A few quibbles from a non-MIT grad (only a Professional Engineer with ~40 years experience in all types of power generation and transmission technologies) - with some engineering thoughts so that policy makers can make informed decisions to achieve their intended objectives):
1) Wind and Solar are NOT "variable" energy resources, which implies that operators can take action to vary their output up or down as desired to cooperate with other generation resources. They are "Intermittent" generation resources, whose output varies as a result of environmental conditions such as wind speed & direction, air qualities such as humidity and particulates, and the time of day - including the daily phenomenon called "night".
2) Yes, energy generators "cooperate", they do not "compete", to ensure that (A) total energy into the Grid = total energy out of the Grid Instantaneously during each of the 8,760 hours in a year (the design cycle of an electric power Grid) and (B) that the instantaneous energy in the Grid is equal to the total instantaneous amount of energy rate payers want to use from the Grid, or Demand, during every hour over those 8,760 hours.
3) Because Grid operators cannot depend on Wind and Solar - cannot send them dispatch orders to produce "Y" amount of energy at "X" point in time, they must read the Demand then subtract the amount of energy being produced by intermittent generation (which therefore act like "negative loads") and send dispatch orders to other generators to change their output to accommodate wind and solar and keep the Grid Balanced. If Wind and Solar aren't generating as projected, they must be backed up by Dispatchable power on standby.
4) These "integration costs" should be borne by wind and solar because they are directly responsible for these costs. In other words, this integration generation is required to maintain Grid stability and would not be required if Grid operators had planned to use only Dispatchable generation - especially the amount of Back up generation.
5) The carbon emissions associated with these integration costs should also be allocated back to these wind and solar generation facilities.
6) After making the adjustments for costs and carbon emissions in wind and solar noted in (4) and (5), one finds their costs now ranges between $200-400/MWh and carbon emissions are ~50% the CO2/kWh of natural gas - far from inexpensive and carbon-free, yet amazingly aligned with the overall system costs of the California and South Australia Grids, as well as their flat or only slightly declining Carbon Intensities over the last 5 years.
7) Based on (6), one wonders what the justification is for continuing the madcap deployment of wind and solar in lieu of a sustained push for both Large (Gen III+) and Small (SMRs and Advanced Reactors) Nuclear given the goal of deploying electric power Grids that are able to provide:
1 - A sufficient Amount of
2 - Reliable
3 - Resilient
4 - Affordable
5 - Safe, and
6 - Sustainable (to address the changing climate)
Electricity for everyone as fast as possible.
FYI: Criteria 1-5 fall under the statutory mandate of FERC. The 6th item, Sustainability, is not addressed by statute, but has been de facto added to the listed via policies and rules,
A few quibbles from a retired energy policy wonk and MIT grad:
1) I think your claims about flexible nuclear generators (likely SMRs?) coexisting well with intermittent sources ignore the economic costs of shutting down a capital-intensive nuclear plant when the weather-dependent generators are humming. Bad enough that SMRs are virtually certain to produce more expensive kwhs than today's big nuclear stations, but virtually all of them run whenever they are capable, and most still need subsidies (after their initial capital costs are written off) to keep going. They are a sad choice to stay idle while the wind blows and the sun shines.
2) Late in the article, you finally acknowledge the fact that any air-sourced heat pump will have a Coefficient of Performance that gradually fade down to 1.00 (the same as resistance heating) as the winter temperature dips. But the arguments you make in the early part of the article are dangerously and importantly oblivious to that fact.
And the short-term victims of that relationship are not the homeowners, unless they have foolishly eliminated all backup heaters, but their electrical utilities! Early in the article you claim that a massive switch from resistance heat to heat pumps will be a boon for utilities because their costs are powerfully linked to their PEAK load. That's true, but you have the bottom line exactly BACKWARDS!
Their peak winter load will be a near-linear function of the peak winter heating load, and that won't drop AT ALL by replacing resistance heat with heat pumps (except in Florida). What WILL drop very significantly is the heating load AWAY from the seasonal peak, and the total amount of electrical energy they will sell to the customers who've made the switch.
So the utility's costs (to meet the peak demand) will stay the same,but their total revenue (to pay those costs) will drop, by 50% or more.
The obvious remedy for the transmission and distribution utilities is to apply for rate reform to eliminate the savings their heat-pump customers have been enjoying for the near term!
My take-home slogan is "Friends don't let friends buy heat pumps!"
BTW, using natural gas instead of resistance electricity for peak-load heating, as backup to a heat pump, obviously doesn't get us to Net Zero, but it also transfers the same financial crisis — and the legitimate need for regulatory rate reform — from the electrical utility companies to the gas utilities.
The challenge for the gas utilities with a significant switch from gas furnaces as primary heat sources to gas furnaces as peak-only backup to heat pumps is even more threatening to their financial sustainability. Imagine the plight of the gas company that no longer has any revenue from selling space heat during "normal" winter weather, but still has to maintain all of its system ("rate base" to the regulators) and virtually all of its profitable O&M expenses. (At least here in Ontario, the cost of commodity natural gas is a pass-through for the distribution utility companies, with retroactive mechanisms to correct their finances when sales don't match the forecasts.)
So those heat-pump owners will face regulatory rate reform from their gas companies that will ensure that they pay every penny that they used to pay to their gas company, minus the actual cost of the commodity gas.
Anybody who expects to save money by investing in a heat pump, EITHER with electric or gas backup for the bitter cold periods, will only save money until the utility regulators get around to correcting the unfair burden that they have shifted to their utility company!
The situation is closely comparable to the unfair savings that BEV buyers get from escaping from paying the fuel taxes that pay for road maintenance. And since BEVs are both heavier and higher-torque than comparable ICE vehicles, they should be paying MORE in road taxes, not less. As soon as we get around to a user-pay system instead of a system that is based on the premise that every BEV buyer is making a heroic and priceless contribution to saving the world, those unfair savings will be clawed back by the rest of us.
BTW, people who use truck-delivered fuel like oil or propane or butane aren't a significant part of this burden shifting AFAICS.
These sorts of 'pulse' demand systems (as high or higher than current peak demand, but much lower average utlization) are one of the biggest challenges of decarbonisation.
I think liquid fuel hybrid systems will be critical for this reason.
GSHP are also far, far more important than ASHP for the simoke reason that they don't loose CoP as ambient air temperature drops. So they help with peak load far more than ASHP...
Thank you for discussing the nuances of heat pumps. I agree that the transition time is measured in decades. particularly for homes built with baseboard heaters. While I was a graduate student in Buffalo, NY, I lived in such a home. We celebrated the cleaner air and heating cost reductions when a natural gas-fired boiler replaced the older oil-fired boiler in the late 1970s. That house was built in the early 1960s. Thus, it might not be rebuilt with a more efficient heating system until the 2040s or later.
I just checked electricity maps https://app.electricitymaps.com/map France, with its predominately nuclear-powered electricity grid shows a minuscule 22 g carbon per kWh at 9:00 AM PDT on 13 September 2024 (Sweden is about half that low value.) . OTOH, Germany, which needlessly shut down its well-maintained zero-carbon nuclear power fleet in 2023 is at 266 g per kWh. At the same time and date. Poland is even worse at 728 g per kWh. Eastern India shows 759 g per kWh. Thus, national (or state) energy policies are the major emissions determinant.
We had a house built in 1980 with a heat pump, in the north Atlanta suburbs. It did not heat well in the depths of winter and we had to supplement it with space heaters.
Heat pumps are popular and make sense in southern areas where the temperature rarely goes below freezing; historically, many of these houses relied on space heaters or small-scale resistance heat such as baseboard heaters. They are also popular money-wise versus central electric resistance heat where gas is either not available or expensive (propane). Versus natural gas the economics make less sense, especially with modern high-efficiency furnaces.
Dual-fuel heat pumps make a lot of sense, using the heat pump for light heating needs and a traditional high-efficiency, low-cost gas furnace to supplement it, but for those who want to kill off fossil furnaces they're a no-go.
In our current house, we replaced two 25 year old entire furnace and A/C systems (10 SEER) with 18 SEER furnace and A/C systems. Our gas bill in the winter stayed the same, despite our cost per therm doubling; our electric bill in the summer has been less than half what it was before.
The big problem is that if you use natural gas as that dual fuel, the peak on the natural gas system doesn't go down, but average demand does. That leads to spiraling cost to supply the NG...
A few years ago we were forced to replace a supposedly eco-friendly radiant heating system that was built into our house. Since there were no air ducts in the house, a heat pump seemed to be the best option. The units themselves were not that expensive.
The real cost was installing pipes running from the ground unit to the wall units. Our master bedroom was on the opposite side of the house from the only possible location for the ground unit and on the third floor. It would have cost far more to have a wall unit in the master bedroom, so instead we put it on the closer side of the house. This made the performance sub-optimal. Not sure we made the correct decision.
My take-away:
1) There are no generic solutions. What type of HVAC system you already have installed in your house really affects the final cost and so does the layout of your house.
2) Take generic expert cost estimates with a grain of salt. Until you get a cost estimate for your house, you do not know.
3) In the USA natural gas is really cheap, so saving energy may not lead to saving money, particularly if you already have the air ducts in your house.
A few quibbles from a non-MIT grad (only a Professional Engineer with ~40 years experience in all types of power generation and transmission technologies) - with some engineering thoughts so that policy makers can make informed decisions to achieve their intended objectives):
1) Wind and Solar are NOT "variable" energy resources, which implies that operators can take action to vary their output up or down as desired to cooperate with other generation resources. They are "Intermittent" generation resources, whose output varies as a result of environmental conditions such as wind speed & direction, air qualities such as humidity and particulates, and the time of day - including the daily phenomenon called "night".
2) Yes, energy generators "cooperate", they do not "compete", to ensure that (A) total energy into the Grid = total energy out of the Grid Instantaneously during each of the 8,760 hours in a year (the design cycle of an electric power Grid) and (B) that the instantaneous energy in the Grid is equal to the total instantaneous amount of energy rate payers want to use from the Grid, or Demand, during every hour over those 8,760 hours.
3) Because Grid operators cannot depend on Wind and Solar - cannot send them dispatch orders to produce "Y" amount of energy at "X" point in time, they must read the Demand then subtract the amount of energy being produced by intermittent generation (which therefore act like "negative loads") and send dispatch orders to other generators to change their output to accommodate wind and solar and keep the Grid Balanced. If Wind and Solar aren't generating as projected, they must be backed up by Dispatchable power on standby.
4) These "integration costs" should be borne by wind and solar because they are directly responsible for these costs. In other words, this integration generation is required to maintain Grid stability and would not be required if Grid operators had planned to use only Dispatchable generation - especially the amount of Back up generation.
5) The carbon emissions associated with these integration costs should also be allocated back to these wind and solar generation facilities.
6) After making the adjustments for costs and carbon emissions in wind and solar noted in (4) and (5), one finds their costs now ranges between $200-400/MWh and carbon emissions are ~50% the CO2/kWh of natural gas - far from inexpensive and carbon-free, yet amazingly aligned with the overall system costs of the California and South Australia Grids, as well as their flat or only slightly declining Carbon Intensities over the last 5 years.
7) Based on (6), one wonders what the justification is for continuing the madcap deployment of wind and solar in lieu of a sustained push for both Large (Gen III+) and Small (SMRs and Advanced Reactors) Nuclear given the goal of deploying electric power Grids that are able to provide:
1 - A sufficient Amount of
2 - Reliable
3 - Resilient
4 - Affordable
5 - Safe, and
6 - Sustainable (to address the changing climate)
Electricity for everyone as fast as possible.
FYI: Criteria 1-5 fall under the statutory mandate of FERC. The 6th item, Sustainability, is not addressed by statute, but has been de facto added to the listed via policies and rules,
A few quibbles from a retired energy policy wonk and MIT grad:
1) I think your claims about flexible nuclear generators (likely SMRs?) coexisting well with intermittent sources ignore the economic costs of shutting down a capital-intensive nuclear plant when the weather-dependent generators are humming. Bad enough that SMRs are virtually certain to produce more expensive kwhs than today's big nuclear stations, but virtually all of them run whenever they are capable, and most still need subsidies (after their initial capital costs are written off) to keep going. They are a sad choice to stay idle while the wind blows and the sun shines.
2) Late in the article, you finally acknowledge the fact that any air-sourced heat pump will have a Coefficient of Performance that gradually fade down to 1.00 (the same as resistance heating) as the winter temperature dips. But the arguments you make in the early part of the article are dangerously and importantly oblivious to that fact.
And the short-term victims of that relationship are not the homeowners, unless they have foolishly eliminated all backup heaters, but their electrical utilities! Early in the article you claim that a massive switch from resistance heat to heat pumps will be a boon for utilities because their costs are powerfully linked to their PEAK load. That's true, but you have the bottom line exactly BACKWARDS!
Their peak winter load will be a near-linear function of the peak winter heating load, and that won't drop AT ALL by replacing resistance heat with heat pumps (except in Florida). What WILL drop very significantly is the heating load AWAY from the seasonal peak, and the total amount of electrical energy they will sell to the customers who've made the switch.
So the utility's costs (to meet the peak demand) will stay the same,but their total revenue (to pay those costs) will drop, by 50% or more.
The obvious remedy for the transmission and distribution utilities is to apply for rate reform to eliminate the savings their heat-pump customers have been enjoying for the near term!
My take-home slogan is "Friends don't let friends buy heat pumps!"
BTW, using natural gas instead of resistance electricity for peak-load heating, as backup to a heat pump, obviously doesn't get us to Net Zero, but it also transfers the same financial crisis — and the legitimate need for regulatory rate reform — from the electrical utility companies to the gas utilities.
The challenge for the gas utilities with a significant switch from gas furnaces as primary heat sources to gas furnaces as peak-only backup to heat pumps is even more threatening to their financial sustainability. Imagine the plight of the gas company that no longer has any revenue from selling space heat during "normal" winter weather, but still has to maintain all of its system ("rate base" to the regulators) and virtually all of its profitable O&M expenses. (At least here in Ontario, the cost of commodity natural gas is a pass-through for the distribution utility companies, with retroactive mechanisms to correct their finances when sales don't match the forecasts.)
So those heat-pump owners will face regulatory rate reform from their gas companies that will ensure that they pay every penny that they used to pay to their gas company, minus the actual cost of the commodity gas.
Anybody who expects to save money by investing in a heat pump, EITHER with electric or gas backup for the bitter cold periods, will only save money until the utility regulators get around to correcting the unfair burden that they have shifted to their utility company!
The situation is closely comparable to the unfair savings that BEV buyers get from escaping from paying the fuel taxes that pay for road maintenance. And since BEVs are both heavier and higher-torque than comparable ICE vehicles, they should be paying MORE in road taxes, not less. As soon as we get around to a user-pay system instead of a system that is based on the premise that every BEV buyer is making a heroic and priceless contribution to saving the world, those unfair savings will be clawed back by the rest of us.
BTW, people who use truck-delivered fuel like oil or propane or butane aren't a significant part of this burden shifting AFAICS.
These sorts of 'pulse' demand systems (as high or higher than current peak demand, but much lower average utlization) are one of the biggest challenges of decarbonisation.
I think liquid fuel hybrid systems will be critical for this reason.
GSHP are also far, far more important than ASHP for the simoke reason that they don't loose CoP as ambient air temperature drops. So they help with peak load far more than ASHP...
Thank you for discussing the nuances of heat pumps. I agree that the transition time is measured in decades. particularly for homes built with baseboard heaters. While I was a graduate student in Buffalo, NY, I lived in such a home. We celebrated the cleaner air and heating cost reductions when a natural gas-fired boiler replaced the older oil-fired boiler in the late 1970s. That house was built in the early 1960s. Thus, it might not be rebuilt with a more efficient heating system until the 2040s or later.
I just checked electricity maps https://app.electricitymaps.com/map France, with its predominately nuclear-powered electricity grid shows a minuscule 22 g carbon per kWh at 9:00 AM PDT on 13 September 2024 (Sweden is about half that low value.) . OTOH, Germany, which needlessly shut down its well-maintained zero-carbon nuclear power fleet in 2023 is at 266 g per kWh. At the same time and date. Poland is even worse at 728 g per kWh. Eastern India shows 759 g per kWh. Thus, national (or state) energy policies are the major emissions determinant.
We had a house built in 1980 with a heat pump, in the north Atlanta suburbs. It did not heat well in the depths of winter and we had to supplement it with space heaters.
Heat pumps are popular and make sense in southern areas where the temperature rarely goes below freezing; historically, many of these houses relied on space heaters or small-scale resistance heat such as baseboard heaters. They are also popular money-wise versus central electric resistance heat where gas is either not available or expensive (propane). Versus natural gas the economics make less sense, especially with modern high-efficiency furnaces.
Dual-fuel heat pumps make a lot of sense, using the heat pump for light heating needs and a traditional high-efficiency, low-cost gas furnace to supplement it, but for those who want to kill off fossil furnaces they're a no-go.
In our current house, we replaced two 25 year old entire furnace and A/C systems (10 SEER) with 18 SEER furnace and A/C systems. Our gas bill in the winter stayed the same, despite our cost per therm doubling; our electric bill in the summer has been less than half what it was before.
There is still room for efficiency gains.
The big problem is that if you use natural gas as that dual fuel, the peak on the natural gas system doesn't go down, but average demand does. That leads to spiraling cost to supply the NG...
A few years ago we were forced to replace a supposedly eco-friendly radiant heating system that was built into our house. Since there were no air ducts in the house, a heat pump seemed to be the best option. The units themselves were not that expensive.
The real cost was installing pipes running from the ground unit to the wall units. Our master bedroom was on the opposite side of the house from the only possible location for the ground unit and on the third floor. It would have cost far more to have a wall unit in the master bedroom, so instead we put it on the closer side of the house. This made the performance sub-optimal. Not sure we made the correct decision.
My take-away:
1) There are no generic solutions. What type of HVAC system you already have installed in your house really affects the final cost and so does the layout of your house.
2) Take generic expert cost estimates with a grain of salt. Until you get a cost estimate for your house, you do not know.
3) In the USA natural gas is really cheap, so saving energy may not lead to saving money, particularly if you already have the air ducts in your house.
There's another option in cities. https://hargraves.substack.com/p/building-heating
This is also the best application of newer geothermal types, espcially closed loop.
This is especially true for smaller systems where a nuclear plant would be overkill, but a few MWt from a geothermal well would be plausible.