Large Quantities

My question is - does anyone have any ideas on how to heat large amounts of water? We are constructing an 25,000 cu. ft. underground building to raise fish and hydroponics (aquaponics.) We'll be using LED lights for the plants and worms for the fish (and oursleves.) The ground temperature is about 50 degrees and we need to raise the water temperature to be 70 degrees. We have wind mills, a fast flowing river, and lots of wood for power sources. Any ideas?

Offered by Rita.

Just a brainstorm idea. Circulate the water through a radiator. Force hot air (from a heater?) through the fins of the radiator to raise the temp. This can then by adjusted with thermostatic controls.

Offered by Roger.

There are many wood fired water boilers that are designed to be operated outdoors away from the home. Make sure you get a high efficiency one that will control the water temperature automatically. Make sure it also produces a low amount of smoke, no sense advertising your presence to others miles away. This is actually very important. There are also thermal conversion devices that will produce electric power directly from heats as well. You can buy a boiler and a steam engine to run from your wood heat. The engine would power the lights. Just a thought. Hearth is a link but buy a few magazines that feature doing it off the grid etc. They had ads for these things.

Offered by Dave.