Grid-Scale Storage of Renewable Energy: The
Impossible Dream
According to a study conducted by "Energy Matters," a group started by Euan
Mearns, entitled Grid-Scale Storage of Renewable Energy: The Impossible
Dream, available online at
http://euanmearns.com/grid-scale-storage-of-renewable-energy-the-impossible-dream,
providing firm power from wind and solar for a year in conditions with
variability for the year 2016 in England and Scotland, would require about
390 watt-hours of storage per average watt of installed capacity, or
about 70 watt-hours per peak watt. Total energy consumption in Britain, in
electricity equivalents, for 2015, was 1610.75 TWe-hours. Solar and wind
provided about 40 TWe-hours electricity (and nothing for transport or any of the
non-electric uses for industry, commerce, domestic...). The rest was provided
by coal, oil, gas, nuclear, hydro, which have capacity factors of about 90%. So
total average electricity-equivalent capacity was 1755 GWe. Using Mearns's 390
Wh/W factor, 680,518 GWe-hours of storage would be necessary to provide 1755 GWe
firm power in an all-electric all-renewable energy system, with 2016
variablilty, in England and Scotland.
The Big South Australian Battery has a capacity of 0.129 GWe-hr. The 2019 price
for a Tesla PowerWall-2 battery is $0.578 per watt hour. At that price, it cost
$74,562,000. Maybe Tesla gave South Australia a volume discount. At 0.129
Gwe-hr each 5,275,334 of them could have assured an all-electric all-renewable
British energy system with firm power if the yearly variation were as in 2016.
At an estimated cost of $50 million for the BSAB, the cost would be "only"
$393,339 BILLION! And lithium batteries only last five years or so. So the
cost would be about $78,668 billion, every year for storage alone!
British GDP for 2016 was $2,619 billion. So Britain would need "only"
30.04 times their 2016 GDP, every year, for batteries alone! Using heat
pumps for space heating and moderate-temperature industrial processes,
electricity for transportation, etc., would result in lower requirements -- but
still too much to contemplate realistically.
In a similar study entitled
Geophysical constraints on the reliability of solar and wind power in the
United States, Shaner et al used 36 years of geophysical data for all
of North America, with one hour resolution. Their conclusion was that storage
capacity of 400-800 watt hours per average watt (Wh/W) of wind and solar
capacity would be required for firm (99.97% available) power.
Norman Rogers reached a similar conclusion in
Is 100 Percent Renewable Energy Possible? Using data from Texas,
he calculated that storage capacity of 400 Wh/W is needed.
I made a rough calculation and concluded that an all-nuclear mostly-electric US
energy economy, using heat pumps instead of resistance for space heating and
some medium temperature industrial processes (food, plastics), direct
reactor-core heat for industrial processes up to 1000 degrees Fahrenheit,
electricity for higher-temperature processes (steel), and making liquid
hydrocarbon fuels for ships, airplanes, heavy construction, and farming, would
require average capacity of 1,700 GWe. So an eventual American economy that
succeeded in making that transition would have about the same requirements, and
would need five million or so of those big batteries -- maybe somewhat fewer
because of our different climate conditions. US 2016 GDP was $18,570 billion.
We would be spending about at least 3.95 times total 2016 GDP (using Mearn's
estimate) or maybe 8.1 times total 2016 GDP (using the estimate from
Shaner et al) for batteries alone, every year! Without nuclear, and
therefore without direct reactor-core heat for industrual processes, more would
be needed.
How much storage will be needed when we have another eruption like
Tambor, which gave us 1816, the "year without a summer?"
Over-reliance on wind and solar is starting to look not only
prohibitively expensive, but positively dangerous!