How 'Green' are solar panels?

Not all the subsidies go to the fossil fuel industry.  Some go to people with solar panels on their roofs.

If the price of energy keeps going up, then my total net energy bills for a year might actually go positive. Over the last few years, the subsidies have more than paid for all my electricity and gas use.

The subsidies are all going to the fossil fuel industry- that’s the problem.  If people had to pay true cost of fossil fuels (including environmental damage) they would soon stop using them.

Except... there is no government subsidy for large scale PV any more.

And yet 12-18 months ago - yes, before the current energy crisis kicked off - the UK solar industry was gearing up to start building big stuff again. This time, projects are competing with conventional generation either directly to the market or by signing energy procurement contracts with large consumers (industry, retail etc) who find solar energy somewhat cheaper than other sources, even if they have to buy any shortfall from the grid.

For sure the government is honouring its historic commitments to the first movers who helped generate the market and lower the price for the rest of us.

Sounds like you had to wait for a crisis for your so called green energy to be viable. Crisis being 20 years of poor government planning.

Fortunately for me I fixed at 17p per kwhr till july 2023 which means I'm not paying so much for your panels.

My solar panels are doing fine at the moment, and have generated 35.3MWh since they were installed.

Thanks to a battery in the loft, I am running on solar power when writing this post at 10:30pm.  My electricity usage from the grid during the spring and summer averages less than 1kWh per day.

You can pay your exhorbitant electricity bills (which will be going up again in October).  I will stick with my "nonsense" solar panels, which should last at least another 10 years.

The economics of solar are now changing as the price of electricity keeps rising.  The break-even point of buying new solar, with no subsidies whatsoever from the government, can be less than 10 years.  That's despite the pitifully low price that electricity companies pay for exported electricity.

Solar panels in the UK are a complete and utter non sense. Northern hemisphere does not give a good enough projection of the sun and in winter is a waste of time. If not for the fact that we pay the green levy these things would.be shelved.

Green Madness

As has already been said, while they do degrade over time they don't suddenly stop working at some nominal year 20/25/30 that the warranty finally expires (I remember going to a trade show a decade or so ago whereat a japanese manufacturer - sadly I cannot remember which - was proudly showing off its module that, at the time, was some 40 years old and still *worked* within the limits of the technology at the time it was manufacture). Obviously quality of manfuacture and damage/abuse in operation may cause early failure but that's no different to any other equipment.

A solar park operator with a nominally end-of-life asset will have three choices: a) Decommission responsibly, using the funds set aside during operation, and stop generating / making any money b) "Re-power" the park with new modules, inverters etc, which will require a large capital investment - including decommissioning costs - representing a significant fraction of building a brand new site, for perhaps 20-25% extra income or c) Eke out the asset as long as it remains safe to do so. This is, of course, not dissimilar to many other industrial plant with a long operational life, and at some point (b) becomes more economic than (c), but at that stage the disposal costs will be built into the business plan.

Obviously time-limited constraints e.g. planning consents may need to be extended for (b) & (c) which may leave (a) as the only option. PV modules are covered by WEEE (see post above) with an established muli-corporation take-back scheme so you can't just take them to the local tip and recycling schemes exist. As others have mentioned there is also a burgeoning market in second-life modules, particularly those removed owing to building demolition.

...So yes, they will reuse / continue to use their asset as long as reasonably possible, and can recycle the asset when it no longer makes sense to do so

Some interesting thoughts on reusing solar panels.

I have read about people making one good Nissin Leaf battery out of two used ones by selecting the best modules of even as far as swapping cells. That must have some risks, but as long as you understand them it should be ok to do.

The problem with the solar PV industry is that most systems, especially large ones, exist as subsidy farms and the owners/operators don’t think reduce/reuse/recycle at all (as noted by those who boosted their solar output with diesel generators).

How could a market/distribution system for used but working solar panel be set up? There will be a cost in removing the panels without damage, transporting them and storing them. A solution would be to significantly increase the cost of landfill (but that also encourages fly tipping) so it is more economical to reuse/recycle. Here, Switzerland, you pay to dispose of anything that cannot be recycled, either at around 90p for a 35L rubbish bag or £1.50 per 5kg at the recycling centre. I am not sure where solar panels would fit in, are they electronic waste, covered by a WEEE supplement when purchased, or building rubble, pay by the kg?

I doubt that a dodgy second hand PV module could destroy an inverter.

In the case of a battery charging system, then the battery voltage into the inverter is roughly constant, with only the charge rate determined by the PV module.

In the case of a grid tie inverter, then these are designed to operate over a very wide range of input voltages. A lower than expected voltage will reduce the energy fed back into the grid, but can not damage the inverter.

I agree. I keep looking at 2nd hand ones just for a project, but it's the inverters which are the expensive bit. And I didn't fancy ponying up £600 for an inverter, only to have a dodgy 2nd hand panel destroy it upon connection.