Rud Istvan has a very instructive article at Judith Curry’s Climate Etc. blog about the challenges of bring wind and solar power into use through electricity grids. Bottom line: Their intermittency greatly increases the costs of electricity while reducing its reliability, bringing threats to people’s health and safety wherever they begin to make up a significant percentage of total power supplied to the grid.

The higher the renewable penetration, the greater this intermittency burden becomes. For Texas’ ERCOT grid with 10.6% wind, the additional costs are ~$19/MWh for generation plus ~$6.50/MWh for transmission. It is now so expensive in Germany (26% renewable generation) that its largest utility, RWE, took a €3.3 billion impairment charge 1Q2014. The second largest, E.ON, took a €4.5 billion impairment charge 4Q2014, and announced it was spinning its conventional generating assets off into an unprofitable separate company. E.ON will also be shutting Irsching 4 and 5, large efficient CCGT units completed in 2010 and 2011! Irsching simply is not viable without being compensated for the forced Energiewende flexing it endures, while selling its electricity against the subsidized renewables with which it is also forced to compete.

So renewables advocates hope for major advances in grid storage to offset wind and solar intermittency. This guest post surveys what might be possible in the future given what is presently known. The focus is on utility scale, but takes an irresistible detour through TESLA’s newly hyped residential Powerwall. Sandia has a more detailed (albeit somewhat dated and hopefully slanted) utility storage analysis than this post, for CE denizens interested in digging deeper.

There are in principle only five ways that generated electricity can be subsequently ‘stored’: potential energy (e.g. pumped hydro), kinetic energy (e.g. flywheels), electrostatic energy (capacitors), electrochemical energy (batteries), and chemical energy (e.g. water hydrolysis). Anyone inventing another is in line for an automatic Nobel Prize (probably two, physics or chemistry plus peace).

Istvan then totes up the costs of the five alternatives. The picture is not pretty for those who for ideological reasons are sold out to wind and solar.

 

 

Featured image courtesy of Steve p2008, Creative Commons, used by permission.