Lewis Bowick
@l-bow.bsky.social
Engineering and economics of the energy transition. Electrification of heat, renewables, energy networks and various other pieces of the jigsaw.
A secondary frustration with the "solar makes HPs make sense" concept is that upfront cost is HPs' greatest challenge IMO. To mainstream this for ordinary households, the last thing we need is to say "you just need to drop a further £8k for it to be worthwhile"
July 26, 2025 at 7:30 PM
A secondary frustration with the "solar makes HPs make sense" concept is that upfront cost is HPs' greatest challenge IMO. To mainstream this for ordinary households, the last thing we need is to say "you just need to drop a further £8k for it to be worthwhile"
What's screwey is that fixed cost are recovered via the energy consumption charge. As a result, electrifying makes you overcontribute to fixed costs, while generation lets you undercontribute. The two cancel each other out, causing the illusion that micro solar complements heat electrification.
July 26, 2025 at 6:49 PM
What's screwey is that fixed cost are recovered via the energy consumption charge. As a result, electrifying makes you overcontribute to fixed costs, while generation lets you undercontribute. The two cancel each other out, causing the illusion that micro solar complements heat electrification.
The idea that micro generation, costing 2-3x as much as grid-scale generation, with a generation profile inversely correlated to the heating season, makes electric heating more economic than using the grid should tell you something's screwey with the price signals
July 26, 2025 at 6:44 PM
The idea that micro generation, costing 2-3x as much as grid-scale generation, with a generation profile inversely correlated to the heating season, makes electric heating more economic than using the grid should tell you something's screwey with the price signals
I'm pretty sure it does more harm than good. Only one third of the retail price of electricity is for energy, so the "true" saving of rooftop PV must be about 8p/kWh of self consumption. The other two thirds are just shifted to everyone else's bills, making electrification even less appealing.
July 26, 2025 at 6:41 PM
I'm pretty sure it does more harm than good. Only one third of the retail price of electricity is for energy, so the "true" saving of rooftop PV must be about 8p/kWh of self consumption. The other two thirds are just shifted to everyone else's bills, making electrification even less appealing.
Ooft. Hadn't thought it might get that bad
July 24, 2025 at 11:46 PM
Ooft. Hadn't thought it might get that bad
The whole reason for CP30 was, I think, that in 2022 it looked like any additional renewable capacity would bring down bills. Now that wholesale has come down and CfDs have risen, I'm not sure there's any merit to a 2030 sprint (besides being the right direction of travel for carbon overall)
July 24, 2025 at 4:57 PM
The whole reason for CP30 was, I think, that in 2022 it looked like any additional renewable capacity would bring down bills. Now that wholesale has come down and CfDs have risen, I'm not sure there's any merit to a 2030 sprint (besides being the right direction of travel for carbon overall)
District cooling is a thing, though I'm not convinced that would be easier than an individual building approach, given the need for co-ordination across many building owners and civil works. It would still need fan coils to be installed indoors. New build is an ideal opportunity for A2A I'd say
July 13, 2025 at 5:36 PM
District cooling is a thing, though I'm not convinced that would be easier than an individual building approach, given the need for co-ordination across many building owners and civil works. It would still need fan coils to be installed indoors. New build is an ideal opportunity for A2A I'd say
Efficiency of air-to-water is very sensitive to the water temperature required by the radiators. If you've got underfloor heating or very big radiators then great, but if not you can get COPs much worse than you would with warm air. I think retrofitting refrigerant pipes more likely!
July 13, 2025 at 4:46 PM
Efficiency of air-to-water is very sensitive to the water temperature required by the radiators. If you've got underfloor heating or very big radiators then great, but if not you can get COPs much worse than you would with warm air. I think retrofitting refrigerant pipes more likely!
Yep air-to-water is the default path for our homes. Just seems like a shame to be rolling out heat-only systems right when we realise we're gonna need AC. If we could combine the cooling perk with decarbonisation it would be a much easier transition.
July 13, 2025 at 4:34 PM
Yep air-to-water is the default path for our homes. Just seems like a shame to be rolling out heat-only systems right when we realise we're gonna need AC. If we could combine the cooling perk with decarbonisation it would be a much easier transition.
UK here, been trying to figure out if mini-splits could work for us at scale. The trouble is we all have whole house hydronic systems, so would need to double up with splits in every room. And how do you deal with bathrooms? More likely is people just put splits in bedrooms and keep using gas heat
July 13, 2025 at 4:27 PM
UK here, been trying to figure out if mini-splits could work for us at scale. The trouble is we all have whole house hydronic systems, so would need to double up with splits in every room. And how do you deal with bathrooms? More likely is people just put splits in bedrooms and keep using gas heat
I was recently talking to Christoph at goeconic.com who are offering this setup
Econic Energy | Heat Pumps | Save Money & Emissions | England
Econic's mission is to build the next wave of energy transition in the UK: the decarbonisation of heating. We are committed to making your transitioin to a green future affordable, easy, and bespoke t...
goeconic.com
July 13, 2025 at 9:15 AM
I was recently talking to Christoph at goeconic.com who are offering this setup
You can have fan coils connected to the pipework as well as radiators, which can provide effective cooling with proper moisture removal. The pipework needs to be insulated to avoid condensation. Probably quite hard to find installers who will do it atm
July 13, 2025 at 9:06 AM
You can have fan coils connected to the pipework as well as radiators, which can provide effective cooling with proper moisture removal. The pipework needs to be insulated to avoid condensation. Probably quite hard to find installers who will do it atm
True, heat pumps will only introduce about 30% as much additional heat to the environment as other forms of heating. So no cooling, but a reduced contribution to urban heat island in winter
July 7, 2025 at 7:14 AM
True, heat pumps will only introduce about 30% as much additional heat to the environment as other forms of heating. So no cooling, but a reduced contribution to urban heat island in winter
I'd be interested to know if these studies have taken into account that the portion of heat being blown onto the street which has been removed from the building is being cancelled out by that building absorbing heat through its leaks. Only the portion covered from electricity is a net addition.
July 7, 2025 at 7:06 AM
I'd be interested to know if these studies have taken into account that the portion of heat being blown onto the street which has been removed from the building is being cancelled out by that building absorbing heat through its leaks. Only the portion covered from electricity is a net addition.
In both heating and cooling mode, heat is moved between indoors and out, plus heat is generated by electricity being burnt off as friction. So in both cases there's a net addition of heat. The hot air blown out is a combination of the heat moved from indoors and the heat added from electricity.
July 7, 2025 at 7:04 AM
In both heating and cooling mode, heat is moved between indoors and out, plus heat is generated by electricity being burnt off as friction. So in both cases there's a net addition of heat. The hot air blown out is a combination of the heat moved from indoors and the heat added from electricity.
Heating just adds heat to a building at the same rate it escapes to outdoors. It's an equilibrium to maintain a steady temperature, so there's no net removal of heat from the environment.
July 6, 2025 at 5:13 PM
Heating just adds heat to a building at the same rate it escapes to outdoors. It's an equilibrium to maintain a steady temperature, so there's no net removal of heat from the environment.
Raises the question of whether we should be insulating pipes at installation to make them cooling-ready
June 30, 2025 at 10:30 PM
Raises the question of whether we should be insulating pipes at installation to make them cooling-ready
Not sure about easy. Freeholder permission needed, and often difficult to pass noise limits due to being close to neighbours' windows. Maintenance at height could be awkward. Feels like flats need fully indoor HPs which duct to outside air
June 19, 2025 at 9:07 PM
Not sure about easy. Freeholder permission needed, and often difficult to pass noise limits due to being close to neighbours' windows. Maintenance at height could be awkward. Feels like flats need fully indoor HPs which duct to outside air
I suppose you can have bypass for the cool night air, then heat exchange to *cool* the fresh air in the afternoon, right? Whereas I have to seal up in the afternoon if I want to keep peak temperatures out, which feels weird!
June 19, 2025 at 8:10 PM
I suppose you can have bypass for the cool night air, then heat exchange to *cool* the fresh air in the afternoon, right? Whereas I have to seal up in the afternoon if I want to keep peak temperatures out, which feels weird!
I suppose I'm basically describing PIV, except timed to run only during cool hours in a heat wave
June 19, 2025 at 11:40 AM
I suppose I'm basically describing PIV, except timed to run only during cool hours in a heat wave
I'm not sure how much relief extract would provide, pulling air into the rooms from other warm rooms? Having supply at outdoor night time temperatures sounds nicer! I guess some of the extract makeup might come through the trickle vents though
June 19, 2025 at 11:39 AM
I'm not sure how much relief extract would provide, pulling air into the rooms from other warm rooms? Having supply at outdoor night time temperatures sounds nicer! I guess some of the extract makeup might come through the trickle vents though
I reckon all it would take would be a fan to duct cool night air into the bedrooms from a quiet side of the house
June 19, 2025 at 11:19 AM
I reckon all it would take would be a fan to duct cool night air into the bedrooms from a quiet side of the house
Poor bloke should have just followed the handy steps on his EPC. Move out of his downstairs to do underfloor insulation, stick a wind turbine on the back wall and put in flue gas heat recovery to save 2% emissions and get a 150 year payback
June 18, 2025 at 10:32 PM
Poor bloke should have just followed the handy steps on his EPC. Move out of his downstairs to do underfloor insulation, stick a wind turbine on the back wall and put in flue gas heat recovery to save 2% emissions and get a 150 year payback