The profit from "green" energy needs to exceed the interest on the loan it takes to build it. Today the loans are still slightly more costly than the profit. It's like 5.9% profit vs 6% cost of a loan. The math get's complex as you need to take into account inflation, the rate of depreciation of your assets, and taxes.
This magnifies the amount of wind farm you can build today. If you had a billion and wanted to donate it to "clean energy" then you could get a loan for 5 billion in wind farms and use your billion to make up the difference. By the time the loan was paid off you would still have some money, but far less than if you had invested it well.
If on the other hand you a billion dollars and built a wind farm without borrowing money then you can keep expanding indefinitely. You would still have less profit but there would be little risk.
PS: With subsidy it is profitable today which is why we are building so many wind farms, but that's just the government handing out money.
This magnifies the amount of wind farm you can build today. If you had a billion and wanted to donate it to "clean energy" then you could get a loan for 5 billion in wind farms and use your billion to make up the difference. By the time the loan was paid off you would still have some money, but far less than if you had invested it well.
If on the other hand you a billion dollars and built a wind farm without borrowing money then you can keep expanding indefinitely. You would still have less profit but there would be little risk.
PS: With subsidy it is profitable today which is why we are building so many wind farms, but that's just the government handing out money.