500 showers heated from one small compost pile: a how-to tutorial. Compost heat can, indeed, be captured to heat water in moments by running black pastic pipe through the heart of the heap. After the hot showers, you have a lovely pile of compost. The moisture from the shower drains away to feed the ground inoculated with edible mushrooms. Hot water, compost and mushrooms. Now that's multi-functional permaculture design!