Solar Panels

[Brixtaan]

Ps I have heard that in places on the continent where these systems have been operating for far longer than here, they have had no lifetime problems or failures so far. There is simply no data for life expectancy which is great news but I do worry about the very salty conditions my house experiences by the sea. I suppose they'll be ok if you look after them but getting on a roof even for a bungalow is tricky/dangerous without scaffolding.
Uncle , I just can't believe that stuff about total shutdOwn if a wire casts a shadow. If it IS true then we need to wait until the household manufacturers get involved en masse, advance technology and actively market it in normal consumer language. Until then, we're in the dark having tO resort to contradictory chatroom opinions.

 

[Deleted member 18477]

If you think they look bad now, just picture it in 25 yrs time.

Look at the development of most technologies such as TV and computers over a 25 year period, then picture where PV panels will be in 25 years. At the moment it requires about 1.6sm of panel to make less than 200watts, so 4KW systems swamp most roofs. In the future panels will be smaller, more efficient and perhaps even with a bit of style to help them blend in.
A system installed today will be totally obsolete and will detract from the selling price of a house much like stone cladding did.

You make a good point!

 

[Seagull over Canaryland]

Interesting to read some NSCers concerns about the reliability of solar PV systems. I agree these are genuine issues to take into account and did give these serious consideration but was assured that the technology is now largely proven in Germany and other countries who are about 10-15 years ahead of the UK and many thousands more systems are in use. Plus it seems sensible to opt for known major manufacturers eg Sanyo (Panasonic) or others. At some point you have to accept they will honour their warranties, just as you would with an expensive Japanese TV or car etc. I have some excellent Japanese products from Panasonic, Honda etc. and invariably they are bullet proof plus you get excellent customer service.

I guess the costs of scaffolding will be a concern for some depending on their situation but our installers brought their own very clever system complete with integrated ladder, working platform and handrails which they assembled in 10 minutes and were working on the roof shortly after. Yes it took them half a day to carefully prepare and install the frameworks for the PV panels but these are then effectively then 'plug in and play'. Apparently they are clever enough to detect if a shadow falls even on a single panel and will still accumulate power from the rest of the system rather than lie dormant.

Inevitably the solar PV technology will get more refined over years to come and systems will become smaller, simpler and more efficient. I am quite happy for the Germans to continue to prove this ahead of us - and then for us Brits to benefit from proven products. Bring it on.

 

[blue2]

Did you pay for them or have you effectively rented out your roof and pass the FIT to the panel supplier? Seems to me this only works if you plan to be in your property for a while.

we paid for them to be fitted its a long term project not planning to move you can look at the figures in a multitude of ways we see it as future proofing energy bills.
The panels have been fitted to the rear of our house which has a clear view to the south and not over looked by any one we could have had additional panels fitted to the front elevation but was not keen to spoil the appearance from the road as I said so far so go we need a couple of years to get an average but from the readings we have to-date it looks like we will cover all our electricity costs with additional income towards the gas bill but only time will tell

 

[beorhthelm]

mention of gas above, one shouldnt over look the solar water systems. can get them for under 2k DIY, cant be too much more for fitting. My Gran has one and doesnt use any gas all summer for hot water, sping/autumn heating is fine, boiler is on occasionally for a dozen or so weeks in the depths of winter.

 

[Uncle C]

mention of gas above, one shouldnt over look the solar water systems. can get them for under 2k DIY, cant be too much more for fitting. My Gran has one and doesnt use any gas all summer for hot water, sping/autumn heating is fine, boiler is on occasionally for a dozen or so weeks in the depths of winter.

You need a massive storage tank and the space to put it.

 

[Uncle C]

@
Uncle C has some points, but i think they are over stated. the panels dont lose all their effeciency (80% expected at 20 yrs?) and i dont recall have much failure rate (non-mechanical after all). i dont recall anything about short life spans of the inverters or (and £700 sounds very cheap) and certainly nothing about shadow effects.

OK
It took me hours of research a while ago and I didn't save the references, A quick google just now finds the following.

Shadows
http://worcesterrenewables.com/solar-pv/solar-pv-panel-shading-problem-solved-part-1/

Inverters section 2
http://www.yougen.co.uk/blog-entry/1516/Inverters+for+solar+PV+panels'3A+your+questions+answered/

I am not casting doubts that in general panels will last 25 years (many have lasted a lot longer in better climates), but there will be failures as there are in any device that sits outside in a vast range of temperatures and humidities we have in the UK.

What annoys me is that suppliers of the technology focus on the positives (obviously). With the new tarrifs it will take well over 10 years to repay the investment, longer if you took out a loan. So all the profit comes in the later years when guarantees have gone and when reliability and costly repairs are at their most likely. Wonder why this is never mentioned in the sales blurb.

 

[beorhthelm]

couple of usful links there Uncle C. i can see the issue with the serially wired panels now, though im not convinced a cable or such would cast enough shadow to deactivate a panel (though i suppose the photovoltaics are in series themselves...). the thing about roofs depends how well/poor insulation is. electical and electronic certainly dont like cold/hot cycles (good reason for not turning TVs off, shortens their life. another subject). though that link said the life span should be longer, its somehting to bear in mind on the guarantees. i have a rule of thumb that guarantees are half the expected average life span of something, otherwise the manufacturer would go bust. if you have a net profit margin of 10% you can only afford to replace one in 20 (to cover the cost of two) on average. another subject again.

 

[Uncle C]

couple of useful links there Uncle C. i can see the issue with the serially wired panels now, though im not convinced a cable or such would cast enough shadow to deactivate a panel (though i suppose the photovoltaics are in series themselves...).

I dont think the panels deactivate themselves. The key is in this sentence which tries to capture the physics of whats happening in the panel.
Without by-pass diodes, that part of the panel in shade, effectively works in reverse and can heat up quite dramatically, test results even show these parts of the panels acting as light emitters. In this case then the output is reduced as opposed to blocked.
Effectively the panel/array is shut down to prevent damage. I think by-pass diodes are helping to sort out this issue, but just try asking the saleman about it and how your own installation will perform with shadows (TV aerials and cables are yet another problem) and he will look at you like you've just landed from Mars.
I personally cant deal with salemen that are either ignorant of their product or corrupt.

 

[KZNSeagull]

Whatever happened to Solar Coatings? We were told a few years ago that the technology was being developed for either paint-on or stick-on coatings for roofs and walls, that would effectively turn your house into one large solar panel. Anybody know anything about those?

It is a requirement in SA now that all newly built houses have solar geysers at least. I have not seen many new houses with solar panels generating electricity though. We have a solar geyser (an very old fashioned one) and it works extremely well, which is a blessing as Electricity is going up here enormously (at least doubled in the last 2 years).

 

[matthew]

Everyone in Germany has them but i doubt it's worth it over here

 

[beorhthelm]

I personally cant deal with salemen that are either ignorant of their product or corrupt.

i think its more a case of asking a technical question and they arent knowledgable enough to answer, as salesman aren't usually engineers. from the link it seems the problem has been resolved.

 

[beorhthelm]

Everyone in Germany has them but i doubt it's worth it over here

care to explain why? im sure this is going to be about latitude or sunshine, but half of Germany is at the same latitude as England. not sure about sunhine, but we certainly get enough down south to make them work all year round, and the panel still generate power when its overcast.

 

[Uncle C]

care to explain why? im sure this is going to be about latitude or sunshine, but half of Germany is at the same latitude as England. not sure about sunhine, but we certainly get enough down south to make them work all year round, and the panel still generate power when its overcast.

The German story in short
Then
In 2004, the German government introduced the first large-scale feed-in tariff system, under a law known as the 'EEG' which resulted in explosive growth of PV installations in Germany. At the outset the Feed-in Tariff (FIT) was over 3x the retail price or 8x the industrial price.
Now
Germany, the world’s biggest solar- panel market, will cut subsidies for photovoltaic power by a record amount next year as the government tries to control the pace of installations and wean the industry off support.

Yet again we see the value of PV installations entirely dependant on subsidies, and how Governments (despite promises) can change them whenever they wish.

BTW its not widely known that the BIT subsidies in the UK are paid for by every customer that pays an electric bill.

 

[skr80]

I have both PV panels (electricity) and Solar panels (water) on my house. So far I have generated 3200KW in 12 months - so that's about £400 in electricity costs saved, plus about £1300 via the feed in tariff payback (guaranteed for 25 years). I had estimated at install initially at about 10 years to recoup costs but (if) fuel costs keep rising then this will reduce.
We did not have the boiler on this summer at all for hot water, and even now the solar takes the edge of the cold water reducing hot water gas costs.
Very pleased so far with them both.

 

[beorhthelm]

...At the outset the Feed-in Tariff (FIT) was over 3x the retail price

thats about the same here, 43p is about 3x the domestic electric rate. so why hasnt it been taken up more here, is it because we're charged more for the installations, is the red tape prohibiting competition (the fitters seem to be such similar pricing) or is it just we dont know when we have a good thing? reminding me that im paying through my bill for someone down the road to have their electicity subsidised and *make* money, makes me more inclided to think i should have gone for it.

 

[matthew]

care to explain why? im sure this is going to be about latitude or sunshine, but half of Germany is at the same latitude as England. not sure about sunhine, but we certainly get enough down south to make them work all year round, and the panel still generate power when its overcast.

Well from all the times i've been there i've found the weather to be much better than England - I would still agree with getting them though, after all sustainability is the way forward.

 

[drew]

@
Uncle C has some points, but i think they are over stated. the panels dont lose all their effeciency (80% expected at 20 yrs?) and i dont recall have much failure rate (non-mechanical after all). i dont recall anything about short life spans of the inverters or (and £700 sounds very cheap) and certainly nothing about shadow effects.

OK
It took me hours of research a while ago and I didn't save the references, A quick google just now finds the following.

Shadows
http://worcesterrenewables.com/solar-pv/solar-pv-panel-shading-problem-solved-part-1/

Inverters section 2
http://www.yougen.co.uk/blog-entry/1516/Inverters+for+solar+PV+panels'3A+your+questions+answered/

I am not casting doubts that in general panels will last 25 years (many have lasted a lot longer in better climates), but there will be failures as there are in any device that sits outside in a vast range of temperatures and humidities we have in the UK.

What annoys me is that suppliers of the technology focus on the positives (obviously). With the new tarrifs it will take well over 10 years to repay the investment, longer if you took out a loan. So all the profit comes in the later years when guarantees have gone and when reliability and costly repairs are at their most likely. Wonder why this is never mentioned in the sales blurb.

I find it incredible that you criticize the suppliers for not focusing on the negatives. On your CV, what do you focus on.

The problem is that the Government has shafted the industry. The tarriffs should have been reviewed in April and, as I understood it, every April. Prior to the reduction, the tarriff were well worth the investment. As for the comment regarding this being a subsidise industry well there are plenty of those. The nuclear industry is subsidised, the railway industry is subsidised, farming receive subsidies etc etc. The point is to trying and move to a more sustainable energy source. If every roof had them them then we wouldn't have to burn so much coal or gas to generate the electricity in the first place. The next thing will surely be to have batteries to store the electricity rather than export it so you use that in the evenings. The big problem is going to be what do the current power companies do to replace the profits they will undoubtedly lose.