Does anybody know of any work that links Theoretical Computer Science and Cheap/Sustainable Energy? i.e is there any work in TCS with the application being in Cheap/Sustainable Energy.
I'm sure there are quite a few, but here's one. The "standard" book on Kolmogorov complexity by Li & Vitanyi has a chapter on physics, information and computation. The part dealing with energy goes back to the likes of von Neumann and Landauer.
The book looks at energy dissipation from the TCS point of view. Basically, advances in the miniaturization and mobilization of devices will at some point require almost dissipationless computing. It seems that there are no physical laws that require reversible computation to dissipate energy. The book looks briefly at some physical implementations of reversible computers that are theoretically possible. There's also a logical model: the reversible Turing machine.
In addition to Li & Vitanyi, you can take a look at  and . You might also be interested in the question Is there an abstract machine that can capture power consumption? on CS.SE.
 R. Landauer. Irreversibility and heat generation in the computing process. IBM J. Res. Develop., 5:183–191, 1961.
 C.H. Bennett and R. Landauer. The fundamental physical limits of computation. Scientific American, 256(7):48–56, July 1985.