This picture has been floating around the internet

[![enter image description here][1]][1]

> On May 8th, 2016, Germany's solar, wind, hydro and biomass plants generated so much energy, power prices actually went negative.

Is this true? I was under the impression that while renewable electricity production was on the rise it still was nowhere near enough to meet the needs of a major nation. Also, if this claim is true, how much power was produced by non-renewable means on that date?

  [1]: https://i.sstatic.net/rK7bU.jpg