Heat Storage Discovery 20X Better than EPA Goals

Brian Westenhaus points to an intriguing breakthrough in heat storage at the University of Arkansas.

The new system is a structured thermocline system which can be bodies of water, such as oceans and lakes, for example, but also smaller units that contain fluids or gas – with distinct boundaries separating layers that have different temperatures.

The plates are made from a special mixture of concrete developed by Micah Hale, associate professor of civil engineering. The mixture has survived temperatures of up to 600º Celsius, or 1,112º Fahrenheit. The storage process takes heat, collected in solar panels, and then transfers the heat through steel pipes into the concrete, which absorbs the heat and stores it until it can be transferred to a generator.

...Modeling results showed the concrete plates conducted heat with an efficiency of 93.9 percent, which is higher than the Department of Energy’s goal and only slightly less than the efficiency of the problematic packed rock bed method. Tests also confirmed that the concrete layers conducted heat without causing damage to materials used for storage. In addition, ...energy storage using the concrete method cost only $0.78 per kilowatt-hour, far below the Department of Energy’s goal of achieving thermal energy storage at a cost of $15 per kilowatt-hour. _NewEnergyandFuel

An order of magnitude improvement in heat storage should have an impact for isolated solar thermal installations, which are inaccessible to cheap shipping or large power grids.

Whether such a development will lead to improvements in grid-scale solar thermal power plants remains to be seen. The full construction and long-term operating costs of large scale solar thermal plants have not been well clarified at this early stage in their development.

But cheap and efficient thermal storage is nothing to scoff at.

Of course, once scalable modular HTGRs are available, the options for heat production in a wide range of locations will expand enormously. It is conceivable that portable HTGRs might even travel from one heat storage depot to another, topping off heat storage as it goes -- in areas that lack viable power grids, such as networks or coops of seasteads in the open ocean, or groups of small to medium colonies in space which are not wealthy enough individually to afford their own HTGR.