The first grid scale battery energy storage is here in the UK. A Tesla system (who else) has been connected to the grid at a 500KWp solar farm in Somerset. One of the major problems is the sun does not always shine and the wind blow etc. This is less of a problem than it might seem but nevertheless with a power system you have to plan for the worst case scenario. Various solutions are covered in our book although the traditional solution has been pumped storage. This is hugely expensive and disruptive. What if you could store the power where its generated in a distributed way? This is what Tesla are aiming for. There is an obvious synergy between batteries in cars and for grid electricity. The biggest cost in an electric car is the battery. If you could expand the market you could bring the price of the batteries down. This is what is happening.
There is one thing that puzzles me about all this. This is a commercial venture apparently without public subsidy. The economics for home PV (or other technologies) system users will be a no brainer when the cost of batteries falls. This is simply because in the UK the export price is so low. Its best to use all the electricity yourself but this is impossible. But a grid system in a field just gets one price and that’s it. You just send it to the grid and get paid for it. The price is better but there no economic reason to store the electricity. I think national grid must be involved in some way. The company involved say Tesla’s system is modular can be installed very fast and is very easy to install. They have another 100MWp in the pipeline and that is just this one installation company. There could be one major problem with all this. The technology is lithium based and relies on there being enough lithium as well as it being mined in a responsible way.