Hot water off grid

Hi all! My family and I have been wanting to go off grid for some time. Recently our oil burning boiler kicked the bucket and we want to use the opportunity to figure out hot water and heating using alternative methods. (We heat mostly with wood from our land, but in the event that we are not home we would like to have a back up. Thus heating our water is our main conern) We would love to go full solar someday and want to have a system that is in line with that. We are concerned with using a heat pump as we hear they can make a basement very cold and with our New England winters we can't be freezing our pipes. What do you do for hot water? Any feedback at all is appreciated. Thanks for your time!

I heat my water with my wood cookstove in the winter.  In the summer I use a heat pump--it heats the water while acting as a room air conditioner and dehumidifier.  It is less than 2000 watts--I don't remember exactly but it will run from my Honda generator if I need to.  

The amish down the road use something similar to this: http://www.antiquestoves.biz/gs/Water_Heaters/index.htm
The fancier ones have a thermostatic damper so they don't boil off the water.  I am going to get one at some point, but it is hard to research the better brands and features because amish businesses don't have websites.

Although I'm living in Hawaii, I'm in a location that doesn't get enough consistent sunshine to have solar hot water. So we use a propane fired on-demand hot water heater. Ours is an old Paloma brand, but there are several other brands available out there. We have ours conveniently located so that we can easily turn it on when we want hot water, then turn it off again. That way we use only 1 gallon of propane a month as compared to 3-4 gallons a month. Yes, the pilot light burns a lot of propane.

We've thought about making a wood fired hot water system, but haven't gotten to it yet. One system we're thinking about uses a rocket mass heater to heat a water filled barrel which has a water coil running through it. One firing should produce enough hot water for showers, dish washing, etc. Another system we're considering is a wood stove with a water coil, and piping the hot water to a storage tank. But for right now we're comfortable with using 1 gallon of propane a month. But if the on-demand heater breaks, we will get more serious about constructing a wood fired system.

Only five miles from me, many people use roof mounted solar hot water systems. The households with limited finances use hoses or piping on their roof to run water through in order to heat it up. Some use swimming pool heating mats. Their heated water is stored in hot water tanks. People with more money use commercial solar hot water units. I don't know exactly how they work. But I'm where there is no freezing weather, so the units are probably simplistic. Nothing fancy is needed for freeze protection.

We use a heat exchanger in our woodstove to heat a tank of water that has the well supply line coiled inside. It works great but will not heat anything when someone is not home for an extended period.

A reverse cycle chiller is a great device that can make gobs of hot water, ac and dehumidification happen at a c.o.p. of at least 2 to 6. They are available in pv direct-drive and operate to very low outdoor temps now.

The dirty secret of many off grid homes is propane but it can be an improvement over having utility supplied gas, and may be required in areas with low access to biomass,
which brings me to bio-diesel furnaces and boilers as a non petrol source. This can be done in many areas.

I like to utilize electricity for as much work as possible because the "fuel" is free and is transported free when available, and then we make up the rest with wood heat.

Automatic pellet fed boilers.

http://www.pellergy.com/wood-pellet-boilers/

Farm size!

http://www.maineenergysystems.com/autopellet-boiler-energy-box/

Here is a hybrid propane/solar combo water heater, it is pv direct, no batteries. It would work automatically.

http://www.sunbandit.us/

I'm going to install an on demand propane tagaki hot water heater. No pilot light.  Theres water temp sensors so if the water coming in is already hot, the water will pass through the heater without turning on the heater. This means if you plumb a solar hot water heater inline it will utilize that first and then back it up when there isn't enough solar heat.  The only downside is that on demand heaters will build up calcium deposits from hard water rather quickly. I'm going to do my install above a laundry sink with the flushing valves so that I can clean it out with vinegar once a month.