solar power

[User482]

If..

1. You have the cash in the bank.
2. You're not planning to move for a few years.
3. You use an MCS accredited installer (so you can claim FITs)

They are a very attractive investment.

On a wider issue, FITs are a gross misuse of public money.

 

[mr_cellophane]

We had a salesman energy advisor round and his figures worked out something like this.

Monthly payments (not allowing for inflation)

Saving on present electric usage £75
Payment for sale of energy back to grid £75

Repayment of loan £300 (over 10 years)

So net monthly outgoing £150 and over 10 years I have "lost" £18,000. It would then take me another 10 years to recoup that money. Which tallies with what someone already posted, that it would take 20 years before my investment showed any return.

 

[sunnyjim]

We had a salesman energy advisor round and his figures worked out something like this.

Monthly payments (not allowing for inflation)

Saving on present electric usage £75
Payment for sale of energy back to grid £75

Repayment of loan £300 (over 10 years)

So net monthly outgoing £150 and over 10 years I have "lost" £18,000. It would then take me another 10 years to recoup that money. Which tallies with what someone already posted, that it would take 20 years before my investment showed any return.

That's the point. The only way to get any return on the investment in solar panels over the lifetime of the hardware - 20 -25 years is if the electricity generated can be sold at several times the market value.

In a real world you'd never get you money back. As silicon is pretty much free, the cost of the panels represents the energy used in their manufacture, which will have been a complete waste. How green is that?

Your £18000 loss was spent on energy to make the panels, so equivalent to burning £18000 worth of petrol - at before tax cost, that's maybe 10000 litres. Enough to drive a gas-guzzler maybe 100K miles.

Anyone who installs solar panels can therefore be considered an environmental villian on a par with a large SUV driver.

 

[Yellow Fang]

That's the point. The only way to get any return on the investment in solar panels over the lifetime of the hardware - 20 -25 years is if the electricity generated can be sold at several times the market value.

In a real world you'd never get you money back. As silicon is pretty much free, the cost of the panels represents the energy used in their manufacture, which will have been a complete waste. How green is that?

Your £18000 loss was spent on energy to make the panels, so equivalent to burning £18000 worth of petrol - at before tax cost, that's maybe 10000 litres. Enough to drive a gas-guzzler maybe 100K miles.

Anyone who installs solar panels can therefore be considered an environmental villian on a par with a large SUV driver.

I don't think that's entirely true. The energy payback of solar PV panels used to be in the order of several years, but now, it is claimed, the payback can be measured in months. Part of the reason these panels have to be connected to the grid is so that all the generated electricity is used.

It is pretty difficult to estimate the energy used in the manufacture of solar PV panel. They used to be made from the off cuts of electronics grade silicon, which weren't quite up to the mark for semiconductors, but good enough for solar panels. In that case, the silicon used to make PV panels could be regarded as waste material. Now that the demand for PV is more than can be supplied by below standard electronics grade silicon, they can be manufactured from solar grade silicon, which is not so quite energy intensive to produce.

However, apart from the silicon, there is also the aluminium framework, inverters and other bits of kit, which all take energy to manufacture.

 

[MarkF]

Yellow Fang made the most important point, projected (subsidised) income is not guaranteed.

It's a minefield, my OAP mother is plagued by these friggin useless salesmen who can't answer the simplest of technical questions (I was an electricain installing energy saving drives for AC induction motors), up and down the country these guys are feeding OAP's with duff information, it's scandalous.

People need to think very carefully and get correct information before signing a contract, even if it means paying an electrical engineer to help nail down realistic projected savings.

Anyway, I would not buy a house that was pug ugly, so why would I make my house pug ugly?

 

[Cheddar George]

If..

1. You have the cash in the bank.
2. You're not planning to move for a few years.
3. You use an MCS accredited installer (so you can claim FITs)

They are a very attractive investment.

On a wider issue, FITs are a gross misuse of public money.

Spot on.

If you have a large south facing roof in the south of Britain and have the money to invest then approx. £ 14 000 will get you 4kw of PV panels installed with a quality inverter giving you a return of £ 2 000 to £ 2 500 per year.

 

[MarkF]

Took me a while to find it, but here is a good article.

Except, that the future paytments, when you get to the small print, are not guaranteed.

 

[User482]

Took me a while to find it, but here is a good article.

Except, that the future paytments, when you get to the small print, are not guaranteed.

Monbiot explains my reference to a misuse of public money. FITs (which come out of everyone's leccy bills) are being used to subsidise the middle classes (who own large roofs and have spare cash) at the expense of the poor (who don't). The money would be far better spent on alleviating fuel poverty.

 

[sunnyjim]

I don't think that's entirely true. The energy payback of solar PV panels used to be in the order of several years, but now, it is claimed, the payback can be measured in months. Part of the reason these panels have to be connected to the grid is so that all the generated electricity is used.

It is pretty difficult to estimate the energy used in the manufacture of solar PV panel. They used to be made from the off cuts of electronics grade silicon, which weren't quite up to the mark for semiconductors, but good enough for solar panels. In that case, the silicon used to make PV panels could be regarded as waste material. Now that the demand for PV is more than can be supplied by below standard electronics grade silicon, they can be manufactured from solar grade silicon, which is not so quite energy intensive to produce.

However, apart from the silicon, there is also the aluminium framework, inverters and other bits of kit, which all take energy to manufacture.

Everyone has to make a profit, and it's not unreasonable to assume that in a competitive market economy profit is generally pushed downwards and spread evenly over the economy within some tolerance, so whether it's a nuclear power company or a solar panel installer making the profit doesn't really matter. Everything is made from materials & energy. There isn't anything else. Profits whatever they are will be paid out to people who buy stuff made from more materials & energy.
As all material - being chunks of the planet - is free, the cost of everything must be closely related to the cost of energy used in making it.


I don't know the numbers for waste silicon, but I'd agree that it's a factor in reducing the total energy needed to make the panels, and presumably reflected in the price paid. (Also assuming that we actually need all these gizmos the good wafers were made for in the first place...)

The responsivity of silicon & power of the sun ain't going to change much, so the 'it is claimed' indicates a price reduction of about 50 times. No one buy solar panels now- wait a bit. The wealthy with their large solar arrays will be able to gather even more of eryone else's money.

I wouldn't claim my argument is 100% 'entirely true' - obviously I don't know the real numbers, but I think it's a valid point. If a solar panel (or windmill, or nuclear power station) doesn't generate more energy over it's life than it cost to make it, it's a waste of resources.

If the solar panels were installed in the Sahara, the numbers might be different, of course. The numbers do have to include all the gubbins - structure, inverters etc - required to actually use the energy produced. This works both ways - a solar powered rural road sign makes perect economic and lifetime energy efficient sense if it saves the cost of miles of mains cables .


The panels never had to be connected to the grid. Anyone can use a solar panel to run the freezer, air conditioning, swimming pool pump, etc. They wouldn't, 'though, because electricity can be bought more cheaply from the grid than making it yourself. When the econonimics start to make sense, people will move to solar energy in droves without being subsidised.

 

[mr_cellophane]

Monbiot explains my reference to a misuse of public money. FITs (which come out of everyone's leccy bills) are being used to subsidise the middle classes (who own large roofs and have spare cash) at the expense of the poor (who don't). The money would be far better spent on alleviating fuel poverty.

Don't forget Sam Cam's father who is, reportedly, earning £375k a year from a wind farm and has applied to build another one.

 

[pubrunner]

General thinking is that solar panel salesmen are the double glazing salesmen of the modern era. Look at your sums very carefully would be my advice. You are not likely to generate a great deal of electricity and it could take years to make your money back, if ever, once you've paid for them and their installation. Personally, I'm really cynical about them - as you can probably guess.

+1

If you have a large south facing roof in the south of Britain and have the money to invest then approx. £ 14 000 will get you 4kw of PV panels installed with a quality inverter giving you a return of £ 2 000 to £ 2 500 per year.

A friend of mine owns a large electrical company; he was offered (free !) solar panelling fitted in his home, on the understanding that he act as an agent for a company selling solar panelling installations. He told me that it is not worth doing, because the panels have to be in exactly the right position to catch the sun. (The glib salesmen won't tell you that)

Secondly, there has to be enough sun. Another consideration, is that the panels are not a fit and forget proposition. Various parts have to be replaced every two or three years = costs for the parts & fitting. (The glib salesmen won't tell you that, either)

Of course, all this is on the assumption, that the installation does not affect the roof in any way - ie, no leaks or damage occur, following the fitting. My friend reckoned that solar panels would be a good idea - but only if he lived in Southern Spain.

Pyramid selling, anyone ?

 

[Yellow Fang]

+1


A friend of mine owns a large electrical company; he was offered (free !) solar panelling fitted in his home, on the understanding that he act as an agent for a company selling solar panelling installations. He told me that it is not worth doing, because the panels have to be in exactly the right position to catch the sun. (The glib salesmen won't tell you that)

They don't have to be pointing due south, just facing in a southerly direction. You may lose a few percentage points of power if your roof is not facing exactly south at the optimum angle, but not much. If you decided to have solar hot water panels then even a roof that faced east one side and west the other side need not be a disaster because you'd get maximum power in the morning and evening when you'd need it most.

Secondly, there has to be enough sun. Another consideration, is that the panels are not a fit and forget proposition. Various parts have to be replaced every two or three years = costs for the parts & fitting. (The glib salesmen won't tell you that, either)

What parts? The only part I have heard of that needs to be replaced, every ten years or so, is the inverter. Batteries would need replacing too every several years, but not with a grid connected system.

 

[sunnyjim]

Yellow Fang made the most important point, projected (subsidised) income is not guaranteed.

It's a minefield, my OAP mother is plagued by these friggin useless salesmen who can't answer the simplest of technical questions (I was an electricain installing energy saving drives for AC induction motors), up and down the country these guys are feeding OAP's with duff information, it's scandalous.

People need to think very carefully and get correct information before signing a contract, even if it means paying an electrical engineer to help nail down realistic projected savings.

Anyway, I would not buy a house that was pug ugly, so why would I make my house pug ugly?

In the 1930's my dad worked for a power company & one of his jobs was to persuade local factories to improve their (lagging) power factor. He had a little book (which I still have) of somewhat dubious examples of how to explain the concept of power factor to people who were not only not technically minded but for whom electricity was still a bit of a novelty. eg a horse slipping while pulling a cart up a smuddy slope.
The usual solution at the time was an unloaded synchronous motor - trying to persuade a suspicious factory owner that buying yet another machine and then running it with no load would actually save money was apparently not easy.

 

[pubrunner]

They don't have to be pointing due south, just facing in a southerly direction. You may lose a few percentage points of power if your roof is not facing exactly south at the optimum angle, but not much. If you decided to have solar hot water panels then even a roof that faced east one side and west the other side need not be a disaster because you'd get maximum power in the morning and evening when you'd need it most.

Solar panel manufacturers quote figures for the “peak power” and “installed capacity” of their products. According to industry standards, these are the amounts of electrical output in watts that they would generate if one kilowatt per square metre of the sun’s energy were to fall on them. But how close is this to the amount of sunshine at your location?

For most of the latitudes that cover England and Wales, the summer insolation is a fraction of that figure. Even Europe’s sunniest place, Limassol in Cyprus, only gets 325 W per square metre. London gets 198 and Edinburgh 172 in July. In December, the figures are 96, 22 and 13 respectively. So in the winter, it’s a lot less -- and that’s when you need more power because the lights will be on for longer.

The further from the equator you travel, the less sense it makes. It’s not just that the amount of power PV panels produce at this latitude is risible, they also produce it at the wrong time. In hot countries, where air conditioning guzzles electricity, peak demand coincides with peak solar radiation. In the UK, peak demand takes place between 5pm and 7pm on winter evenings. Subjected to one season of wind, rain and snow and they’ll require mending anyway.

The best way to make money from solar power would be by bypassing the solar panels and connecting the incoming wire to the outgoing wire . By buying electricity for 7p and selling it for 44p (if you sell power to the grid rather than using it yourself, you get an extra 3p), you’ll make a massive profit.

Trees are my solar panels and dead wood is my stored energy. And CO2 feeds more trees.

Every Sunday morning, I spend half an hour or so collecting wood for our solid-fuel burner; I get exercise by doing it, I'm clearing the local verges and the wood (which lasts all week) is all free !!! The payback is instant, 'cos the heat warms the house right away. My only outlay is on boxes of matches and on firelighters - far cheaper than solar panels.

This is so efficient in heating our house through the winter months, that our central (oil-fired) heating bills have reduced dramatically.

 

[pubrunner]

What an excellent idea, you don't really need any solar panels, just a contract and the inverter/meter, could retire on 4kw

Think of it, as a pension !