I was trying to stay within the non-electric aspect of this. Solar isn’t exactly something you can make yourself. Methane however is vaguely doable given a bit of effort and skilling up.
You can very easily do a solar installation yourself. But even more interestingly, even biomass-derived methane is more efficiently burned in a CCGT plant (>60% efficiency) to generate electricity for charging an e-bike than in an ICE engine on a moped (~20-25%?). And even better, a smart charger can charge an electric vehicle from an electric mix (NG/wind/solar/nuclear) optimally, so you can run from whatever is best at that moment.
From a global warming perspective, harvesting free methane and burning it is probably a net benefit given how much stronger methane is of a warming agent than the CO2 it burns into.
Would you insist that you should be able to "make" the moped? Nobody will be as self-sufficient as the early Neolithic people ever again. For me, "making" things by building them from mass-manufactured components such as solar panels is perfectly fine. People don't shy from installing solar panels just because they can't manufacture them themselves from sand anymore then they shy from buying electric motors or CPUs.
