Intermittency, Storage, & Politics — The Case For & Against Super Grids
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Intermittency is the new buzzword in the clean energy revolution. For opponents of renewables, it is the reason why we should stop building all those solar power plants and wind turbine farms. Better to just use good old fashioned coal the way our great grandfathers did. “The sun doesn’t always shine and the wind doesn’t always blow!” they cry, and of course, on a very superficial level, they are right. In order to supply the electrical needs of the world, we need wind and solar, and something else — something that can keep the lights on when the winds turn calm and the sun goes behind a cloud.
In a recent interview with PV Magazine, Indra Overland, a member of the International Renewable Energy Agency’s research panel for the global commission on the geopolitics of the energy transition, says “In any given place, the sun will not shine or the wind will not blow sometimes. But the greater the number of locations that are connected into one grid, the more likely it is that the sun will be shining and the wind blowing on some part of the grid, which can then supply the other parts.”
Super Grids
The obvious answer to intermittency is battery storage, but Overland suggests there is another possibility — Super Grids that span large distances, especially if they are oriented east to west so the sun is always shining and the wind always blowing somewhere on the grid. Such idea of such massive interconnections has been bandied about in several places around the world.
Lots of European nations are casting covetous eyes on the vast, sun-soaked sands of the Sahara Desert. We reported recently on a proposal for large wind farms in southern Greenland supplying the Continent. And some visionaries in Australia see that country’s rugged interior as the perfect place to generate renewable energy to sell to Indonesia and other Asian countries. Such Super Grids are technically possible but may not be politically attractive. A rising tide of authoritarian populism around the globe makes the prospects for effective international cooperation fairly dim.
The alternative, Overland says, is for nations to become prosumer states — generating their own renewable energy. “The advantages of becoming a prosumer state are potentially massive, in terms of improving the trade balance, bringing home jobs, creating opportunities for the development of technologies and local businesses, reducing both local air pollution and greenhouse gas emissions, strengthening energy security, and reducing dependency on authoritarian and unstable fossil fuel exporters,” he says.
“For prosumers to get by without grids, radically improved energy storage technology would have to emerge,” Overland says. “Research is ongoing on a wide range of battery technologies. Whether, when, and which of these might be subject to a breakthrough is impossible to predict, but there are so many options on the table that a breakthrough would not come as a surprise. Such a breakthrough could be a game changer for renewable energy. It is the main remaining missing technological link in the energy transition.”
“Prosumers in a renewables-based grid are not like some kind of subsistence farmers, surviving on what they can produce on their own,” Overland adds. “Rather, they are both buyers and sellers of electricity, shifting back and forth between these roles depending on whether their solar panels or wind turbines are generating surplus electricity or not.”
He sees opportunities for improved international cooperation as a result of such trans-boundary trade of solar and wind power because it would foster more symmetrical relationships between prosumer countries than does the current, unidirectional gas and electricity market model. As most countries would be both exporters and importers of energy at various times, they would be mutually dependent and there would be fewer one-way power relationships and dependencies. That could lead to reduced conflict. “There would still be many things to quarrel about in the world, but energy would be less likely to be one of them,” he said.
How Much Would Super Grids Cost?
Overland cautions that international Super Grids would be frightfully expensive to build. “The increasing electrification of societies and the intermittency of renewable energy are strong reasons for connecting more grids. However, to solve these challenges, it is sufficient to connect large areas. Connecting the whole world is not necessary and would be more of a symbolic act, and an expensive one at that.”
We wrote recently about the cost of building new transmission lines in Germany, a necessary evil needed to unite the renewable energy resources currently installed or under development in that country with consumers. Our story focused on the cost of such infrastructure upgrades as being the primary reason for higher utility bills as more renewables become available.
That generated a response from Laurent K Béland, an assistant professor of mechanical and materials engineering at Queen’s University in Ontario. Dr. Béland had some insights on rising electric rates. He argues that the levelized cost of energy (LCOE) of solar/wind shouldn’t be compared to the LCOE of gas/nuclear/coal, but rather to the fuel cost per kWh of gas/nuclear/coal. Here is his analysis.
A traditional gas fired generating station produces electricity for about 6 cents per kWh. Half of that is attributable to building and maintaining the facility and half of that is attributable to the cost of the gas needed to make the electricity. He estimates a wind or solar facility costs about 5 cents per kWh for the equipment. Of course, there is no fuel cost.
But to deal with intermittency, traditional gas-fired facilities must be kept ready for use, which means the 3 cents per kWh fixed cost of the gas facility must still be figured in, hence the actual cost of the renewable energy is 5 cents plus 3 cents for a total of 8 cents — 2 more cents per kWh than the cost of the gas facility before the renewable supply became available.
When too much renewable energy is available, it gets wasted, so the 6 cents per kWh of a gas plant continues as does the 5 cents per kWh of the renewables, meaning the cost of electricity is now 11 cents per kWh or nearly double what it was without the renewables. Pumped hydro storage adds 15 cents per kWh and battery storage adds 35 cents per kWh, he maintains. And that’s why utility bills are rising, Béland suggests.
I am a writer, not an academic, and so I am offering no rebuttal to Dr. Béland’s scenario. But since he provided it to me in an e-mail, I thought I should share it with the CleanTechnica community to see whether you find his analysis persuasive. In any event, it is clear that there is no free lunch when it comes to renewables and the cost of upgrading electrical grids is going to have a significant impact on energy prices for consumers. In other words, the era of electricity that is too cheap to meter is still quite a long way off.
The key to the energy future is storage and whoever can figure out how to do it cheaper than current technology allows will profit accordingly.
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