CSP and an Advancement in Thermal Heat Storage

Many of us occupy ourselves, in otherwise inactive moments, by contemplating what the future of energy may be like. We need to keep in mind that, since the earth receives more than 6,000 times more power from the sun than all of us humans are consuming, we are presented with the challenge of harvesting only a tiny fraction of the incident solar energy.

Certainly the most obvious ways of making this happen at a large scale are expansions and extensions of our current approach to solar and wind, made increasingly cost-effective via the continued decline in prices of PV and wind turbines. Yet, as we all know, these resources are variable, and thus, if this is to happen in a big way, there is an imperative to store energy for times when the sun is not shining and the wind is not blowing.

To that end, there has been a great deal of talk about solar thermal, aka concentrated solar power, used in conjunction with thermal energy storage, perhaps in the form of molten salt. The attraction is easy to understand: storing energy as heat is far easier and cheaper than storing it as electricity.  Sure we can build batteries or implement pumped hydro, but all of these are expensive and inconvenient, and come with significant energy components themselves.

Developers of CSP have implemented molten salt energy storage in some cases, with a large degree of success. Yet a limiting factor is the upper temperature to which the medium can be raised. Salt tops out at about 800° C, and, since the laws of thermodynamics tell us that higher temperatures mean much higher efficiencies in terms of the transfer of heat energy, hotter is better.

To that end, I invite you to check out the article linked here on the use of sand at 1000° C as a storage medium.

Apparently, there is a great deal of development in this space going on in Dubai. Guess what they have a lot of in Dubai.