Combo Electric and Diesel
What we like about a Combo Hybrid/ Diesel:
While motoring by electric pod they are quiet, they don't smell, and they don't burn diesel for 3-5 hours a day when running off batteries recharged by solar panels. In fact, on 90% of the days we make a passage, we won't burn any diesel fuel at all if we have electric propulsion. You also have more range than a diesel or hybrid boat, because you can motor off electric when you have the battery power, then switch to the more economic diesels (versus a generator), which gets rid of some of the conversion losses (see the fuel comparison below). Finally, you have more horsepower available than either of the other options because you may choose to power the boat from both engines and pod motors, simultaneously. This is excellent in a situation where power is needed for a short time where we may use up to 130 hp (110 hp from the diesels, 20 hp from the pods).
Why people will tell you this option is worse:
The two combined systems are heavier than either of the separate option above. This is true, but a lot of that weight is in the batteries, and we plan to have a lot of battery power anyway, so the added weight is not as significant as you might imagine. With extra battery power and the pods, they total about 300 extra pounds.
People will also tell you that this system will require more maintenance, which is also true (but only over a Hybrid boat). Yet, how much more? Compared to the diesel boat, there would actually be less maintenance because the diesel engines will run so much less often, as will the sail drives, and the electric system is extremely low maintenance. However, compared to the Hybrid system, the Combo boat will require more maintenance since there is an additional diesel engine to service, and two sail drives. (The Hybrid has two generators while the Combo has 2 diesel engines, plus a generator, and two saildrives).
Below is a fuel use comparison of all three propulsion types, on different types of passages.
1) Short Passage Less than 6 hours
(36 nautical miles or less trips)
2) Single Day Passage During Daylight (60 nautical mile trip)
3) Single Day Passage During Night (60 nautical mile trip)
4) Single Day Passage During Daylight (90 nautical mile trip)
5) Two Day Passage with 2 days of sunlight (260 nautical mile trip)
6) 21 Day Atlantic Crossing (3,000 miles)
7) 21 Day Passage over the Equator (3,000 mile trip).
8) Same as above, but becalmed for 7 days (3,000 mile trip).
|Passage Length||Miles||Winner||Over Diesel||Over Hybrid|
|Passage One||35||Hybrid or Combo||1.5 gallons||Equal|
|Passage Two||60||Hybrid or Combo||1.5 gallons||Equal|
|Passage Three||60||Combo||1.7 gallons||0.6 gallons|
|Passage Four||90||Combo||2.62 gallons||0.47 gallons|
|Passage Five||260||Combo||4.14 gallons||2.85 gallons|
|Passage Six||3000||Combo||25.5 Gallons||26.5 Gallons|
|Passage Seven||3000 (3 days becalmed)||Combo||26.62 gallons||39 gallons|
|Passage Eight||3000 (7 days becalmed)||Combo||20 gallons||47.6 gallons|
In the examples above, the Diesel boat saves fuel over the Hybrid in three cases (all the longer passages). While the Hybrid beats the Diesel in all the shorter passages. However, in all but the two short passages, where they tie, the Combo boat beats the Hybrid on fuel savings. Against the Diesel boat the Combo always saves fuel over that boat, long or short passages. Therefore, when it comes to fuel savings, the Combo boat wins, hands down.
Initial Cost to add Hybrid system
Initial Cost to add Combo system
After calculating all our passages on our sixteen year voyage around the world and the Ring of Fire, we come up with approximately $50,000 savings in diesel and propane fuel for the Combo and a little less for the Hybrid, about $48,000. Figuring in less maintenance, we save about $37,000 with the Hybrid and $15,000 with the Combo (it still has diesels and saildrives, but they run far less hours than the diesel only boat). Total savings (fuel and maintenance) equals $85,000 for the Hybrid and $65,000 for the Combo.
That means, after subtracting fuel and maintenance savings from the purchase costs of the two systems, we save about $17,000 going with the Combo over a Diesel boat while the Hybrid loses about $11,000 compared to the Diesel boat.
Therefore, the Combo saves us money, being half the cost of a Hybrid propulsion system. Even though the Hybrid saves in maintenance, in the end, it still looses $11,000 compared to the Diesel boat due to the high initial cost to add the system. When it comes to the Combo boat, it actually saves $17,000 over a Diesel boat, due to fuel and maintenance savings over the whole voyage. Winner, Combo Boat Propulsion system as the least expensive option (in the long run).
The Hybrid boat is woefully underpowered when in certain situations while the Combo boat beats the Diesel with 20 more total horsepower. Horsepower is the category that eliminates the Hybrid from our consideration, since it does not have enough power in a dire or required situation so get us where we need to go, while the Combo boat is the best. Yet, both the Hybrid and the Combo are better than the Diesel boat in all situations where you don't need all that horsepower, like maneuvering around in a marina where electric gives you full torque at any RPM, or when you are departing early from your anchorage and don't want to have to warm up the smelly, noisy, fuel wasting, diesel engines. Winner, obviously, the Combo boat.
The Combo wins in every category we have listed, with only two negatives, weight (compared to the Diesel Boat) and maintenance (over the Hybrid). The extra 300 lbs. can be mitigated by reducing weight in other places and the maintenance is less than a standard Diesel boat (though more than the Hybrid).
We get all the comforts of electric propulsion and far less times where we must obtain diesel fuel compared to either the Hybrid or Diesel boats. We have no need for propane, eliminating those hassles and dangers. We also get rid of the dangers and limitations of an underpowered Hybrid boat. Therefore, the Combo boat propulsion system is our winner, by a long shot. And though an initial $22,000 to install the pod motors is a hard pill to swallow, in the long run, it saves us $17,000 and adds a whole lot of comfort to the voyage.
Created with Mobirise site template