James Twallin
@twallinjames.bsky.social
Reposted by James Twallin
... then you might enjoy this chart, kindly shared by @twallinjames.bsky.social. It shows how an air-to-air heat pump can heat up a nearly 300 year-old church that is only used occasionally.
Source: www.linkedin.com/posts/activi...
Source: www.linkedin.com/posts/activi...
November 20, 2025 at 6:25 PM
... then you might enjoy this chart, kindly shared by @twallinjames.bsky.social. It shows how an air-to-air heat pump can heat up a nearly 300 year-old church that is only used occasionally.
Source: www.linkedin.com/posts/activi...
Source: www.linkedin.com/posts/activi...
I'm adding download buttons right now.
November 19, 2025 at 9:15 PM
I'm adding download buttons right now.
wait - so you're getting something of value from it? It appears to me that you are a wind dev consultant and my site is giving you insight for free? If I could provide some premium features, would you pay?
November 19, 2025 at 7:45 PM
wait - so you're getting something of value from it? It appears to me that you are a wind dev consultant and my site is giving you insight for free? If I could provide some premium features, would you pay?
Thanks for the feedback!
November 16, 2025 at 10:57 PM
Thanks for the feedback!
Please could you reshare? The link has expired. Thank you!
October 23, 2025 at 5:01 PM
Please could you reshare? The link has expired. Thank you!
Link to survey: www.gov.uk/government/p...
National Transmission System hydrogen blending: study
The project sets out analysis on the potential impacts of hydrogen blending in the national transmission system (NTS) at blend percentages of up to 2%, 5% and 20%.
www.gov.uk
October 21, 2025 at 10:34 AM
Link to survey: www.gov.uk/government/p...
Why?
Hydrogen has 1/3 the energy density of natural gas. Sites reported reduced power output, 2-6 year modification lead times, combustion instabilities, safety concerns from embrittlement/leakage, and increased NOx emissions.
Hydrogen has 1/3 the energy density of natural gas. Sites reported reduced power output, 2-6 year modification lead times, combustion instabilities, safety concerns from embrittlement/leakage, and increased NOx emissions.
October 21, 2025 at 10:34 AM
Why?
Hydrogen has 1/3 the energy density of natural gas. Sites reported reduced power output, 2-6 year modification lead times, combustion instabilities, safety concerns from embrittlement/leakage, and increased NOx emissions.
Hydrogen has 1/3 the energy density of natural gas. Sites reported reduced power output, 2-6 year modification lead times, combustion instabilities, safety concerns from embrittlement/leakage, and increased NOx emissions.
This "breakthrough" appears to use a brand new hydrogen-specific turbine installed last year - not existing infrastructure.
A govt-commissioned Arup survey of existing UK gas stations tells a different story: Almost all reported significant challenges accepting blended hydrogen:
A govt-commissioned Arup survey of existing UK gas stations tells a different story: Almost all reported significant challenges accepting blended hydrogen:
October 21, 2025 at 10:34 AM
This "breakthrough" appears to use a brand new hydrogen-specific turbine installed last year - not existing infrastructure.
A govt-commissioned Arup survey of existing UK gas stations tells a different story: Almost all reported significant challenges accepting blended hydrogen:
A govt-commissioned Arup survey of existing UK gas stations tells a different story: Almost all reported significant challenges accepting blended hydrogen:
Steady state is a hangover from fossil fuels, but when electricity changes in both cost and carbon, we need to account for thermal mass and use it as a store.
October 8, 2025 at 12:30 PM
Steady state is a hangover from fossil fuels, but when electricity changes in both cost and carbon, we need to account for thermal mass and use it as a store.
Personally I'd throw both MCS's heat loss calculator and SAP's methodology into the fire.
Both are very static and hopelessly out of date.
My main issue with MCS's approach is the lack of thermal mass consideration and insistence on steady state heating.
Both are very static and hopelessly out of date.
My main issue with MCS's approach is the lack of thermal mass consideration and insistence on steady state heating.
October 8, 2025 at 12:25 PM
Personally I'd throw both MCS's heat loss calculator and SAP's methodology into the fire.
Both are very static and hopelessly out of date.
My main issue with MCS's approach is the lack of thermal mass consideration and insistence on steady state heating.
Both are very static and hopelessly out of date.
My main issue with MCS's approach is the lack of thermal mass consideration and insistence on steady state heating.
Brits are using less energy to heat their homes
It's a key input for heat pump design in the MCS heat loss calculator (well it's a lookup). See here: lnkd.in/ebMeZgXG. A quick eyeball of the figures in that table seems to indicate an update is well overdue!
It's a key input for heat pump design in the MCS heat loss calculator (well it's a lookup). See here: lnkd.in/ebMeZgXG. A quick eyeball of the figures in that table seems to indicate an update is well overdue!
LinkedIn
This link will take you to a page that’s not on LinkedIn
lnkd.in
October 8, 2025 at 11:32 AM
Brits are using less energy to heat their homes
It's a key input for heat pump design in the MCS heat loss calculator (well it's a lookup). See here: lnkd.in/ebMeZgXG. A quick eyeball of the figures in that table seems to indicate an update is well overdue!
It's a key input for heat pump design in the MCS heat loss calculator (well it's a lookup). See here: lnkd.in/ebMeZgXG. A quick eyeball of the figures in that table seems to indicate an update is well overdue!
If you've not seen the concept of a 'heating degree day' before, it's pretty simple. You take 15.5°C and subtract the average daily temperature. HDD has a floor of 0.
For example. -2°C becomes 17.5HDD. 22°C is 0HDD (since it is above 15.5°C).
For example. -2°C becomes 17.5HDD. 22°C is 0HDD (since it is above 15.5°C).
October 8, 2025 at 11:32 AM
If you've not seen the concept of a 'heating degree day' before, it's pretty simple. You take 15.5°C and subtract the average daily temperature. HDD has a floor of 0.
For example. -2°C becomes 17.5HDD. 22°C is 0HDD (since it is above 15.5°C).
For example. -2°C becomes 17.5HDD. 22°C is 0HDD (since it is above 15.5°C).
Based on NHS procurement costs
October 1, 2025 at 4:53 PM
Based on NHS procurement costs
I did some back of the envelope calculations, and based on the aperture size and the pressure, I estimate something on the order of 1 million tonnes of CO2eq.
September 28, 2025 at 3:25 PM
I did some back of the envelope calculations, and based on the aperture size and the pressure, I estimate something on the order of 1 million tonnes of CO2eq.
That's what you're seeing. It's choked flow, meaning the gas is coming out at supersonic speeds. Moving from high pressure to low pressure very quickly, it's cooling down.
September 28, 2025 at 1:31 PM
That's what you're seeing. It's choked flow, meaning the gas is coming out at supersonic speeds. Moving from high pressure to low pressure very quickly, it's cooling down.