Debunking the 100% Renewables Fantasy
http://www.realclearenergy.org/articles/2017/07/18/debunking_the_100_renewables_fantasy_110240.htmlBy Jason Scott Johnston, July 18, 2017
On May 31, the day before President Trump announced that the U.S. will withdraw from the Paris Agreement on climate change, the California Senate passed a bill mandating 100% of all electrical generation be from so-called “renewable” sources that emit no carbon dioxide by 2045. As the vote was strictly along party lines, this means that the General Assembly will also likely pass it and send it to Governor Brown for signature.
California isn’t alone. The “100% renewables” movement has been sweeping across American colleges, and similarly “progressive” towns and some states, such as Hawaii and Vermont. This movement has resulted in state laws, local ordinances and policies at both levels that require 100% of a city or state’s electricity to come from renewable power sources such as wind and solar.
The first and most basic problem with the 100% renewables goal is that if by “renewable” one means sources of electric power that neither generate CO2 emissions or emissions of conventional pollutants such as particulates and sulfur dioxide, then such a goal is impossible. The sun is beneath the horizon half of the time, and near it for another two hours or so, dramatically reducing incident radiation on passive solar panels. Wind is highly variable. Thus, wind and/or solar can supply 100% of electricity demand only if it can be stored for later use.
At present, the only commercially feasible way to store sufficient electrical energy to deal with the daily fluctuations in wind and solar production is pumped hydro storage in which water is pumped uphill at night (when electricity demand is low) to a storage reservoir, and then released during the day, spinning a generation turbine.
But solar with pumped hydro is extremely expensive. For example, even assuming a solar plant capable of providing power during the day for a city of 160,000 people with the other half of the energy produced used to pump water uphill, the total capital cost of solar including storage is likely to be at least ten times the cost of electricity from a natural gas power plant, according to Philip Dowd, a member of the Board of Visitors at Carnegie Mellon University.
This is a best case scenario. During the winter, when solar generation is at its lowest, enormous amounts of hydro storage would need to be provided to ensure that power would be available when winds are light. Ironically the lowest temperatures of the year, which can produce the highest demand for electricity, often occur under calm conditions. ...
