Many people move off grid and fall in love of the idea of free solar power. Yes we use solar power year round and unfortunately, there are limits to it. To come up with a reasonable answer, it really depends on three things. 1) Location, 2) Power lifestyle, and 3) System cost. Pick any two items and it will really determine the third.
For example, choose your location and power lifestyle and that pretty much determines the number of panels and components to create that power throughout the winter. Or, choose your system cost and power lifestyle, and it will determine how much power you need to live with in the winter.
Technically, the best places for solar power are on the equator. Of course this must be balanced with which country to live in, and how well you enjoy those climates. For me, the abundance of solar power would have to go into running air conditioning since I don’t do well in the heat.
On the other extreme, moving above the arctic circle would mean no solar for a couple months or more each year.
Most of the time, the location is already chosen because you live there or desire to. Not many folks decide to move off grid with the luxury of choosing which state or country to start with. We enjoy the Cascade mountains and the experience of seasons, so that makes winter a little more of a challenge.
Solar maps can help you determine approximately how many equivalent solar hours of Sun to expect for your worst case design. Just remember, its human nature to pick the higher number if you are near one of the lines on the map. Trust me, pick the lower number because when it comes to wintry overcast times, Mr Murphy always wins
Will you really need to run AC? Will you try electric heat? Nope, not likely with a solar power system. However, it is quite helpful to go through the exercise of working on a power budget and we good resources for that here.
If you want to pay as you go, then it may be awhile until all three factors are satisfied. Some things like battery banks must be purchased all at the same time. The initial cost of an all solar power system can be very high, and thats why we advocate starting with a decent genverter system first.
Our solar experience
Where we live on the East side of the Cascade mountains, the solar map indicates a minimum of 3.5 to 4 hours a day. That may be the average over an entire year, but we see long periods where we are in the fog (clouds) for weeks on end. I would take an enormous battery bank and solar array to produce any significant power under those conditions.
After 11 years, we’ve seen the early winter fog experience range from three to six weeks. Its really beautiful with the long hoar frost that grows on everything. It is impossible on power without our genverter system! Even during normal winter times, we see anywhere from 160 – 250 WH produced on overcast days and up to 1000 WH on sunny January days. Its a far cry from the peak power produced in the summer of nearly 3,300 WH.
With the genverter system there is nothing like “virtual sunshine” on demand during the winter! However, there is fuel cost exchanged for the convenience. Consider alternative fuels like propane, bio-diesel, or methane bio-gas to fuel your Green-er sunshine on demand. I’ve waiting to hear from a friend in Tasmania, the old wood-gas system. It was used back in WWII to run a generator or motor using the fumes that come off of wood burned a special way.
To summarize, a solar only power system is a poor and risky investment unless you live in a perfect year round solar environment. Design and use a genverter system to create you virtual sunshine when the sky doesn’t treat you well and you’ll be much better off power-wise.
I our case, we’d need 10 or twenty times the solar panels to get us through the bad solar times in winter! not practical!
What do you think? Agree, disagree? Share your thoughts now in the comment section below!