Why 100% Renewable Energy Is Less Realistic Than a Unicorn

Guest “you can’t get there from here” by David Middleton

16 Sep 2019 | 14:45 GMT
How Inexpensive Must Energy Storage Be for Utilities to Switch to 100 Percent Renewables?
MIT researchers list the energy storage technologies that could enable a 100 percent renewable grid

By Prachi Patel

[…]

Electricity and heat production are the largest sources of greenhouse gas emissions in the world. Carbon-free electricity will be critical for keeping the average global temperature rise to within the United Nations’ target of 1.5 degrees Celsius and avoid the worst effects of climate change. As world leaders meet at the United Nations Climate Action Summit next week, boosting renewable energy and energy storage will be major priorities.

Wind and solar skeptics are quick to point out that such systems are expensive and can’t keep the lights on 24/7. The first argument is wilting as renewables become cost-competitive with fossil fuels. The second one also boils down to cost: that of energy storage, which will be essential for sending large amounts of renewable energy to the grid when needed.
“Low-cost storage is the key to enabling renewable electricity to compete with fossil fuel generated electricity on a cost basis,” says Yet-Ming Chiang, a materials science and engineering professor at MIT.

But exactly how low? Chiang, professor of energy studies Jessika Trancik, and others have determined that energy storage would have to cost roughly US $20 per kilowatt-hour (kWh) for the grid to be 100 percent powered by a wind-solar mix. Their analysis is published in Joule.

That’s an intimidating stretch for lithium-ion batteries, which dipped to $175/kWh in 2018. 

[…]

Energy storage would have to cost $10 to $20/kWh for a wind-solar mix with storage to be competitive with a nuclear power plant providing baseload electricity. And competing with a natural gas peaker plant would require energy storage costs to fall to $5/kWh.

But those figures are only for scenarios in which solar and wind meet power demand 100 percent of the time. If other sources meet demand just 5 percent of the time, storage could work at a price tag of $150/kWh. Which technologies could hit that target?

[…]

Editor’s note: This story is published in cooperation with more than 250 media organizations and independent journalists that have focused their coverage on climate change ahead of the UN Climate Action Summit. IEEE Spectrum’s participation in the Covering Climate Now partnership builds on our past reporting about this global issue.
This post was updated on 16 September 2019. 

IEEE Spectrum

The paper, published in Joule, was discussed in this August 8 WUWT post. This article provides a little more detail. In order for wind & solar to actually be competitive, energy storage costs would have to drop to:

• $10-20/kWh to be competitive with nuclear power for baseload.
• $5/kWh to be competitive with natural gas peaker power plants.

Nuclear power and natural gas peakers (CT) are the two most expensive dispatchable electricity generation sources, after than coal with CCS.

If energy storage costs would have to fall to $5/kWh for wind & solar to be competitive with natural gas peaker power plants ($77.70-89.30/MWh) and $10-20/kWh to be competitive with nuclear power ($77.50/MWh) baseload, how low would it have to get to be competitive with natural gas combined cycle ($41.20-46.30/MWh) baseload?

The article then bizarrely notes…

If other sources meet demand just 5 percent of the time, storage could work at a price tag of $150/kWh.

Firstly, you can’t run baseload power plants 5% of the time. Secondly, the $20/kWh only applies to “resource-abundant locations such as Texas and Arizona” and, since there is no such thing as a nuclear powered peaker, the $150/kWh cost target is more likely to be achieved through freezing in the dark…

We estimate that energy storage capacity costs below a roughly $20/kWh target would allow a wind-solar mix to provide cost-competitive baseload electricity in resource-abundant locations such as Texas and Arizona. Relaxing reliability constraints by allowing for a few percent of downtime hours raises storage cost targets considerably, but would require supplemental technologies. 

Science Direct

Since unicorn schist is unlikely to appear on the energy scene any time soon and most energy consumers prefer to not freeze in the dark, it should come as little surprise that according to the US EIA’s Annual Energy Outlook, in 2050 we’ll be getting 48% of 31% of our electricity from solar PV. For the math-impaired, that’s 15%… While, we’ll be still getting 17% of our electricity from coal-fired power plants.

Of course, electricity generation is only one part of the energy puzzle. Primary energy includes transportation, electricity generation, industrial, commercial and residential consumption.

The green curve is “other renewables,” primarily wind (both onshore and offshore) and solar, the gray curve is “coal,” the blue curve is “natural gas.” Note that in 2050, “other renewables” will have barely overtaken “coal,” while “petroleum and other liquids” and “natural gas” will each be 3-4 times the Quad Btu as “other renewables.”

Are EIA projections always right? No. They’re “projections”. EIA totally missed the Shale Revolution. If frac’ing was a unicorn, then solar/wind plus storage could actually compete with natural gas… because that would mean that unicorns actually existed.

Reference

Ziegler, Micah, Joshua Mueller, Gonçalo Pereira, Juhyun Song, Marco Ferrara, Yet-Ming Chiang & Jessika Trancik. (2019). “Storage Requirements and Costs of Shaping Renewable Energy Toward Grid Decarbonization”. Joule. 10.1016/j.joule.2019.06.012.