ESPcat Version III Solar Generator (electric solar powered catamaran)

I’ve been a bit busy for the last month with multiple overseas visitors so now it’s back to the solar powered boat project.  This project has become a metaphor for life in that there have been multiple setbacks and multiple opportunities to give up.  The whole “giving up” thing really isn’t all that much fun so here I am constructing V3.0 of the Solar Generator which is why I’m smiling.

Now I am not the first person in the world to build a solar generator.  There are about a million designs out there but my solar generator is designed for my boat so I am doing it my way.  My Solar generator has the following:

1 – 1 kWh lithium-ion battery (24 volts at 50 amp-hours)
2 – 2kw inverter with 240 Vac output to run a small refrigerator etc.
3 – 13.3 Vdc output to charge the 12 V lead-acid battery for: engine starting, toilet, lights, water pump, marine radio, depth sounder
4 – twin 100 W solar panel input

This time I’m doing things a bit differently.  For one thing, I am giving up on the trash can housing as it’s not rugged enough and not fire proof enough.  This time I’m using an aluminium tool box as the housing.


The toolbox is much less fragile with lots more fire protection.  It is really bad publicity for your solar powered boat to catch fire, which has been the case with one particular manufacturer on multiple occasions.   I decided that I didn’t want to listen to any fans so I replaced the MPT-7210A solar charge controller with a quiet controller of my own design.

I don’t have all the components yet but I am going to incorporate a timer system so that I have the option of cycling the inverter on and off or running the inverter continuously.  The reason I want to cycle the inverter on and off is that the inverter uses about 15 watts even if it is doing nothing.  The average power of the refigerator is 22.8 watts.  By running the inverter only part of the time (economy mode) the refrigerator should still stay cold but the average standby power of the inverter will be much less.  If I want to run something continuously such as a drill or saw, I can temporarily switch from economy mode to continuous mode.


Above is a view inside the solar generator showing the blue lithium-ion batteries and a bit of the electronics.  I am doing lots of testing and still waiting for more components before I add the timer circuitry.

I usually try to fit in something about US politics but there isn’t anything really interesting going on there.  New Zealand politics is a bit interesting however.  I was commenting on something my old school mate Sam Webb said about Socialism.  I noted what a great example of socialism Air New Zealand is.  ANZ is 52% owned by the government and is traded on the New Zealand Stock Exchange.  ANZ is very modern with its international fleet boasting Boeing 787 Dreamliners and the latest self check-in equipment.  Both the NZ government as well as the capitalist share holders, get a hefty dividend every year. The whole thing is an example of socialism at its best.  Anyone who is afraid of socialism should consider Air New Zealand of an example of how well socialism can work of structured properly.  By the way, several other business models were tried unsuccessfully before the current model was implemented.

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