at least a factor of ten. It also starts delivering benefits right away, not twenty years down the line when the plant finally starts producing.
Plus everything smoke said.
None of this stuff is new, and neither is the dinosaur squeezings industry's FUD around it. If you're interested in learning more, Amory Lovins has made a career out of doggedly and persistently refuting Big Energy propaganda, with footnotes.
posted by flabdablet at 9:04 PM on February 20, 2020 [2 favorites]
azpenguin, a good way to store the excess solar power from your roof is as hot water in your water heater at times of day when it's otherwise going to be wasted. And if you're going to do that, it probably becomes more economical to have an entirely electric water heater, rather than a gas-electric hybrid or a preheater, despite the small grid loss in efficiency. Especially as utility-scale storage is coming online. This kind of flexability is sorta the point of electrifying everything.
posted by joeyh at 9:17 PM on February 20, 2020 [1 favorite]
posted by joeyh at 9:17 PM on February 20, 2020 [1 favorite]
store the excess solar power from your roof is as hot water in your water heater at times of day when it's otherwise going to be wasted
and if that water heater is built around a heat pump rather than a resistive element, attach a secondary tank and store four times the energy your roof panels are converting.
Every time I hear people talking about fusion power as The Ultimate Answer I can only agree. Our local fusion plant has had an absolutely stellar reliability record for four and a half billion years, as has its associated world-wide wireless power distribution system operating in the 300-800THz radio band. All we really need to do is get better at designing and deploying receiving stations.
posted by flabdablet at 10:32 PM on February 20, 2020 [4 favorites]
and if that water heater is built around a heat pump rather than a resistive element, attach a secondary tank and store four times the energy your roof panels are converting.
Every time I hear people talking about fusion power as The Ultimate Answer I can only agree. Our local fusion plant has had an absolutely stellar reliability record for four and a half billion years, as has its associated world-wide wireless power distribution system operating in the 300-800THz radio band. All we really need to do is get better at designing and deploying receiving stations.
posted by flabdablet at 10:32 PM on February 20, 2020 [4 favorites]
To add to that point... I'm using a thermal solar collector as it's twice as efficient as PV solar for hot water.
The way it works is quite fascinating. Tank water has to be maintained at 65°C to prevent growth of of bacteria such as legionella. However due to the danger of burns, lower temperature water is desired at the tap - it takes 1 second to cause a full thickness burn at 70°C but 5 minutes to cause a full thickness burn at 50°C so the margin of safety provided is substantial.
Hence a tempering valve is mandated to mix hot water from the tank with cold water, allowing a max water temp of 50°C or a max of 43°C when installed in a facility for children (schools, child care, etc).
So how the thermal solar collectors work is that a heating element at the bottom of the tank constantly heats the tank to 60°C. The thermal solar collector on the roof cycles water from the collector back into the tank when it hits some preset temperature, say 90°C. This gradually heats up the water in the tank, say to 80°C.
Say in summer you use 80L of water per shower, and the current temperature in your tank is 80°C and the tank size is 300L. Typical shower temperature is 40°C so that's a 66% mix of 50°C hot water and 33°C mix of cold water at 20°C mains temperature. This would pull 50L from your hot water outlet, which itself comes from the tempering valve which would have drawn only 26L from the 300L hot water tank.
Your 300L tank is now 26L short, and it refills using 26L from the mains water at 20°C. Thus this shower drops your overall tank temperature from 80°C down to 74°C.
Remember your heater only kicks in when the temperature drops below 60°C... so in theory over summer your hot water bill is close to zero.
I'm not a fan of using heat pumps for hot water. They're expensive due to their low production volumes, potentially have noise and maintenance issues, and by the time you have solar thermal and solar PV lowering your energy requirements, the heat pump is not really adding that much more efficiency to the system.
I read an article once about energy storage - why should we use a battery for energy storage? New houses could in theory have a single solar powered heat pump that is attached to two large tanks of water in the ground, pumping heat between them - one hot water tank kept to near 100°C and one tank of solid ice / slush. You'd draw down the energy in them overnight and top them up during the day, for climate control, refrigeration, showering, etc - rather than having separate appliances for all of them. It's almost like going back to the old days when houses had a block of ice delivered to their door each day to put in their icebox - we'd "store" heat and cool in different tanks and use it as needed, rather than converting it to electricity in expensive batteries and converting it back to heating and cooling using additional heat pumps / heating elements.
posted by xdvesper at 10:49 PM on February 20, 2020
The way it works is quite fascinating. Tank water has to be maintained at 65°C to prevent growth of of bacteria such as legionella. However due to the danger of burns, lower temperature water is desired at the tap - it takes 1 second to cause a full thickness burn at 70°C but 5 minutes to cause a full thickness burn at 50°C so the margin of safety provided is substantial.
Hence a tempering valve is mandated to mix hot water from the tank with cold water, allowing a max water temp of 50°C or a max of 43°C when installed in a facility for children (schools, child care, etc).
So how the thermal solar collectors work is that a heating element at the bottom of the tank constantly heats the tank to 60°C. The thermal solar collector on the roof cycles water from the collector back into the tank when it hits some preset temperature, say 90°C. This gradually heats up the water in the tank, say to 80°C.
Say in summer you use 80L of water per shower, and the current temperature in your tank is 80°C and the tank size is 300L. Typical shower temperature is 40°C so that's a 66% mix of 50°C hot water and 33°C mix of cold water at 20°C mains temperature. This would pull 50L from your hot water outlet, which itself comes from the tempering valve which would have drawn only 26L from the 300L hot water tank.
Your 300L tank is now 26L short, and it refills using 26L from the mains water at 20°C. Thus this shower drops your overall tank temperature from 80°C down to 74°C.
Remember your heater only kicks in when the temperature drops below 60°C... so in theory over summer your hot water bill is close to zero.
I'm not a fan of using heat pumps for hot water. They're expensive due to their low production volumes, potentially have noise and maintenance issues, and by the time you have solar thermal and solar PV lowering your energy requirements, the heat pump is not really adding that much more efficiency to the system.
I read an article once about energy storage - why should we use a battery for energy storage? New houses could in theory have a single solar powered heat pump that is attached to two large tanks of water in the ground, pumping heat between them - one hot water tank kept to near 100°C and one tank of solid ice / slush. You'd draw down the energy in them overnight and top them up during the day, for climate control, refrigeration, showering, etc - rather than having separate appliances for all of them. It's almost like going back to the old days when houses had a block of ice delivered to their door each day to put in their icebox - we'd "store" heat and cool in different tanks and use it as needed, rather than converting it to electricity in expensive batteries and converting it back to heating and cooling using additional heat pumps / heating elements.
posted by xdvesper at 10:49 PM on February 20, 2020
The fact that thermal energy is way cheaper and easier to store than electricity is a dot. The fact that the overwhelming majority of electrical energy delivered to the average household gets converted to thermal energy is another. It is indeed well past time those two got joined.
posted by flabdablet at 11:03 PM on February 20, 2020
posted by flabdablet at 11:03 PM on February 20, 2020
why should we use a battery for energy storage?
Mainly because the one we already paid for inside one of our electric cars holds enough charge to run our whole house for two to five days, and we don't often make trips long enough to need anywhere near a full charge. It would be a bit sad just to leave all that capex sitting idle.
posted by flabdablet at 12:19 AM on February 21, 2020
Mainly because the one we already paid for inside one of our electric cars holds enough charge to run our whole house for two to five days, and we don't often make trips long enough to need anywhere near a full charge. It would be a bit sad just to leave all that capex sitting idle.
posted by flabdablet at 12:19 AM on February 21, 2020
I agree the frack-til-you-cack paradigm is a false hope, but unless we re-embrace nuclear, we don't have a good option for carbon-free baseload power generation at levels we are accustomed to. I'm not psyched about that, either. A true dilemma.
We don't need "baseload". That was a concept that existed because it matched the most efficient way of operating coal power plants which is steady-state. In other words, we created the concept because of a supply side constraint, not a demand-side one.
What we need is to match, in real-time, generation and load on the network. The best complement to variable renewables is dispatchable generation, storage, and demand side response, not baseload. Ideally that generation will be renewable as well. Hydro, pumped storage, concentrated solar power, and biogas are all possible in that space. We may use some open cycle gas turbines and reciprocating gas engines for now to balance the system while grid infrastructure is built out.
smoke posted some good links, one of which refers to a 2014 study which modelled the US power grid on a 30s granularity to show that with additional transmission grid build-out and a pretty modest amount of storage you could run the whole US grid on renewables.
That same team has recently repeated this work for 143 countries showing essentially the same thing worldwide - this is achievable and with much less storage than had previously been thought.
One of the key findings of that work is electrifying transport and heating actually makes this easier. Admittedly I was surprised that this was the case with heating but in this case it is because the whole US is treated as a single grid and long distance transport is maximised. This makes inter-season variations smaller since warm area air conditioning loads and cold area heating loads peak in opposite seasons.
If you’re in an area where the bulk of the electric comes from natural gas, you’re better off using natural gas at home for heating and cooking. We have a long way to come on cleaner energy before that’s not the case. For example, our water heater and stove are natural gas. We can get the water warmed or food cooked with a gas flame doing the work quickly. Or... we can get electricity from the utility that’s generated from natural gas, with a lot of the energy potential in gas lost in the generating process, and even more lost due to inefficiency in transmission. The utility’s generators would burn several times more gas than we would to accomplish the same thing.
That is true but that "If" is doing a lot of heavy lifting.
At some point, increasing renewable penetration leads to a crossover point where the carbon intensity increase due to thermodynamic losses is balanced out by reducing average carbon intensity of electricity due to renewable share.
Here is a link showing that for the UK, we are now past the point where even resistive electric heating has lower carbon intensity than an efficient, correctly maintained condensing boiler and radiator system.
We also cannot ignore the time dependent aspect of this. Even in areas that are still pre-crossover, the installation of long-lived heating systems, especially in new housing, still benefits from a net carbon benefit over its lifetime is that crossover point is reached at a reasonable point during the lifetime of the system.
posted by atrazine at 4:51 AM on February 21, 2020 [2 favorites]
We don't need "baseload". That was a concept that existed because it matched the most efficient way of operating coal power plants which is steady-state. In other words, we created the concept because of a supply side constraint, not a demand-side one.
What we need is to match, in real-time, generation and load on the network. The best complement to variable renewables is dispatchable generation, storage, and demand side response, not baseload. Ideally that generation will be renewable as well. Hydro, pumped storage, concentrated solar power, and biogas are all possible in that space. We may use some open cycle gas turbines and reciprocating gas engines for now to balance the system while grid infrastructure is built out.
smoke posted some good links, one of which refers to a 2014 study which modelled the US power grid on a 30s granularity to show that with additional transmission grid build-out and a pretty modest amount of storage you could run the whole US grid on renewables.
That same team has recently repeated this work for 143 countries showing essentially the same thing worldwide - this is achievable and with much less storage than had previously been thought.
One of the key findings of that work is electrifying transport and heating actually makes this easier. Admittedly I was surprised that this was the case with heating but in this case it is because the whole US is treated as a single grid and long distance transport is maximised. This makes inter-season variations smaller since warm area air conditioning loads and cold area heating loads peak in opposite seasons.
If you’re in an area where the bulk of the electric comes from natural gas, you’re better off using natural gas at home for heating and cooking. We have a long way to come on cleaner energy before that’s not the case. For example, our water heater and stove are natural gas. We can get the water warmed or food cooked with a gas flame doing the work quickly. Or... we can get electricity from the utility that’s generated from natural gas, with a lot of the energy potential in gas lost in the generating process, and even more lost due to inefficiency in transmission. The utility’s generators would burn several times more gas than we would to accomplish the same thing.
That is true but that "If" is doing a lot of heavy lifting.
At some point, increasing renewable penetration leads to a crossover point where the carbon intensity increase due to thermodynamic losses is balanced out by reducing average carbon intensity of electricity due to renewable share.
Here is a link showing that for the UK, we are now past the point where even resistive electric heating has lower carbon intensity than an efficient, correctly maintained condensing boiler and radiator system.
We also cannot ignore the time dependent aspect of this. Even in areas that are still pre-crossover, the installation of long-lived heating systems, especially in new housing, still benefits from a net carbon benefit over its lifetime is that crossover point is reached at a reasonable point during the lifetime of the system.
posted by atrazine at 4:51 AM on February 21, 2020 [2 favorites]
Your 300L tank is now 26L short, and it refills using 26L from the mains water at 20°C. Thus this shower drops your overall tank temperature from 80°C down to 74°C.
Remember your heater only kicks in when the temperature drops below 60°C... so in theory over summer your hot water bill is close to zero.
Main reason I still favour using a heat pump to get the backup heat into the tank is that this is not quite how tank temperatures work.
Water flow inside a hot water service's storage tank is deliberately smoothed and slowed to minimize mixing and promote stratification, with the hottest water forming a layer that floats on the cooler water underneath. This is why when a storage hot water service runs out of hot water, the shower goes cold so suddenly and so thoroughly: the intermediate mixed region between the hot water layer being drawn off at the top and the cold water coming in at the bottom is not very tall at all.
So in fact the temperature at the bottom of the tank, where the resistive heat element (or the heat pump's condenser) is at, drops pretty quickly to that of the incoming cold water once any decent amount of hot water has been drawn off from the top. The main reason that solar thermal collectors work as well as they do is that in most installations the backup heating is on a timer and only runs overnight, when off-peak electricity is cheap.
To get the best savings out of a hot water service with a solar thermal collector, you want your peak hot water demand to happen in the morning. This gives the solar thermal collector most of the day to cook the whole tank back up above the cut-in temperature for the backup heating element.
posted by flabdablet at 6:23 AM on February 21, 2020 [1 favorite]
Remember your heater only kicks in when the temperature drops below 60°C... so in theory over summer your hot water bill is close to zero.
Main reason I still favour using a heat pump to get the backup heat into the tank is that this is not quite how tank temperatures work.
Water flow inside a hot water service's storage tank is deliberately smoothed and slowed to minimize mixing and promote stratification, with the hottest water forming a layer that floats on the cooler water underneath. This is why when a storage hot water service runs out of hot water, the shower goes cold so suddenly and so thoroughly: the intermediate mixed region between the hot water layer being drawn off at the top and the cold water coming in at the bottom is not very tall at all.
So in fact the temperature at the bottom of the tank, where the resistive heat element (or the heat pump's condenser) is at, drops pretty quickly to that of the incoming cold water once any decent amount of hot water has been drawn off from the top. The main reason that solar thermal collectors work as well as they do is that in most installations the backup heating is on a timer and only runs overnight, when off-peak electricity is cheap.
To get the best savings out of a hot water service with a solar thermal collector, you want your peak hot water demand to happen in the morning. This gives the solar thermal collector most of the day to cook the whole tank back up above the cut-in temperature for the backup heating element.
posted by flabdablet at 6:23 AM on February 21, 2020 [1 favorite]
Some storage hot water services will have a secondary heating element quite some way up the tank as well as the one at the bottom. This lets the heater produce usefully hot water more quickly, because stratification means that the top element simply doesn't get exposed to the bulk of cold water that remains in place below it, so it only has to heat part of the tank and that happens more quickly. Only once the water temperature at the upper element reaches its preset level does the heater then enable the bottom one.
posted by flabdablet at 6:33 AM on February 21, 2020
posted by flabdablet at 6:33 AM on February 21, 2020
That is true but that "If" is doing a lot of heavy lifting.
Around here... no, no it’s not. The major utilities spent a lot of money to get favorable regulators elected to the Corporation Commission. One of the priorities of the commission after that was to end net metering for solar and lower the rates the utilities paid for power sent back to the grid by solar owners. I know one of the Phoenix area utilities was making it prohibitively expensive for homeowners to connect a solar array to the grid. So they’re actively working at the state level to hamstring rooftop solar. The utilities are adding more and more renewables to their supply mix, but it’s still only a fraction of total use. (TEP should have about a gigawatt online by next year. That’s still less than 30% of demand.) However... the utilities are making massive investments in new natural gas generation. The power plant within sight of my house is replacing old NG steam units with new NG combined cycle units. They’re also adding hundreds more MW outside the city in faraway locales (To their credit, they’re getting almost completely away from coal.) Natural gas as the bulk of the power grid is going to be here for quite a while.
I will say that a lot of builders have been building all electric homes over the past decade or two. That’s not spurred by renewables but by other factors. The power bills on some of these homes have been pretty obscene. Out here, an electric water heater costs 3-4x more to run than a gas unit. We can talk about the carbon factor, and that’s a legitimate concern, but when someone’s bringing home $600 per week, an extra $50-60 a month to the power company is an issue when the gas bill is far less. (The issues of wealth inequality that prevent us from taking bolder steps to address energy issues would be a whole ‘nother post.)
posted by azpenguin at 6:50 AM on February 21, 2020
Around here... no, no it’s not. The major utilities spent a lot of money to get favorable regulators elected to the Corporation Commission. One of the priorities of the commission after that was to end net metering for solar and lower the rates the utilities paid for power sent back to the grid by solar owners. I know one of the Phoenix area utilities was making it prohibitively expensive for homeowners to connect a solar array to the grid. So they’re actively working at the state level to hamstring rooftop solar. The utilities are adding more and more renewables to their supply mix, but it’s still only a fraction of total use. (TEP should have about a gigawatt online by next year. That’s still less than 30% of demand.) However... the utilities are making massive investments in new natural gas generation. The power plant within sight of my house is replacing old NG steam units with new NG combined cycle units. They’re also adding hundreds more MW outside the city in faraway locales (To their credit, they’re getting almost completely away from coal.) Natural gas as the bulk of the power grid is going to be here for quite a while.
I will say that a lot of builders have been building all electric homes over the past decade or two. That’s not spurred by renewables but by other factors. The power bills on some of these homes have been pretty obscene. Out here, an electric water heater costs 3-4x more to run than a gas unit. We can talk about the carbon factor, and that’s a legitimate concern, but when someone’s bringing home $600 per week, an extra $50-60 a month to the power company is an issue when the gas bill is far less. (The issues of wealth inequality that prevent us from taking bolder steps to address energy issues would be a whole ‘nother post.)
posted by azpenguin at 6:50 AM on February 21, 2020
Purely as a matter of principle I'd like to install a solar water heating system, but my annual cost to heat water is $115 (based on this past year) so it simply doesn't make any sense to do it. Which, frankly, is driving me a little nuts (simply typing out that sentence aggravated me).
posted by aramaic at 9:51 AM on February 21, 2020
posted by aramaic at 9:51 AM on February 21, 2020
There's a huge set of issues associated with hydrocarbons that I happily acknowledge, but a huge amount of natural gas produced is 'associated gas'. This is gas that naturally comes up when you pull oil out of the ground. So, if you want oil (which isn't going away anytime soon), you end up with a bunch of natural gas as well. What do you do with this gas? Well, you can flare it, but that does nobody any good. Or you can just release it into the atmosphere, but that's even worse.
Therefore, it just makes sense to make use of what is essentially 'hydrocarbon garbage'. Up here in Alberta, it's not much more than that. We have strong regulations regarding the conservation of natural gas and so companies are basically giving it away. In fact, we've had days where the value of natural gas went negative, literally making it a kind of garbage to them that they had to pay to get rid of.
Anyway, because of this situation, it just makes sense to continue to use natural gas. I also understand that this is not the case in many places around the world, where decarbonization makes way more sense.
posted by Phreesh at 2:15 PM on February 21, 2020
Therefore, it just makes sense to make use of what is essentially 'hydrocarbon garbage'. Up here in Alberta, it's not much more than that. We have strong regulations regarding the conservation of natural gas and so companies are basically giving it away. In fact, we've had days where the value of natural gas went negative, literally making it a kind of garbage to them that they had to pay to get rid of.
Anyway, because of this situation, it just makes sense to continue to use natural gas. I also understand that this is not the case in many places around the world, where decarbonization makes way more sense.
posted by Phreesh at 2:15 PM on February 21, 2020
Out here, an electric water heater costs 3-4x more to run than a gas unit.
Where are you getting this from? A heat pump certainly doesn't. Even in an existing home, it's cheaper.
I don't know if you'd link will work on my phone,but it's an actual study by the south West Energy Efficiency Project, and heat pumps are cheaper in new homes, everywhere in the Southwest. (for existing hones, it varies).
but a huge amount of natural gas produced is 'associated gas'.
I cannot find any evidence this is true, what constitutes a huge amount? Associated gas is a thing, of course, but it is nowhere close to the majority of gas produced.
There is so much misinformation and anecdote when it comes to energy. Before reporting something you've heard or think is true,
1) consider the source
2) Check if your assumptions are up to date or if the technology and costs have changed, as they are changing all the time.
posted by smoke at 4:13 PM on February 21, 2020
Where are you getting this from? A heat pump certainly doesn't. Even in an existing home, it's cheaper.
I don't know if you'd link will work on my phone,but it's an actual study by the south West Energy Efficiency Project, and heat pumps are cheaper in new homes, everywhere in the Southwest. (for existing hones, it varies).
but a huge amount of natural gas produced is 'associated gas'.
I cannot find any evidence this is true, what constitutes a huge amount? Associated gas is a thing, of course, but it is nowhere close to the majority of gas produced.
There is so much misinformation and anecdote when it comes to energy. Before reporting something you've heard or think is true,
1) consider the source
2) Check if your assumptions are up to date or if the technology and costs have changed, as they are changing all the time.
posted by smoke at 4:13 PM on February 21, 2020
3) If you're about to support nuclear power, or in fact any power generation method relying on gigawatt-scale generation plant and a mine->use->dispose fuel cycle, go back to step 1.
posted by flabdablet at 7:35 PM on February 21, 2020
posted by flabdablet at 7:35 PM on February 21, 2020
Where are you getting this from? A heat pump certainly doesn't. Even in an existing home, it's cheaper
I was talking about water heaters, not home heating and cooling systems. I do know that heat pumps are getting more and more efficient, and I have clients that are installing 20 SEER units that are ridiculously efficient (although a lot more expensive than a 16.) We’re looking at getting a mini-split system installed in a couple of years, and those tend to run around 15 SEER last I checked.
posted by azpenguin at 9:12 PM on February 21, 2020
I was talking about water heaters, not home heating and cooling systems. I do know that heat pumps are getting more and more efficient, and I have clients that are installing 20 SEER units that are ridiculously efficient (although a lot more expensive than a 16.) We’re looking at getting a mini-split system installed in a couple of years, and those tend to run around 15 SEER last I checked.
posted by azpenguin at 9:12 PM on February 21, 2020
Heat pump water heaters are a thing, both air sourced and ground sourced.
posted by flabdablet at 9:15 PM on February 21, 2020
posted by flabdablet at 9:15 PM on February 21, 2020
Sorry I'm off my phone now; Here's a proper link to the study.
It, and I, were referring to heat pump hot water systems. For new builds, they are still better, for existing in Phoenix, they are marginally better, but it varies by location.
posted by smoke at 9:59 PM on February 21, 2020
It, and I, were referring to heat pump hot water systems. For new builds, they are still better, for existing in Phoenix, they are marginally better, but it varies by location.
posted by smoke at 9:59 PM on February 21, 2020
"electrify everything" i really don't like. climate and resources are so different across the usa and the globe.
living in a cold and wet northern climate(northeast usa), surrounded by acres of compostable solar batteries(trees), heating with wood in a masonry/mass heater is really amazing. truly local. low below ground carbon(some chainsaws). very efficient(burns hot and short duration, massive thermal battery slow release). very human comfortable. very resilient.
maybe "electrify all cities" is ok, but that also frightens me because inevitably that electricity will be produced in some rural area and citizens in that rural area will have their rights and voices squashed in order to supply the city with "clean" energy, where "clean" really often just means "not made within city limits".
posted by danjo at 1:54 PM on February 22, 2020
living in a cold and wet northern climate(northeast usa), surrounded by acres of compostable solar batteries(trees), heating with wood in a masonry/mass heater is really amazing. truly local. low below ground carbon(some chainsaws). very efficient(burns hot and short duration, massive thermal battery slow release). very human comfortable. very resilient.
maybe "electrify all cities" is ok, but that also frightens me because inevitably that electricity will be produced in some rural area and citizens in that rural area will have their rights and voices squashed in order to supply the city with "clean" energy, where "clean" really often just means "not made within city limits".
posted by danjo at 1:54 PM on February 22, 2020
heating with wood in a masonry/mass heater is really amazing.
Wood burning is terrible for the environment.
But even the cleanest, highest level of eco-certified wood stoves generate more particulate matter per hour than 18 newer diesel passenger cars — and the wood stove may be right beside you.
From Health Canada
In communities where wood heating is common, wood smoke can be responsible for as much as 25% of the airborne particulate matter
posted by xdvesper at 2:25 PM on February 22, 2020 [1 favorite]
Wood burning is terrible for the environment.
But even the cleanest, highest level of eco-certified wood stoves generate more particulate matter per hour than 18 newer diesel passenger cars — and the wood stove may be right beside you.
From Health Canada
In communities where wood heating is common, wood smoke can be responsible for as much as 25% of the airborne particulate matter
posted by xdvesper at 2:25 PM on February 22, 2020 [1 favorite]
maybe "electrify all cities" is ok, but that also frightens me because inevitably that electricity will be produced in some rural area and citizens in that rural area will have their rights and voices squashed in order to supply the city with "clean" energy, where "clean" really often just means "not made within city limits".
Wherever do you think gas plants are now?? They are not in the cities.
This seems very reactionary and knee jerk.
posted by smoke at 4:00 PM on February 22, 2020
Wherever do you think gas plants are now?? They are not in the cities.
This seems very reactionary and knee jerk.
posted by smoke at 4:00 PM on February 22, 2020
I live in a city. I can walk out the door and see a 160mW gas plant. Hell, I can walk to it in ten minutes. (Thank goodness they converted to CNG from coal. If the wind was right, the smell was really bad coming from there.) It makes the prettiest steam plumes on cold mornings.
posted by azpenguin at 10:14 PM on February 22, 2020
posted by azpenguin at 10:14 PM on February 22, 2020
160 milliwatts is pretty small for a gas plant :-)
Just out of interest, how much land area does a 160MW gas plant occupy?
posted by flabdablet at 12:25 AM on February 23, 2020
Just out of interest, how much land area does a 160MW gas plant occupy?
posted by flabdablet at 12:25 AM on February 23, 2020
Not that much, less than a city block. I answer because I used to live in Tulsa, where there is a gas-fired CHP system that produces steam and chilled water with the remainder used for electricity that is about that size.
They can be a lot smaller now that gas turbines are a thing, even with a steam generator and heat recovery apparatus. Small also means cheap, which is why generation has been able to move away from coal at an astonishing pace compared to what was thought likely 20 years ago.
Think what we could do if we could make companies care about climate change as much as they care about the lower cost of natural gas.
posted by wierdo at 3:23 AM on February 23, 2020
They can be a lot smaller now that gas turbines are a thing, even with a steam generator and heat recovery apparatus. Small also means cheap, which is why generation has been able to move away from coal at an astonishing pace compared to what was thought likely 20 years ago.
Think what we could do if we could make companies care about climate change as much as they care about the lower cost of natural gas.
posted by wierdo at 3:23 AM on February 23, 2020
Following azpenguin, Denton TX might or might not count as a city to many folks here, but when we lived there we were in a yuppie-slum complex across the railroad tracks from a big gas turbine plant. Had a few buildings with (I assume) several turbines each.
posted by GCU Sweet and Full of Grace at 6:37 AM on February 23, 2020
posted by GCU Sweet and Full of Grace at 6:37 AM on February 23, 2020
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