Earth Notes: Diarycast - Year In Review (2025)
Updated 2025-12-30.The 2025 EOU diary, and a full year without fossil gas... #yearInReview #heatPump #fossilFree
Diarycast
The DHD/EOU diary for .
No audio for this one again, just words!
- : Google search AI seems to know of the
bad setback effect
as covered by my research! - : it looks like total demand for the heat pump
hph4over 12 months has been ~1.2MWh cf a typical fossil gas ~3MWh+ for the same period, so an overall CoP of ~3. That heat pump demand is a little less than grid imports; they are close because most imports now happen in winter for space heating. - : I sketched out how the Octopus Cosy electricity tariff might work for us...
- : NHS bowel cancer screening test result arrived today by post dated :
Your result showed that no further tests are needed at this time.
The screening repeats every two years until age 75 (or morale improves). Dentist 6M check-up this afternoon resulted in an exhortation to brush my front teeth better, and a cleaning of them, and a band-1 payment. - : it does not fit my world view, but I feel compelled in fairness to report ... When I told a friend a few days ago that we had been in the wait queue for months for tickets for the Green Man music festival in August, she said that she would manifest them for me, and today via a peculiar route they became available!
- : according to my
@DamonHD@mastodon.socialWrapstodon my not-quite-viral most-boosted toot got a whole 13 boosts, out of 14,939 toots! - : just taken sample at home for NHS bowel cancer screening tests; next up checking company accounts before submitting them...
- : trying out some of my suits since I have a slightly posh appointment at the Institute of Directors' Champagne bar this evening; one had drycleaning tickets from ...
- : gas has now dropped out of a year's utility flows and 16WW has been a net electricity exporter:
At 16WW over 366 days from to : electricity import 3.7kWh/d (net -0.8kWh/d).
- : according to the room (not TRV) sensors, late afternoon inside is a fairly uniform 18°C in all 16WW rooms (17.9–18.7°C) at ~8°C outside, TRVs notwithstanding...
- : the heat-pump was on from mid-afternoon a year ago, though officially commissioned the following day; our last unit of gas was consumed by .
- : we have a house guest from tomorrow until , so the heating officially went on this evening ~Z and TRV in
2bwas turned up from 'frost' for the duration. - : 16WW is getting an enforced upgrade from FTTC to FTTP soon because OpenReach is retiring copper connections early next year; download speed is nominally slightly higher, and without analogue on the path the connection may be more reliable. A new router may mean that we need not reboot every day!
- : the yellow sodium light in the car park outside my window has this afternoon been replaced with a smaller more efficient (and I understand, remotely controllable) white LED lamp. Like the previous one, this has a light sensor on top.
- : full-length warm brushed cotton nightshirt tonight!
- : gloves on to venture out this evening at ~1°C...
- : heating still just in pipe-freeze protection mode so a chilly ~17°C in the house, HDD12=7.9 (so not far above freezing),
hph4yesterday was 7kWh of which ~1.5kWh will likely have been DHW. Total consumption ~12kWh, including grid imports of ~10.5kWh. - :
even though the heating is officially still off, the anti-pipe-freeze protection kicked on briefly this morning and will be on again this evening and overnight (outside <~6°C), so we will be getting some low heat anyway... The next few days will feature more of the same sorts of temperatures. ~2kWh extra electricity demand today, an extra ~4kWh the next, roughly corresponding to a heat demand of 1.5kWh/HDD12 and a CoP of 4. - : my tips today for someone wanting to put together a small community energy system... Tier 1 panels. AC couple your batteries so that all the components can work independently and can be swapped out. Make sure your batteries are modular, eg easily expandable: I have expanded mine by 5x in 3 rounds. Make sure that all will work (even if not optimally) without an Internet connection, and can be at least monitored, but preferably controlled, locally. Aim to have stuff pay for itself, including maintenance, in 10Y. If you are going to interact with ToU tariffs, have enough battery to cover ~max winter day kWh consumption including heat pump and top up overnight to run from all day, leaving room for any PV generation, else go for max summer day.
- : Thames Water keeps SPAMming me (mainly SMSes, but also emails and phone calls) to fit a water meter at 16WW. I have today asked TW to remove my mobile phone number and email address from their systems under GDPR, because, for example, their messages are interrupting my work and yesterday at a university seminar. I asked TW to note in text form on my account log that the house is relatively soon due to be pulled down, and not to repeat the waste of installing as they did for houses at the other end of our road which were in the process of being vacated and demolished as the installations were being done... And I believe that we are low water users so TW gets no actual benefit from an installation. I would be happy with extra numbers to observe, but Jean does not want to go there.
- : after discussion raised temperature of initial/main DHW period starting at to 'comfort' (48°C) from eco (45°C).
- :
very warm few nights with little daily temperature swing, apparently due to jet stream japes. - : Brewster Kahle of Internet Archive fame said nice things about my data-to-music work!
- : finally during Repair Café today got to try the new
D01843soldering iron bits for my old MaplinN78ARTemperature Control Solder Station
and it physically fits at least! Thank you Jason L from RCK for the suggestion, ie that the Maplin iron is simply a rebadged DuratoolD01843. - : today at university I cosplayed an impact investor as part of the entrepreneurship
Global Graduate Award
. - : collated my Hogsmill bat observations into a 78 data rows of machine-readable CSV dataset [hart-davis2025hogsmill].
- :
heat from the heat pump DHW top-ups can be seen leaking into the 3lradiator temperature record. - : today at university I gave a sustainable technology innovation lecture, and received positive feedback including being asked to give it again next year!
- : Skip short strolls — a longer daily walk is better for your heart:
Walking for at least 15 minutes without stopping is ideal, it says. That's about 1,500 steps in a row...
[delpozocruz2025step]. When at home my target each day is a 1 mile walk (2,000 steps) around the local cemetery, plus 10 squats and 30 push-ups. - : given that it is below 16°C in my room, the rest of the family is away, and I refuse to put the heating on, I have put on thermals under my trousers for the first time at this end of the year! (And two pairs of socks, and an old t-shirt under my long-sleeved shirt, under my gilet... And heated insoles late afternoon...)
- : the heat pump's pipe freeze protection (~0.5kWh over 3h?) kicked in a few degrees above freezing a little after the clocks went back this morning, so October's
hph4is not purely DHW. Looks like this also happened . - : running a full hot bath mid-morning caused the heat pump to draw a little under 0.7kWh to top up the DHW after. Total demand from the heat pump for DHW plus some pipe-freeze protection for the day was 2.7kWh, compared to a recent typical ~1.5kW, so maybe 1kWh in total for the bath at a DHW CoP of ~4.
- : feet are a little chilly tonight so I am testing my USB-powered heated insoles briefly before bed!
- :
DHW tank pasteurisation ran from about Z for less than 2h (with the grid 'super-green' due to the passing storm) and used ~2.9kWh, peaking at ~1.7kW (1.9kW from grid total), having been unable to get enough energy by PV diversion for several days. There was one interruption: STOPPED 2025-10-23T01:35:01Z 1884W frequency low at 49.89Hz. - : subject to final corrections I think I have finished my lecture slides [hart-davis2025sustech] for the end of the month; my first spoken run-through was quite close to my target 40 minutes!
- : received a letter from SGN (the gas distribution operator) noting that there will soon have been no gas meter on our pipe for a year; if we do not want to use gas then the pipework will need to be checked for safety. (Or the gas supply pipe might be disconnected from our property entirely.)
- : deviated from my daily walk to pop into the local pharmacy/chemist and get myself a 'flu jab (£25 — I am neither old nor frail enough to get it free this year):
Cell-based Trivalent Influenza Vaccine (Surface Antigen, Inactivated) Seqirus 2025/2026 Season, Lot 3051272, EXP:
; A/Wisconsin/67/2022 (H1N1)pdm09-like strain (A/Georgia/12/2022, CVR-167), A/District of Columbia/27/2023 (H3N2)-like strain (A/Victoria/800/2024, CVR-289), B/Austria/1359417/2021-like strain (B/Singapore/WUH4618/2021, wild type). No side-effects and was out clubbing the following night... - : I watched Cleaning Up with John Pettigrew outgoing CEO of National Grid: one notable absence was enthusiasm for hydrogen or "renewable gas" for dunkelflaute (or interseasonal) storage.
- : I have brought forward the DHW 'eco' start (45°C) to (down the demand curve and less likely to disappoint at the hot tap) and removed the 5A heat pump power limit for winter as there does not seem to be a 'except when defrosting' value.
- : putting together a lecture for Surrey undergrads later in the month. [hart-davis2025sustech]
- : a delayed Open Home visit happened this morning, taking the usual 1h! Then went in to campus to support a PhD classmate doing her viva: no corrections!
- : I am not directly measuring it, but I may currently be achieving a DHW CoP from the heat pump of 3–4; eg bath yesterday (typically 4kWh heat) increased
hph4to ~2kWh from typical ~1kWh. - : sartorially confused with double socks, tank top and gilet. Have been in steering group meeting for KEHS. Working through admin (and paper) for Journal Club and Inventors' Club. I know the next tiny planning and modelling steps for my research so aim to get to some of them...
- : this evening I just put an extra pair of socks on because my feet are cold, but I was wearing a tank top and was far too hot in my flight jacket; truly the crux of autumn!
- : a pasteurisation cycle did not quite complete today (tank got up to ~61°C after ~2.5kWh) so modification to merit order and frequency response has been made to not interrupt diversion to heater 1 for usual low frequency and other reasons. Pasteurisation completed with ~2.3kWh the next day; possibly the last pasteurisation by diversion rather than boost until about March.
- : this evening () Thames Water seem finally to be working on the leak a few doors up, slightly noisily for about , though the barriers remain in place and there is still a big hole in the ground. Late morning works on the hole were in progress and finished (paving relaid, some plastic barriers to be collected) before .
- : starting Monday morning with fog and empty electric and heat batteries; due to be sunny today and tomorrow though.
- : note that a T11 (type 11) Flomasta White Single Panel powder-coated mild-steel radiator (EAN 5059340420813), (W)800mm x (H)600mm, nominal 400W at delta-T to room of 30K, weighs 12.99kg empty and 15.39kg full ie containing 2.4l of water, and retails for ~£50. A typical small heat-pump can output 4kW and requires ~24l minimum volume, 10 of those radiators or equivalent, and thus requires no volumiser or the like when there are no TRVs; simple for installers but likely sub-optimal in efficiency and/or comfort.
- : today was our "Sustainable September" Open Home, but no one booked to visit! (An email request came on Sunday but I missed it.)
- : today Thames Water contacted us again (attempt 3 according to its messages) by SMS and email and phone to put in a water meter. As I explained (again) on the phone the house has a limited remaining life (TW put in meters at the other end of our road for houses that were in the process of being vacated and demolished), and I believe us to be low water users; the caller apologised and hung up. Meanwhile a few doors up a pipe break is leaking water at possibly l/min and likely much more than our home consumption, closing the footway, and has continued for many days for which TW has apparently only lifted a paving flag and put up a couple of barriers. It is possible that this leak was ultimately caused by TW fitting meters. Leak still going at 10 days with sign still claiming fix by when I last looked; leak stopped late ...
- :
I fired up the heating as a test in the morning as it was (just) cold enough outside (≤15°C) to run the heating at all, and sunny enough not to need to draw from the grid. I needed to switch on the OpenTRV base unit and ensure that at least one TRV was calling for heat (3lwas). - : today the KEHS Bitesize short talks took place and went largely to plan; maybe 30 members of the public attended the event.
- : this morning a bath and two showers have been taken in quick succession with the Thermino nominally starting at ~+20% full and ending ~-40% (just about down to ~21°C mains inlet temperature) totalling ~4kWh (took 2.4kWH to get back to 0%), and the heat pump made extra DHW ramping up to a peak of a little under ~1kW totalling 0.86kWh today in so maybe ~2.5kWh heat out. From about solar noon manually forcing/allowing diversion (~1kW+) to Thermino ignoring 'red' grid status etc.
- : this morning is the first time that the AC-coupled battery effectively hit empty this side of Spring.
- : just renewed a personal DNS domain/zone for five years; no discount for more years but less admin overhead.
- :
Light rain showers and a gentle breeze
shown for today — possibly excluding the thunderstorm and close-by forked lightning and gusts that were lofting chunks of building construction in the cemetery! - : a few days ago I bought a discounted student licence for DesignBuilder; its technical support is fast.
- : made a quick response to a government consultation [govUK2025visibility].
- : because the master bedroom faces east, during September and March it is possible to be blinded by direct sunlight in the morning while still in bed! Careful deployment of the curtains (often to the middle rather than sides) can allow the room to be bright without the blinding...
- : pasteurisation run ~4.4kWh from assumed ~33°C starting point. ( ~3d after pasteurisation run 40°C, 37°C.)
- : based on today's flows, 16WW vacant background consumption without DHW use (heat-pomp DHW is off) or losses seems to be ~2kWh/d in summer, maybe ~3kWh/d with Thermino DHW losses. Leakage DHW diversion seems to be ~0.3kWh/d, and DHW tank from a couple of samples stable at ~34°C.
- : off ~400km to Ravenglass for a week for a festival by train, then in August ~1000km to Vias (via Agde) by train for a fortnight family holiday, so ~3000km by mainly-electrified public transport in a month.
- : moved from Vodafone after actually decades (~30Y?) to ID for 30% of the cost for essentially the same service levels and limits, and my use of calls, SMS and data was/is far below the limits. I still use mobile data like it is on GPRS! The final breakup was Vodafone wanting to charge extra for roaming in France for a couple of weeks, where ID has it for free.
- : first attempt to replace all (or most) of my coffees today with cold-brew overnight in the 'bonus' French press cafetière that I acquired through someone's else's botched logistics... This might save ~0.1kWh (per day) in kettle use. Three tablespoons of coffee in 800ml+ water seems to cover 3 mugs and a whole day, when started at ~ the previous night.
- : repaired my older/backup MacBook Air — replaced the keyboard which had liquid damage and the battery which was wearing out — £150 all in, done in three hours close to the University. (Four keys has stopped working:
Z,X,controlandoption.) The battery capacity reports as 102% as of ! - : I am now a Fellow of the Institute for Sustainability at Surrey.
- : today I updated the heat pump space WC heating adjustment schedule, obviously...
- : a French press (cafetière) was misdelivered to a friend and the logistics company would not come to collect it (legally abandoned I assume), so now I get to make more cold brew coffees and save a few more Wh not heating water.
- : first blackberry of the year in the cemetery.
- :
2025: year to date (6 months) 29kgCO2 net, full-year linearly projected (more-of-the-same) 59kgCO2 net.
- : living on the wild side, I have decided to try light-responsive (not polarised) sunglasses, and punted for a pair of (almost) the cheapest possible from Specsavers with my varifocal prescription as an experiment — making sure that I am not missing out in my twilight years!
- : high ('red', upper-quartile over 7 days) grid carbon intensity blocked PV diversion today, in particular postponing a pasteurisation cycle. Given 27°C in the kitchen (34°C outside) that is probably win-win!
- : a maths education event
to encourage more female students to study maths
that I helped to fund ran last Thursday, attended by 40! - :
weird ~6GW extra gap between transmission and nation demand forecast for : us propping up the French grid because of its overheating nukes? - :
I am pleased with the eheatand grid net import/export profiles since I started delaying some diversion until solar noon (more). - : I finally signed up to the OpenEnergyMonitor forum for a couple of reasons, one being that even though I am not using OEM equipment I may have heat-pump insights to contribute.
- : still tweaking the threshold for the 'postpone final part of Thermino diversion until noon' algorithm for robustness...
- : Morgan just came back from a post-GCSE-exam jaunt to Naples with friends, and Eloise is off shortly to Sicily, so a short-haul return flight each so far this year, but no more currently planned.
- : spanning the solstice:
At 16WW over 7 days from 2025-06-16 to 2025-06-23: electricity import 0.3kWh/d (net -16.8kWh/d).
- : had a yucky rotten wisdom tooth extracted without pain in about 20 minutes: a miracle of modern dentistry!
- :
grid-friendliness idea first pass: once heat battery is more than ~50% full, block further diversion until after ~Z to minimise spill to grid around solar noon. Implemented next day with 67%-full and Z thresholds, and on shown in the chart most (~2.5kWh) diversion is delayed until after solar noon (cf ~17kWh exports). - : Thames Water emailed me to say
As you've probably noticed, we've had lots of warm, dry weather recently. In fact, it's been the driest spring in 69 years.
- : I managed to debug a slightly vexing heat loss problem in my
bungalow-2model-in-progress. I had the new roof segments on 'upside down' even though they have only one layer and are actually walls. (Don't ask ... yet... Maybe I'll understand what I'm doing in a few months!) - : according to Enphase Enlighten, in 2025 so far 16WW has a net import from grid of 139kWh, with 1.7MWh generated, 1.8MWh consumed, 709kWh imported, 570kWh exported. So there is a chance of net export for the year, and also of being net carbon negative.
- : power-cycling the Purrmetrix gateway box (this is the second time) did not this time allow numbers to flow to the interface again.
- : on a sunny bank holiday I note that the Dynamic Containment price (as shown on The Energy Current) is £7.81/MW/h, which implies that my ~1kWh/d of frequency response might be worth ~1p per day!
- :
I gave a Pint of Science talk [PDF] in Guildford tonight at The Star Inn (photo by Dr Caroline Shenton-Taylor). - : at Tottenham Court Road my baseball cap was blown onto the Central Line tracks!
- : it took about 8h on the phone over about a week (though 5h was over Sun/Mon) to return my savings at one UK bank to my main account with the UK bank that just bought them: absolutely shambolic failure of their anti-fraud process punishing the innocent. I was awarded compensation on three points from my upheld observations made on my first complaint.
- : reduced 'power' limit for heat pump to be 5A, thus the Enphase can support it entirely when not empty to minimise imports.
- : the cemetery is open again today.
- : for the last couple of days the cemetery next door has been closed to most people (eg me taking a walk) and guarded by police: Kingston Cemetery: Woman in hospital with life-changing injuries.
- : I spent ~5h over last 2d to do part of a transaction to transfer some savings back from my old bank to my account with its new owner. I have filed a couple of complaints that I hope will make someone in senior management weep. But I also wrote some interesting control code in a place that it should not live, based on inferences about key data that I can not get to, and it seems to work!
- : visited the Wimbledon Art Fair and may have spoken to most of the (180!) artists with their studios open: my brain is full!
- : managed the Kingston's Efficient Homes Show 2025 short talks by day, and went out for several beers in the evening.
- : filed a response to the government's
Boiler Upgrade Scheme and Certification requirements for clean heat schemes consultation
. - : TTK AGM tonight...
- :
the off-grid system powered the router overnight, possibly for the first time this year. - : sent in my slides for the 2025 University of Surrey PGR/ECR conference.
- : after my son took a bath last night and the other two took showers today, I thought that my hot bath today was doomed: in the end 0.7kWh of heat pump DHW top up went in after I drew my bath, saving a bit of diversion for the grid in due course!
- : mains voltage reported as 233.3V during 3kW kettle demand in evening (no PV, ~100W other demand, battery supplying ~1.3kW), 237.7V when the kettle finished.
- : total PV generation reported on the SunnyBoy is 60,738.2kWh as of Z, ie over 60MWh.
- : fifth Enphase ACB installed today, at around noon.
- : sunny morning, watching an exact apparent match of the dishwasher consuming 2.3kWh with the PV generation the same, with both the battery and grid connection idle...
- : for the first time in many months, I was able to do a full orbit of the sunny cemetery today, with the flooded path by the north (Bonner Hill Road) fence and the brambles overgrowing the path at the east boundary both under control.
- : today I went to Solar and Storage Live at Excel London, and learned that £1k/kWh is probably still a reasonable installed price for home AC-coupled storage, with the typical range in prices being maybe 40% with FoxESS at the budget end (~£200/kWh wholesale). And a ~450Wp mid range solar panel wholesales for £50–£100 so it really is the labour and other installation costs that matter! Oh and a big packaged battery system for about 1 month of winter consumption for us at 16WW towers (~300kWh) from Prime Batteries for ~EUR80k (~4t, ~9m^3)!
- : at just this time of year (and a mirror couple of weeks in the Autumn) the sun rises directly over the houses outside our bedroom window and blinds me while I set in bed unless I pull the curtains!
- : Enphase ACB, DHW cylinder, Thermino heat battery and the off-grid battery were all full by just after solar noon ( BST)!
- : did not quite fill up all the energy stores today: Enphase and DHW cylinder both were full, Thermino estimated <1kWh capacity left.
- :
a partial solar eclipse landed ~ to ~ here with blue/hazy skies, so obviously also the perfect time to run (possibly the first) 'intense' (65°C) dishwasher maintenance wash of the year while avoiding importing from the grid! GB grid solar generation seemed to dip ~16GW/~15% at ~, looking at Sheffield Solar. This also seems like a good day to stop taking vitamin D until autumn; I have been intermittent the last few days. - : assuming that I can resolve my current long-running dispute with Enphase about read-only local access to my data, eg battery SoC, I am contemplating adding 1 or 2 more ACB units to improve self-consumption outside winter.
- : we are due a pasteurisation cycle, so PV diversion priority has automagically been set to the DHW cylinder. And because the grid carbon intensity in the wee hours was too high to do it that way, PV diversion is being hoped for, and indeed is much preferred. Reader, it all worked: ~3kWh to the DHW cylinder and ~1.4kWh to the Thermino.
- : blue skies (though chilly outside); Enphase and Thermino (ie electric and heat batteries) both charging well before noon, and my laptop is being powered off-grid. ~5kWh each into the Enphase and Thermino by EOD. At ~ we turned off the space heating and the OpenTRV unit; the pipe-freeze protection means that the pump and compressor will still run at low settings when outside is cold (~≤6°C). The bathroom MHRV fan was also turned off to save ~2W.
- : 53 minutes of grid-response by the Eddi today (~27% of active)! By mid-evening for March so far our PV generation was almost identical to consumption (including diversion) at ~170kWh, though ~43kWh was still imported and ~26kWh exported. About one third of consumption (a bit under 4kWh/d) passed through the Enphase ACB.
- : we are contemplating turning heating off in the middle of next week when daily temperatures seem set to stay at or about 12°C.
- : last of my set of four favourite 'tulip' wine glasses died today — I noticed a big L-shaped crack as I was pouring red wine. Three of them died within a few months and the set was maybe at least a decade old...
- : I just manually scheduled my dishwasher run water-heating demand around a 30:1 (3366W peak down to 111W trough in 7 minutes) swing in PV generation — blue sky direct sun to hail and then slowly back — 'flexible demand' and 'self consumption' for the win ...
- : I am using up in porch Radbot
4oa couple of pairs of old AA alkaline cells of unknown remaining capacity, for recycling after, as a break from the usual parade of NiMHs. - : SVN repo version to 62008 before this comment committed!
- : we seem to be booking a full family holiday this year, woven around various other dates such as GCSE results and degree retake dates...
- : daytime outside temperatures in these sunny early days in March are high enough (over 15°C) to turn off the space heating entirely for the duration, except the circulation pump when the OpenTRV boiler controller calls for heat. In April turning that base unit off alongside space heating would save maybe ~20W. (I managed a little shirt-off sunbathing in the garden this afternoon, and I am giving the house an airing.)
- : a pasteurisation cycle ran overnight for the DHW tank, and then some diversion to the Thermino heat battery started -ish.
- : I accidentally forced the Ecotricity bill a day early, but in any case for this month it is ~£99 vs ~£20 more last February.
- : I saw inside an A&E (US: "emergency room") for the first time, at UCL, accompanying a friend there. Got to the front of the queue after ~5 minutes, triaged after another ~10 minutes, discharged ~90m from arrival.
- : external temperatures up to ~15°C in the afternoon; technically we barely need space heating, which is handy as I completely powered down the heat pump to help reconnecting the heat battery.
- : I posted a talk proposal for the NLUUG spring conference.
- : I filed a claim with Thames Water for a surface water drainage rebate (~£50/y) on the grounds that all our rain run-off goes to soakaways, eg as listed under Non-energy things done
: installed roof downpipe/downspout with 200l+ water butt for watering garden ... Run-off is to garden which should very slightly reduce strain on drains during a rain storm.
- : PV diversion to the DHW tank before noon...
- : the off-grid battery hit FULL today, and there was a smidge of diversion on-grid to the DHW tank.
- : unexpectedly giving a talk on my start-ups [PDF] tomorrow at the Hackathon17 that I am helping out with again; the hackathon is all weekend.
- : a bit of solar spill to grid before 1pm...
- : new glasses today, with a slight prescription change.
- : I have been delivered a new shiny toy - an Etekcity Lasergrip 1080 infrared thermometer!
- : according to the new pretty dashboard on AlDente Pro 1.30 my MBA's battery's peak capacity (after 272 cycles) is ~86% of FCS having dropped off a cliff from ~93% to ~88% on , so I am recalibrating in case that helps.
- : ARRRGH! — the Eddi stopped working properly yesterday evening apparently due to some latent old code causing undervoltage fault 47 and other weird behaviour and the live values I can see are not being properly stored in the myenergi database for later access, and the OpenTRV stats receiver seemed to have gone at least partly deaf though improved when power cycled and moved a few cm away from the outside wall and ~30cm from the Purrmetrix gateway (currently indicating that it is using 3G)... Readings from to inclusive were unreliable or absent.
- : Octopus declared "job done" today and I paid the balance of their fee. Another tentacle SPAMed me the next day offering me 10% off solar PV...
- : I attended a useful all-morning AI seminar for researchers in the engineering school at university, which taught me the current/new art terms for things I had had to work out myself in my GA (genetic algorithm) fiddling before university the first time ~40 years ago: "reward shaping"! Spent quite some time before, during and after the event comparing Octopus Daikin home heat-pump installation notes with a recent head of my department (AD)...
- : new fibre optics have just been laid today into the part of the estate due to be bulldozed, including close to me...
- :
to slightly lighten my footprint, on my personal Mastodon/Fediverse account I have set posts to evaporate (auto-delete) after a year if they have not been liked or boosted etc, which should trim storage requirements a little with minimal loss of value. - : daughter back to uni today, so she did not get to see out of a fixed window!
- : the window people did not show today (looks like the work did not get booked in on their side)...
- : had to use MailChimp today for the first time (historically I have been SPAMmed crazy through it) for Kingston Invents.
- : actually during my PhD supervision, one of my supervisors had his gas meter removed, so both he and I have switched from gas heating to heat pumps and 'defossilised' this winter!
- : reduced my review rating for the Enphase system from 4.5 to 2 because of the continuing failure to make stats available across the LAN as before which breaks lots of my integrations.
- : outside temperatures touched -2°C first this this morning making for some pretty frost on our windows in the morning sunshine, and an iced-up bathroom fan overnight. The new heat pump is working well, and at noon was being entirely powered by our PV, which I did not expect to happen in winter!
- : we used less electricity last month than the previous (warmer) December, so the heat pump seems to be doing its job.
Year-End Heat-Pump Setup
State of the heat-pump (space-heat and DHW) setup at end of :
References
- [delpozocruz2025step] Step Accumulation Patterns and Risk for Cardiovascular Events and Mortality Among Suboptimally Active Adults
- [govUK2025visibility] Open call for evidence: Improving the visibility of distributed energy assets
- [hart-davis2025hogsmill] Hogsmill River Bridge at Villiers Road Kingston-upon-Thames Bat Activity
- [hart-davis2025sustech] Sustainable Tech
(Count: 4)