phasing out of fossil fuels - programme

[IanD]

1 hour ago, peterboat said:

I have read it's 29 to 32%, which is way better than the 19% that your graph shows for NBs at similar speeds and that's with a 65% loading on the genny. We also have other advantages in that the coolant can be used to heat water and run central heating which in normal electric production doesn't happen. I would think its fair to say with solar in the mix series hybrids have real potential for cutting emissions by a large amount and save plenty of dosh.

I will report my findings when this latest modification is finished but that's going to be a while for obvious reasons 

The 25% generator efficiency figure is actual test results from the Victron whitepaper "Victron Energy Marine Generator Test 2007" from https://www.victronenergy.com/support-and-downloads/whitepapers

 

The 19.4% diesel efficiency at 3kW/4bhp is calculated from Beta measured fuel consumption curves and a propellor power absorption curve scaled from measurements on a 22"x13" prop. In other words all these numbers are from actual measurements, not some theoretical best-case calculation, which I would guess your 29% to 32% figure comes from because not a single generator from the 20 tested got anywhere close to this.

 

To do an apples-to-apples comparison you also need to include losses in the two systems; an asynchronous PMAC motor like the Engiro is maybe 95% efficient at these power levels, a brushed or synchronous motor (which I think you have?) will be at best 90%. On top of this the controller is maybe 95% efficient, so power losses are 10%-15%, plus a small loss for battery charge/discharge (even with LiFePO4) means the series hybrid ends up around 22% efficient at cruising power levels if power comes from the generator. For the diesel we have about 4% gearbox loss plus a bit for belts etc, so probably end up around 18% -- which as you say is terrible, but then the hybrid isn't that much (about 20%) better.

 

The bigger gains with the hybrid are where the diesel is even worse, only 11% efficient at 0.9l/hour=1kW/1000rpm (passing moored boats), and 0% in locks where it still uses 0.5l/hour.

 

It can use solar power if the sun is shining -- though you'll never get peak rated power and can only fit about a 2kW array on a narrowboat, this probably yields about 1kW on a nice summer's day, which will provide enough to pass moored boats without any battery drain and will charge up the batteries when stopped in locks. But of course you can also fit solar to a diesel to charge the house batteries, which means that energy doesn't have to come from the engine via the alternators, so this is the same for both too when you look at the complete energy budget.

 

A generator can be used to provide hot water if it can be plumbed in (e.g. Beta Marine generators -- many can't be...), but then so does a diesel so there's no difference here.

 

So the emissions/economy difference come down to the hybrid using about 20% less fuel when cruising at 3kW, 50% less when passing boats at 1kW, and 100% less when stopped in a lock. How much time you spend doing each of these affects the overall saving, so lets pick some numbers.

 

Assume that in an 8 hour cruising day we spend 4 hours cruising, 2 hours passing boats, and 2 hours in locks.

 

Diesel : 4 hours x 1.5l/h + 2 hours x 0.9l/hr + 2 hours x 0.5l/hour = 8.8l/day

Hybrid : 4 hours x 1.2l/hour + 2 hours x 0.4l/hr + 2 hours x 0l/hour = 5.6l/day (36% reduction)

Saving : 1.2l cruising + 1l passing boats + 1l in locks = 3.2l/day

 

Then you need to look at what happens when not cruising, comparing using the generator to charge the batteries (hybrid) instead of running the engine (diesel). Generator efficiency (fuel to battery) will be 25%, but the diesel will be *much* lower. Let's be generous and assume big alternators are used (e.g. 100A + 175A) to put 2.5kW into the batteries, at 50% typical alternator efficiency this will demand 5kW from the engine at around 1600rpm, consuming 2l/hour at 24% engine efficiency meaning 12% overall efficiency. Using a TravelPower instead of alternators will push this up to maybe 16% because the efficiency is better.

 

To put 10kWh (800Ah) into the batteries you would have to run the diesel engine for 4h and consume 8l of diesel, the generator would only need 4l of fuel to provide the same charge so 50% fuel saving (4l/day). How often you need to do this obviously depends on battery bank size and energy usage, but when you do it the hybrid uses half the fuel if the diesel uses alternators (or two-thirds if it uses a TravelPower).

 

It is left as "an exercise for the reader" (like it says in the maths textbooks) to plug in their own numbers to see what the savings would be depending how much time they spend doing what, but the conclusion is that by far the biggest fuel/energy/emissions savings with a series hybrid are due to the low fuel consumption when battery charging and passing boats and zero in locks, this is much bigger than the saving due to better efficiency when cruising, and a reasonable guesstimate would be around 40% lower fuel consumption and emissions overall.

 

 

Edited January 10, 2021 by IanD

[peterboat]

44 minutes ago, IanD said:

The 25% generator efficiency figure is actual test results from the Victron whitepaper "Victron Energy Marine Generator Test 2007" from https://www.victronenergy.com/support-and-downloads/whitepapers

 

The 19.4% diesel efficiency at 3kW/4bhp is calculated from Beta measured fuel consumption curves and a propellor power absorption curve scaled from measurements on a 22"x13" prop. In other words all these numbers are from actual measurements, not some theoretical best-case calculation, which I would guess your 29% to 32% figure comes from because not a single generator from the 20 tested got anywhere close to this.

 

To do an apples-to-apples comparison you also need to include losses in the two systems; an asynchronous PMAC motor like the Engiro is maybe 95% efficient at these power levels, a brushed or synchronous motor (which I think you have?) will be at best 90%. On top of this the controller is maybe 95% efficient, so power losses are 10%-15%, plus a small loss for battery charge/discharge (even with LiFePO4) means the series hybrid ends up around 22% efficient at cruising power levels if power comes from the generator. For the diesel we have about 4% gearbox loss plus a bit for belts etc, so probably end up around 18% -- which as you say is terrible, but then the hybrid isn't that much (about 20%) better.

 

The bigger gains with the hybrid are where the diesel is even worse, only 11% efficient at 0.9l/hour=1kW/1000rpm (passing moored boats), and 0% in locks where it still uses 0.5l/hour.

 

It can use solar power if the sun is shining -- though you'll never get peak rated power and can only fit about a 2kW array on a narrowboat, this probably yields about 1kW on a nice summer's day, which will provide enough to pass moored boats without any battery drain and will charge up the batteries when stopped in locks. But of course you can also fit solar to a diesel to charge the house batteries, which means that energy doesn't have to come from the engine via the alternators, so this is the same for both too when you look at the complete energy budget.

 

A generator can be used to provide hot water if it can be plumbed in (e.g. Beta Marine generators -- many can't be...), but then so does a diesel so there's no difference here.

 

So the emissions/economy difference come down to the hybrid using about 20% less fuel when cruising at 3kW, 50% less when passing boats at 1kW, and 100% less when stopped in a lock. How much time you spend doing each of these affects the overall saving, so lets pick some numbers.

 

Assume that in an 8 hour cruising day we spend 4 hours cruising, 2 hours passing boats, and 2 hours in locks.

 

Diesel : 4 hours x 1.5l/h + 2 hours x 0.9l/hr + 2 hours x 0.5l/hour = 8.8l/day

Hybrid : 4 hours x 1.2l/hour + 2 hours x 0.4l/hr + 2 hours x 0l/hour = 5.6l/day (36% reduction)

Saving : 1.2l cruising + 1l passing boats + 1l in locks = 3.2l/day

 

Then you need to look at what happens when not cruising, comparing using the generator to charge the batteries (hybrid) instead of running the engine (diesel). Generator efficiency (fuel to battery) will be 25%, but the diesel will be *much* lower. Let's be generous and assume big alternators are used (e.g. 100A + 175A) to put 2.5kW into the batteries, at 50% typical alternator efficiency this will demand 5kW from the engine at around 1600rpm, consuming 2l/hour at 24% engine efficiency meaning 12% overall efficiency. Using a TravelPower instead of alternators will push this up to maybe 16% because the efficiency is better.

 

To put 10kWh (800Ah) into the batteries you would have to run the diesel engine for 4h and consume 8l of diesel, the generator would only need 4l of fuel to provide the same charge so 50% fuel saving (4l/day). How often you need to do this obviously depends on battery bank size and energy usage, but when you do it the hybrid uses half the fuel if the diesel uses alternators (or two-thirds if it uses a TravelPower).

 

It is left as "an exercise for the reader" (like it says in the maths textbooks) to plug in their own numbers to see what the savings would be depending how much time they spend doing what, but the conclusion is that by far the biggest fuel/energy/emissions savings with a series hybrid are due to the low fuel consumption when battery charging and passing boats and zero in locks, this is much bigger than the saving due to better efficiency when cruising, and a reasonable guesstimate would be around 40% lower fuel consumption and emissions overall.

 

 

It's  a strange one most genny buyers aren't that bothered about efficient gennys they just want them to work. When I started in 75 as a genny mechanic in the Army we were similar, over the years that changed with single fuel policy we scrapped loads of onan petrol gennys. Towards the end we had turbocharged gennys which were half the size and much better output than when I started. At the end I had 2 Rolls Royce eagle series powered gennys that I ran solid for 6 months 12 hours about (to get rid of the red diesel instead of paying someone to remove it) They are expensive to run but I didn't care as it was still cheaper than the alternative. Nowadays they are more efficient diesel engines are way better than in 2007 DI is the normal and that's 20% better than IDI versions. Electronic controls also help instead of simple pumps and injectors. The figures I quoted are reasonable some of the latest gennys will be better as long as they aren't loaded with cats, DPFs and ad blue etc.

The reason Riccy is going to build his own gennys is because he wants better than most of the offerings, me I don't expect to run mine that often so I can live with 25 to 30% ish

[IanD]

15 hours ago, peterboat said:

It's  a strange one most genny buyers aren't that bothered about efficient gennys they just want them to work. When I started in 75 as a genny mechanic in the Army we were similar, over the years that changed with single fuel policy we scrapped loads of onan petrol gennys. Towards the end we had turbocharged gennys which were half the size and much better output than when I started. At the end I had 2 Rolls Royce eagle series powered gennys that I ran solid for 6 months 12 hours about (to get rid of the red diesel instead of paying someone to remove it) They are expensive to run but I didn't care as it was still cheaper than the alternative. Nowadays they are more efficient diesel engines are way better than in 2007 DI is the normal and that's 20% better than IDI versions. Electronic controls also help instead of simple pumps and injectors. The figures I quoted are reasonable some of the latest gennys will be better as long as they aren't loaded with cats, DPFs and ad blue etc.

The reason Riccy is going to build his own gennys is because he wants better than most of the offerings, me I don't expect to run mine that often so I can live with 25 to 30% ish

Most buyers aren't bothered about efficient gennies because they don't have to be, and most of them are very similar anyway (around 25% at these power levels) -- but here we're testing the claim that serial hybrids use a lot less fuel than straight diesels, so it does matter. For those who are bored with numbers, you don't need to read the rest of this ?

 

I agree that modern common-rail DI turbodiesels are more efficient, but there are reasons why this doesn't apply to ~10kVa 1500rpm generators like the ones we're talking about for boats...

 

Adding a turbo increases power (a lot!) and efficiency (a bit) by recovering energy from the exhaust, increasing overall CR, and enabling a much smaller engine with lower frictional losses to be used to generate the same power. The 1.9l XUD diesel in my 1980s Citroen BX generated 65bhp which is 34bhp/l, modern diesels the same size are around 100bhp/l and common-rail DI is essential for this -- they run at high speed (e.g. 5000rpm) with high boost pressure so very precise ultra-high-pressure injection control is needed (up to 6 phased micro-injections) to reduce noise and emissions and get fast burning, and the pumping losses of IDI are high at these speeds, at least 10% of power would be wasted squeezing the air in and out of the prechamber -- put all this together and you're up around 40% efficiency, which as Peter says is indeed about 20% better than IDI.

 

But none of this applies to our case. IDI pumping losses are proportional to rpm^2 so are probably around 1% at 1500rpm, and to get the extra ~10% CR DI turbo efficiency bonus you'd need to run at around 50bhp/l at 1500rpm. The Betagen 10 engine puts out 12.3bhp, so a high-pressure turbodiesel would need to be a few hundred cc (1 cylinder?) to generate the same power with all the efficiency gains -- absolutely tiny and would in theory be ~10% more efficient, but try finding a turbo and common-rail DI systems small enough, they just don't exist. The cost would also be very high -- cats/DPF/AdBlue increase cost even further and reduce maximum power a bit but unlike petrol engines have little effect on efficiency.

 

So at 10kVa the traditional IDI 1500rpm generator can't really be improved much, which is why all the generators on the market look very much the same. Higher efficiencies like 30% are possible but only on bigger generators (50kVa and above) where the CR/DI/turbo cost increase is also less important. If you've got any real figures which show otherwise I'd be happy to be proved wrong ?

 

Anyway you're guilty of favouring your own solution by using modern technology, and what's sauce for the goose is sauce for the gander -- if you can do this (using newer more efficient technology, if it exists) for your hybrid, the diesel camp can do it as well, and it's actually easier for them because the engines are bigger and higher power. What we need is a fair series hybrid/diesel comparison, and fortunately we have exactly that...

 

The Betagen 10 engine (3-cyl 1100cc Kubota BD1103) puts out 12.3bhp (9.2kW) at 1500rpm to generate 7.1kW at 230V/50Hz while consuming 2.7l/h, which is 0.38l/kWh. The Beta 43 (4-cyl 2000cc Kubota BV2002) when cruising at 1400rpm consumes 1.5l/h while putting out 3.1kW, which is 0.48l/kWh -- this is 19.4% efficiency, so the Betagen 10 efficiency is 24.7%, which funnily enough is almost exactly the 25% that I estimated ?

 

To be fair to both cases we should ignore electrical loads on the boat (230V or 12V battery charging) because the energy has to come from the same places for both (either engine/generator or solar) and just look at propulsion. For the diesel we have a typical gearbox loss of 3% bringing it down to 18.8%. For the series hybrid we have a larger number of losses; at least 4% going from 230Vac (generator output) to 48Vdc in the combo to charge the batteries, then at least the same again (4%) in the motor controller, and the same again in the motor itself even assuming the best possible PMAC motor running at maximum efficiency (96% for Engiro, everything else is worse than this e.g. Lynch is 88%) -- and note that I've used the best possible cases (maximum efficiency) for all these losses, which are unlikely to all happen together. Same engine (even same manufacturer), exactly the same technology so apples-to-apples.

 

All of which brings the hybrid down to 21.9% compared to 18.8% for the diesel, which means 14% lower cruising fuel consumption (at 3kW/4bhp) -- not quite as good as the approximate numbers I worked out earlier, but this only gets better at lower speeds and in locks, and especially when charging the batteries when moored. It's reasonable taking all this together to expect around 40% lower fuel consumption and emissions for a series hybrid (maybe 35%-45% range depending on usage case) compared to a diesel with Travelpower (again, to make a fair comparison), but any claims for more than this should be taken with a pinch of salt because the numbers don't back this up.

 

Note that for all this to work LiFePO4 batteries are essential, with any lead-acids (lead-carbon, AGM, gel, flooded, whatever...) the charge/discharge losses and high-current capacity loss and need for hours of extended charging for equalisation will wipe out any series hybrid efficiency savings.

 

This is one reason why Hybrid Marine concluded that a parallel hybrid was more efficient, with lead-acids this is definitely true but not with LiFePO4 -- the cost of these dropping has made the cost adder for serial hybrids much lower, still more than a lead-acid parallel hybrid today but the gap is closing rapidly.

 

And of course the drive towards "zero-emissions" (yes, I know...) is strongly in favour of hybrids.

 

Conclusions: straight diesel is going to become a dinosaur for new boats, parallel hybrids with LA have had their day, series hybrids with LiFePO4 are the future -- more expensive now but the cost will continue to fall -- and give about 40% lower fuel consumption/emissions than diesels, assuming there are no charging stations on the canals/rivers.

 

Obviously if/when charging stations appear a series hybrid moves closer and closer to being all-electric, but this will take some time, it'll be many years before the diesel generator (which will probably be running on biodiesel) will be discarded completely.

 

Blimey, I'm (mostly) agreeing with Peter ?

Edited January 11, 2021 by IanD

[peterboat]

3 hours ago, IanD said:

Most buyers aren't bothered about efficient gennies because they don't have to be, and most of them are very similar anyway (around 25% at these power levels) -- but here we're testing the claim that serial hybrids use a lot less fuel than straight diesels, so it does matter. For those who are bored with numbers, you don't need to read the rest of this ?

 

I agree that modern common-rail DI turbodiesels are more efficient, but there are reasons why this doesn't apply to ~10kVa 1500rpm generators like the ones we're talking about for boats...

 

Adding a turbo increases power (a lot!) and efficiency (a bit) by recovering energy from the exhaust, increasing overall CR, and enabling a much smaller engine with lower frictional losses to be used to generate the same power. The 1.9l XUD diesel in my 1980s Citroen BX generated 65bhp which is 34bhp/l, modern diesels the same size are around 100bhp/l and common-rail DI is essential for this -- they run at high speed (e.g. 5000rpm) with high boost pressure so very precise ultra-high-pressure injection control is needed (up to 6 phased micro-injections) to reduce noise and emissions and get fast burning, and the pumping losses of IDI are high at these speeds, at least 10% of power would be wasted squeezing the air in and out of the prechamber -- put all this together and you're up around 40% efficiency, which as Peter says is indeed about 20% better than IDI.

 

But none of this applies to our case. IDI pumping losses are proportional to rpm^2 so are probably around 1% at 1500rpm, and to get the extra ~10% CR DI turbo efficiency bonus you'd need to run at around 50bhp/l at 1500rpm. The Betagen 10 engine puts out 12.3bhp, so a high-pressure turbodiesel would need to be a few hundred cc (1 cylinder?) to generate the same power with all the efficiency gains -- absolutely tiny and would in theory be ~10% more efficient, but try finding a turbo and common-rail DI systems small enough, they just don't exist. The cost would also be very high -- cats/DPF/AdBlue increase cost even further and reduce maximum power a bit but unlike petrol engines have little effect on efficiency.

 

So at 10kVa the traditional IDI 1500rpm generator can't really be improved much, which is why all the generators on the market look very much the same. Higher efficiencies like 30% are possible but only on bigger generators (50kVa and above) where the CR/DI/turbo cost increase is also less important. If you've got any real figures which show otherwise I'd be happy to be proved wrong ?

 

Anyway you're guilty of favouring your own solution by using modern technology, and what's sauce for the goose is sauce for the gander -- if you can do this (using newer more efficient technology, if it exists) for your hybrid, the diesel camp can do it as well, and it's actually easier for them because the engines are bigger and higher power. What we need is a fair series hybrid/diesel comparison, and fortunately we have exactly that...

 

The Betagen 10 engine (3-cyl 1100cc Kubota BD1103) puts out 12.3bhp (9.2kW) at 1500rpm to generate 7.1kW at 230V/50Hz while consuming 2.7l/h, which is 0.38l/kWh. The Beta 43 (4-cyl 2000cc Kubota BV2002) when cruising at 1400rpm consumes 1.5l/h while putting out 3.1kW, which is 0.48l/kWh -- this is 19.4% efficiency, so the Betagen 10 efficiency is 24.7%, which funnily enough is almost exactly the 25% that I estimated ?

 

To be fair to both cases we should ignore electrical loads on the boat (230V or 12V battery charging) because the energy has to come from the same places for both (either engine/generator or solar) and just look at propulsion. For the diesel we have a typical gearbox loss of 3% bringing it down to 18.8%. For the series hybrid we have a larger number of losses; at least 4% going from 230Vac (generator output) to 48Vdc in the combo to charge the batteries, then at least the same again (4%) in the motor controller, and the same again in the motor itself even assuming the best possible PMAC motor running at maximum efficiency (96% for Engiro, everything else is worse than this e.g. Lynch is 88%) -- and note that I've used the best possible cases (maximum efficiency) for all these losses, which are unlikely to all happen together. Same engine (even same manufacturer), exactly the same technology so apples-to-apples.

 

All of which brings the hybrid down to 21.9% compared to 18.8% for the diesel, which means 14% lower cruising fuel consumption (at 3kW/4bhp) -- not quite as good as the approximate numbers I worked out earlier, but this only gets better at lower speeds and in locks, and especially when charging the batteries when moored. It's reasonable taking all this together to expect around 40% lower fuel consumption and emissions for a series hybrid (maybe 35%-45% range depending on usage case) compared to a diesel with Travelpower (again, to make a fair comparison), but any claims for more than this should be taken with a pinch of salt because the numbers don't back this up.

 

Note that for all this to work LiFePO4 batteries are essential, with any lead-acids (lead-carbon, AGM, gel, flooded, whatever...) the charge/discharge losses and high-current capacity loss and need for hours of extended charging for equalisation will wipe out any series hybrid efficiency savings.

 

This is one reason why Hybrid Marine concluded that a parallel hybrid was more efficient, with lead-acids this is definitely true but not with LiFePO4 -- the cost of these dropping has made the cost adder for serial hybrids much lower, still more than a lead-acid parallel hybrid today but the gap is closing rapidly.

 

And of course the drive towards "zero-emissions" (yes, I know...) is strongly in favour of hybrids.

 

Conclusions: straight diesel is going to become a dinosaur for new boats, parallel hybrids with LA have had their day, series hybrids with LiFePO4 are the future -- more expensive now but the cost will continue to fall -- and give about 40% lower fuel consumption/emissions than diesels, assuming there are no charging stations on the canals/rivers.

 

Obviously if/when charging stations appear a series hybrid moves closer and closer to being all-electric, but this will take some time, it'll be many years before the diesel generator (which will probably be running on biodiesel) will be discarded completely.

 

Blimey, I'm (mostly) agreeing with Peter ?

Good post Ian

 

Ian miles away on fuel consumption, have a look at the chart mine is 6kw and is 460cc and uses the lightweight Mitsubishi L2A engine but spinning at 3000 RPM, its old but still current it uses approx 1 litre per hour.

So the savings for serial Hybrids would be better but more importantly the emissions are reduced and with solar they would be reduced even more. The above is why Riccy is building his own gennys in the future, no doubt as they are turbo experts [and they are Ian on the car side its all they do is fast jap cars] they will have a small turbocharged diesel running at higher RPM with cleanup equipment to meet emission regs

Generator Size Approximate Diesel Fuel Consumption ¼ Load (litres/hr) ½ Load (litres/hr) ¾ Load (litres/hr) Full Load (litres/hr) 8kW / 10kVA 0.8 1.3 1.8 2.4 10kW / 12kVA .9 1.6 2.2 2.9 12kW / 15kVA 1.1 1.9 2.7 3.6 16kW / 20kVA 1.5 2.5 3.6 4.8 20kW / 25kVA 1.8 3.1 4.5 6.0 24kW / 30kVA 2.2 3.7 5.4 7.2 32kW / 40kVA 2.9 5.0 7.2 9.6 40kW / 50kVA 3.6 6.2 9.0 12.0 60kW / 75kVA 5.4 9.4 13.5 18.0 80kW / 100kVA 7.2 12.5 18.0 24.0 120kW / 150kVA 10.8 18.8 27.0 36.0 160kW / 200kVA 14.4 25.0 36.0 48.0 200kW / 250kVA 18.0 31.2 45.0 60.0 280kW / 350kVA 25.2 43.7 63.0 84.0 400kW / 500kVA 36.0 62.4 90.0 120.0

Edited January 11, 2021 by peterboat

[Jackofalltrades]

A very interesting discussion, especially as I (we) will soon be going down the electric propulsion route on a narrowboat shell.

 

However, although it is interesting to see a fair comparison of hybrid and straight diesel systems, what the comparison seems to be failing to take into account is the much larger solar array on an electric propulsion boat. A diesel powered boat might have say 600 watts of solar (an average?) solely to keep the domestic batteries charged whereas a boat with an electric motor as a sole means of propulsion will have as much solar on the roof as it's physically possible to install and from my own calculations I will be disappointed if we end up with less than 2.2 Kw.

 

In the summer months when most cruising is done we expect (from what we have read elsewhere) to be able to cruise for a day on battery power and solar alone. We then plan to spend a few days in each location wherever possible to maximise solar charging of the batteries (weather permitting) before setting off for another day of cruising. For our use case we expect our diesel generator usage to be negligible in the summer months and outside of these months we still expect the solar array to make a noticeable contribution to the battery bank - especially as we would be moving less when it's colder and wetter - and in the depths of winter the boat will be in a marina on shorepower. We think our diesel use over the course of a full year of cruising will be somewhere in the region of 70-80% less than using a straight diesel engine for propulsion. That's 70-80% less pollution too.

 

That's the theory anyway. I'll post some real life figures after the boat is launched early summer, all being well.

 

Edited to add: Hello everyone - I've lurked for a while and only just realised this is my first post.

Edited January 11, 2021 by Jackofalltrades

[IanD]

1 hour ago, peterboat said:

Good post Ian

 

Ian miles away on fuel consumption, have a look at the chart mine is 6kw and is 460cc and uses the lightweight Mitsubishi L2A engine but spinning at 3000 RPM, its old but still current it uses approx 1 litre per hour.

So the savings for serial Hybrids would be better but more importantly the emissions are reduced and with solar they would be reduced even more. The above is why Riccy is building his own gennys in the future, no doubt as they are turbo experts [and they are Ian on the car side its all they do is fast jap cars] they will have a small turbocharged diesel running at higher RPM with cleanup equipment to meet emission regs

Generator Size Approximate Diesel Fuel Consumption ¼ Load (litres/hr) ½ Load (litres/hr) ¾ Load (litres/hr) Full Load (litres/hr) 8kW / 10kVA 0.8 1.3 1.8 2.4 10kW / 12kVA .9 1.6 2.2 2.9 12kW / 15kVA 1.1 1.9 2.7 3.6 16kW / 20kVA 1.5 2.5 3.6 4.8 20kW / 25kVA 1.8 3.1 4.5 6.0 24kW / 30kVA 2.2 3.7 5.4 7.2 32kW / 40kVA 2.9 5.0 7.2 9.6 40kW / 50kVA 3.6 6.2 9.0 12.0 60kW / 75kVA 5.4 9.4 13.5 18.0 80kW / 100kVA 7.2 12.5 18.0 24.0 120kW / 150kVA 10.8 18.8 27.0 36.0 160kW / 200kVA 14.4 25.0 36.0 48.0 200kW / 250kVA 18.0 31.2 45.0 60.0 280kW / 350kVA 25.2 43.7 63.0 84.0 400kW / 500kVA 36.0 62.4 90.0 120.0

Peter, you might need to be more careful about detailed fuel efficiency/power ratings (not just "generator size") before saying my numbers are wrong ?

 

The Betagen 10 has a headline rating of 10kVA, which turns out to be the maximum (short-term) output for the 3-phase version. The "prime output" (continuous) for the single-phase version is 8.8kVA at a power factor of 0.8, but what matters for charging batteries is the load power which is 7.1kW (31A/230V) at a consumption of 2.7l/h, or 0.38l/kWh (24.7% efficiency).

 

If the table you give is correct then 2.4l/hr to generate 8kW is 0.3l/kWh which is 21% lower consumption, and I'd say this is pretty unlikely (31.3% efficiency) but not totally impossible -- as I said, if you dig deep into the details like I did for the Betagen and these figures are correct and based on measurements, then I'll believe them. They might be experts in Jap turbo cars, but I'd like to know where they can get a small enough turbo and CR DI system for a <500cc diesel...

 

But I simply don't believe the numbers in the table, because in almost every case (except the 10kW) the full-load fuel consumption is exactly 0.300l/kWh -- a suspiciously round number, and it's just not credible that every size from 8kW to 400kW has the same specific consumption. If a supplier presented me with this table I'd tell them it was obviously based on a rough (and possibly optimistic) guesstimate and to come back with more accurate figures which reflect the real consumption. I wouldn't even be convinced they've built and measured an actual generator of any size unless they provided real measured data, I've seen these kind of numbers on too many occasions to believe them ?

 

Generating 6kW using 1l/hour (your text) is completely impossible, this would be 0.17l/kWh or 56% thermal efficiency from fuel in to electricity out. You wouldn't even get that with a 2000-ton 100,000hp marine diesel and a superconducting generator ?

 

And as I keep saying, even if whatever magic dust Riccy sprinkles on his generators is real (which I doubt given the numbers above) and they do deliver 20% lower fuel consumption and emissions in a series hybrid, this doesn't make the advantage over a diesel any bigger if they do exactly the same ?

17 minutes ago, Jackofalltrades said:

A very interesting discussion, especially as I (we) will soon be going down the electric propulsion route on a narrowboat shell.

 

However, although it is interesting to see a fair comparison of hybrid and straight diesel systems, what the comparison seems to be failing to take into account is the much larger solar array on an electric propulsion boat. A diesel powered boat might have say 600 watts of solar (an average?) solely to keep the domestic batteries charged whereas a boat with an electric motor as a sole means of propulsion will have as much solar on the roof as it's physically possible to install and from my own calculations I will be disappointed if we end up with less than 2.2 Kw.

 

In the summer months when most cruising is done we expect (from what we have read elsewhere) to be able to cruise for a day on battery power and solar alone. We then plan to spend a few days in each location wherever possible to maximise solar charging of the batteries (weather permitting) before setting off for another day of cruising. For our use case we expect our diesel generator usage to be negligible in the summer months and outside of these months we still expect the solar array to make a noticeable contribution to the battery bank - especially as we would be moving less when it's colder and wetter - and in the depths of winter the boat will be in a marina on shorepower. We think our diesel use over the course of a full year of cruising will be somewhere in the region of 70-80% less than using a straight diesel engine for propulsion. That's 70-80% less pollution too.

 

That's the theory anyway. I'll post some real life figures after the boat is launched early summer, all being well.

 

Edited to add: Hello everyone - I've lurked for a while and only just realised this is my first post.

There's absolutely nothing stopping a diesel boat having the same size solar array (6 x 380W panels is about the most on a 57' boat, as you say) as a hybrid, and several people have done exactly that because it's an excellent idea. Using the solar power to avoid running the engine/generator has exactly the same benefits for both -- in fact bigger for a straight diesel due to lousy efficiency compared to a generator when battery charging (about half with alternators, about two-thirds with a TravelPower).

 

If you can completely charge up with solar between travels then you use no diesel at all, but don't forget the solar has to provide the electric power you're using on the boat as well as recharging the batteries. And a 2.2kWh (max) array will give you maybe 6kWh/day typical in summer, so recharging will take several days even without allowing for onboard use. You need to do a power audit to see how this would all work for you, not just assume that solar will fix everything.

 

(the situation for Peter is different, he's got a widebeam with >5kW of panels IIRC which makes being diesel-free much more practical, at least in the summer)

Edited January 11, 2021 by IanD

[Jackofalltrades]

17 minutes ago, IanD said:

There's absolutely nothing stopping a diesel boat having the same size solar array (6 x 380W panels is about the most on a 57' boat, as you say) as a hybrid, and several people have done exactly that because it's an excellent idea. Using the solar power to avoid running the engine/generator has exactly the same benefits for both -- in fact bigger for a straight diesel due to lousy efficiency compared to a generator when battery charging (about half with alternators, about two-thirds with a TravelPower).

No, using solar to avoid running the engine/generator has very different benefits.

 

On a diesel engined boat all the solar will do is charge domestic batteries. If you want to move the boat you have to fire up the diesel engine.

 

On an electric propulsion boat the solar will charge the propulsion batteries. If you want to move the boat you do not have to fire up the generator.

 

Edited to add: Are we talking about the same things? I'm comparing a serial electric propulsion narrowboat with solar array and backup generator to a conventional diesel engined narrowboat.

Edited January 11, 2021 by Jackofalltrades

[IanD]

25 minutes ago, Jackofalltrades said:

No, using solar to avoid running the engine/generator has very different benefits.

 

On a diesel engined boat all the solar will do is charge domestic batteries. If you want to move the boat you have to fire up the diesel engine.

 

On an electric propulsion boat the solar will charge the propulsion batteries. If you want to move the boat you do not have to fire up the generator.

 

Solar only charges up the batteries for propulsion if there's enough of it, if the onboard power use is low enough, and if you wait long enough -- do a power audit to see if this is the case, making sure you use realistic assumptions for average solar panel output across the year. Don't just believe the guy selling you the "electric boat" if he tells you that "you'll never use the generator".

 

If it is, you never have to run the generator, and have a huge advantage over a diesel boat. If it isn't, you do -- you still have an advantage, but not quite as big. For sure, if you want to travel for more than one day in a row or upstream or in winter, solar won't be enough and the genny will be needed to recharge. It's all power in vs. power out, regardless of whether the power comes from solar or diesel/genny.

 

Series hybrids are a great idea (and what I'd install if I was having a boat built today), but even with solar are not the perfect solution -- you still need a generator to cover the times when solar can't keep up with your power requirements. Even Peter has one, and he's got >5kW of solar...

 

I gave the numbers so you can work all this out for your usage case ?

Edited January 11, 2021 by IanD

[Dr Bob]

30 minutes ago, Jackofalltrades said:

 

In the summer months when most cruising is done we expect (from what we have read elsewhere) to be able to cruise for a day on battery power and solar alone. We then plan to spend a few days in each location wherever possible to maximise solar charging of the batteries (weather permitting) before setting off for another day of cruising. For our use case we expect our diesel generator usage to be negligible in the summer months and outside of these months we still expect the solar array to make a noticeable contribution to the battery bank - especially as we would be moving less when it's colder and wetter - and in the depths of winter the boat will be in a marina on shorepower. We think our diesel use over the course of a full year of cruising will be somewhere in the region of 70-80% less than using a straight diesel engine for propulsion. That's 70-80% less pollution too.

 

 

All I can say is ......Trees!

It's all very well saying that you can park up for a few days and recharge with the glorious sunshine we get each day in the summer but there are a lot of trees on the canals which can seriously limit the amount of sunshine available. We are out and about from normally April to october and on our old boat used 500W of solar to recharge our 660Ahr LA's and latterly Li's. I try and avoid trees as I like to run our satellite TV but it then becomes quite restricting on where you moor. When it gets hot, you tend to want to go under the trees to keep the boat cool and having 500W of solar on the roof then doesnt provide much.

Not sure how noisy your internal genny is but try and run it when you are moving so it is less annoying to your neighbours. I am not sure how much 'genny running' will be required in a week where we have cloud and rain and you are under trees but I would hope it is a silent genny if it needs to be run 8 hours a day.

Hope it all goes well though. What type and how many batteries do you have?

[Alan de Enfield]

44 minutes ago, Jackofalltrades said:

For our use case we expect our diesel generator usage to be negligible in the summer months and outside of these months we still expect the solar array to make a noticeable contribution to the battery bank

Are you looking at a fully installed, marine, water cooled diesel generator, or a "lift ashore" portable generator ?

[IanD]

29 minutes ago, Dr Bob said:

All I can say is ......Trees!

It's all very well saying that you can park up for a few days and recharge with the glorious sunshine we get each day in the summer but there are a lot of trees on the canals which can seriously limit the amount of sunshine available. We are out and about from normally April to october and on our old boat used 500W of solar to recharge our 660Ahr LA's and latterly Li's. I try and avoid trees as I like to run our satellite TV but it then becomes quite restricting on where you moor. When it gets hot, you tend to want to go under the trees to keep the boat cool and having 500W of solar on the roof then doesnt provide much.

Not sure how noisy your internal genny is but try and run it when you are moving so it is less annoying to your neighbours. I am not sure how much 'genny running' will be required in a week where we have cloud and rain and you are under trees but I would hope it is a silent genny if it needs to be run 8 hours a day.

Hope it all goes well though. What type and how many batteries do you have?

A correctly-angled south-facing tilted unshaded 2.2kW array (the biggest you can easily fit on a normal narrowboat) will average ~8kWh/day in summer and less than 2kWh/day in winter (1kWh minimum). If your panels are flat, reduce these by at least 10%, so ~7kWh/day in summer. This assumes no shade and open view of the sky, which is obviously not always the case on a narrowboat -- in the shade output will be much less than this. Over many days and moorings you'll be lucky to exceed 5kWh/day average even in summer.

 

What output were you assuming in summer months?

 

Depending on what electrical stuff you've got on the boat and how much you use it (TV, computer, washer/drier...) there will be days when solar is enough to supply all the power you need with some to spare (full sun, middle of summer, moored up), and others when it can't (moored in shade, bad weather, autumn/winter, heavy electrical use like washing/drying -- and most important, travelling) -- when you need to run a genny or have shoreline power.

 

Incidentally, the 8-hour day of travelling I described further up comes out at about 15kWh, which stacks up with figures quoted from hybrids that I believe -- you may come up with a smaller figure, but recharging this from solar while using some onboard power is going to take several days.

 

Only a detailed analysis of power use (in and out) over the year (including varying solar, shade, weather etc) will tell you how many days fall into which category...

Edited January 11, 2021 by IanD

[Dr Bob]

2 minutes ago, IanD said:

This assumes no shade and open view of the sky, which is obviously not always the case on a narrowboat -- in the shade output will be much less than this.

That is why I said .....Trees!

[Jackofalltrades]

42 minutes ago, IanD said:

Solar only charges up the batteries for propulsion if there's enough of it, if the onboard power use is low enough, and if you wait long enough -- do a power audit to see if this is the case, making sure you use realistic assumptions for average solar panel output across the year. Don't just believe the guy selling you the "electric boat" if he tells you that "you'll never use the generator".

 

If it is, you never have to run the generator, and have a huge advantage over a diesel boat. If it isn't, you do -- you still have an advantage, but not quite as big. For sure, if you want to travel for more than one day in a row or upstream or in winter, solar won't be enough and the genny will be needed to recharge. It's all power in vs. power out, regardless of whether the power comes from solar or diesel/genny.

 

Series hybrids are a great idea (and what I'd install if I was having a boat built today), but even with solar are not the perfect solution -- you still need a generator to cover the times when solar can't keep up with your power requirements. Even Peter has one, and he's got >5kW of solar...

 

I gave the numbers so you can work all this out for your usage case ?

No salesmen involved! All based on my own research, reading and power audit. We know a generator will be needed as there are no CRT shorepower points along the canals and we want to be out there cruising as much as possible with the least amount of pollution possible but still have a life! Summer should be OK mainly on solar. Spring/autumn generator required to supplement the solar. Winter = negligible solar so into a marina and plug in to shorepower.

 

 

[IanD]

Just now, Jackofalltrades said:

No salesmen involved! All based on my own research, reading and power audit. We know a generator will be needed as there are no CRT shorepower points along the canals and we want to be out there cruising as much as possible with the least amount of pollution possible but still have a life! Summer should be OK mainly on solar. Spring/autumn generator required to supplement the solar. Winter = negligible solar so into a marina and plug in to shorepower.

 

 

Looks like you've done your homework then :-)

 

What output from the solar panels were you assuming? This is very often too optimistic given by numbers some people have floated around...

 

I still suspect your 70%-80% fuel saving is too optimistic, unless you move very little and are very energy-frugal on board ?

[Jackofalltrades]

47 minutes ago, Dr Bob said:

All I can say is ......Trees!

 

What type and how many batteries do you have?

Yes, trees. We'll carry a chainsaw.  < joke.

 

We'll manage as best we can, dodging the rain, trees, shadowing from clouds and Grockles passing by...

 

Only the shell is on order.  Batteries - not ordered yet - but leaning towards Leoch 2v lead carbon. Lithium too expensive. By the time the lead carbons are ready to be retired lithium batteries will be old tech and dirt cheap and we'll probably be discussing solid state batteries or something more exotic.

 

Everything is a compromise.

41 minutes ago, Alan de Enfield said:

Are you looking at a fully installed, marine, water cooled diesel generator, or a "lift ashore" portable generator ?

Yes, fully installed marine diesel generator. Hopefully fitted in the bow but that's still to be discussed with the shell builder to see if it's really possible. Can't say I'm aware of many narrowboats with gens in the bow?

 

Nice cat BTW. FP Athena?

Edited January 11, 2021 by Jackofalltrades

[Jackofalltrades]

12 minutes ago, IanD said:

Looks like you've done your homework then :-)

 

What output from the solar panels were you assuming? This is very often too optimistic given by numbers some people have floated around...

 

I still suspect your 70%-80% fuel saving is too optimistic, unless you move very little and are very energy-frugal on board ?

We have a sailing boat with 400w solar array so we have a good feel for output. In the summer that's more than enough. In December - not worth mentioning. But as most of our canal cruising will be done in the summer the 2.2Kw array should be sufficient if we don't cruise every day. As I said, spring/autumn generator will be required to supplement the solar. Winter months we''ll be on shorepower.

 

We'll be very happy if we only have to run the generator 20 - 30% of the time. We think that's doable on average. We'll see.

[IanD]

20 minutes ago, Jackofalltrades said:

Yes, trees. We'll carry a chainsaw.  < joke.

 

We'll manage as best we can, dodging the rain, trees, shadowing from clouds and Grockles passing by...

 

Only the shell is on order.  Batteries - not ordered yet - but leaning towards Leoch 2v lead carbon. Lithium too expensive. By the time the lead carbons are ready to be retired lithium batteries will be old tech and dirt cheap and we'll probably be discussing solid state batteries or something more exotic.

 

Everything is a compromise.

Yes, fully installed marine diesel generator. Hopefully fitted in the bow but that's still to be discussed with the shell builder to see if it's really possible. Can't say I'm aware of many narrowboats with gens in the bow?

 

Nice cat BTW. FP Athena?

Lead carbon (or lead acid of any type) are not a good choice for a series hybrid; power lost in charging/discharging is high (at least 20%), they don't like the high motor drive currents of a series hybrid (capacity drops off dramatically at high currents), and even lead-carbon need long charging times after they're at 100% capacity to equalise the cells and prevent sulphation -- though they are less bad with partial SoC than normal LA batteries, they still need at least a couple of hours regular equalisation to get anywhere near the data sheet lifetimes, though this fact is either not mentioned (by Leoch) or well hidden -- go and dig into the Northstar Blue+ technical manual, there's far more information than anything from Leoch.

 

I thought the Leoch pure lead-carbons were a good idea too until I dug into the hidden details, now I'd go for LiFePO4 even though the cost is maybe double -- what size and cost bank are you going for?

 

There are a few boats with generators in the bow, here's an example which also uses the Leoch batteries:

 

https://www.canalboat.co.uk/canal-boats/boat-test-mothership-marine-s-solar-powered-semi-trad-1-6215195

Edited January 11, 2021 by IanD

[peterboat]

1 hour ago, IanD said:

Peter, you might need to be more careful about detailed fuel efficiency/power ratings (not just "generator size") before saying my numbers are wrong ?

 

The Betagen 10 has a headline rating of 10kVA, which turns out to be the maximum (short-term) output for the 3-phase version. The "prime output" (continuous) for the single-phase version is 8.8kVA at a power factor of 0.8, but what matters for charging batteries is the load power which is 7.1kW (31A/230V) at a consumption of 2.7l/h, or 0.38l/kWh (24.7% efficiency).

 

If the table you give is correct then 2.4l/hr to generate 8kW is 0.3l/kWh which is 21% lower consumption, and I'd say this is pretty unlikely (31.3% efficiency) but not totally impossible -- as I said, if you dig deep into the details like I did for the Betagen and these figures are correct and based on measurements, then I'll believe them. They might be experts in Jap turbo cars, but I'd like to know where they can get a small enough turbo and CR DI system for a <500cc diesel...

 

But I simply don't believe the numbers in the table, because in almost every case (except the 10kW) the full-load fuel consumption is exactly 0.300l/kWh -- a suspiciously round number, and it's just not credible that every size from 8kW to 400kW has the same specific consumption. If a supplier presented me with this table I'd tell them it was obviously based on a rough (and possibly optimistic) guesstimate and to come back with more accurate figures which reflect the real consumption. I wouldn't even be convinced they've built and measured an actual generator of any size unless they provided real measured data, I've seen these kind of numbers on too many occasions to believe them ?

 

Generating 6kW using 1l/hour (your text) is completely impossible, this would be 0.17l/kWh or 56% thermal efficiency from fuel in to electricity out. You wouldn't even get that with a 2000-ton 100,000hp marine diesel and a superconducting generator ?

 

And as I keep saying, even if whatever magic dust Riccy sprinkles on his generators is real (which I doubt given the numbers above) and they do deliver 20% lower fuel consumption and emissions in a series hybrid, this doesn't make the advantage over a diesel any bigger if they do exactly the same ?

There's absolutely nothing stopping a diesel boat having the same size solar array (6 x 380W panels is about the most on a 57' boat, as you say) as a hybrid, and several people have done exactly that because it's an excellent idea. Using the solar power to avoid running the engine/generator has exactly the same benefits for both -- in fact bigger for a straight diesel due to lousy efficiency compared to a generator when battery charging (about half with alternators, about two-thirds with a TravelPower).

 

If you can completely charge up with solar between travels then you use no diesel at all, but don't forget the solar has to provide the electric power you're using on the boat as well as recharging the batteries. And a 2.2kWh (max) array will give you maybe 6kWh/day typical in summer, so recharging will take several days even without allowing for onboard use. You need to do a power audit to see how this would all work for you, not just assume that solar will fix everything.

 

(the situation for Peter is different, he's got a widebeam with >5kW of panels IIRC which makes being diesel-free much more practical, at least in the summer)

Ian the genny I have will give those sort of figures, remember we rarely run full bore so 50% is about right for all sorts of reasons.

Now Riccy needs are different 500 cc two cylinder engines are around in plentiful numbers I have one in my genny. He plans a 48 volt system using the same type of motor that propels the boat to generate 48 volts, his engine will spin beyond the 1500 rpm because he needs the turbo to work for both power and cleanliness, because of his specific needs he will build exactly what he wants. Turbos are easy its his business in the car tuning game and the japs with their micro cars have plenty of 500cc turbo engines pushing them along.

[Jackofalltrades]

4 minutes ago, IanD said:

Lead carbon (or lead acid of any type) are not a good choice for a series hybrid; power lost in charging/discharging is high (at least 20%), they don't like the high motor drive currents of a series hybrid (capacity drops off dramatically at high currents), and even lead-carbon need long charging times after they're at 100% capacity to equalise the cells and prevent sulphation -- though they are less bad with partial SoC than normal LA batteries, they still need at least a couple of hours regular equalisation to get anywhere near the data sheet lifetimes, though this fact is either not mentioned (by Leoch) or well hidden -- go and dig into the Northstar Blue+ technical manual, there's far more information than anything from Leoch.

 

There are a few boats with generators in the bow, here's an example which also uses the Leoch batteries:

 

https://www.canalboat.co.uk/canal-boats/boat-test-mothership-marine-s-solar-powered-semi-trad-1-6215195

Well, lead carbons are much better than flooded and better than gell and AGM. Weight isn't an issue (ballast) and although lithiums are better - no denying it - lead carbons are significantly cheaper. Victron MPPT and Quatro charge controllers will ensure the batteries are charged correctly.

 

Batteries need looking after. What we've done thus far is check the weather forecast and if it looks like being a sunny day and the batteries aren't too discharged then let the solar look after them. Less good weather and/or batteries more discharged then crank up the generator for a while in the morning and let the solar top the batteries off. ...Although lead carbons lessen the worry about partial state of charge.

 

As I've said, everything is a compromise.

[peterboat]

28 minutes ago, Jackofalltrades said:

Yes, trees. We'll carry a chainsaw.  < joke.

 

We'll manage as best we can, dodging the rain, trees, shadowing from clouds and Grockles passing by...

 

Only the shell is on order.  Batteries - not ordered yet - but leaning towards Leoch 2v lead carbon. Lithium too expensive. By the time the lead carbons are ready to be retired lithium batteries will be old tech and dirt cheap and we'll probably be discussing solid state batteries or something more exotic.

 

Everything is a compromise.

Yes, fully installed marine diesel generator. Hopefully fitted in the bow but that's still to be discussed with the shell builder to see if it's really possible. Can't say I'm aware of many narrowboats with gens in the bow?

Jack from experience the 2 volt cells wont work, I am assuming that you will operating at 48 volts? If so other options are better either like me with secondhand  valence batteries or 48 volt packs made up from cells with a BMS or Balance board. Also repurposed EV battery banks are around in both the long and short term this will save you money and time charging. As Ian says I have a lot of solar and have wandered around moving every couple of days late spring summer early autumn, before and after that is hard work hence the installation of the genny. I have done two electric boats and I am helping someone with a third and can safely say you will enjoy the experience of silent cruising if you want a chat PM me

[IanD]

4 minutes ago, peterboat said:

Ian the genny I have will give those sort of figures, remember we rarely run full bore so 50% is about right for all sorts of reasons.

Now Riccy needs are different 500 cc two cylinder engines are around in plentiful numbers I have one in my genny. He plans a 48 volt system using the same type of motor that propels the boat to generate 48 volts, his engine will spin beyond the 1500 rpm because he needs the turbo to work for both power and cleanliness, because of his specific needs he will build exactly what he wants. Turbos are easy its his business in the car tuning game and the japs with their micro cars have plenty of 500cc turbo engines pushing them along.

Like I said, I'll believe Riccy's numbers when he has actual measurements on a real generator. My prediction is that they won't achieve the 0.3l/kWh in the table, which is what I would call "Powerpointware" if somebody showed it to me.

 

Yes the Jap microcars have small 660cc turbo engines, which also happen to develop about 50kW -- way too much for a boat generator. If you run them down at a quarter of this power, funnily enough they become less efficient...

[peterboat]

5 minutes ago, IanD said:

Like I said, I'll believe Riccy's numbers when he has actual measurements on a real generator. My prediction is that they won't achieve the 0.3l/kWh in the table, which is what I would call "Powerpointware" if somebody showed it to me.

 

Yes the Jap microcars have small 660cc turbo engines, which also happen to develop about 50kW -- way too much for a boat generator. If you run them down at a quarter of this power, funnily enough they become less efficient...

Yes Ian because those cars are around so are the turbos which is the bit he needs 500cc ish twin cylinder diesels are plentiful he will add one to the other to create what he wants. His company has built 1000+ hp Honda race  K16 engines, he is not an amateur its his job along with the many employees for that company and Finesse. 

[IanD]

10 minutes ago, Jackofalltrades said:

Well, lead carbons are much better than flooded and better than gell and AGM. Weight isn't an issue (ballast) and although lithiums are better - no denying it - lead carbons are significantly cheaper. Victron MPPT and Quatro charge controllers will ensure the batteries are charged correctly.

 

Batteries need looking after. What we've done thus far is check the weather forecast and if it looks like being a sunny day and the batteries aren't too discharged then let the solar look after them. Less good weather and/or batteries more discharged then crank up the generator for a while in the morning and let the solar top the batteries off. ...Although lead carbons lessen the worry about partial state of charge.

 

As I've said, everything is a compromise.

Lead carbons are better than gel/AGM, but for a narrowboat if you can't afford lithium then flooded 2V traction cells are probably the best bet -- the cycle life is similar and they're half the price, and have been well proven in hybrid boats over the last ten years or so.

 

The Leoch lead carbon are neither fish nor fowl -- considerably more expensive than 2V LA traction cells (about 2x?) and not much better (and there's not much real data about actual lifetime in a boat application), and nothing like as good as lithium. They are better for PSoC but don't believe the quoted lifetime unless you regularly equalise them (see Northstar manual).

 

As I said, how big a bank are you considering and what is the cost? Compared to the overall cost of a new boat the cost adder for lithium doesn't look so bad even with new batteries, and the huge advantage is that they can just be treated like a "power bucket" (assuming a good BMS which talks to the Quattro/MPPT).

[Jackofalltrades]

9 minutes ago, peterboat said:

Jack from experience the 2 volt cells wont work, I am assuming that you will operating at 48 volts? If so other options are better either like me with secondhand  valence batteries or 48 volt packs made up from cells with a BMS or Balance board. Also repurposed EV battery banks are around in both the long and short term this will save you money and time charging. As Ian says I have a lot of solar and have wandered around moving every couple of days late spring summer early autumn, before and after that is hard work hence the installation of the genny. I have done two electric boats and I am helping someone with a third and can safely say you will enjoy the experience of silent cruising if you want a chat PM me

Yes 48v. Interested in why you think the 2v cells won't work. They have a higher stated cycle life that the equivalent 12v batteries and I can't find anything (apart from what you've just said) that suggests they won't work.

 

Might be interested in secondhand batteries but it depends on price, age, cycles consumed already (how do you know?) and capacity. Is there an online seller?

 

[IanD]

4 minutes ago, peterboat said:

Yes Ian because those cars are around so are the turbos which is the bit he needs 500cc ish twin cylinder diesels are plentiful he will add one to the other to create what he wants. His company has built 1000+ hp Honda race  K16 engines, he is not an amateur its his job along with the many employees for that company and Finesse. 

You still don't get the point -- I've no doubt he can build them, but operating a 50kW-capable engine at 12kW output in a generator drops efficiency, which you claimed was his big advantage (and bears zero relation to a 1000hp race engine). If he can get the numbers you claim then I take my hat off to him, but not until he shows real measurements -- until then, it's vapourware.

Edited January 11, 2021 by IanD