[freebeard]

• Remember there is a difference between renewable and zero carbon.
• Conservation reduces waste heat as well as costs.
• Batteries work best in mild climates
• [W]e will likely see big improvements in both chemistry and packaging in next 15 years.

All true. What's your point?

What else is renewable? Helium.

"A dream. It's perfect": Helium discovery in northern Minnesota may be biggest ever in North America
CBS News on MSN.com | 4 days ago
For a century, the U.S. Government-owned the largest helium reserve in the country, but the biggest exporters now are in Russia, Qatar and Tanzania. With this new discovery, Minnesota could be joining that list.

https://www.msn.com: Helium discovery in northern Minnesota may be biggest ever in North America

MINNEAPOLIS — Scientists from around the world converged on Babbitt in St. Louis County to dig more than a half mile underground, and have confirmed a major helium discovery in northern Minnesota. Experts think this could be the biggest such discovery in North America.
....
If you think this is all about balloons and blimps, the reality may deflate your expectations. Party balloons make up just 3% of the billion-dollar helium market worldwide. The other uses include rockets, aerospace, semiconductors, cryogenics, welding and MRI machines.