This is highly misleadling. Nobody is setting the price, it is determined by an open market. This naturally drives it towards the price of the cheapest energy source with available capacity (often natural gas). It would be irrational to sell electricity for cheaper than this. If more batteries get deployed, the price will more often get set by battery storage instead.

The quotes are because it's a quote. It was part of Energy secretary Ed Miliband's statement which is quoted in the article.

That's just marginal pricing, which is the pricing in many (most?) markets.

It just means that the price is determined by the price where the demand curve crosses the supply curve.

It sounds like a crazy system. But wouldn't it also make deploying renewables there wildly profitable? Sunlight is free but you get paid like you burned natural gas.