States vary on the max motor for an ebike (750W or 1,000W), but the max street speed is widely 20 mph.
With an LCD display, it is common that you can very easily reprogram the controller for “off-road” use - typically producing 24-28 mph (just change one setting). Almost nowhere in the States are speed limits enforced on ebikes like that operating on the street.
I have weak experience mechanically, but it was always something that I would have liked to get better at - because my father valued it, and had me tag along when he fixed things.
You point out that these simple electric motors have some advantages in efficiency and reliability (and almost no maintenance), but the gasoline engines pack the big punch (energy density in the fuel, total horsepower). As the batteries get better, electric will be competitive in more niches.
You might get around some of the recharging issues with electric vehicles, by using modular powerpacks that can be swapped out in a minute for a fully charged one. They are still not competitive with gasoline engines for range or cost though.
Battery technology is the long pole in the tent for electric vehicles - and they would change the equation for solar power systems as well. Many new battery technologies are coming out of the labs now, with a variety of improvements.
Graphene batteries will be a big jump in performance, and they are just starting to hit the market. They can make it possible for electric cars to have 500 mile ranges before recharging, and to recharge in minutes rather than hours. Also, you can get five times the power per pound of battery. They will be working their way into products over the next few years, but starting now.
Graphene cells for laptops have been unveiled this May. They will soon be bundled for ebikes (lots of current ebike batteries are bundles of standard laptop 18650 size LI-ion cells). I am actually planning to hold off until next summer to get a back up battery for my ebike, hoping for graphene options by then.
Lots of other new battery technologies have been demonstrated, that will be providing big cost/function improvements over the next 5-10 years.
I hadn’t been looking lately; I took a look at one of the local ebike dealers in the Seattle area.
http://www.electricbikeseattle.com/collections/e-bikes
I am shocked by the prices. I am certain you could do it yourself, but if you live somewhere in the Northwest I would be glad to give you a hand installing a hub motor kit on a normal bicycle. It probably would save you a lot of expense.
I used the gas powered bike on local roads, but I knew that if the police saw me it would be a large ticket. They most likely never would have noticed the bike with the electric motor even if I had been traveling at a quick pace on the flat.
We also had a solar panel on our trailer which helped keep the two golf cart deep cycle batteries on it charged. It made more sense than on the camper van. The people here who probably have the most experience with alternative power and living off the grid are probably people who are RV’ers.
My interest is still in manufacturing faired trikes on a small scale with electric motor assist. Checking component prices and seeing the prices being charged for normal ebikes makes me feel more confident that this might actually be getting closer to being feasible.
http://www.electricbikeseattle.com/products/ti-trike-t250-recumbent-ebike
I would like to produce a variant with a fairing that would provide additional visibility to other vehicles, shelter from the weather, streamlining and have some cargo carrying capability, a solar panel that would appeal to potential customers but keep the price in this same range. I think that it is getting close to being doable.