We've been thinking of having solar power installed on the roof.
Does anyone know of a good source of accurate and unbiased information?
Searching with Google most of the sites seem to be run by the Solar Power comanies themselves and are hardly unbiased.
pfj
You get money for all the power you generate whether you use it yourself or export it. When it first came out, it was nearly 50p/Kwh. Much less now,
The other saving is for electricity you save by using solar power instead. ie Using electricity when the sun shines. Esp.in Summer. If you are at home all day, big saving. The alternative is to use timers or solar switches. Harder if you are all at work. The cost of solar panels has fallen dramatically You have to get your pencil out.
To start with, you could do worse than read the relevant page in David MacKay's book 'Without the Hot Air'.
Bear in mind also that solar power in the UK produces on average throughout the year somewhere in the range of 10-15% of the total rated capacity of the panels, depending on their orientation, angle of inclination, shading by trees or other buildings etc. The figure can be as high as 25-30% in Summer, and as low as 4 or 5% in winter.
This chap has been charting the output of his solar panels for a few years, to give you an idea of what to expect in practice
There was a lengthy discussion on domestic solar panels here back in the Summer of 2015.
Harry, who regularly boasts here about his solar panels and has already posted an answer to your query, gave some details in that 2015 thread. His panels are Mitsubishi Model TD185MF5. See
For data on a commercial solar farm in the South of England, see
ISTR the government withdrew the subsidy on small-scale domestic solar panel installations a while ago.
PS:
The efficiency quoted by solar panel manufacturers is the efficiency in converting solar energy into electricity. The MacKay link gives the solar insolation at mid-day in the UK as 1000 watts/sq.m. A solar panel with an area of 1 sq.m. and an efficiency as quoted by the manufacturer of 13.4% would provide 134 watts of electric power. If the sun shone at full strength 24/365 you would get 1.17 MWh of electrical energy out of that panel in a year (134 x 24 x 365). That is the maximum amount of electricity you could ever get from that panel.
But the sun doesn't shine 24/365; solar panels produce less electricity in cloudy conditions, depending on just how cloudy, and don't produce any at all when it's dark. The amount of electricity they _actually_ produce in say a year, as a percentage of the absolute maximum they could produce when fully illuminated 24/365, is known as the capacity factor. In the three examples I gave in the previous post, that capacity factor is in the range 10-15% for the UK, averaged over the year, higher in the Summer, miserably low in the Winter.
+1
If there is any shading by trees then forget it (or zap the trees). I have seen a solar roof in a "green" woodland facility - I estimate they never got all their panels in sunlight at the same time. Current output is severely restricted by the one with the weakest output.
Here is another one - an early adopter physicist that I know:
With realtime graphs of import and export of power on various timescales daily to a few years he has been collecting data for years. ISTR One interesting feature on cold sunny winters days is that the peak output at midday is helped by the cooler PV panels despite the low elevation.
Also some warnings about some of the cowboys in this game and what bogus claims to watch out for. Has it improved at all?
There's some useful numbers here:
That would suggest EUR250-450 for a 1kWp panel, which in the same ballpark as eg:
And then of course there's the inverter and installation on top. (DIY?)
So I think the ROI can be a bit better, but you have to match the demand side: better to replace power you don't take from the grid at 15p/kWh than the current FIT export price of 4.4p/kWh.
Theo
If you can use the stuff you generate to do stuff you normally use electricity for even without any FIT etc it's worthwhile. If you have to fit a battery then I'd say it's not.
One example would obviously be if you have A/C because your house cooks in the summer then it's worth it. Also it provides a degree of roof shading reducing the heat absorbed by tiles and slows down the accumulating heat build-up in the loft and subsequent migration to the rooms below as the summer goes on. If you have East/West facing roof you get a longer (more usable) spread of power and it's kinder to the national grid but a bigger investment on panels.
If you have an old mechanical meter that goes backwards then you can lend your electricity to all your neighbours during the day and use the electricity they would have used during that period for yourself at night. So I've heard.
If all you're going to do is shove your energy into heating a tank full of water that gas does significantly cheaper before pushing it to the grid and expecting a handsome return from F.I.T. simply skip the electrical conversion and go with a small thermal set-up, F.I.T. won't make it worthwhile.
From my own perspective running a pond with 3 water pumps, air pump(s) and 100W UV etc somewhere around 500-600W continuous during summer months it's nice not to be worrying about how much electricity it's using. Haven't got around to doing A/C yet but it's on the cards.
The point is that if you stick a couple of grand in a fund, you might get 8% and teh money is still there in 10 years. In ten years you will have spent £300 a year servicing the panels and they will still be scrap.
What fund is that? :-) No chance of 8% at the moment except on very high risk investments I would have thought.
In the UK, the only practical use of solar power is to heat water.
The problem is there's no money in that, so it's rarely done. Which is another strike against the AGW doom-mongers. If AGW was that serious, you wouldn't be pratting about trying to make money from it.
Well you go on thinking then
I'll go on investing in the top half dozen performing funds.
My high performance depends on you investing in shit.
Or drive heat pumps.
Indeed. All reneable energy cannot stand on its own two feet - why lese do we have all thso 'climate change' crap? To sell reneable energy. And rip te cionsumer off.
Consumers best off with nuclear power as in France, BUT no one else makes money out of it. Nit Gazprom, not Putin, not Siemens, not Dong...not Harry...not the EU, Greenpeace FOE or the British government.
Ultimately, the prospect of really free energy (as in so cheap you just give it away) terrifies the ruling classes. And that's the long and short of it.
If the Russkies really wanted to wipe out the west, they'd find a way of providing something like a 100KW power source in the size of a TEU, and just litter Africa and South America with them.
I love the idea that it's possible (if not practical) to build a little fusion power source - about the size of a car battery ? - which could power a house for millennia ....
Possible? Only by suspending some of the laws of nature, I suspect.
It used to be argued that Jupiter might be close to producing some energy from fusion. (I'm not up to date with the current science).
Why ? If you can smash a couple of hydrogen atoms to make a helium, you're pretty much there. Given the size of atoms, you could cram enough into a test tube to keep going for ages.
OK, you have to solve the engineering problem of containing the energy and getting it to do useful work. But that doesn't make it "impossible" just difficult.
Personally, I've always seen the Apollo missions as engineering challenges, not scientific ones. After all, the science was pretty well understood for centuries before. It may turn out fusion was the same.
Turnip's as good an IFA as he is at most other things.
I don't invest in anything much except the houses I own.
I note that you don't actually answer my question, which suggests you don't actually have an answer.
What fund offers 8% on 'a couple of grand' at the moment?
They buried all those bronze axe heads that they used for money, when the iron age got going...
First European economic crisis
Quantum tunneling MIGHT result in a bit of fusion...and thats wht leads to 'cold fusion' crap...
I woyodnt be surprised if one day quantum effects allow some for of access to massive amounts of energy.
In the meantime there is 10,000 years or uranium and thorium at least...
Ah well what we wanyt is the 'internal fuson engine' where a piston comes up and mashes deuterium together before a megawatt laser ignites it.
Make a great F1 engine!
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