[William Hardy]

Yes, they can be worthwhile if you want to set up a society in the forests without any human intervention, then it is one of the only few choices.

[Petrochemicals (OP)]

I'm missing something? Well, the original claim of this entire thread was that it took 2560 kg of CO2 to make 1 kW of solar panels:

https://www.linkedin.com/pulse/rapid-fall-solars-embodied-carbon-chris-worboys

Strange, other people like Michael Moore say different. If only there was some sort of government or European industry standard.

[Petrochemicals (OP)]

Yes, they can be worthwhile if you want to set up a society in the forests without any human intervention, then it is one of the only few choices.

You would need to cut the trees down 1st.

[wolfekeeper]

Yes, they can be worthwhile if you want to set up a society in the forests without any human intervention, then it is one of the only few choices.

Yeah, that's not what I've found. We've just put down a deposit for an on-grid solar panel/battery system here, and we don't live in a forest. The panels will provide about half the electricity over the entire year, and the battery will help store significant amounts of cheap off-peak rate electricity for use during the day as well as buffering usage and production during the day and night. The long term cost for the solar is about 8p per kWh, and hopefully should have a 30 year plus life, with under 15% degradation. Based on careful modelling I expect the system to pay down the cost in about ten years (an APR of about 10%, which under the current economic climate is really good), but the exact rate depends on the tariff costs, but the curve is quite flat. The financial optimum seems to be around where the average generation by the panels is used entirely within the household over summer, which largely prevents importing from the grid, and where the battery is big enough to fill out the production in the 'shoulder months' of Spring and Autumn with stored off-peak electricity.

Off-peak electricity is lower carbon because it's baseload and wind and nuclear are a higher percentage on average, and solar generation during the day is low carbon too, contrary to the misinformation that has been posted here.

The cheapest off-peak right now are the 'EV tariffs' which give you just 4 or 5 hours to charge the house battery at super low tariffs of 5-12p/kWh. Economy 7 can also be used but isn't quite as good. During the winter, the battery doesn't have enough capacity for the whole day, so expensive 'peak rate' electricity is imported, which is even more expensive than normal, but the ratios are such that it's still somewhat cheaper than conventional tariffs over winter, and the rest of the year, the costs are ridiculously low.

Basically, the core idea is to run the household on off-peak and solar power as much as possible, because it's simply far cheaper to do so. In winter, using wind power is the way to go, but fitting wind turbines to homes is probably a bad idea, but the grid is increasingly wind powered, so importing electricity in winter is likely to be a good strategy going forward.

[Petrochemicals (OP)]

Given the un have just agreed this

https://www.bbc.com/news/science-environment-64019324.amp#scso=_1_ugY8DtNpOGgQaPxaeoDg_31:307.5555419921875

 anywhere large enough to make it reasonably worthwhile with respect to carbon is going to be out except if you live in a nice desert.

[wolfekeeper]

Emphasis is mine:

Average output of a solar unit in the UK is 10% of its rated power, so that's 25600 kg of CO2 to produce 1 kW for 20 years (performance falls off towards the end of life) - 175000 kWh, say 0.156 kg CO2 per kWh. That's about 2.5 times the energy per unit CO2 that you'd get by burning coal, or 1.5 times what you'd get from diesel fuel, so it's marginally economic as long as you don't need to store the electricity, in which case the climate would probably be better off with coal.

If you need to replace all your internal combustion and gas heating systems in order to use solar electricity, and build electrical  storage systems, the carbon break even period looks more like 200 years.

I'm missing something? Well, the original claim of this entire thread was that it took 2560 kg of CO2 to make 1 kW of solar panels:

https://www.linkedin.com/pulse/rapid-fall-solars-embodied-carbon-chris-worboys

But this is an out of date claim going back to 2015. The figure in 2020 was 76% lower 615 kg CO2e/kWp:

https://www.linkedin.com/pulse/rapid-fall-solars-embodied-carbon-chris-worboys

So actually when you put these two posts together:

100%-76% = 24%

24% of 0.156g/kWh is 37g/kWh.

Compare that with coal which is usually more like 800g/kWh or even natural gas in CCGT power plants which is more like 350g/kWh.

37g/kWh is around the number I've seen quoted elsewhere, and the carbon intensity of solar panel's production is still going down.

Solar panels are RIDICULOUSLY low carbon.

[Grazzironi]

Hi everyone! Yes, IMO, solar panels are definitely worthwhile. They are a great investment for both the environment and your wallet. Not only do they reduce your carbon footprint, but they can also save you money on your electricity bill in the long run.

[Bored chemist]

normally you have at least 8 hours a day of full sun here

Somewhere on an oscillating planet? It tends to rise and set in most places.

Did you know that some people live in the tropics?

[alancalverd]

"full sun"? Assuming no cloud and a tropical equinox, the sun elevation will be 45 deg or less for 18 hours. 

And in comparison, I passed a British solar farm last week where the panels were all covered with snow!

[evan_au]

I had a look at my electricity bill recently...
- The amount of kWh I export to the grid..
- Is roughly the same as the amount of kWh I import from the grid (but at different hours)
- The bill doesn't tell me how much I consume onsite, without exporting to the grid

I installed the solar panels 2 years ago, by which time all the really attractive sell deals had been scrapped.
- So I get paid a lot less for electricity exported to the grid than the electricity consumed from the grid
- But I'm happy that my electricity consumption is now fairly much carbon-neutral (averaged over a week or so)

...now all we need is a good grid-scale battery technology to align peak production (around midday) with peak consumption (around 7am/7pm).

[Petrochemicals (OP)]

I had a look at my electricity bill recently...
- The amount of kWh I export to the grid..
- Is roughly the same as the amount of kWh I import from the grid (but at different hours)
- The bill doesn't tell me how much I consume onsite, without exporting to the grid

I installed the solar panels 2 years ago, by which time all the really attractive sell deals had been scrapped.
- So I get paid a lot less for electricity exported to the grid than the electricity consumed from the grid
- But I'm happy that my electricity consumption is now fairly much carbon-neutral (averaged over a week or so)

...now all we need is a good grid-scale battery technology to align peak production (around midday) with peak consumption (around 7am/7pm).

Batteries are not too bad these days and electricity is very expensive, I could put a link Mr moderator. My smart meter says I am using around 150kwh per month, so a 5kw battery would be a good investment at 30 pence a kwh, £45 per day or £540 per year.

[Bored chemist]

And in comparison, I passed a British solar farm last week where the panels were all covered with snow!

Did you miss this?

True, but there are other places that are not UK weather wise

[alancalverd]

The problem is that the places that don't have British weather, don't need as much electricity.

[evan_au]

British weather

I am planning to visit there in May, and the chances of cloud look quite significant.
- It should make for some atmospheric photos, I guess...
- For an Australian just coming out of Summer, definitely hat, gloves and scarf weather...

London_Cloud_Cover.png (110.33 kB . 1127x781 - viewed 93 times)

From: https://weatherspark.com/y/45062/Average-Weather-in-London-United-Kingdom-Year-Round