Note: I wrote this in December 2023, and am revisiting the idea. Component parts have come down in price. It might be time to do it. Not much has changed in my thinking since I drafted this. A thread on Trawler Forum helped me in my thinking.
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I’ve been thinking for the last year or so about my perfect boat. I’ve got to say, Escapade feels pretty good on me. But it’s not perfect.
It’s all use case dependent, of course. And my boating budget is far from limitless. But it’s fun to contemplate.
One idea that’s been simmering as an alternative to swapping boats is tinkering with Escapade. And building out a solar powered hybrid power train has been on my mind for a while.
What would it entail? Basically installing as much solar capacity as possible, then harnessing the energy provided to reduce my fuel consumption.
I should say that in three years of cruising on Escapade I’ve only spent time on the top deck a handful of times. I don’t want a flybridge or sunning space. The sun is not my friend. I’m happy with the open access to the outside in the pilothouse and shaded cockpit.
So here’s the basic proposal: build an aluminum cage structure from the deck up, and cover it with solar panels. Panels would cover most of the length and breadth of the boat. I think I could get about 500 square feet with good orientation and no shade. That’s about 10kw in capacity. My experience with my existing panels indicates I can expect 35-40 kwh per day yield on average. Maximum daily might be 60 kwh.
That energy can be stored in a 48v battery and used for any of the following:
- Existing house loads (2-5 kwh/day)
- Heat/hot water (3kw electric in hydronic system, also uses waste engine heat)
- Propulsion
- It could also be used for air conditioning, but I have none installed. A 240v reverse cycle mini split might look attractive if I had the power, and would also work for heat at dockside.
- Powering stabilization system (in my dreams!)
For the time being I’m expecting the majority of the solar power will go into propulsion. My working plan is to install two electric saildrive units, each about 6 kw. My plan would be to use some combination of diesel and electric when underway. I’m quite confident that I’ll be able to travel at 6 knots under electric only, which is often fast enough for me, but I’m also thinking that I can blend electric with diesel easily by using both to travel the same speed with less fuel.
There are a bunch of ancillary benefits for me. Limited get-home propulsion is really nice to have in a single engine boat. And the idea of having the boat under a permanent protective covering of panels doesn’t bother me a bit. Silent running at times would be nice.
So what’s the payback going to be in reduced fuel consumption? I just called up some numbers from my last full loop:
Distance Traveled: 10,007 NM / 18,500 km
Engine hours: 1,537 @ 1.4 gph 5.5 l/hr
Furnace hours: 958 @ 1.7 l/hr
Total fuel used: 10,050 l
I’ve used 1.0 l/NM as my standard estimate on both Mazurka and Escapade and it’s been remarkably consistent.
What might a repeat with solar/electric look like?
Boating Adventures 