[zwentz]

Isn't one of the big problems with solar collection towers, heating the fluid at night? They've been researching different types of salts and fluids that stay hot longer, so they can essentially run 24/7. With this, couldn't they store the heat and use that to heat up the fluid at night?

Or am I just way off here?

[GregBuchholz]

That's exactly right. The interesting questions are what temperatures are needed to activate this, and what temperatures can be recovered?

http://www.photofileit.com/doe-storage-projects.htm

[dmlorenzetti]

You're not way off at all. In a lot of climates (SF bay area is a classic example, but also think deserts), the average temperature is comfortable even if the extremes are not. So if you have a good way to store heat during the day, and use it to avoid heating at night, you can avoid direct use of energy for heating and cooling, and yet stay comfortable most of the year.

In this case, they're not exactly storing heat, since it sounds like they require sunlight to charge up the store. However to the extent that peak cooling corresponds with peak insolation, the material might be very useful for the design of passive/net-zero-energy housing.