Negative energy prices are a bad thing! That means that someone is dumping energy into the grid (you should be paying the grid if you have solar panels!!) In the UK all renewable energy had to be called 'experimental' so that the pricing was fixed and the government picks up the tab - that's not good. Check this map - right now the wind isn't blowing and solar hasn't got out of bed - so most of the countries using renewables are looking shit - later today solar will kick in, but tonight it will be bad again. That isn't a solution.