Concept in Energy Storage
A fellow in Sudan wrote to ask me about energy storage by compressing a large spring, pointing out, quite correctly, that the force associated with compressing a spring is a function of the distance over which the force is applied, (F = -kx), and that the work done in compressing the spring is ∫ F dx. Here are some of his drawings and calcs. He surmises that the energy loss (outside of the motor to compress the spring and the generator to convert the energy back into electricity) would be very low.
Uncharacteristically, I can’t think of any reason this doesn’t make at least some measure of sense. It reminds me of “advanced rail energy storage,” which I’ve written about frequently.
Anyone?
For centuries, clocks worked on the principle of a wound spring, and efficiency can be high. I would say however that there are probably 2 limitations. The first, that energy density will probably not be very high, and the other that the spring would probably suffer significant mechanical degradation over thousands of cycles. In addition, I guess that at longer storage times, the spring may tend to suffer plastic deformation and lose its spring.