part p manual

multitask said:

I guess from that reply that you were one of the ones born that minute, and got your wallet pv burnt.

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No - I've got more sense than to think that domestic PV is anything more than a novelty in this country.

OK - there may be one or two off-grid people committed to the use of renewables who use it as one way to make electricity that they store and cannot/will not take account of the cost, but for your average guy in a grid connected house who wants to save a bit of money it's pointless.

Based on a system lifetime of 25 years the cost of the PV generated electricity
was found to be between 20.9p/kWh and 184.7p/kWh with an average of
47.5/kWh. If known underperforming systems are removed, the average and
maximum costs are 39.1p/kWh and 77.8p/kWh respectively.

OK - that's based on a study done 5-10 years ago, and I'm sure that technology has improved and got cheaper since then, but I still think that PV is a chimera, and a much better ROI is obtained from solar heating of water and/or spending the PV budget on better insulation and heat recovery.

londonboy said:

The prices are crazy too!

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You got that right! A 2.5kw installation paying for somebody to connect to the grid comes in at £12k. Buying the panels for DIY install costs half that. But you cannot connect to the grid without being certified.....

Just prices seen on the net, obviously may differ, and I also understand there are extra bits and bobs of kit. However if you can get the work its going to be very lucrative in the short term until the great unwashed realise there is money to be made and drive prices down.

The recent published prices for selling to the grid makes it interesting, perhaps, but only at DIY prices, perhaps. Of course solar PV at northern european latitudes will not make sense without this sort of subsidy for some time to come. If wholesale electricity/gas prices rise to the level to make it worth while then we have far more important things to worry about.

What does make sense is putting massive banks of them in the Sahara and piping it across the med using DC.

Problem is, next year (and the year after that) they will be more efficient and cheaper, so when does one invest?

http://www.ibpsa.org/proceedings/BS2009/BS09_0789_796.pdf

For every kVA of PV generation you have to have a kVA of reliable back-up generation, so you can't save the capital cost of generation.

Peak demand on the UK generation is 5pm to 5.30pm someday during December and January. Peak demand from residential consumers - same times.

It's always dark at the time of peak, when you'll get no PV generation. PV generation is only viable if it is provided with a massive subsidy, even more than the coal industry was subsidised in the 1980's.

Aside from costs, the idea some people have that by throwing one silly little 100-watt PV panel on the roof that they're helping to save the planet is also ridiculous. Granted, efficiency is gradually improving, but a calculation done just a few years ago based on typical manufacturing costs (in terms of energy) versus typical gain in the the U.K. over the life of the panel showed no net energy savings. The amount of energy used in constructing the panel (the firing of silica requiring huge amounts of power) plus transport, installation, and so on would simply never be recovered over the anticipated lifespan of the panel in such an application.

The son of a neighbor of mine has a small combination PV and wind system on some agricultural land which I installed some years ago, but it's only a few hundred watts, just enough for some low-energy lights, TV, radios, etc. in the mobile home he has on the land. He has a 5kVA diesel generator which he fires up when it's time to use the washing machine, and that also runs a 60A charger so he can give the batteries a good boost while it's in use or when the wind/PV haven't been able to keep the levels up.

After around 6 years of use, he's just had to replace about 800Ah of batteries, and is now looking at adding some extra PV generating capacity to reduce on generator usage in winter with the escalating cost of diesel fuel (even the cheaper "red" diesel).

The only reason he ever went down this route was that EDF quoted over £50,000 to get grid power to the site, which was simply out of the question at the time. In my opinion, this is really the only sort of reason for going for PV. Anyone who already has grid power is living in cloud cuckoo land if he thinks that spending a fortune on PV is ever going to save him money - Or he's been brainwashed by the "install a PV panel to save the planet" brigade.