The scale of the problem

It’ll take 41 % of the water in the Great Lakes if we tried to solve the renewable energy storage problem with hydropower alone.

The scale of the challenge to decarbonize energy can sometimes be difficult to conceptualize. After all, what does 6 billion lightbulbs or 5 million cars actually mean in our heads. At some point, a big number is just another number: 5 million feels the same as 50 million. The scale is lost to us. So, here’s how we appreciate the scale of the problem at Celadyne instead.

Let us consider the decarbonization of energy use in the US using the most prevalent renewable energy technology solution today: hydroelectric power. Then, since we are in Chicago, let’s compare that to the Great Lakes.

Amount of energy used in the USA in 2020: 27238 TWh (terrawatt hours)
Consumption to storage ratio for the USA*: 7.83

Amount of energy we need to store for a decarbonized future: 3478 TWh
Potential energy of a liter of water stored (mgh) at 500 feet: 1493 Joules
Megawatt hours of energy generated a year (90% efficiency): 11.8 MWh

Amount of water we need to store: 2240 cubic miles
Amount of water in the Great Lakes: 5400 cubic miles
Average Elevation of the Great Lakes: 513 feet

Percentage of water in the Great Lakes: 41 %

Put simply, if we want to decarbonize energy usage in the US today using hydroelectricity, we can do it if we can dam the Great Lakes and drain about 41 % of all of the water there and then refill it every season. If that feels untenable, well, it is. That is why we need to commercialize other energy storage solutions, be it flow batteries, thermal batteries or hydrogen.

*Consumption to storage ratio for the US from: Nuria Creixell, M.S Thesis 2018