ElectronVault Inc, and one of the founders of Tesla motors (the battery guy)
, emailed me:
Love what you are doing and the fantastic data sets you have made available. Well done!
A question: would it be possible to get some higher frequency data (perhaps 60s or faster bins?) for a single day with some clouds and some clear? I'm trying to find some actual data like that to feed into a simulation I've built of storage smoothed systems, and while I have simulated data, nothing beats real.
Well, flattery will get you everywhere, and I gave him a bunch of my raw 10-min data (apparently intraday PV data is rare on the Web, astonishingly), and he drew me some nice graphs from it in return. Any remaining strangeness is not for want of effort on his part!
Remember that the PV system has been enlarged twice during the data set that he graphed.
Robert H wrote to me 2012-08-05 re my Register piece How I built a zero energy cost, zero carbon home server:
I enjoyed your article about the zero energy cost, zero carbon home server, of a year and a half ago. Have you looked into the new Raspberry Pi computers? $35 and (someone needs to update Wikipedia) 512 megs of memory... Two watts on a heavy load... And a fantastic community to help out, too! And you can change OS just by sticking in a new SD card and rebooting, as well...
To which I responded that I had ordered an RPi, but for a friend in the US. I wouldn't be able to use it for my main server because of the lack of a battery-backed real-time clock especially given that I serve NTP.
But I do have a CuBox sitting on my desk waiting for me to pay it some attention instead, with more memory and less power than the SheevaPlug (and more/better I/O).
In late June (2012) Ed Davey, Secretary of State for Energy and Climate Change, challenged the TTK (Transition Town Kingston) energy group of which I'm a member to find a way to help people take advantage to their freedom to switch energy (especially electricity) suppliers to get themselves a better deal. Mr Davey had been pleased to announce in Parliament earlier in the year an average saving of £123 per household in an earlier Which? deal.
In TTK EG I think it's fair to say we'd rather energy costs went up (with protection for the fuel-poor) to focus minds on energy efficiency, so instead we were more keen on chunk of "green" along with any money savings.
To that end I sent the following to Dale Vince, CEO of Ecotricity:
As you may be aware I am a member of Transition Town Kingston's Energy Group and we have recently been made a proposal by our local MP and Secretary of State for Energy and Climate Change Ed Davey. He would like TTK to support and encourage local energy-switching and bulk energy purchase in order to alleviate fuel poverty, but, while many of us are sympathetic with this aim, we do not see it as a priority for an environmental group, unless it involves switching to green energy. But we are also aware that at the moment green energy is a bit of a luxury, something only the committed and moderately well off would buy or invest in.
Given my commitment to Ecotricity's aims [...] I have been asked to find out if there could be a good deal from Ecotricity for bulk switching, and if so, what the terms would be and whether they would make green energy a viable purchase for people suffering from fuel poverty.
Mr Vince wrote back:
We looked into the idea of mass switching when Which ran their recent big campaign. We declined to take part [as] we consider it to be unethical.
Giving better prices to new customers while making existing ones pay more is the problem, it's a bad practice that some of the industry is getting away from, consumer groups are rightly against it.
We have one price for all customers, no matter when they joined us or how they pay, and everyone's price goes up or down together. That's at the core of our ethical price policy. No lock in or exit fees being another part.
That's our basic prob with mass switching.
I'm aware politicians have latched on to it as the answer to the dysfunction in the energy market — but IMO it's an illusion, switching is not the answer, building new sources of green energy here in Britain is.
That is also the answer to the problem of energy poverty, because that problem is exacerbated by the relentless rise in global energy prices, which we depend on. Solve one and we solve (or severely reduce) the other.
I also think it's a bit odd to put the fuel poor at the forefront of green energy initiatives — there's a fundamental mis match — green energy costs more to make and the fuel poor struggle (by definition) to pay for brown energy.
So we're trying to find a slightly different tack with Ecotricity, given their principled stance on this, which I can't object to at all.
Peter F wrote to me 2012-05-10 and said:
... You have inspired me to get Solar panels. Which we got installed in January using A Shade Greener and they have already generated over 1100kWh which is great.
In my quest for better efficiency for our home, I was thinking about installing a MHRV Vent-Axia HR25H in our bathroom after reading your log and also reviews on other sites. Since you had it installed for a while now I though I'd ask how it's been for the past 5 months and would you suggest getting one considering the cost? I've found it for ~ £260.
Good work on the PV!
I think that our MHRV has probably been an important factor in allowing to keep the central heating off since the end of March, ie I think it has helped the house retain heat from the day and the odd ray of sunshine without the air getting too stuffy and stale. So I would do it again, and I am considering another unit for elsewhere in the house since we need a bit more ventilation than it provides on its own.
Geraint E wrote to me 2012-04-12 and said:
I am trying to convert the numerous halogen bulbs in my kitchen to LED but am having terrible problems burning out bulbs (I've just burnt out 4 G4 LED disc bulbs which isn't so wallet friendly).
I was interested in your comment saying that for halogen bulbs, light fittings are designed to hold heat in while for LED bulbs heat needs to be dissipated. If this is the case then I can only assume that my LED bulbs are overheating and then burning out? Do you think there is any solution for this?
Also, I've only been able to find LED bulbs for sale on the internet. Do you know if they're for sale on the high street at all?
I noted that:
Geraint is going to give Maplin a whirl, having found them helpful before, and also noted that I may need to change my transformer — I've been reading some comments on Amazon where people are saying that some transformers require a minimum power draw.
I noted that a friend who was trying some of my 12V LED MR16s out had to add extra load to his existing transformers to make them work correctly for testing.
Michael K asked 2012-03-16:
How is your room doing with the Spacetherm insulation? When you said you had some condensation problems was it in this room?
Also, it sounds like when the Spacetherm is up then it would be a problem to put any shelving back up, or anything that needed to be drilled into the brickwork? This would create thermal bridging and sounds like it would be hassle with the snagging that seems to happen with drills?
I've got a sample coming to me. Not sure I will do it, but we're decorating our eldest daughter's (15) room and so need to consider options. Thinking pavadentro too. Struggling for time though to teach myself about dew points!
I said that we don't have load-bearing brickwork being timber-frame, and so I expect any new finish/board to take any load rather than fastening through it. Stainless steel screws seem to be less bad than one might imagine for thermal bridging... Fermacell-faced aerogel may be part of the solution.
As to the condensation, I said that we do have some condensation problems in general, not particularly in the aerogel rooms and certainly none on the walls that we did that I have noticed.
* Note from the future (2022): sometimes we do get condensation on the wall next to my daughter's bed. We sometimes use the dehumidifier to help reduce the problem.
I agreed that subject of dew points and interstitial condensation is a tricky one: the rule of thumb seems to be to have it most of the way out through the insulation, and with any VC inboard of that, ie so that there should never be condensation on the VCL. But I'm really no expert.
He then followed up with:
We've got a solid brick 1926 4 bed detached house. Guy who came around from Wrexham to check us out for solar thermal was cringing about insulating this place lol
The exterior is pebble-dashed (before our time) and my goal has always been to do external wall insulation with a nice render, but that ends up going in the complicated-and-expensive-so-put-it-off bin.
I'm very wary about VOCs and internal emissions in general so have stayed away from internal insulation for those reasons too. I can heartily recommend these guys for paints etc:
You don't need a gas mask when you use their gloss.
The aerogel appealed for some of those reasons: seems stable and inert....
Will let you know if I progress and share the lessons, but feel like I'm moving back to external walls....
The folks at the GreenBuildingForum.co.uk would share your inclination to EWI, because then you get the thermal mass of your bricks inside the insulation, and you can improve air- and weather- tightness of the entire structure with the new 'tea cosy'.
Maybe you don't have to do it all at once; EWI the wall(s) of the most-used room first, like I concentrated on our living room?
Danny T wrote to me 2012-03-01 with an interesting question concerning biomass-based electricity generation on the UK mainland / GB grid, with reference to the Tilbury Power Station in particular (that caught fire at the end of February):
I was wondering with Tilbury power station in Essex now having been converted to run on 100% biomass and a few 100% biomass plants under construction, is there anyway of showing this within the live grid carbon intensity page? Is it still shown under COAL or is it now under OTHER?
I can understand that with Tilbury supplying only around 1% of the UKs electricity and the embeded carbon with respect to sourcing the woodchip the overall grid intensity wouldn't be altered too significantly. But at 750MW when run at full capacity it is providing more renewable energy than hydroelectricity currently.
To which I responded:
The simple answer to your question is "I don't know", and the same will apply in a smaller way to co-firing at Drax for example.
There is no scope in the current data formats to allow that, and it will certainly add error to my results.
(OTHER is only invoked vary rarely in the data feed and is thus apparently not covering any ongoing biomass burning at present.)
Often in stats such as those from DECC, for example, solar PV is lumped in with wind as a zero-carbon fuel, and a biomass plant may actually claim to be wind in future, or a new BIOMASS column/key could be added, but I don't see any of that in the pipeline until at least the year end. You prompt me to ask Elexon though: I'll let you know if they say anything sensible.
Danny said (very thought-provokingly!):
I wasn't sure if the value of carbon intensity for coal took into account a small proportion of co-firing, though I guess this would just be likely to add more error into the calculation.
I wonder about it being under 'OTHER' as on the website for the station says that they expect it to be operational fully on biomass by the end of January 2012 and according to this graph using the NETA data 'OTHER' has been used intermittently upto the capacity of about 700MW since the end of January. Also on the graph 'other' drops suddenly from 650MW to ~150MW at a time which would coincide with the recent fire there. These could just be coincidences — it will be interesting to hear what elexon say about where it is under.
I wasn't aware that PV was lumped in under wind by DECC, but I guess whilst its peak capacity is only small it makes sense. It'd be nice for them to have a similar feature as this for UK PV, I've suggested it to the EST website but they haven't got back to me and I don't think they will.
I had in fact kinda sorta noticed that OTHER wasn't at its usual zero.
I cogitated a little more and and given RWE's ~70%-less-than-coal claim I adjusted the live intensity page to assume that OTHER is 0.3kgCO2/kWh and that it will be some sort of biomass. Probably a better approximation than 0.61 (ie like OIL) for now.
I also suggested that Danny approach SMA in the UK about doing an equivalent of its 'PV in Germany' page linked above...
Danny said:
70% CO2 reduction on coal given the transportation and slight reduction in efficiency really doesn't sound that bad at all. I think 0.3kg/kWh as biomass is a fair assumption to make until further information becomes available.
I've emailed SMA making a suggestion about doing a similar PV thing for the UK, surprised I didn't think to ask them first!
Tania T wrote to me 2012-02-20 (edited for clarity):
Thanks for freezer comments — very interesting. I've just started using my AlertMe to monitor my Miele and I'm surprised how much it's using. Btw, did you know you can move your AlertMe so it monitors your PV? If you don't, it just includes your PV in the total electricity used — bit of a drawback.
I said that I did indeed comment on using AlertMe to monitor PV and that she is absolutely right about the problem doing so, plus the general inaccuracy anyway, in The Register, and to look at the reader comments too!
Tania replied:
Ha! No wonder you knew what you were talking about :-) thanks for the link - that was very helpful; particularly your point about watts vs kwh/15 min. I was about to go fishing for that data.
I do really like my AlertMe, for all its foibles. It's helped clarify my thinking re how much I'm producing & how much I'm using. There are other ways of doing this, but not ones that are so neat and, especially as you don't need a subscription now, as someone said, people spend plenty more money on things that are less useful. You never hear of payback time for the latest tv/stereo/game... sorry, I'm clearly ranting to the converted here ;-)
Will be interesting tho to see how long it takes alert me to bring out a more generation friendly version...
I fear from a conversation with AlertMe that the microgen-friendly version may be some way away for rather larger reasons.
An offer of free training to do home energy audits came up, and though I couldn't take up the training, the organiser, Kinga P, kindly provided me with a checklist that we should all consider in auditing a home's energy efficiency:
- PROPERTY DETAILS — fabric of the house, space heating, water heating & bathroom features
- Energy performance/measures — loft and wall insulation, HW tank and pipes insulation, floor insulation
- Draught proofing
- Lighting — energy efficient one?
- Appliances — age, rating
- Renewable energy systems — any installed? Could it be installed?
- Energy use and energy use awareness