Power to 2050, page-10

You can always step up/step down voltage where required but the issue with solar is that if it's very concentrated in a certain area it can wreck havoc on the transformers and alter the voltage regulation.

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This won't affect EPW very much in any case, it will totally wreck the economics of the baseload expensive (black) coal power plants as the peaks during the day will generally be smoothened but the coal plants aren't fast enough to react to smaller larger peaks where EPW can still alter output within 20 minutes.