Negative price events are consistently growing more frequent from one year to the next in Europe – see our battery price article this week. That’s good for battery developers, but for renewable generation it’s a menace – at best making batteries mandatory, at worst reflecting a broad trend of price cannibalization. As prices become more volatile – inevitable as intermittent sources become more prevalent – then it’s natural that batteries will become the most appealing form of renewable energy power project. It’s perhaps surprising to see it happen so soon, however. Spain is a good example of the trend as it hosts around 30 GW each of solar and wind capacity, producing 14% and 24% of total electricity output in…