If you live off the grid and have well water , how do you get water when the POWER goes out ? Better yet , HOT WATER ? By trade, I'm a HIGH END designer and builder of FINE furniture and cabinetry ! Fact is , I make organic decomposing material for a living ,(SAW-DUST,ETC.) ! My wife and I have run our own humble little business for over 25 years ! It has taken me almost two years to perfect my system , "LET THE POWER GO OUT ! A simple "compost-pile" will generate heat by decomposition and weight! The bigger the pile , the more heat and energy potential.! 1-All pumps are rated by capacity , gals. per minute.! I have an old fashion hand pump (back-up), with a capacity of 4 gals. per minute , That don't seem like much , but it only takes me 14 minutes to fill my tub with enough 115 degree water! 2-Where does the heat come from? Two years ago , I had my neighbor with her small "BACO" dig me a hole 6x6x4deep! This year we dug it up and made it larger. Now , 12ft.x12ft.x 5ft.deep! Before putting fill back on , I took 150ft. roll of 3/4", "FLEX" pipe ,not rubber, made a "Coil" , two inches of sand one the bottom to aid in drainage . Placed fill back over coil and waited. All fill was organic by nature so you need decomposition to produce heat. 3-day one , water went from 47 degrees to 56 ! Day two water up to 68 and so on. It holds right around 110-115 pretty much,but it took a lot of material! 4-You must be a "stickler" for details for this to function efficiently ! Insulate all things possible , pipes , compost pile is is covered by cheap "POLY-TARP" , keep it dry and it will produce faster ! Hope this helps..!