When the sun don't shine and the wind don't blow... we can still have reliable supplies of renewable energy
Wind turbines and solar panels in Bavaria, Germany. Frank Bienewald
An authoritative Yale e360 article, co-written by long-standing renewables guru Amory Lovins, refuting one of the regular charges against an energy shift to renewables: their occasional inability to supply constant electricity.
We were alerted to this piece by this tweet, which quotes from the article: “Bloomberg NEF estimates that solar & wind are the cheapest source for 91 percent of the world’s electricity—but is being held back by misinformation & myths".
Lovins dismantles in detail the three myths of renewable energy -
Energy grids are unreliable if they depend on renewables
Countries like Germany must continue to rely on fossil fuels to stabilize the grid and back up variable wind and solar power
Because solar and wind energy can be generated only when the sun is shining or the wind is blowing, they cannot be the basis of a grid that has to provide electricity 24/7, year-round.
Read the piece to get the details. We liked Lovins and Ramana’s closing conclusions about how “large batteries” aren’t the only way to deal with the variable supply of renewables:
Most discussions of renewables focus on batteries and other electric storage technologies to mitigate variability. This is not surprising because batteries are rapidly becoming cheaper and widely deployed. At the same time, new storage technologies with diverse attributes continue to emerge; the U.S. Department of Energy Global Energy Storage Database lists 30 kinds already deployed or under construction.
Meanwhile, many other and less expensive carbon-free ways exist to deal with variable renewables besides giant batteries.
The first and foremost is energy efficiency, which reduces demand, especially during periods of peak use. Buildings that are more efficient need less heating or cooling and change their temperature more slowly, so they can coast longer on their own thermal capacity and thus sustain comfort with less energy, especially during peak-load periods.
A second option is demand flexibility or demand response, wherein utilities compensate electricity customers that lower their use when asked — often automatically and imperceptibly — helping balance supply and demand.
One recent study found that the U.S. has 200 gigawatts of cost-effective load flexibility potential that could be realized by 2030 if effective demand response is actively pursued. Indeed, the biggest lesson from recent shortages in California might be the greater appreciation of the need for demand response. Following the challenges of the past two summers, the California Public Utilities Commission has instituted the Emergency Load Reduction Program to build on earlier demand response efforts.
Some evidence suggests an even larger potential: An hourly simulation of the 2050 Texas grid found that eight types of demand response could eliminate the steep ramp of early-evening power demand as solar output wanes and household loads spike.
For example, currently available ice-storage technology freezes water using lower-cost electricity and cooler air, usually at night, and then uses the ice to cool buildings during hot days. This reduces electricity demand from air conditioning, and saves money, partly because storage capacity for heating or cooling is far cheaper than storing electricity to deliver them.
Likewise, without changing driving patterns, many electric vehicles can be intelligently charged when electricity is more abundant, affordable, and renewable.
A third option for stabilizing the grid as renewable energy generation increases is diversity, both of geography and of technology — onshore wind, offshore wind, solar panels, solar thermal power, geothermal, hydropower, burning municipal or industrial or agricultural wastes. The idea is simple: If one of these sources, at one location, is not generating electricity at a given time, odds are that some others will be.
Finally, some forms of storage, such as electric vehicle batteries, are already economical today. Simulations show that ice-storage air conditioning in buildings, plus smart charging to and from the grid of electric cars, which are parked 96 percent of the time, could enable Texas in 2050 to use 100 percent renewable electricity without needing giant batteries.
To pick a much tougher case, the “dark doldrums” of European winters are often claimed to need many months of battery storage for an all-renewable electrical grid. Yet top German and Belgian grid operators find Europe would need only one to two weeks of renewably derived backup fuel, providing just 6 percent of winter output — not a huge challenge.
The bottom line is simple. Electrical grids can deal with much larger fractions of renewable energy at zero or modest cost, and this has been known for quite a while. Some European countries with little or no hydropower already get about half to three-fourths of their electricity from renewables with grid reliability better than in the U.S. It is time to get past the myths.