This has come up often before, and as a more or less long time solar professional I am fully aware of what solar can do. BUT.......along with what solar can do, what someone needs to design and market, is a super small lightweight gas generator, using something like the miniature 4 stroke Honda engines like this one:
https://engines.honda.com/models/model- ... erformance. Then couple it to a purpose built alternator, specially wound for the engine torque curve and of course for the power needed. And this is where it gets tricky, get greedy and try and put too much juice out, and the motor will lug down. Like choosing a prop actually, you want the engine happy, in it's sweet spot, and then you load it down with whatever electrical power draw it can handle for long periods of time.
Here is why I've been cogitating on this.......sure there would be a market for camping pilots, but also there is a large pent up demand by the new and growing throng of e bikers, I am in both camps of course. Don't bother to post here on the currently available small gen sets on the market, they are all too damn big and heavy! Ideally I'd want something that could put out about 250 to 500 watts. It could be 12 VDC, to keep it real simple, and then a small inverter could be used to produce 120 VAC. Or in my case, a 12 VDC to 58 VDC converter to charge my 52 VDC bike batteries. IF the weight could come in around 10 to 12 lbs.....it could be marketed at a premium. I'd be willing to pay up to around $1,000.00 for one. Sure, you can buy a 1000 watt Honda for $799.00, but it's TOO DAMN HEAVY. Not to mention bulky. Someone, please bring such a gen set to the market, before I take it upon myself, seriously. I'd draw upon my airplane connections (a cool looking carbon fiber enclosure, AN hardware where appropriate, and anything else I could think of to push a pilot's buttons), plus my renewable energy contacts (I know a few outfits that can easily handle the engineering on the electrical side of things, making a custom wound alternator for any purpose), the remaining design trick would be the all important interface between the engine and the alternator. Direct drive? Reduction system? Each would have advantages and disadvantages, and when you combine the choices there along with the marketing considerations ( like what if direct drive turned out to be by far the most efficient, but required a alternator that cost three times as much, or weighed more) it all makes my head hurt and I forget about going into production of this theoretical gen set and I just go to work running my crane, making money and waiting for some else to figure it all out so I can just buy one.
Just saw Rob's post, 28 lbs for the littlest Honda, the smallest and equally well regarded Yamaha is 27. Some POS imports of unknown quality are around 21 or 22. That market is already covered, Half the power, 500 watts, at half the weight, there is nothing out there. Before others mention the newer power packs that contain a lot of energy, nothing beats good old gasoline for energy for pound of weight. Anybody who lives in a off grid home knows this, 1 gallon of gas, when converted into electrical power, is an awesome thing and why we all use the damn stuff.