I'm no electrician myself, but I know that it's not easy to generate a really good sine wave with a constant frequency and match it to the grid. While electron

I'm no electrician myself, but I know that it's not easy to generate a really good sine wave with a constant frequency and match it to the grid. While electronic componentes are making big steps in that direction, "classic" mechanical generators are still superior for this as they are running very constant. That's why lots of people fear that solar panels with their sudden power generation (as in "clouds are gone, let's bring it on!") might be a danger to the grid as they are fluctuating quite a bit.