Yes, pumped hydro is a very efficient solution for long-term storage. Plus, it is quickly available when needed (on the order of seconds). While the solutions

Yes, pumped hydro is a very efficient solution for long-term storage. Plus, it is quickly available when needed (on the order of seconds). While the solutions seem simple, putting all the pieces together is the real hard part. It's pretty common to have no data available on the distribution grid and the sensors themselves are expensive and then you need all the related infrastructure.