Originally Posted by bobmcgov
... costs around $7500 IIRC.
Truth is, with solar PV down to ~$1US per watt and improvements in flexible films, power density, and shading compensation, that is increasingly the most attractive RE solution for boaters. As hellosailor noted, people have been trying hydro-gens for five decades without much traction. Now, as we get the boat speeds, rare-earth magnets, and composite materials that make good ones feasible, better PV has made them irrelevant. Their time may have gone before it has come.
The huge costs to many customers of these products are the reasons many of these products do not make it very far in the market... many of these companies and start-ups fail due to huge costs in engineering, tooling, manufacturing, certifications only to see not many customers and hence...
Solar PV is the best return in terms of watts/cost... they have come a long way since their initial use in the space program... but unlike computer chips which have undergone magnitudes of orders every two years... the technology for propulsion units and energy have not... if propulsion would be similar to computer chips in terms of magnitudes of advancement we would have 'Star Trek' type propulsion and energy from nuclear power units the size of our Honda 2000 generators producing 100Kws or more in power... Current propulsion for aircraft really has not advanced since the engines of the 1960's... the only improvements are small ones and mainly lightweight high strength materials, and improvements in efficiency, etc....
So there are many new exciting technologies in the labs at MIT, Scandia Labs, and many labs in universities with energy producing devices... one in particular I'm looking into is use of saltwater right from the sea to produce electricity and so far the idea is in the lab stages and produces a small amount of electrical output in milliwatts but it may be many decades away from a real product due to finding the proper membrane material... but imagine the bottom of a boat hull with this device maybe painted to the hull producing 10Kw or more depending on hull size...