What to do when the wind "don't blow an' the sun don't shine"

Solar and wind are the most talked about renewables when it comes to alternate energy sources. But when the wind doesn't blow, and the sun "don't" shine, how does one meet one's power needs?

A logical approach is to store electricity when those types of generators are out peak output, for consumption later. Batteries can be environmentally unfriendly, costly, and not meet performance goals.

Vanadium flow batteries offer the kind of low cost, high capacity energy storage solutions that will help transform the wind and the sun into power sources that rival fossil fuel plants for stability and reliability, but as always there are a couple of obstacles: where to get the transition metal vanadium, at a reasonable cost? One possibility is to recover the metal from other industrial activities, such as oil/gas production, or from recycling.

On a related note, why is the cost of solar so much less in Germany compared to the US? One possibility is that this s primarily due to Germany's more mature market, so market scale and associated learning-induced "cost reductions" are at work. However, as this article discusses, it seems the tax structure in the US is skewed away from adoption-incentives, resulting in higher costs for American buyers of solar over German ones.