To further share some information on solar systems for off grid living, lets discuss the components of a solar system.
The power is collected from the solar panel and goes through a charge controller into the battery bank. The charge controller just monitors solar energy coming in, it controls over charging and under charging of the batteries. With me so far? The battery bank is storing DC power. Your normal home uses AC power, so the battery bank connects to the inverter which converts the power from DC to AC so you can use it on your electronics and appliances. That’s it in a nutshell.
While I was researching how to setup the electricity in the house, I did come across this idea of having DC lights and plugs so you could run items directly off the battery. In essence you would wire your house with 2 lines of electricity – one for AC and one for DC. With DC power connected directly to the battery you don’t have the power loss of converting the power, or if your inverter quits, you would still have some power. After much discussion and weighing in, we decided to go with one electric system that uses AC power. Yes, hindsight being what it is, and all the troubles we have had, it probably would have been a good idea. If you are building a solar system, it might be worth your while to research this idea of running a separate DC system through your house.
The other decision that had to be made is what are you planning to use in your house for electronics and appliances. We did the big debate on solar versus propane. My argument was that propane is cheap now, but what about in the future? and what if we can’t get propane or cannot afford it? The other half of my argument is that once you invest in the solar system there is no cost involved once your system is up and running. In the end, we have a propane cook top, a propane on demand water heater, and that’s it. The rest is wood heat and solar. We did install some electric baseboard heaters for future use so we could keep a constant temperature during the winter months, but currently don’t have the ability to run these power hogs.
The electric items we use are the LED lights, plug in electronics, television and DVD player (the nights get long in winter, it is dark by 6:00pm) water pump, exhaust fan, refrigerator, and of course my blow dryer. We have eliminated other small appliances which are power hogs. We did make a conscious decision not to have an oven. We invested in an electric roaster oven, for special occasions, and we also have a propane smoker, which acts like an oven if you don’t add wood chips for flavor.
The refrigerator was also a huge pain in my butt! I researched propane versus electric. The cost of a propane fridge in Alberta is high, because of the high demand for these fridges, there aren’t any used ones out there, and the new ones run approx $1500. We decided to go with a small energy star fridge. Your refrigerator is probably the biggest energy sucker in your home, so it was a huge source of angst for me. I researched our options, and came up with a few.
Chest Freezer Conversion: you can convert a chest freezer into a fridge with a conversion kit. This concept is that your cold air does not escape when you open the chest freezer from the top, whereas when opening a front door fridge, all the cold air escapes and you use more power to cool it down every time you open it. The conversion kit allows the freezer to run at refrigeration temperatures. You just drop the thermostat into the back of the freezer, then plug in the kit to electrical outlet. Very simple, but you have to store your food in baskets and lift them out when you are looking for something in the chest fridge. The following is a link to a good article on converting a chest freezer.
Cold Storage: our strategy if we could not get the fridge running on solar was to use an ice chest. You could dig a root cellar which stays cold all year. The small version of that is to bury a chest in the ground, provide drains, and put ice in with your food. This is inefficient if you plan to stay more than a few days.
We also researched other alternative energy sources such as wind and water turbines, and are very interested in exploring this in future, but at our current site neither of those systems are feasible – we are in the trees and get limited wind, and are not close enough to a suitable water source to generate power. Those are on the wish list for features of a future property. We get alot of wind in Alberta and a small stream could produce all of the electricity a tiny house would need.