Comments

What we have learned about renewable energy storage from this and other studies:

1. As with all investments, an energy portfolio is based on a selection of a hierarchy of investments with the greatest ROI. At the top of that RCIT & electrical supply hierarchy are EEU investments. In energy as in all investments, FTF.
2. The major renewables – hydro, solar, wind – have a complementary variability.
3. Although variable, renewables are not unpredictable; renewable predictability is at least as accurate as demand.
4. Renewable supplies emphasize again the importance of EEU, demand matching, and grid storage.
5. Renewable energy costs are decreasing rapidly; non-renewable energy costs – fossil, nuclear – are increasing rapidly as sources become more difficult to find and exploit, and as more honest bookkeeping tracks the real costs of the subsidies and collateral damage of these sources. Reference:
6. Non-renewable suppliers often neglect the maintenance and emergency downtimes of their centralized power plants that can sometimes be weeks and months (10-12% of the time) when they point out the variability of the renewables. The breakdown of centralized legacy power plants is one of the main reasons for an energy grid.
7. Non-renewable suppliers often neglect the security, flexibility and reliability of distributed supplies.
8. Non-renewable suppliers also neglect the power of sustainable renewable self-sufficiency.
9. Complementary to distributed energy supply is distributed energy storage. Distributed storage can be used for load balancing, time shifting of supply, and making demand more flexible.
10. Examples of high demand flexible end use energy storage are: smart charging electric vehicles, renewable energy driven EEU water desalination & water storage, high storage air conditioning… End use storage is the medium and the message
11. An interesting distributed energy storage concept requiring further research and analysis is seasonal storage. Reference:
12. The most cost effective ways to make the grid more reliable and flexible are: distributed smart storage, small hydro, biogas turbines, geothermal…
13. The most expensive ways to make the grid more reliable and flexible are: bulk storage, centralized fossil fuel power plants… And they should be used last, not first.
14. Already in practice in Europe are renewable electricity supply scenarios that supply 25-58% of the demand more reliably than US suppliers of electricity.
15. The USNREL has choreographed economic renewable scenarios that supply 80-90% of the electricity demands of the lower 48 states.
16. Renewable energy storage scenarios require detailed and careful analysis by professionals. Pseudo scientists and pseudo engineers with hidden agendas are not qualified to even comment.

“Whatever exists is possible.” (RMI, 2014-07-08)