ScottC
Guru
- Joined
- Nov 2, 2019
- Messages
- 1,631
- Location
- SWEDEN
- Vessel Name
- ABsolutely FABulous
- Vessel Make
- Greenline 33 Hybrid (2010)
[FONT="]I'll share some more detail regarding my diesel/hybrid experience. It may seem long and rambling, but I think it may contain some information that could be useful for making an informed decision.[/FONT]
[FONT="] [/FONT]
[FONT="]Firstly, for the Greenline 33, LOA = 32.77 feet. LWL=32.32 feet. Yes, you read that correctly. It's has basically a vertical bow, like some sailboats. Published draught is 2.46 feet for the lighter non-hybrid model, dry/empty. For the heavier, hybrid model, loaded with fuel, water, thruster batteries, bicycles and other gear for long-distance cruising the draught can come to 3 feet.[/FONT]
[FONT="] [/FONT]
[FONT="]I bought my 2010 GL33 (in 2011). It came with a 48v (11kw 240Ah) LiPo battery and a solar panel array having a total maximum rated output of 1.3kw. Electric motor is 7kw (doubles as a 5kw generator for charging while in diesel mode). Diesel engine is 165hp. The marketing material at the time indicated one could cruise 20nm on electric. It also indicated that it could go 6 knots on electric. [/FONT]
[FONT="] [/FONT]
[FONT="]Imagine my surprise when I found I could only go for 60-75 minutes at 6 knots! I’ve learned a LOT about electric propulsion, batteries and charging since then and Greenline has moderated their marketing material too. The original marketing claim of 20nm was made for a nearly empty boat (sitting high in the water -> less friction drag) on a PERFECT day with no wind, no waves, no current, inverter not running and most likely a single person on board. Hello! Does anyone ever really cruise like that? Oh, and they failed to mention that to achieve the aforementioned 20nm, one would have to run in this manner no faster than about 4 knots. Thus, the literature was, ummm, shall we say optimistic in the extreme! There was a lot of discussion online over the years on that. Greenline’s literature today, I believe, is not quite so “optimistic” and also provides more clarity about assumptions and conditions for the numbers they claim. STILL, I would not use the numbers claimed directly in order to make your decision. You need to apply an adjustment factor to these numbers to bring them into the real world. So, I will share some experience below that I hope will help.[/FONT]
[FONT="] [/FONT]
[FONT="]With my 11kw 48v battery, 7kw motor, solar panel array (providing ~10-25 Amps input) fully loaded boat, 2 passengers, inverter on (consuming ~7 amps to run the 220v refrigerator, phone & pc chargers, stereo and towel warmer), I have experienced the following:[/FONT]
[FONT="] [/FONT]
[FONT="]Canal cruising, with little wind and no current: Max ~18nm @ 3.3 knots (the typical speed limit in European canals)[/FONT]
[FONT="]Cruising in the sea, <1 foot waves and light wind: Max ~10nm @ 4.5 knots[/FONT]
[FONT="]Cruising in the sea, <1 foot waves and light wind: Max ~6nm @ 5.5 knots[/FONT]
[FONT="] [/FONT]
[FONT="]I did an experiment: no wind, no current, no inverter, loaded boat, 2 passengers, moderately sunny summer day at 55 degrees north latitude (i.e. ~45 degree angle of sun above the horizon). Found I could go 2.1 knots with “infinite” range. i.e. the solar panels were providing as much power as the motor was consuming.[/FONT]
[FONT="] [/FONT]
[FONT="]FYI – running the 7kw motor (and nothing else) wide open draws 138 Amps.[/FONT]
[FONT="]Also, keep in mind that having any growth on the bottom can easily draw down the performance by 10-20%.[/FONT]
[FONT="]Furthermore, keep in mind that the Greenline hull is basically a sailboat hull. As such, it is designed to go through the water with a minimum of resistance. Not sure about your Carver hull design, but I suspect it was meant for “big power” and speed and not efficiency.[/FONT]
[FONT="] [/FONT]
[FONT="]I fear I have not painted such a pretty picture for electric cruising, but don’t misinterpret! I love it and would buy the same boat if I were to do it all over again. Here’s why I like electric cruising:[/FONT]
[FONT="] [/FONT]
[FONT="]1) [/FONT][FONT="]The silence[/FONT]
[FONT="]2) [/FONT][FONT="]The electric motor is low torque and enables precision handling when docking, locking and going under bridges with questionable clearance. Virtually eliminates the risk of damage from a handling mistake[/FONT]
[FONT="]3) [/FONT][FONT="]Having household current available at all times. Nice not to have to run the generator while at anchor![/FONT]
[FONT="]4) [/FONT][FONT="]The silence[/FONT]
[FONT="]5) [/FONT][FONT="]The electric motor also serves as a “get home” option if the diesel engine should fail. Had this happen once in a stormy 3 foot wave scenario and it got me safely to port.[/FONT]
[FONT="]6) [/FONT][FONT="]Did I mention? The silence![/FONT]
[FONT="] [/FONT]
[FONT="]Notice that I did not mention “to save on fuel costs” above! [/FONT]
[FONT="] [/FONT]
[FONT="]Electric cruising may net you less out-of-pocket for long-distance canal cruising when you can cruise daily on battery and charge up nightly at marinas (generally for no additional fee… however I expect this will change as electric boating becomes more popular). For general cruising, however, you won’t save enough money to make a dent in your overall boating expense. In fact it might be the other way around, if you factor in having to replace a LiPo battery every 8-10 years. I just replaced mine, along with a new BMS to ensure its long-range health. €17,000. Looked into trying to replace it with a larger battery, but nothing compatible existed. Also considered adding a second battery, but size and weight precluded that. Also, as somebody already rightly pointed out in this thread, charging batteries while running on diesel is great to be able to do, but it is inefficient compared to charging while plugged into shore power. Every time you convert energy from one form to another, you lose some. Just physics.[/FONT]
[FONT="] [/FONT]
[FONT="]Finally, I don’t believe all the marketing claims about electric cruising being environmentally friendly. Consider the environmental cost of manufacturing and disposing of solar panels. Same for batteries.[/FONT]
[FONT="] [/FONT]
[FONT="]So, you really need to think carefully about WHY you want to do electric cruising. If saving on fuel costs comes near the top of your list, then I would think again about converting your boat fully to hybrid. I also would think about how docking, locking and maneuvering might be with a ½ electric and ½ diesel setup. I can’t imagine it would be a very friendly experience to use just one engine or the other or both, given that they will have dramatically different torques, rpm’s and possibly even propeller sizes.[/FONT]
[FONT="] [/FONT]
[FONT="]Firstly, for the Greenline 33, LOA = 32.77 feet. LWL=32.32 feet. Yes, you read that correctly. It's has basically a vertical bow, like some sailboats. Published draught is 2.46 feet for the lighter non-hybrid model, dry/empty. For the heavier, hybrid model, loaded with fuel, water, thruster batteries, bicycles and other gear for long-distance cruising the draught can come to 3 feet.[/FONT]
[FONT="] [/FONT]
[FONT="]I bought my 2010 GL33 (in 2011). It came with a 48v (11kw 240Ah) LiPo battery and a solar panel array having a total maximum rated output of 1.3kw. Electric motor is 7kw (doubles as a 5kw generator for charging while in diesel mode). Diesel engine is 165hp. The marketing material at the time indicated one could cruise 20nm on electric. It also indicated that it could go 6 knots on electric. [/FONT]
[FONT="] [/FONT]
[FONT="]Imagine my surprise when I found I could only go for 60-75 minutes at 6 knots! I’ve learned a LOT about electric propulsion, batteries and charging since then and Greenline has moderated their marketing material too. The original marketing claim of 20nm was made for a nearly empty boat (sitting high in the water -> less friction drag) on a PERFECT day with no wind, no waves, no current, inverter not running and most likely a single person on board. Hello! Does anyone ever really cruise like that? Oh, and they failed to mention that to achieve the aforementioned 20nm, one would have to run in this manner no faster than about 4 knots. Thus, the literature was, ummm, shall we say optimistic in the extreme! There was a lot of discussion online over the years on that. Greenline’s literature today, I believe, is not quite so “optimistic” and also provides more clarity about assumptions and conditions for the numbers they claim. STILL, I would not use the numbers claimed directly in order to make your decision. You need to apply an adjustment factor to these numbers to bring them into the real world. So, I will share some experience below that I hope will help.[/FONT]
[FONT="] [/FONT]
[FONT="]With my 11kw 48v battery, 7kw motor, solar panel array (providing ~10-25 Amps input) fully loaded boat, 2 passengers, inverter on (consuming ~7 amps to run the 220v refrigerator, phone & pc chargers, stereo and towel warmer), I have experienced the following:[/FONT]
[FONT="] [/FONT]
[FONT="]Canal cruising, with little wind and no current: Max ~18nm @ 3.3 knots (the typical speed limit in European canals)[/FONT]
[FONT="]Cruising in the sea, <1 foot waves and light wind: Max ~10nm @ 4.5 knots[/FONT]
[FONT="]Cruising in the sea, <1 foot waves and light wind: Max ~6nm @ 5.5 knots[/FONT]
[FONT="] [/FONT]
[FONT="]I did an experiment: no wind, no current, no inverter, loaded boat, 2 passengers, moderately sunny summer day at 55 degrees north latitude (i.e. ~45 degree angle of sun above the horizon). Found I could go 2.1 knots with “infinite” range. i.e. the solar panels were providing as much power as the motor was consuming.[/FONT]
[FONT="] [/FONT]
[FONT="]FYI – running the 7kw motor (and nothing else) wide open draws 138 Amps.[/FONT]
[FONT="]Also, keep in mind that having any growth on the bottom can easily draw down the performance by 10-20%.[/FONT]
[FONT="]Furthermore, keep in mind that the Greenline hull is basically a sailboat hull. As such, it is designed to go through the water with a minimum of resistance. Not sure about your Carver hull design, but I suspect it was meant for “big power” and speed and not efficiency.[/FONT]
[FONT="] [/FONT]
[FONT="]I fear I have not painted such a pretty picture for electric cruising, but don’t misinterpret! I love it and would buy the same boat if I were to do it all over again. Here’s why I like electric cruising:[/FONT]
[FONT="] [/FONT]
[FONT="]1) [/FONT][FONT="]The silence[/FONT]
[FONT="]2) [/FONT][FONT="]The electric motor is low torque and enables precision handling when docking, locking and going under bridges with questionable clearance. Virtually eliminates the risk of damage from a handling mistake[/FONT]
[FONT="]3) [/FONT][FONT="]Having household current available at all times. Nice not to have to run the generator while at anchor![/FONT]
[FONT="]4) [/FONT][FONT="]The silence[/FONT]
[FONT="]5) [/FONT][FONT="]The electric motor also serves as a “get home” option if the diesel engine should fail. Had this happen once in a stormy 3 foot wave scenario and it got me safely to port.[/FONT]
[FONT="]6) [/FONT][FONT="]Did I mention? The silence![/FONT]
[FONT="] [/FONT]
[FONT="]Notice that I did not mention “to save on fuel costs” above! [/FONT]
[FONT="] [/FONT]
[FONT="]Electric cruising may net you less out-of-pocket for long-distance canal cruising when you can cruise daily on battery and charge up nightly at marinas (generally for no additional fee… however I expect this will change as electric boating becomes more popular). For general cruising, however, you won’t save enough money to make a dent in your overall boating expense. In fact it might be the other way around, if you factor in having to replace a LiPo battery every 8-10 years. I just replaced mine, along with a new BMS to ensure its long-range health. €17,000. Looked into trying to replace it with a larger battery, but nothing compatible existed. Also considered adding a second battery, but size and weight precluded that. Also, as somebody already rightly pointed out in this thread, charging batteries while running on diesel is great to be able to do, but it is inefficient compared to charging while plugged into shore power. Every time you convert energy from one form to another, you lose some. Just physics.[/FONT]
[FONT="] [/FONT]
[FONT="]Finally, I don’t believe all the marketing claims about electric cruising being environmentally friendly. Consider the environmental cost of manufacturing and disposing of solar panels. Same for batteries.[/FONT]
[FONT="] [/FONT]
[FONT="]So, you really need to think carefully about WHY you want to do electric cruising. If saving on fuel costs comes near the top of your list, then I would think again about converting your boat fully to hybrid. I also would think about how docking, locking and maneuvering might be with a ½ electric and ½ diesel setup. I can’t imagine it would be a very friendly experience to use just one engine or the other or both, given that they will have dramatically different torques, rpm’s and possibly even propeller sizes.[/FONT]