Robert Osfield
@robertosfield.bsky.social
Project lead of open source VulkanSceneGraph and OpenSceneGraph projects, software consultant, runner, tech transition tracker and family man.
They certainly can. Achieved a combined COP of 4.07 this week!
Over 5 times better efficiency than our old combi boiler and no noxious emissions to boot.
Over 5 times better efficiency than our old combi boiler and no noxious emissions to boot.
January 31, 2026 at 6:46 PM
They certainly can. Achieved a combined COP of 4.07 this week!
Over 5 times better efficiency than our old combi boiler and no noxious emissions to boot.
Over 5 times better efficiency than our old combi boiler and no noxious emissions to boot.
The most noticeable market development in 2025 was the solid growth of BEV +23.9% and PHEV +34.75% segments.
While HEV +7.2% saw modest growth pure Petrol -8% and Diesel -15.6% shrank.
In December BEV's 32.2% closed to gap to Petrol's 39.4% share respectively vs 31 & 42.2% in 2025.
While HEV +7.2% saw modest growth pure Petrol -8% and Diesel -15.6% shrank.
In December BEV's 32.2% closed to gap to Petrol's 39.4% share respectively vs 31 & 42.2% in 2025.
January 6, 2026 at 10:24 AM
The most noticeable market development in 2025 was the solid growth of BEV +23.9% and PHEV +34.75% segments.
While HEV +7.2% saw modest growth pure Petrol -8% and Diesel -15.6% shrank.
In December BEV's 32.2% closed to gap to Petrol's 39.4% share respectively vs 31 & 42.2% in 2025.
While HEV +7.2% saw modest growth pure Petrol -8% and Diesel -15.6% shrank.
In December BEV's 32.2% closed to gap to Petrol's 39.4% share respectively vs 31 & 42.2% in 2025.
@smmt-ukauto.bsky.social have published there UK new car registrations for December 2025. Again the BEV market share peaked above the 30% market share line.
Growth through 2025 stayed pretty close to the Later S-Curve, suggesting a 50% market share mid 2027.
Growth through 2025 stayed pretty close to the Later S-Curve, suggesting a 50% market share mid 2027.
January 6, 2026 at 10:10 AM
@smmt-ukauto.bsky.social have published there UK new car registrations for December 2025. Again the BEV market share peaked above the 30% market share line.
Growth through 2025 stayed pretty close to the Later S-Curve, suggesting a 50% market share mid 2027.
Growth through 2025 stayed pretty close to the Later S-Curve, suggesting a 50% market share mid 2027.
Heat pump out has maxed out at 6kW according to the Valiant sensors but... I would not trust this.
We have a 5kW Valiant Aerotherm+ which has a theoretical max output higher than 5kW but that's in ideal conditions...
We have a 5kW Valiant Aerotherm+ which has a theoretical max output higher than 5kW but that's in ideal conditions...
January 4, 2026 at 9:39 AM
Heat pump out has maxed out at 6kW according to the Valiant sensors but... I would not trust this.
We have a 5kW Valiant Aerotherm+ which has a theoretical max output higher than 5kW but that's in ideal conditions...
We have a 5kW Valiant Aerotherm+ which has a theoretical max output higher than 5kW but that's in ideal conditions...
The house is presently warming up after the overnight 16°C setback.
Flow temp of 35°C is plenty for warming the house even with a delta to outside of 22°C.
Flow temp of 35°C is plenty for warming the house even with a delta to outside of 22°C.
January 4, 2026 at 9:35 AM
The house is presently warming up after the overnight 16°C setback.
Flow temp of 35°C is plenty for warming the house even with a delta to outside of 22°C.
Flow temp of 35°C is plenty for warming the house even with a delta to outside of 22°C.
Unfortunately we don't have an Open Energy Monitor kit on our heat pump so can't provide robust and accurate figures for max cold weather output.
It's -5.8°C here in the Trossachs so below the design temp of -4°C...
It's -5.8°C here in the Trossachs so below the design temp of -4°C...
January 4, 2026 at 9:27 AM
Unfortunately we don't have an Open Energy Monitor kit on our heat pump so can't provide robust and accurate figures for max cold weather output.
It's -5.8°C here in the Trossachs so below the design temp of -4°C...
It's -5.8°C here in the Trossachs so below the design temp of -4°C...
Our 5kW Valiant Aerotherm+ required 2,451kWh of energy to generate 6,572kWh of heat and 2,860kWh if hot water with a seasonal COP if 3.85.
Our 25 year old Gas boiler would used 13,500kWh so the heat pump 5 times more energy efficient!
Our 25 year old Gas boiler would used 13,500kWh so the heat pump 5 times more energy efficient!
January 2, 2026 at 4:01 PM
Our 5kW Valiant Aerotherm+ required 2,451kWh of energy to generate 6,572kWh of heat and 2,860kWh if hot water with a seasonal COP if 3.85.
Our 25 year old Gas boiler would used 13,500kWh so the heat pump 5 times more energy efficient!
Our 25 year old Gas boiler would used 13,500kWh so the heat pump 5 times more energy efficient!
In 2025 we covered 11,535 miles in our MG5.
We used 3340kWh of electricity of which 804kWh from public charging (24%.)
Public charging costs including subscription was £397.62.
Home charging was most at the overnight @ocitopus go rate if 8.1p/kWh but occasionally we charged during the day to.
We used 3340kWh of electricity of which 804kWh from public charging (24%.)
Public charging costs including subscription was £397.62.
Home charging was most at the overnight @ocitopus go rate if 8.1p/kWh but occasionally we charged during the day to.
January 2, 2026 at 3:53 PM
In 2025 we covered 11,535 miles in our MG5.
We used 3340kWh of electricity of which 804kWh from public charging (24%.)
Public charging costs including subscription was £397.62.
Home charging was most at the overnight @ocitopus go rate if 8.1p/kWh but occasionally we charged during the day to.
We used 3340kWh of electricity of which 804kWh from public charging (24%.)
Public charging costs including subscription was £397.62.
Home charging was most at the overnight @ocitopus go rate if 8.1p/kWh but occasionally we charged during the day to.
Happy New Year Folks :-)
2025 was our first full year as a de-carbonized household so we are now able to review all the monetary and carbon costs of having heat-pump, household battery, solar and an fully electric car.
Our running and carbon costs are now 63% & 93% lower than before transitioning!
2025 was our first full year as a de-carbonized household so we are now able to review all the monetary and carbon costs of having heat-pump, household battery, solar and an fully electric car.
Our running and carbon costs are now 63% & 93% lower than before transitioning!
January 2, 2026 at 3:40 PM
Happy New Year Folks :-)
2025 was our first full year as a de-carbonized household so we are now able to review all the monetary and carbon costs of having heat-pump, household battery, solar and an fully electric car.
Our running and carbon costs are now 63% & 93% lower than before transitioning!
2025 was our first full year as a de-carbonized household so we are now able to review all the monetary and carbon costs of having heat-pump, household battery, solar and an fully electric car.
Our running and carbon costs are now 63% & 93% lower than before transitioning!
I have only quickly scanned through the articles on the shift to EV and there are some oddities in there like the discussion on EVs on grid demand.
I've been an EV owner for a year now, and 75% of our charging is done overnight between 12:30am and 5:30am aligned with low demand not peak.
I've been an EV owner for a year now, and 75% of our charging is done overnight between 12:30am and 5:30am aligned with low demand not peak.
December 18, 2025 at 3:37 PM
I have only quickly scanned through the articles on the shift to EV and there are some oddities in there like the discussion on EVs on grid demand.
I've been an EV owner for a year now, and 75% of our charging is done overnight between 12:30am and 5:30am aligned with low demand not peak.
I've been an EV owner for a year now, and 75% of our charging is done overnight between 12:30am and 5:30am aligned with low demand not peak.
This research on modern household heat pump performance finds an average SCOP of 3.86, 40% better than older studies.
Our heat pump has achieved a SCOP of 3.85 so far this year.
Our heat pump has achieved a SCOP of 3.85 so far this year.
December 18, 2025 at 12:04 PM
This research on modern household heat pump performance finds an average SCOP of 3.86, 40% better than older studies.
Our heat pump has achieved a SCOP of 3.85 so far this year.
Our heat pump has achieved a SCOP of 3.85 so far this year.
@iea.org coal report "Analysis and forecast to 2030" suggests coal use is at it's peak and will fall slightly by the end of this decade:
www.iea.org/reports/coal...
Personally I suspect the rapid drop in cost of solar & batteries will drive a move from coal faster than the IEA forecasts.
www.iea.org/reports/coal...
Personally I suspect the rapid drop in cost of solar & batteries will drive a move from coal faster than the IEA forecasts.
December 17, 2025 at 4:47 PM
@iea.org coal report "Analysis and forecast to 2030" suggests coal use is at it's peak and will fall slightly by the end of this decade:
www.iea.org/reports/coal...
Personally I suspect the rapid drop in cost of solar & batteries will drive a move from coal faster than the IEA forecasts.
www.iea.org/reports/coal...
Personally I suspect the rapid drop in cost of solar & batteries will drive a move from coal faster than the IEA forecasts.
While the new Renault 5 is lovely and no doubt selling well it sadly isn't in the the top 10.
www.smmt.co.uk/vehicle-data...
www.smmt.co.uk/vehicle-data...
December 5, 2025 at 4:02 PM
While the new Renault 5 is lovely and no doubt selling well it sadly isn't in the the top 10.
www.smmt.co.uk/vehicle-data...
www.smmt.co.uk/vehicle-data...
Despite growth in BEVs Tesla shrank 5.91% year on year, increasing competition in the BEV space and folks being sick of Elon Musks conduct both having an effect.
Toyota fared even worse down 9.87%, despite HEV and PHEV segments growing. Once a leader in electrification of cars is being left out.
Toyota fared even worse down 9.87%, despite HEV and PHEV segments growing. Once a leader in electrification of cars is being left out.
December 4, 2025 at 10:52 AM
Despite growth in BEVs Tesla shrank 5.91% year on year, increasing competition in the BEV space and folks being sick of Elon Musks conduct both having an effect.
Toyota fared even worse down 9.87%, despite HEV and PHEV segments growing. Once a leader in electrification of cars is being left out.
Toyota fared even worse down 9.87%, despite HEV and PHEV segments growing. Once a leader in electrification of cars is being left out.
BEV, PHEV and HEV segments all grew year on year, while both Petrol and Diesel continue to shrink.
December 4, 2025 at 10:45 AM
BEV, PHEV and HEV segments all grew year on year, while both Petrol and Diesel continue to shrink.
@smmtgroup.bsky.social have published their UK new car registration data for November and while BEVs only grew 3.6% year on year they did this despite the overall market shrinking 1.6% and remains on track for 50% share around mid 2027.
December 4, 2025 at 10:38 AM
@smmtgroup.bsky.social have published their UK new car registration data for November and while BEVs only grew 3.6% year on year they did this despite the overall market shrinking 1.6% and remains on track for 50% share around mid 2027.
At national scale we can also see how energy demand isn't always upward.
Here in the UK electricity demand has fallen steadily over the past 2 decades.
ourworldindata.org/grapher/elec...
Here in the UK electricity demand has fallen steadily over the past 2 decades.
ourworldindata.org/grapher/elec...
November 11, 2025 at 10:18 AM
At national scale we can also see how energy demand isn't always upward.
Here in the UK electricity demand has fallen steadily over the past 2 decades.
ourworldindata.org/grapher/elec...
Here in the UK electricity demand has fallen steadily over the past 2 decades.
ourworldindata.org/grapher/elec...
Solar prices have dropped from $128/Watt in 1975 to $0.26/Watt in 2024. This astonishing drop can be viewed on a linear scale, but this makes it look like price drops have dropped little in the past 20 years.
Logarithmic scale shows the relative price drops have accelerated since 2008!
Logarithmic scale shows the relative price drops have accelerated since 2008!
November 10, 2025 at 9:53 AM
Solar prices have dropped from $128/Watt in 1975 to $0.26/Watt in 2024. This astonishing drop can be viewed on a linear scale, but this makes it look like price drops have dropped little in the past 20 years.
Logarithmic scale shows the relative price drops have accelerated since 2008!
Logarithmic scale shows the relative price drops have accelerated since 2008!
@janrosenow.bsky.social's original post was about Europe, so just looking at Europe we can see how far we've come in moving away from Coal.
November 7, 2025 at 4:00 PM
@janrosenow.bsky.social's original post was about Europe, so just looking at Europe we can see how far we've come in moving away from Coal.
That graph is just so wrong.
For a clearer picture of what is going on here's the actual up to date data:
ourworldindata.org/grapher/coal...
For a clearer picture of what is going on here's the actual up to date data:
ourworldindata.org/grapher/coal...
November 7, 2025 at 3:53 PM
That graph is just so wrong.
For a clearer picture of what is going on here's the actual up to date data:
ourworldindata.org/grapher/coal...
For a clearer picture of what is going on here's the actual up to date data:
ourworldindata.org/grapher/coal...
The pure Petrol car segment remains the largest but shrank substantially from last year. While BEV has been 2nd largest segment since October 2023 and growing rapidly it looks likely that BEVs will be become the biggest car segment next year.
November 5, 2025 at 9:11 PM
The pure Petrol car segment remains the largest but shrank substantially from last year. While BEV has been 2nd largest segment since October 2023 and growing rapidly it looks likely that BEVs will be become the biggest car segment next year.
@smmt-ukauto.bsky.social have published their UK October 2025 new car registration figures, with BEV and PHEVs both show strong growth while pure Petrol and Diesel segments shrinking.
If BEVs continue to follow this growth trajectory then they'll likely be half of UK new car sales in 2027.
If BEVs continue to follow this growth trajectory then they'll likely be half of UK new car sales in 2027.
November 5, 2025 at 9:06 PM
@smmt-ukauto.bsky.social have published their UK October 2025 new car registration figures, with BEV and PHEVs both show strong growth while pure Petrol and Diesel segments shrinking.
If BEVs continue to follow this growth trajectory then they'll likely be half of UK new car sales in 2027.
If BEVs continue to follow this growth trajectory then they'll likely be half of UK new car sales in 2027.
Is this what they really mean?
October 30, 2025 at 5:58 PM
Is this what they really mean?
Last week visited a client in Belgium and chose to drive & take the Hull-Rotterdam ferry rather fly.
It took 24hrs door to door in both directions including Ferry. Driving. Not quick but lower CO2 and more flexible.
Total cost of home and public charging was £80.62, which is 9p/mile.
Ferry £303!
It took 24hrs door to door in both directions including Ferry. Driving. Not quick but lower CO2 and more flexible.
Total cost of home and public charging was £80.62, which is 9p/mile.
Ferry £303!
October 29, 2025 at 7:44 PM
Last week visited a client in Belgium and chose to drive & take the Hull-Rotterdam ferry rather fly.
It took 24hrs door to door in both directions including Ferry. Driving. Not quick but lower CO2 and more flexible.
Total cost of home and public charging was £80.62, which is 9p/mile.
Ferry £303!
It took 24hrs door to door in both directions including Ferry. Driving. Not quick but lower CO2 and more flexible.
Total cost of home and public charging was £80.62, which is 9p/mile.
Ferry £303!
Amusingly both Toyota and Tesla's sales have dropped in the UK this year, all while both PHEV and BEV sales they are known for have boomed in 2025.
From @smmt-ukauto.bsky.social:
www.smmt.co.uk/vehicle-data...
From @smmt-ukauto.bsky.social:
www.smmt.co.uk/vehicle-data...
October 29, 2025 at 1:02 PM
Amusingly both Toyota and Tesla's sales have dropped in the UK this year, all while both PHEV and BEV sales they are known for have boomed in 2025.
From @smmt-ukauto.bsky.social:
www.smmt.co.uk/vehicle-data...
From @smmt-ukauto.bsky.social:
www.smmt.co.uk/vehicle-data...