Some states and utilities are driving the growth, while others lag.

The Solar Energy Industries Association has urged the U.S. Federal Energy Regulatory Commission to dismiss a petition to scrap net metering, solely on legal grounds. A filing by Solar United Neighbors, Vote Solar, and other groups makes a legal case and also rebuts the petition’s claims about net metering.

First Solar has backed carbon pricing in comments submitted to the U.S. Federal Energy Regulatory Commission. The company also co-founded a global policy institute to support carbon pricing as a “cost-effective, equitable and politically viable climate solution.”

Solar plants are now expected to last 32.5 years and cost $17 per kW/year to operate, as shown by a Berkeley Lab survey of industry participants.

Compressed hydrogen is “the first viable option” to help meet wintertime electricity demand in a high-renewables grid, says DNV GL.

Former surface mines in central Appalachia could be re-purposed for solar. Environmental group The Nature Conservancy is exploring the options.

With openings in the fence and improved growth of plants vital for tortoise survival, solar farms in Nevada can provide better habitat than the surrounding desert. First Solar has found similar habitat gains in California.

To get long-duration storage costs down to $0.05/kWh, research teams funded by ARPA-E are pursuing breakthroughs in flow batteries, hydrogen storage and other technologies – even thermovoltaics.

Google pre-qualified bidders and used reverse auctions to obtain the lowest price for renewable energy. Reverse auctions for corporate purchases could potentially benefit solar developers, if their transparency and simplicity can influence more corporations to procure green power.

This has been a breakthrough year for non-battery storage, with key advances in pumped hydro, power-to-gas, and thermal storage technologies. Many industry players are moving beyond pilot projects to contracted projects, which could lead to increased scale and lower costs.