Solar panels and the green argument...?
Discussion
I've noticed an increasing number of houses with solar (photovoltaic) panels installed on the roof.
Now, I guess the owner has probably had them installed for a number of reasons - to save money in the long-term; to be eco-friendly; because our government gives them a grant for doing so - but the over-riding reason is that they are seen as decreasing the impact our energy needs have on our environment.
This got me wondering... These things are made of glass, silicon, thermal cements, copper, aluminium, etc. There must be a huge impact on the environment from the manufacture of solar panels.
Everyone goes on about their solar panels "paying (££) for themselves in 20 years" assuming they are still able to generate electricity when they are that old.
But how long would it take for the environmental benefit of one panel generating solar power to outweigh the impact on the environment from its manufacture?
Disclaimer: I'm not an environmentalist but we do our bit by recycling and not being wasteful. I just wondered if solar panels are yet another 'Prius-batteries-head-in-the-sand' short term answer to a longer term problem.
Now, I guess the owner has probably had them installed for a number of reasons - to save money in the long-term; to be eco-friendly; because our government gives them a grant for doing so - but the over-riding reason is that they are seen as decreasing the impact our energy needs have on our environment.
This got me wondering... These things are made of glass, silicon, thermal cements, copper, aluminium, etc. There must be a huge impact on the environment from the manufacture of solar panels.
Everyone goes on about their solar panels "paying (££) for themselves in 20 years" assuming they are still able to generate electricity when they are that old.
But how long would it take for the environmental benefit of one panel generating solar power to outweigh the impact on the environment from its manufacture?
Disclaimer: I'm not an environmentalist but we do our bit by recycling and not being wasteful. I just wondered if solar panels are yet another 'Prius-batteries-head-in-the-sand' short term answer to a longer term problem.
It's an interesting question that's for sure.
I've got Solar Panels on my house, the house came with them, 18 months and they've been utterly maintenance free, with no moving parts to wear out and assuming the Sun can't do them any harm I can't see a reason why they'd ever stop working, I was told a bit like a fuel cell, they might seem very high tech, but the technology is actually incredibly simple.
How many years of electricity generation it'll take to offset the green cost of building the things, god knows.
I've got Solar Panels on my house, the house came with them, 18 months and they've been utterly maintenance free, with no moving parts to wear out and assuming the Sun can't do them any harm I can't see a reason why they'd ever stop working, I was told a bit like a fuel cell, they might seem very high tech, but the technology is actually incredibly simple.
How many years of electricity generation it'll take to offset the green cost of building the things, god knows.
However long it takes for them to recoup the environmental cost, that cost must be far lower than digging up coal or burning gas indefinetly, which is also just unsustainable. So logically, even if they are not as perfect as tehya re made out to be, they are still a better alternative to the good old fossil burning.
Witht he recent energy price hikes, there is a chance the offtake of panels will increase, thus making the technology cheaper still.
Witht he recent energy price hikes, there is a chance the offtake of panels will increase, thus making the technology cheaper still.
I still think the solar panels are at an early stage of their development. When double glazing was in it's infancy , one of the benefits was better insulation . The quoted benefits in cost saving for double glazing were terrible at the time. The cost now is much much lower through better techniques and competition.
Hope to see some better panels soon
Hope to see some better panels soon
RSGulp said:
... but the over-riding reason is that they are seen as decreasing the impact our energy needs have on our environment.
I'd argue with this. I know 6 people / families who have these things on their roof. All of them have done it to save money - even the 2 families of lentil eating green voters had said that saving money was the over-riding factor, and if they didn't save money they wouldn't have bothered.Anyway, I recon some day a Govt is bound to get in and tax us unless x% of our energy per household comes from a renewable source, meaning we'll all have to have windmills / solar panels / wave machines / some b
ks on the roof.isee said:
However long it takes for them to recoup the environmental cost, that cost must be far lower than digging up coal or burning gas indefinetly, which is also just unsustainable. So logically, even if they are not as perfect as tehya re made out to be, they are still a better alternative to the good old fossil burning.
Witht he recent energy price hikes, there is a chance the offtake of panels will increase, thus making the technology cheaper still.
Part of the recent hike in energy prices is caused by us, the consumer, having to pay for all these overpriced green initiatives.Witht he recent energy price hikes, there is a chance the offtake of panels will increase, thus making the technology cheaper still.
Cock Womble 7 said:
According to a recent Jeremy Vine show, it would take eleven solar panels to boil a kettle.
Is that point them at the sun and plug the kettle in. Or save up energy from the entire day then plug the kettle in?If the former then you could probably heat up a bath load of water in one day, its a start.
RSGulp said:
I think you're right that as individuals the main driver is to save money, but the over-arching reason for their existence and for the government helping to fund the installation is environmental/cleaner/less CO2/etc.
It's not the government helping to fund these PV cells, it is the tax-payer. Only the early adopters will benefit from the installation subsidies and the advantageous feed-in tariffs, both of which are not sustainable in the long-term.jas xjr said:
I still think the solar panels are at an early stage of their development. When double glazing was in it's infancy , one of the benefits was better insulation . The quoted benefits in cost saving for double glazing were terrible at the time. The cost now is much much lower through better techniques and competition.
Hope to see some better panels soon
PV cells have been in existence since 1883. Those developed 70 years later still only had a typical efficiency of around 6% at best. Most of the best performing commercial systems available today don't fare significantly better - maybe 14% - so much for being at an early stage of their development. Hope to see some better panels soon
Efficiency is particularly important in the UK where the light levels are low especially in winter when most power is required.
High efficiency cells (around 30%) are exorbitantly expensive, typically 100 times more expensive than the 8% units generally fitted to UK houses today. The cost of the raw materials used to make these super efficient cells means they are unlikely to become significantly cheaper in future.
The Green argument here is actually a good one, even in the UK climate.
The serious, more -than-vaguely academic studies I have read summed the total energy from ore-to-generation payback as under 2.5years for polycrystalline PV panels (the least efficient kind). PCPV panels are generally quoted as25year lifetimes, but in fact this is only the warranty period, in which output is guaranteed not to drop below 80% of nominal. Actual panel lifetimes are 40-50yrs minimum, proved by long term tests ongoing since the early 60s.
Yes, in the UK climate Solar Thermal panels offer better immediate returns, nearly 6x in fact - if you can use all the hot water. But PV generation definitely has a place, and given the 15-25x energy returns over lifetime , it IS worth doing.
(I'd add for balance - PV is therefore much more worthwhile than some other obvious targets: La Ranche, the great French tidal lagoon/hydro generation project took well over 20 years just to reach construction-energy break-even. That's about the lifetime of the original generators and turbines. So far these sort of questions haven't even been asked of China's 3 Gorges dam..or even the various Severn barrage ideas over the years)
The serious, more -than-vaguely academic studies I have read summed the total energy from ore-to-generation payback as under 2.5years for polycrystalline PV panels (the least efficient kind). PCPV panels are generally quoted as25year lifetimes, but in fact this is only the warranty period, in which output is guaranteed not to drop below 80% of nominal. Actual panel lifetimes are 40-50yrs minimum, proved by long term tests ongoing since the early 60s.
Yes, in the UK climate Solar Thermal panels offer better immediate returns, nearly 6x in fact - if you can use all the hot water. But PV generation definitely has a place, and given the 15-25x energy returns over lifetime , it IS worth doing.
(I'd add for balance - PV is therefore much more worthwhile than some other obvious targets: La Ranche, the great French tidal lagoon/hydro generation project took well over 20 years just to reach construction-energy break-even. That's about the lifetime of the original generators and turbines. So far these sort of questions haven't even been asked of China's 3 Gorges dam..or even the various Severn barrage ideas over the years)
I thought that to break even on a cost basis you need to have them on the roof for about 25 years. Seeing that not many people will stay in the same house for that long, would your house value increase because of these systems or are they like car mods and you don't get any resale benefit?
I am no greenie either, my company is in the process of setting up a branch to install Solar PV and Solar Thermal and the main driver for almost all people we are researching is the money saving aspect and if the goverment do the locked in feed in tariffs it could very likely benefit. If I hadn't planned on moving soon I would be considering it myself as I am just fed up of stupidly high energy bills.
Interesting question though, I am still learning all about it as the project sets up so might pose the question to the right person.
Interesting question though, I am still learning all about it as the project sets up so might pose the question to the right person.
Funnily enough, market rates for PV panel yields have very nearly followed Moore's Law - from >>$10 per watt installed down, in the last 8 years. Today, in the Uk about £2 per installed/delivered watt will cover the PV units and the install costs - before any kind of rebate.
Which means that , at 11p/KWh unit for Mains power, without Govt bribes the simple payback on even domestic-scale is now around or under 17yrs today. If you want to allow for future unit price increases it becomes much shorter in a hurry.
Example: I've a close friend who put up a 2.5Kw wind turbine 4 years ago, at a net cost of £6.5k. He figured the payback was 16years against the household use. 4yrs later, with the shift up in unit KwH prices, his family is down to 9yrs total payback on capital - ie only 5yrs to go - and they now use less per annum partly as a result of watching the meter spin backward! F & partner now wish they could have afforded a 5Kw turbine instead... as it is they export about 1MwH per year.
Which means that , at 11p/KWh unit for Mains power, without Govt bribes the simple payback on even domestic-scale is now around or under 17yrs today. If you want to allow for future unit price increases it becomes much shorter in a hurry.
Example: I've a close friend who put up a 2.5Kw wind turbine 4 years ago, at a net cost of £6.5k. He figured the payback was 16years against the household use. 4yrs later, with the shift up in unit KwH prices, his family is down to 9yrs total payback on capital - ie only 5yrs to go - and they now use less per annum partly as a result of watching the meter spin backward! F & partner now wish they could have afforded a 5Kw turbine instead... as it is they export about 1MwH per year.
Tycho said:
I thought that to break even on a cost basis you need to have them on the roof for about 25 years. Seeing that not many people will stay in the same house for that long, would your house value increase because of these systems or are they like car mods and you don't get any resale benefit?
More like 8 years with the feed-in tariff. The scheme is guaranteed for 25 years right now. The pay back on wind is closer to 5 years for any turbine, with the scheme guaranteed for 20 years. I've been working for a renewables company over summer while I'm not at Uni and have heard that people try to sell their house and keep the revenue they generate through the feed-in tariff, but still provide the new home-owners with electricity to save on their bills. No noticeable increase in value really.
It is only in the last 10 years that photovoltaic panels have been able to generate more power over their entire life than they consume in their construction. Or so it was stated in an electronics industry magazine article anyway, and I can easily believe it. People vastly over-estimate how much energy a 1m^2 panel can generate. The efficiency of photovoltaics does decrease over time too. Hot water panels are considerably more efficient in that regard, and in terms of overall financial savings.
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