He's got a bunch of solar stuff, some dedicated to charging li-ion. I've gotten a bit of stuff from him -- he's a good guy. Even if you aren't gonna buy his stuff, there's likely to be some good ideas there.
edit: should note that his stuff is portable power... not fixed. Some of the subsequent posts made me think that I'd missed the point of the original question.
Any problems/annoyances you have had that you would like to share?
Any surprises? Both positive and negative?
I would like to go off grid sometime in the future and I've always been surprised by the little nuggets of info that actual off grid residents have been able to give. Things you never find in any litterature.
The system is self designed and self built. The panels are second hand from Morocco, the charge controller is from The US and the inverters are Dutch but sourced from the UK. I live in Southern Spain so we have quite a lot of sunshine, even in winter.
The panels are capable of supplying 5.5kW and the inverters can supply a steady 12kW and peak to 24kW. Obviously the batteries supply the extra when the load exceeds what the panels are supplying. I run the system at a nominal 48 volts.
I also have a 20kW 3 phase diesel generator for emergencies or if I need to maintain the solar system.
The big thing of course is to keep an eye on the sun. If I am not too greedy using the power, I can last 5 days without sunshine. The next thing I need is a 48 volt charger that I could top up the batteries with on cloudy days, this could be powered from a small petrol generator. The diesel generator can consume up to 4 litres of fuel an hour if it is running at its maximum.
This time of year I watch the weather forecast for snow which reduces output if it settles on the panels.
I can't remember exactly but it was less than half the price of hooking up to the grid and I dumped that idea when the ever spiralling price went over 50k (Euros). i could have had a grant towards the system but that would have meant using an approved contractor who would have used his suppliers and with the labour costs would have cost me significantly more.
Most normal families could get away with a smaller set-up. I have a swimming pool pump to run and air conditioning. A significant proportion of the cost is the batteries, if you have the opportunity to stay on the grid and sell your surplus back then you don't need batteries.
I don't know the name of the principles involved, nor the authors/inventors credited, but I know the principle itself.
Electromagnetic force can generate current.
Current can create (and negate) magnetic force.
This kind of generator requires some power for initial spin up, and turns self sufficient once it achieves a certain RPM threshold.
Magnet's attraction is used to "generate" rotation, small current is used to nullify generating opposite attraction (or "wheel" slowing down) at a precisely timed short moment. Magnets attract for a longer period of time, current is used to nullify the magnetic force for a short(er) period of time.
This is NOT perpetuum mobile. Magnetic force is driving the whole thing, with a manual spinup + battery for storing energy acting as an energy buffer. Energy/power used to nullify the magnetic force at those short intervals is less than energy generated by the motor itself.
Also, efficiency of this generator can reach and even exceed 100%.
Search youtube, there are videos and sites with working prototypes. I even found a video of a complete home system that replaces any grid power. I have no idea what it was called or I'd paste the link.