Electric Auxilliary Motor Selection
The Torqeedo Cruise 10.0 FP SD-mount is a 20 HP, 48V pod drive. The cost is $8,999. Since it is a pod drive it saves space but will require potentially very expensive fiberglass work to install and is a somewhat irreversible decision.
The QuietTorque 10.0 Electric Motor from Electric Yacht is undersized a bit but less expensive than Torqeedo options due in part to price ($5,995 vs $8,999) but also due to ease of installation. The QuietTorque 10.0 Sport is a cost reduced version of the QuietTorque 10.0, with the primary difference being limitations in regeneration. The QuietTorque 10.0 allows limited regeneration, while the QuietTorque 10.0 Sport supports full regeneration or none.
Either Torqeedo or QuietTorque frees a lot of space in the engine compartment. The QuietTorque adds only 65 lbs. The pod drive frees even more space but is costly. Electric Yacht seems also to be far more responsive and eager to help with details on their products. Torqeedo support is unresponsive.
Elco was also considered. The Elco EP-20 Electric Inboard is a 8.5 kW (14.1 peak) replacement auxilliary. At 260 lbs it is very heavy and it requires a 72V battery bank eliminating it from consideration. It is also expensive at $8,995.
GreenStar, based in Sweeden, provides a 9.6 kW, 32 kg auxilliary replacement. The GreenStar 18X might be suitable, but product information is too sparse and the company seems unresponsive to requests for information or pricing.
Additional Considerations
An electric sail drive saves space in the engine compartment and avoids the need for a potentially leaky prop shaft packing box or dripless seal. A pod drive takes up no room inside the hull. The disadvantage is a sail drive or pod drive is the expense of installing it and the difficulty if the hull has a v-shape carried aft. The hull has a sharp v-shape carried aft and so is a poor candidate for a pod drive.
Customer service is also a consideration. Electric Yacht is very responsive, knowedgeable, and helpful. Torqueedo and GreenStar are completely unresponsive to support questions. Elco has a good reputation for support though I did not contact them.
Electric Yacht Products
Electric Yacht sells most components needed for a complete electric auxilliary solution including electric motors, batteries, and chargers. The motors cover the range of 5kW to 30kW, though these are peak power ratings with continuous load ratings typically 80% of that figure.
The Electric Yacht motors mount on the existing engine stringers. Each motor has a stock shaft coupler with options for alternate flanges if needed. For the 10kW motors the stock coupler is a 4" Hurth/Borg Warner flange. Each motor comes with an anodized aluminum throttle with key and a system monitor which acts as a battery monitor. They also come with a Blue Seas switch, 500A relay, and fuse. All of the smaller motors are air cooled.
Some Electric Yacht products considered were the QuietTorque 10.0 Sport Electric Motor, QuietTorque 10.0 Electric Motor and QuietTorque 20.0 Electric Motor. The latter is sized for larger boats (45ft, 22,000 lbs) and seems oversized. The 10kW motors seem just slightly undersized (34ft, 12,000 lbs) but are closest to ideal size. It initially was unclear from the online product description and data sheets what the difference was between the two 10kW motors other than $900. An email cleared this up quickly. The less expensive has some control electronics simplifications which removes the ability to limit regeneration power rather than have full regen either enabled or disabled.
| Electric Yacht Motors | |||||||
| Motor | Power | Voltage | Size (LxWxH) | Weight | Price | Comments | |
| Peak | Continuous | ||||||
| QuietTorque 10.0 Sport | 10 kW | 8 kW | 48V (36-65V) | 17L x 9.8-18.3 x 13.5+7.6 | 70 lbs | $4,495 | Same as QuietTorque 10.0 but fixed regen |
| QuietTorque 10.0 | 10 kW | 8 kW | 48V (36-65V) | 17L x 9.8-18.3 x 13.5+7.6 | 70 lbs | $5,395 | Slightly undersized but adequate |
| QuietTorque 20.0 | 20 kW | 16 kW | 48V (36-65V) | 26.7 x 18.5 x 16.5+7.6 | 135 lbs | $8,695 | Oversized |
Prices were as of late October 2019 and just recently dropped $500 (on sale). The sale ended by the time a purchase was made but the $4,995 plus $80 shipping for the QuietTorque 10.0 Sport seems to be a good deal relative to other product offerings.