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.
Location
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 
Power Lifestyle
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.
System Cost
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!
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You mentioned wood gas. This is a subject I have recently been exploring. To my surprise and delight a google search produced plenty of hits ranging from making a hiker camp stove using empty tin cans to some pretty elaborate power plants used to propel pickup trucks. Somewhere in between these extremes there is a power plant suited to powering a single family dwelling off grid.
North America has chosen to turn a blind eye and deaf ear to the subject of alternative fuels. Other countries have done better. There are any number of websites dealing with how to harness or generate fuels suited to power our homes and even out vehicles. Should industry decide to develop and manufacture the machinery required to power our homes we would be so reliant on foreign imported oil. China is already leading the US in just about every catagory of energy production including non traditional renewable sources. Their leaders have already recognized the foolishness of being so reliant on oil.
China has more installed wind power and plans to build 6 nuclear reactor each year for the next decade.
Methane and wood gas production from what is at this time considered waste material could easily help put off grid people in the pace setting lead.
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Marshall if you were to do it again would you spend the extra to mount your Pv on a sun tracker mount?
Depends on initial budget. mounting on a nice tracking pole requires all the mount spots to be filled with the same type of panel. With my static mount, I was able to add the really old, inexpensive panels from BP 25 years old. They are low producing, but I purchased them based on my actual measurements, and it was a good deal. It would not make sense to mount these particular panels on a pole. Given a good budget upgrade however, I do the tracker pole in a minute! (reinforced for our wind loads).
There does seem to be an explosion of innovation in the solar power industry. But, I am not sure that it will be something that can be completely relied upon anytime in the near future.
Is there a reason you left out wind power as a supplemental generation source?
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I recently had a request for quotation from someone in Fort St. Johns. The man wanted solar panels to generate 64kWh per day in a location having only 1.9 sun insolation hours during the winter. The man wanted to stay grid tied and just wanted to be carbon neutral and null out his utility meter billing. I don’t know about innovation but there sure seems to be a lot of misleading advertisement going around these days.
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I must admit this design ( no, not mine ) is somthing to look at, a Youtube vid, Une solution énergétique pour le Proche-Orient? http://www.youtube.com/watch?v=5aZrWD4gRuE (it starts in french, but is mostly in english). This guys a jewish english bloke now living & working in Israil has look at solar cells & their ability to take heat, and is using a tracking, low cost dish to focus down to 1 single cell, so you can buy one good cell & a lot of cheap mirror…but there is one draw back ( OK OK two ) in good weather there will be electrical energy under production as the cell heats up. So a cooler / heat sink, would be a good addition. The other draw back, i think it’s patent covered.
One question, in a couple of months time ( end of October ) i’m traveling round California for a couple of weeks….any ideas on alternative energy projects to visit ? We are going from San Fran to LA and back, any ideas ?
Regards Bob
Several projects by PG&E involve solar thermal including the SES power farm east of LA. I did see a news bulletin where this plant would be converted to PV from photothermal because maintenanc costs would be less.
Somewhere out near Ontario CA there is a methane digester project. They have extensive feed lot operations so it’s a ready source of feed stock for a methane digester. They use the product gas to power a generator.
Solar thermal is a vastly under rated system approach.
Very well explained you had indeed shared an informative insight about solar panel installation. Solar Panel is indeed a great idea to try but not all can do or use this kind of energy source specially if you live in the arctic. If you plan to install a solar panel you have to make sure that you are in a perfect location for it.
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