In the winter, it is easy to use the energy from a heliostat since light can be converted directly to heat simply by shining it on, for example, a wall. At this time of the year though, it's hot enough that I'm far more interested in cooling things down than heating them up.
Here's a neat project that is actually able to do exactly that, use heat for cooling. It's called A Solar Absorption Ice Maker. There is a fair amount of information on them scattered around the net, but this is the first PDF I found that actually explains the process in plain English.http://www.solarhaven.org/AmmoniaAbsorptionIcemaker.pdf
It's something that I definitely want to try at some point. You figure if I already have a heliostat array set up, then I wouldn't need to build the parabola part of this ice maker. The rest of it actually looks relatively simple.
I once did a "quick" test with a chest freezer to see how long it would take to freeze about 5 gallons of water. I wish I had written it down, but I think it took about 4 days to completely freeze all of the ice. It also took roughly an equal amount of time to thaw again. This is why I posted this in the "Energy Storage Projects" section of this forum. If you can use the extra energy available on a sunny day to make enough ice for extended food storage, then you are (sort of) also storing energy. ("sort of" because ice is more of an absence of energy, yeah I'm confused too.)
It would be interesting to see if anyone else has tried something like this.