Gray photovoltaic solar energy? Profitable?

[zorglub]

parameter to take into account, the efficiency of the cells over time.
what performance in 5, 10, 15 years?
what is the effect of aging? external conditions? chemical and other pollution? manufacturing quality? quality of the raw material?
I think we don't have a lot of experiences on it

[Remundo]

the drop in yield is a phenomenon which is marginal enough to judge the return to gray energy which takes place roughly in the first 5 years.

PV manufacturers all guarantee at least 80% of the new yield after 20 years, even 25 years.

At worst, after 5 or 6 years, with a linear drop in performance, we still produce 100-5 * 20/25 = 96% of production in year 1.

[Christophe]

A) +1 Remundo and I would even say more:

The FINANCIAL yield will drop well before the (TECHNOLOGICAL) yield !!

I have no concerns about this!


B) Not stupid the CO2 method ... it indirectly allows to recover the gray energy ...

So if we have 100 gr / kWh PV produced and we suppose that 100% of the CO2 emissions of PV are produced during its production / installation then we can arrive at another estimate of the gray energy.

By cons I do not understand your method 25 / 4.6 = 5.5 years ???

[Christophe]

Continuation of B)

a) 100 gr CO2 / kWh PV produced

b) Effective lifetime of a panel at 100% of its production (smoothed) = 50 years. Indeed; it is estimated that a PV panel loses 1% per year of its initial power.

Power of the year x (in%) = 100 - x

c) Each m² of NEW PV with 100% efficiency and 15% yield will produce in France (1200 kWh / m².year of irradiation) around 180 kWh per year

d) Over 50 years 1 m² of PV will therefore have produced: 50 * 180 kWh = 9000 kWh and therefore rejected 9000 * 0.1 = 900 kg of CO2 equivalent ...

Does that mean that manufacturing 1m² of PV would release 900 kg of CO2? At 150 Wp per m² it is 6 kg CO2 / Wp PV ... that's a lot.

Isn't there a bug somewhere there? In any case with this method, the more the panel produces, the more CO2 it releases ...

Because even if I take only 25 years of life at 100% we are still at 450 kg of CO2 ... it is the equivalent of burning 170 L of fuel oil.

It's a lot, but you have to put it into perspective knowing that these 170 L would have produced around 170 * 10 * 0.3 = 510 kWh in a group at 30% efficiency against 25 * 180 = 4500 kWh for PV ...

The PV would therefore be almost 10 times cleaner on CO2 than an oil-fired power plant.

So what was the question again? Got lost there ...

[Forhorse]

It's not logical as a calculation.
The quantity of CO2 produced, as well as the energy necessary for its production is fixed.
We can't index that on the amount of energy produced, that doesn't mean anything

[Christophe]

Well, yes, but how is the 100 gr CO2 / kWh found?

It's crazy to find no relevant university study on it ... because the subject is really relevant!

What does Ademe do?

[recyclinage]

I have a question

someone talk to me about silicon pollution concentrate panels

you will tell me that this is not a problem due to the recycling of the dismantled panels


but every 5 years the clouds have the annoying tendency to drop tennis balls like hailstones

what could be done to fix it ?

[Christophe]

Recy, do you know that there is a form of pollution which is bad grammar / spelling ...

[Remundo]

Well, yes, but how is the 100 gr CO2 / kWh found?

It's crazy to find no relevant university study on it ... because the subject is really relevant!

What does Ademe do?

This is what Ademe does
It is far from being a well-supported thesis

[Forhorse]

I've always heard that the silicon industry is one of the most polluting in the world.
It may be a little exaggerated, but to have a colleague who worked in an integrated circuit "foundry" in the Paris region, given what he tells us on this subject, I want to believe that it is far from 'be clean!
Now, should we really condemn photovoltaics so far? difficult to say until we have an objective study on the subject.