It sounds like you've built what serves your purpose but there are a number of stumbling blocks trying to take what you've done and apply it to a production builder
- I missed the size of your boat, which threw off my speed assumptions a bit but even so, it sure looks like your cruise speed is 4kts if you want any range. This is a common point of dispute. If you build a one off boat and accept lower speeds, that's fine. Try to sell a boat that has a cruising speed limit of 4kts, and it doesn't sell so well. Take that up to 5 or 6 kts which is what the buying
public will expect and you just doubled or tripled the power consumption
- You are essentially generating about 2.8hp peak (most of the day, it's much lower an at night nothing. 3hp might get a 26' cat up to 4kts. I really question the conditions if you are claiming 1.25hp (20amps at 48v) gets you 4kts. It's certainly questionable as you move into the 30'+ range.
But let's say you really are able to cruise for several hours per day at 4kts.
- At roughly $1/w for uninstalled sola panels
- 400amp-hr (at 48v) lead acid batteries - $2500 but you can't run lead acid more than 50% if you want them to last long so $5000 for 800amp-hr. Assuming 6v deep cycle, that's 1000lbs of batteries in a 26' boat. That eats up a lot of storage space.
- Lithium would save space and weight but jack up the cost even further.
- You still need to by at least 1 electric motor
(looks like you have two). Let's be generous and say $2000 for an electric outboard
costs can be minimal.
- Misc wire, charge controller, etc... say another $500.
That totals up somewhere around $10k without installation
costs. When we bought our gemini, we added a new 25hp outboard
for $5k installed. In the 9yrs we had her (including 1.5 times around the great loop mostly under power), we haven't used $3k in fuel
. Most owners won't even burn that much. For your boat and the speeds you are willing to live with, you could drop back to a 4hp outboard for something around $1500 (haven't priced them lately so maybe $2000) and if you cap the speed at 4kts, you are probably going to see 3-4times the fuel
efficiency we saw drastically reducing fuel consumption
. When talking about mass market appeal, that's a tough hurdle to overcome.
Remember, you built yours yourself, so you probably considered the labor to do all the installation fun time. Put a couple of guys that cost the builder $100hr (with overhead) and that's going to tack on a few thousand more to the cost of installing the drivetrain.
Reality is I suspect, something is off in the numbers you have shared. As mentioned, the record with a purpose built extreme boat is 5.3kts.
PS: The aluminum hull is a different discussion but its not the internal bulkheads that are difficult to fabricate. It's the complex hull shapes. It can certainly be done but unless you get into true mass production, it's tough to justify the hardware
. There are some aluminum bass boats that are basically press formed but I believe they are looking at several thousand year not a couple hundred. If you are talking about bending sheets of aluminum into complex shapes by hand and welding them together, it takes time and skill. Much easier to do fiberglass in a mold
with guys of moderate skill. That's why I suggested a wharram type design as the hull is a simple V shape, so it's relatively easy to form out of sheets. The downside is they are not the most efficient hulls.