#Climatechange: the cost of #WindEnergy is dropping significantly https://arstechnica.com/information-technology/2017/11/economics-working-against-coal-as-cost-of-wind-solar-power-drops/
and:
Major advance in battery technology (Vanadium Redox Flow Battery) increases the ability of Energy storage https://spectrum.ieee.org/green-tech/fuel-cells/its-big-and-longlived-and-it-wont-catch-fire-the-vanadium-redoxflow-battery