Tesla’s new solar roof tiles.

Elon Musk and his Tesla company are making multi-billion dollar investments in a number of mutually reinforcing technologies, which taken together point to a very different energy future. His $5bn gigafactory is being built near the appropriately named settlement of Sparks, Nevada. When completed in 2020 it will be the biggest building in the world and will be churning out electric cars and batteries on a prodigious scale. It will be powered entirely by its own on-site solar, wind and geothermal energy, with no doubt plenty of battery storage!

Tesla has just unveiled solar photovoltaic roofing tiles that look great and are cheaper and more durable than building a traditional roof and then retro fitting ordinary solar panels. I see this as the future for solar roofs on new houses, and on many retrofits. Simultaneously Tesla is in the process of buying SolarCity for $2.6 bn, which will give them a huge entrance into the solar roof market. Tesla has also recently unveiled the new Powerwall 2, a higher capacity, more energy dense battery for domestic households. Many Californian households will be able to generate all their household and motoring energy from their own roofs, and store it to match domestic supply and demand. They might also use the battery to buy cheap grid electricity at times of oversupply on the grid and sell it back at times of peak demand, so making money in the process, and helping the grid level out fluctuating supply and demand.

A few weeks ago Tesla signed a contract with Southern California Edison to supply 80MWh of their Powerpack grid scale energy storage batteries. These grid scale batteries and the domestic batteries, combined with various other storage technologies, are changing the nature of the electricity industry. Couple this with falling demand as a result of ever increasing energy efficiency, and the results are profound. Baseload becomes an obsolete concept. Pacific Gas & Electric have just announced that they plan to shut down the huge 2.2 GW Diablo Canyon Nuclear Power Plant in 2025, many years earlier than planned, simply because it is too costly and inflexible to operate. It is old technology. Diablo Canyon is the last nuclear power plant in California. Coal has pretty much ended as a part of the Californian energy mix but its place has largely been taken by gas, but that too will diminish as efficiency plus renewables plus storage become ever more important. It is a moot point which should be phased out first, gas with its carbon emissions or nuclear with its risks (and Diablo is very close to geological fault!). Either way, California is heading toward a 100% renewable energy future. It will be fascinating to see how Tesla develops over the next decade and what contribution it makes to that 100% renewables goal.