We could use the waste heat from data centers to dehydrate food. The powers involved are substantial, but the temperatures relatively low as computer hardware doesn’t tolerate getting too hot.
Consumer hardware can run up to ~100 C before thermal shutdown, though I’ve seen most gaming setups run between 40 and 80 C. That’s the chip temperature though, not the input or output air.
I’m surprised to see that datacenter cooling guidance (e.g. this guide) puts the max temperatures closer to 15-30 C intake temperature, though with a minimum temperature increase of 20 C, which would give an exhaust temperature of 35-50 C.
That’s not tremendously hot, but could be used to dry fruits and vegetables.