The Aberration experiment continues, and I am making almost continuous modifications to Aberration based on operational experience and the availability of new technologies.
When I ran the boat to its winter storage at Scarano Boatyard in Albany, the standby diesel generator was smoking a little and this spring I suppose I will have to figure out what is causing it.
Worst case, I will have to replace the generator even though it has less than 600 running hours. That would be a bummer, If that were the case, I would replace the 15 kW diesel generator with a smaller generator in the 8-10 kW range. The 15 kW generator simply is bigger than I need.
In one of my earlier blogs on the boat I already mentioned that the generator was bigger than necessary, but with subsequent modifications, I reduced the battery charging capacity, which is now 7.6 KW max. I also increased the battery capacity by 30% and, together, that provides a new operational envelope balance that I like better. In Hybrid systems finding that operational envelope sweet spot is the crux of the matter and incredibly difficult to figure out.
While all these modifications cost money, it is satisfying to have designed modularity into the whole system, which makes the effort to change things quite low. As a matter of fact, if needed, I think I could swap the generator out for a different model in about 8 hours and that would include the removal of the old generator and the rigging in place of the new and smaller generator. It would basically be plug and play.
Meanwhile, I hope the present generator will last a while longer, since from a Zombie proofing point of view (well, more realistically, from a carbon neutral point of view), I want my next electrical generator to be methanol powered.
Assuming that methanol will be reasonably available at the water’s edge, I would install a methanol powered electrical generator to become more carbon neutral. Based on present technological forecasts I could install a methanol IC generator or methanol fuel cells.
The latter would be much preferred because they are more efficient and mostly silent so I can run silent on both batteries and on methanol and use less methanol to boot.
If I had to run an IC methanol electrical generator I would have to increase my tank capacity.
Fortunately, the boat’s tween deck has plenty of space in the right location to increase fuel tank capacity and, again, that change would take no more than a few hours. While methanol is not as flammable as gasoline, I would probably have to swap in aluminum fuel tanks for the present plastic tanks, but the piping fills and vents would not change.
I would have to rely on the fuel gauges rather than the convenience of simply looking at the transparent tanks, but that would demote me no lower than the rest of the boating world.
But let’s get back to Zombie proofing. What if I could produce my own methanol with my solar panels? On sunny laydays, I produce more solar than I need. What if that excess energy could be used to produce methanol? I would need fresh water, CO2, an electrolyzer, and a methanol converter that produces methanol from the hydrogen and CO2.
The process exists and the components exist but not (yet) in the integrated fashion where it would fit aboard Aberration.
What is a little weird to consider is that a methanol fuel cell will produce CO2 and water that can be the feedstock for new methanol. As such, I could set up a closed loop system if I can store the CO2 when the fuel cell is running and I don’t have solar power to produce more methanol. Storing the water is easy and the present tanks are sufficiently large. At present the boat does not have a reverse osmosis unit. However, that would be an easy installation and then also would provide drinking water (a good Zombie proof feature anyway) and closed loop makeup water for methanol production. Storing CO2 is more difficult, maybe compressing would be best. I do not need a lot of storage capacity and maybe I would also install a small air capture CO2 generator.
The bottom line is this: Would it all be worth the cost and how inefficient would it be?
Well, if you need to Zombie proof, no price is too high, so let’s not worry about that.
Getting back to inefficiency. 4 kW solar produces at best 16 kWh per day. 16 kWh is about two gallons of fuel on a diesel generator efficiency level (it takes about two gallons of diesel fuel for my generator to produce 16kWh.) If my methanol production system is 10% efficient it would generate 1.6 kWh diesel generator fuel per day. That is nothing to write home about. It would be much more efficient to move my boat on solar alone than on the fuel I can produce, but wasting excess solar would be a bummer.
However, systems that are initially inefficient do not necessarily stay that way. Since conventional fuel cells are twice as efficient at using fuel as IC generators, the 1.6 kWh diesel generator fuel is actually 3.2 kWh produced by the fuel cell. On the other side, installing more efficient solar cells may increase my solar electric production to, say, 22kWh per day, that will charge my batteries quicker and therefore add to my ability to produce methanol. And as far as that 10% efficiency methanol production process is concerned, let’s take a look at efficiency increases in the various components of the type we need over the last years.
This is the efficiency by weight of batteries in the last few years. This is going so fast that I expect to be dumping my present batteries in the new few years if I want to stay on the cutting edge.
While I don’t think there is one on the shelf ready to install in my boat, electrolyzer efficiencies run at 70% today, while a few decades ago nobody believed they could run better than 30% and there are serious claims of 80% and higher efficiencies.
Methanol Synthesizers can achieve efficiencies in the 90% range, but at present there are no mini synthesizers that would fit on Aberration.
Current direct methanol fuel cells are 30 to 40% efficient, which is still more efficient than a small diesel generator, but the maximum theoretical energy conversion efficiency is 97% and there is intensive ongoing research in improving the efficiency.
This is my favorite PV solar cell graph. NREL updates it continuously. In 2000 the best cells ran at 30% and today the best cells run at 48%, that is a 60% increase in efficiency. Those supercells are not commercially available, but similar efficiency increases are happening with all cell types.
These trends may not continue since there are specific physical limits to methanol production component efficiencies. However, if the entire process gets up to 60% efficiency and the production equipment weighs less than 300 pounds, I probably would not have to worry about running out of fuel during the Zombie apocalypse.
Hmmm, maybe I can also use that methanol in a nice handy dandy flame thrower.
