I will be in a public inquiry tomorrow trying t persuade an inspector (who will be reporting to the Secretary of State) that the upfront carbon emitted in the building of a new road is certain and damaging for ever and the claimed carbon avoided by the reduced emissions is uncertain and could be saved in any number of forms of demand management and electrification of the road system. Upfront carbon is the (poisoned) apple and cannot be compared and conflated with the promise of (sweet) oranges over the next twenty or thirty years. The carbon illiteracy displayed in respect of upfront is very worrying. And speaking of electric cars (and their upfront carbon), the most effective and equitable way of sharing green electrons would be lower speed limits; The most efficient speed for EVs is around 30mph, even lower than the 50mph that would improve the mileage of residual ICEs.
Living in Virginia we like many others face the challenge of having assistance for both heating and cooling as our local climate becomes more like that of our Carolina neighbors to the south, at least over then short term. We open the house as much as possible and are partially shaded still by trees and have green space around at least three sides while that backyard space is noticeably cooler than the front thanks to be generally shaded all day long. The point is that while this article talks extensively about heating a home it says nothing that I could see about then cooling the same building in season which is a reality for many.
All these points are good. As are all the counterarguments you brought to the table. But don't all of us doing this work know that every project has its own unique circumstances? We can make efforts towards decarbonization on most buildings given budgets from $0 to infinity. Decarbonization will be one of many sustainability goals and sustainability will be one of many building priorities. The context and client priorities dictate the path, this heirarchy is largely irrelevant when considering individual projects. Where a heirarchy like this can be relevant is in policy-making, and in that case, I think you need to prioritize based on the goals of government, cost effectiveness, and enforcement capacity. What action comes first is a more complicated cocktail and is dictated by what can reasonably be legislated and enforced.
Been reading your stuff forever Mr alter! Glad to discover your on substack!
Good points, thanks Lloyd. Evelyne's graph is of course a simplification as there are emissions from maintenance and replacement, not least the heat pump refrigerant as you note.
I posted this below as a comment in your post from the PH conference last week. I would not advocate that all buildings are candidates for Deep Energy Retrofits, but taking a building with a thermal EUI of, say, 50 kBTU/sf/yr and just converting to heat pumps seems foolish to me. And a key aspect of determining the appropriate level of fabric upgrade is to carefully understand all of what I call "existing deficiencies" of the building that lead to poor indoor environmental quality, discomfort, and high maintenance. Examples are: water intrusion, frozen pipes, ice dams, space conditioning systems located outside the thermal enclosure, mold, insects and rodents, failing masonry and mortar, etc.
From a previous comment: I bought a small poorly built house here on Martha's Vineyard in 2012 and in 2013 we gutted it and made it into a Zero Net Energy Deep Energy Retrofit. I have been a beta tester for the BEAM tool that analyzes embodied (or upfront) carbon and just used the new V1.1 about-to-be-released version in my testing to analyze the DER. The upfront carbon of the retrofit works out to 83 kgCO2e/m2, which is in the range you show in the graph in this post. I estimate the carbon payback of the retrofit at under two years (house was pretty bad before, I can only estimate its energy use under the previous owner, but an 1,144 sf house was over 3,100 CFM50 on the blower door test and used propane for thermal loads. The retrofit is all electric.)
Note that the house is still double the German PH standard for heating. It makes no sense to go to that level, the marginal gains vs. extra investment are so small. The retrofit includes triple glazed windows with U value under 0.2 (IP units) and the house is well under Passive House airtightness maximum. Out of an annual energy use of 5,712 kWH last year, heating/hot water/ventilation was 35%, plug loads/lighting/appliances was 32%, and the EV was 33%. PVs in the same period made 5,643 kWh, so we were 1% away from Zero Net Energy including my wife's driving.
Thanks for this! You make a very clear & sound point that I've been attempting to articulate for some time. That is: by improving the envelop, more electric power is freed up to replace things that rely on fossil fuel!
I am disappointed to see in all the IRA funding for energy efficient upgrades that we're not seeing a bigger focus on take- back programs for heat pumps or any appliance with coolant (or education around it for end of use). The older coolant formulations have tremendous GWP formulations. I'm a big fan of heat pumps and also bio- based insulation, so I'd like to see both upgrades wherever possible so the appliances are small and there are higher amounts of carbon stored durably in walls. Thanks for offering the comparisons and pointing out the grid problem.
I will be in a public inquiry tomorrow trying t persuade an inspector (who will be reporting to the Secretary of State) that the upfront carbon emitted in the building of a new road is certain and damaging for ever and the claimed carbon avoided by the reduced emissions is uncertain and could be saved in any number of forms of demand management and electrification of the road system. Upfront carbon is the (poisoned) apple and cannot be compared and conflated with the promise of (sweet) oranges over the next twenty or thirty years. The carbon illiteracy displayed in respect of upfront is very worrying. And speaking of electric cars (and their upfront carbon), the most effective and equitable way of sharing green electrons would be lower speed limits; The most efficient speed for EVs is around 30mph, even lower than the 50mph that would improve the mileage of residual ICEs.
Living in Virginia we like many others face the challenge of having assistance for both heating and cooling as our local climate becomes more like that of our Carolina neighbors to the south, at least over then short term. We open the house as much as possible and are partially shaded still by trees and have green space around at least three sides while that backyard space is noticeably cooler than the front thanks to be generally shaded all day long. The point is that while this article talks extensively about heating a home it says nothing that I could see about then cooling the same building in season which is a reality for many.
All these points are good. As are all the counterarguments you brought to the table. But don't all of us doing this work know that every project has its own unique circumstances? We can make efforts towards decarbonization on most buildings given budgets from $0 to infinity. Decarbonization will be one of many sustainability goals and sustainability will be one of many building priorities. The context and client priorities dictate the path, this heirarchy is largely irrelevant when considering individual projects. Where a heirarchy like this can be relevant is in policy-making, and in that case, I think you need to prioritize based on the goals of government, cost effectiveness, and enforcement capacity. What action comes first is a more complicated cocktail and is dictated by what can reasonably be legislated and enforced.
Been reading your stuff forever Mr alter! Glad to discover your on substack!
Good points, thanks Lloyd. Evelyne's graph is of course a simplification as there are emissions from maintenance and replacement, not least the heat pump refrigerant as you note.
hi Lloyd,
I think your source for electricity intensity of grids
you list the uk as 485 gCO2/kWh, but in 2023 actual carbon intensity was 162 gCO2/kWh
https://www.carbonbrief.org/analysis-uk-electricity-from-fossil-fuels-drops-to-lowest-level-since-1957/#:~:text=Overall%2C%20the%20electricity%20generated%20in,hour%20(gCO2%2FkWh).
I posted this below as a comment in your post from the PH conference last week. I would not advocate that all buildings are candidates for Deep Energy Retrofits, but taking a building with a thermal EUI of, say, 50 kBTU/sf/yr and just converting to heat pumps seems foolish to me. And a key aspect of determining the appropriate level of fabric upgrade is to carefully understand all of what I call "existing deficiencies" of the building that lead to poor indoor environmental quality, discomfort, and high maintenance. Examples are: water intrusion, frozen pipes, ice dams, space conditioning systems located outside the thermal enclosure, mold, insects and rodents, failing masonry and mortar, etc.
From a previous comment: I bought a small poorly built house here on Martha's Vineyard in 2012 and in 2013 we gutted it and made it into a Zero Net Energy Deep Energy Retrofit. I have been a beta tester for the BEAM tool that analyzes embodied (or upfront) carbon and just used the new V1.1 about-to-be-released version in my testing to analyze the DER. The upfront carbon of the retrofit works out to 83 kgCO2e/m2, which is in the range you show in the graph in this post. I estimate the carbon payback of the retrofit at under two years (house was pretty bad before, I can only estimate its energy use under the previous owner, but an 1,144 sf house was over 3,100 CFM50 on the blower door test and used propane for thermal loads. The retrofit is all electric.)
Note that the house is still double the German PH standard for heating. It makes no sense to go to that level, the marginal gains vs. extra investment are so small. The retrofit includes triple glazed windows with U value under 0.2 (IP units) and the house is well under Passive House airtightness maximum. Out of an annual energy use of 5,712 kWH last year, heating/hot water/ventilation was 35%, plug loads/lighting/appliances was 32%, and the EV was 33%. PVs in the same period made 5,643 kWh, so we were 1% away from Zero Net Energy including my wife's driving.
Thanks for this! You make a very clear & sound point that I've been attempting to articulate for some time. That is: by improving the envelop, more electric power is freed up to replace things that rely on fossil fuel!
I am disappointed to see in all the IRA funding for energy efficient upgrades that we're not seeing a bigger focus on take- back programs for heat pumps or any appliance with coolant (or education around it for end of use). The older coolant formulations have tremendous GWP formulations. I'm a big fan of heat pumps and also bio- based insulation, so I'd like to see both upgrades wherever possible so the appliances are small and there are higher amounts of carbon stored durably in walls. Thanks for offering the comparisons and pointing out the grid problem.