phasing out of fossil fuels - programme

[peterboat]

6 minutes ago, ditchcrawler said:

I often wonder how many liters of red diesel is used in feeding this place every year

https://bioenergyinternational.com/biogas/biocow-inaugurate-uks-largest-biomethane-to-grid-plant

Lots I would suspect, it would be better if it was biodiesel but it won't happen any time soon unfortunately 

[ditchcrawler]

1 minute ago, peterboat said:

Lots I would suspect, it would be better if it was biodiesel but it won't happen any time soon unfortunately 

Plus all the fertilizer 

[bizzard]

Class 93.  To be tri mode. Overhead supply, diesel and battery.

[Mike Todd]

22 hours ago, Alan de Enfield said:

So if they manage to get 'near' to the 14 million by mid Feb, do you accept that they might 'get near' to hitting their 'marine plan' ? (say 2051 instrad of 2050 )

I need to eat 'umble pie: and be grateful that the NHS Gods were not eavesdropping on here to look for sceptics!

 

We have just been offered our first vaccinations next week - and we are not even 80!

[peterboat]

13 hours ago, bizzard said:

Class 93.  To be tri mode. Overhead supply, diesel and battery.

Lovely but will never be as pretty as a steam engine because they are alive

[NB Alnwick]

14 hours ago, bizzard said:

Class 93.  To be tri mode. Overhead supply, diesel and battery.

Hopefully this is the way to go - if the changeover between power modes could be as seamless they are on our GM designed Ampera, it would be possible to partially electrify routes thus saving money by not having to rebuild stations, raise bridges, or expand tunnels to provide catenary clearance.

[NB Alnwick]

What I do see as irony when it comes to railway motive power - a Century ago we were producing locomotives and exporting them all round the world. It could be said that we had the best locomotive engineers and the best production units. These new locomotives although largely designed to British specifications are being built in Spain at a cost of £4m each.

We had the lead and we threw it away . . .

[Guest]

1 hour ago, Mike Todd said:

I need to eat 'umble pie: and be grateful that the NHS Gods were not eavesdropping on here to look for sceptics!

 

We have just been offered our first vaccinations next week - and we are not even 80!

According to figures on last nights local news our area, North East and Yorkshire has immunised 46% of all over 80's  which is bloody good going in my book. Figures over the next few days may be impacted by the bad weather briefly though. Some people were being told to re-book their appointments rather than travel. I don't think they want wards full of elderly people with broken hips!

 

Our elderly over 80's friend gets hers on Saturday.

 

Some are clearly being run on a 'factory' basis, images last nights showed people being given them in their cars through the windows. They didn't even have to get out.

6 minutes ago, NB Alnwick said:

What I do see as irony when it comes to railway motive power - a Century ago we were producing locomotives and exporting them all round the world. It could be said that we had the best locomotive engineers and the best production units. These new locomotives although largely designed to British specifications are being built in Spain at a cost of £4m each.

We had the lead and we threw it away . . .

 

Unfortunately we did that with a lot of stuff, from loco's, to ship building to steel production.

[Alan de Enfield]

1 minute ago, The Happy Nomad said:

Some are clearly being run on a 'factory' basis, images last nights showed people being given them in their cars through the windows. They didn't even have to get out.

 

They had started to do that around us, but were then (apparently) told to stop as there was no 15 minute 'monitoring period' after the jab.

[Guest]

1 minute ago, Alan de Enfield said:

 

They had started to do that around us, but were then (apparently) told to stop as there was no 15 minute 'monitoring period' after the jab.

I did wonder about that but I could see some cars parked up with people in them so I assumed they had chosen a site with sufficient space in that instance.

 

But TBH I couldn't say for sure. It was definitely recent though because it was snowing in the pics! and the staff had water proofs on.

[bizzard]

2 hours ago, peterboat said:

Lovely but will never be as pretty as a steam engine because they are alive

Alive alright.

[IanD]

To get back to the subject, I had a go at doing a power audit for a series hybrid/electric narrowboat -- if you disagree with any of the numbers I've used (which are all reasonable but won't fit everybody) don't shoot the messenger, you can plug your own numbers in but I don't expect the conclusions will change ?

 

(they're different for a wideboat with 2.5x solar, I'm sure Peter can provide some numbers -- but he'll still need a genny in winter...)

 

Boat: 30kWh battery bank (600Ah 50V), 7kW 230Vac generator, Quattro 48/10000, 2.2kW solar (6 x 380W panels) + MPPT

Motor power use per travel day: 3kW normal cruising x 4h, 1kW slow cruising x 2h, zero in locks x 2h = 14kWh/day

Domestic power use : 4kWh/day in summer, 5kWh/day in winter (more lights, Ebersplutter etc)

Solar panel power : 8kWh/day typical in summer, 4kWh/day typical in spring/autumn, 1kWh/day minimum in winter

 

So we end up with the following -- like Mr. Micawber, it's the balance of income and expenditure that matters ?

 

Summer : 4kW/day surplus power from solar = 28kWh/week = battery capacity

-- enough solar-only power for 2 days cruising per week

-- could solar charge up while moored for 5 days (weekday), then travel for 2 days (weekend), then repeat

-- diesel cost is nil, as are emissions ?

-- for every extra cruising day (14kWh), need to run generator (7kW) for 2h to recharge batteries or use charging stations (but not needed every day)

Spring/autumn :  solar power equals domestic power use

-- no generator needed if moored, but no spare power for travelling

-- for every cruising day, need to run generator for 2h to recharge batteries or use charging stations (not needed every day)

-- fuel cost is 5.4l per cruising day compared to 9l/day for diesel ==> 40% reduction in cost and emissions

Winter :  domestic power use exceeds solar by 4kWh/day = 28kWh/week = battery capacity

-- need to run generator for 4h/week if moored, only needed once per week if you use full SoC -- or plug-in once a week

-- generator fuel cost for domestic power is 10.8l/week ==> 50% lower than diesel+alternators, 30% lower than diesel+Travelpower ==> take 40% average

-- for every cruising day, need to run generator for 2h to recharge batteries or use charging stations more often

-- fuel cost for propulsion is 5.4l/day ==> 40% lower than diesel

 

Now to look at savings in fuel/emissions compared to a diesel...

 

In summer, if you travel for no more than a couple of days per week the fuel/emission saving is 100%.

 

For every day extra you travel in summer (or all travel days in spring/autumn) the saving is 40%.

 

In winter the saving is 40% whether you travel or not.

 

So the overall fuel/emissions saving depends on how much you travel and at what time of year, the minimum is 40% and the maximum (summer solar only) is 100%.

 

The boat can travel for typically 2 days (a bit more in summer, a bit less in winter) between recharges (generator or plug-in charging); if the battery has been emptied, to fill it back up needs about 4h of generator running or an overnight plug-in charge, for which a 13A/3kW socket is fine. This means if you want to avoid generator use and rely on plug-in recharging, you need to plug in every other night -- which at least means if there's no station where you moor for one night (or they're all taken) it doesn't matter.

 

It does mean that recharging stations shouldn't be more than a days travel apart and half a day would be better, which funnily enough is the same as water points -- and overnight ones don't need any special power, any town/village/pub/marina/boatyard/supermarket/restaurant/house can provide 3kW per charging socket. If we want to have faster charging stations for daytime top-ups (e.g. at water points or boatyards or marinas) then the limit is the Quattro which can only charge batteries at 7kW (140A/50V), which would give about half a day extra cruising (more in summer, less in winter) for each hour plugged in.

 

Of course all this goes out of the window if you use/need full power for any length of time, for example on a river in winter, in which case your batteries will go from full to flat pretty damn quick even if you're running the genny. This is one reason for the big (30kWh) battery bank, the other is being able to recharge every two days instead of daily on a long cruise, which will be especially useful if/when overnight plug-in charging becomes the norm, especially for hire boats doing trips like the Cheshire Ring in a week ?

 

All of which makes boats like this (electric with onboard genny) practical even today; fuel usage/emissions will certainly be less than a diesel, the exact amount depends on your usage, but the genny will be essential if travelling a lot, or at all outside summer, and all the time in winter, unless you can plug in. As charging stations emerge the need to run the genny will go down but it'll be a long time before it can be removed completely to get a true all-electric boat -- until then, this is a series hybrid.

[Dr Bob]

17 minutes ago, IanD said:

All of which makes boats like this (electric with onboard genny) practical even today; fuel usage/emissions will certainly be less than a diesel, the exact amount depends on your usage, but the genny will be essential if travelling a lot, or at all outside summer, and all the time in winter, unless you can plug in. As charging stations emerge the need to run the genny will go down but it'll be a long time before it can be removed completely to get a true all-electric boat -- until then, this is a series hybrid.

So how long will the genny have to be run each day in a cloudy spell and are these gennys silent.....as most of the time they will be running when moored?

[IanD]

30 minutes ago, Dr Bob said:

So how long will the genny have to be run each day in a cloudy spell and are these gennys silent.....as most of the time they will be running when moored?

I'll let you work out the numbers for that particular case ?

 

If I was having a boat like this built (which I plan to do...) I'd use a cocooned generator inside a soundproofed bow locker, which would be far quieter than any engine running for battery charging as well as needing to run for half the time.

 

Anyway there's no other solution until charging points become widely available so complaining about the noise is as helpful as complaining about the British weather -- the key is to make them as quiet as possible, and keep running time down, the worst case was about 2h/day which is less than a lot of noisy smoky diesels are run for ?

Edited January 15, 2021 by IanD

[Guest]

1 hour ago, bizzard said:

Alive alright.

Indeed......

[peterboat]

2 hours ago, IanD said:

To get back to the subject, I had a go at doing a power audit for a series hybrid/electric narrowboat -- if you disagree with any of the numbers I've used (which are all reasonable but won't fit everybody) don't shoot the messenger, you can plug your own numbers in but I don't expect the conclusions will change ?

 

(they're different for a wideboat with 2.5x solar, I'm sure Peter can provide some numbers -- but he'll still need a genny in winter...)

 

Boat: 30kWh battery bank (600Ah 50V), 7kW 230Vac generator, Quattro 48/10000, 2.2kW solar (6 x 380W panels) + MPPT

Motor power use per travel day: 3kW normal cruising x 4h, 1kW slow cruising x 2h, zero in locks x 2h = 14kWh/day

Domestic power use : 4kWh/day in summer, 5kWh/day in winter (more lights, Ebersplutter etc)

Solar panel power : 8kWh/day typical in summer, 4kWh/day typical in spring/autumn, 1kWh/day minimum in winter

 

So we end up with the following -- like Mr. Micawber, it's the balance of income and expenditure that matters ?

 

Summer : 4kW/day surplus power from solar = 28kWh/week = battery capacity

-- enough solar-only power for 2 days cruising per week

-- could solar charge up while moored for 5 days (weekday), then travel for 2 days (weekend), then repeat

-- diesel cost is nil, as are emissions ?

-- for every extra cruising day (14kWh), need to run generator (7kW) for 2h to recharge batteries or use charging stations (but not needed every day)

Spring/autumn :  solar power equals domestic power use

-- no generator needed if moored, but no spare power for travelling

-- for every cruising day, need to run generator for 2h to recharge batteries or use charging stations (not needed every day)

-- fuel cost is 5.4l per cruising day compared to 9l/day for diesel ==> 40% reduction in cost and emissions

Winter :  domestic power use exceeds solar by 4kWh/day = 28kWh/week = battery capacity

-- need to run generator for 4h/week if moored, only needed once per week if you use full SoC -- or plug-in once a week

-- generator fuel cost for domestic power is 10.8l/week ==> 50% lower than diesel+alternators, 30% lower than diesel+Travelpower ==> take 40% average

-- for every cruising day, need to run generator for 2h to recharge batteries or use charging stations more often

-- fuel cost for propulsion is 5.4l/day ==> 40% lower than diesel

 

Now to look at savings in fuel/emissions compared to a diesel...

 

In summer, if you travel for no more than a couple of days per week the fuel/emission saving is 100%.

 

For every day extra you travel in summer (or all travel days in spring/autumn) the saving is 40%.

 

In winter the saving is 40% whether you travel or not.

 

So the overall fuel/emissions saving depends on how much you travel and at what time of year, the minimum is 40% and the maximum (summer solar only) is 100%.

 

The boat can travel for typically 2 days (a bit more in summer, a bit less in winter) between recharges (generator or plug-in charging); if the battery has been emptied, to fill it back up needs about 4h of generator running or an overnight plug-in charge, for which a 13A/3kW socket is fine. This means if you want to avoid generator use and rely on plug-in recharging, you need to plug in every other night -- which at least means if there's no station where you moor for one night (or they're all taken) it doesn't matter.

 

It does mean that recharging stations shouldn't be more than a days travel apart and half a day would be better, which funnily enough is the same as water points -- and overnight ones don't need any special power, any town/village/pub/marina/boatyard/supermarket/restaurant/house can provide 3kW per charging socket. If we want to have faster charging stations for daytime top-ups (e.g. at water points or boatyards or marinas) then the limit is the Quattro which can only charge batteries at 7kW (140A/50V), which would give about half a day extra cruising (more in summer, less in winter) for each hour plugged in.

 

Of course all this goes out of the window if you use/need full power for any length of time, for example on a river in winter, in which case your batteries will go from full to flat pretty damn quick even if you're running the genny. This is one reason for the big (30kWh) battery bank, the other is being able to recharge every two days instead of daily on a long cruise, which will be especially useful if/when overnight plug-in charging becomes the norm, especially for hire boats doing trips like the Cheshire Ring in a week ?

 

All of which makes boats like this (electric with onboard genny) practical even today; fuel usage/emissions will certainly be less than a diesel, the exact amount depends on your usage, but the genny will be essential if travelling a lot, or at all outside summer, and all the time in winter, unless you can plug in. As charging stations emerge the need to run the genny will go down but it'll be a long time before it can be removed completely to get a true all-electric boat -- until then, this is a series hybrid.

The only figure I would disagree with is the 3kw cruising I only use 3.3kw and my boat is 12 foot wide,  Finesse and others are quoting less but maybe they are averaging it? I think I would want the genny, batteries and calorifier in the stern or my preference would be a trad with engine room at the stern along with washing machine and dishwasher. 

[IanD]

43 minutes ago, peterboat said:

The only figure I would disagree with is the 3kw cruising I only use 3.3kw and my boat is 12 foot wide,  Finesse and others are quoting less but maybe they are averaging it? I think I would want the genny, batteries and calorifier in the stern or my preference would be a trad with engine room at the stern along with washing machine and dishwasher. 

Hybrid Marine (who have lots of hybrids out there) use 3kW. 3kW is the prop loading at 1400rpm on a Beta 43 (2:1 gearbox so 700rpm at prop) which I've always found to be normal cruising rpm on a normal depth/width canal (no big wash, certainly not breaking). 3kW is what various other people have also come up with. A 12 foot wide boat needs more power but maybe not as much as you'd think -- how much does your boat weigh/draw? Also I guess you're on a deep canal where less power is needed.

 

It's very dependent on how fast you go, but I simply don't believe 1kW while cruising -- this is 1000rpm (just above tickover) on a Beta 43 which is what you normally pass moored boats at, and *far* slower than most people travel at -- unless they're the kind of boaters who pootle along dead slow holding up everyone behind them. The average over a day for my estimates was 14kWh/8hours which is 1.75kW average, so maybe if the Finesse figures are average and cruising slower than normal they're believable. All the power numbers and how long you spend at what speed is bound to vary, I simply gave a set of numbers as an example which add up and check against various other sources.

 

Boat layout is personal preference. I'd have a reversed layout with the bedroom at the front, with calorifier (and centreline black water tank) underneath, which puts it close to the 230Vac generator (keel cooled but also heats one calorifier coil) and Ebersplutter in the bows (other calorifier coil), along with the fuel tank and silencers, also bow thruster and 24V batteries for it (and the generator). In the stern are all the high-current 50V bits -- motor/controller (liquid cooled), batteries, combo, inverter, MPPT. Kitchen (washer, dishwasher etc) is at the rear, though with 230V this doesn't really matter. Apart from the layout preference, complete silence from the generator at the steering position is another reason for this choice -- but again, this is all personal preference.

Edited January 15, 2021 by IanD

[peterboat]

5 minutes ago, IanD said:

Hybrid Marine (who have lots of hybrids out there) use 3kW. 3kW is the prop loading at 1400rpm on a Beta 43 (2:1 gearbox so 700rpm at prop) which I've always found to be normal cruising rpm on a normal canal (no big wash, certainly not breaking). 3kW is what various other people have also come up with. A 12 foot wide boat needs more power but maybe not as much as you'd think -- how much does your boat weigh/draw? Also I guess you're on a deep canal where less power is needed.

 

It's very dependent on how fast you go, but I simply don't believe 1kW for cruising -- this is 1000rpm (just above tickover) on a Beta 43 which is what you normally pass moored boats at, and *far* slower than most people travel at -- unless they're the kind of boaters who pootle along dead slow holding up everyone behind them. The average over a day for my estimates was 14kWh/8hours which is 1.75kW average, so maybe if the Finesse figures are average and cruising slower than normal they're believable. All the power numbers and how long you spend at what speed is bound to vary, I simply gave a set of numbers as an example which add up and check against various other sources.

 

Boat layout is personal preference. I'd have a reversed layout with the bedroom at the front, with calorifier (and centreline black water tank) underneath, which puts it close to the 230Vac generator (keel cooled but also heats one calorifier coil) and Ebersplutter in the bows (other calorifier coil), along with the fuel tank and silencers, also bow thruster and 24V batteries for it (and the generator). In the stern are all the high-current 50V bits -- motor/controller (liquid cooled), batteries, combo, inverter, MPPT. Kitchen (washer, dishwasher etc) is at the rear, though with 230V this doesn't really matter. Apart from the layout preference, complete silence from the generator at the steering position is another reason for this choice -- but again, this is all personal preference.

I can see the problem, they are dragging the gearbox around as well sapping power as it's a parallel hybrid, knock 1kw off for that hey presto 2 kWh cruising and less genny running 

[IanD]

Just now, peterboat said:

I can see the problem, they are dragging the gearbox around as well sapping power as it's a parallel hybrid, knock 1kw off for that hey presto 2 kWh cruising and less genny running 

Nope, numbers don't work like that, gearbox doesn't have 33% losses -- typical loss is 4% at max rpm, might go up at low revs due to oil pump -- or might go down because frictional/pumping losses are reduced.

 

3kW at 1400rpm is power absorbed by the prop according to measured curves, any losses mean the engine power is bigger than this not that the prop power is lower.

 

I'm happy with the 3kW number while travelling as are many other sources, of course you can use something lower if you want to ?

[peterboat]

4 minutes ago, IanD said:

Nope, numbers don't work like that, gearbox doesn't have 33% losses -- typical loss is 4% at max rpm, might go up at low revs due to oil pump -- or might go down because frictional/pumping losses are reduced.

 

3kW at 1400rpm is power absorbed by the prop according to measured curves, any losses mean the engine power is bigger than this not that the prop power is lower.

 

I'm happy with the 3kW number while travelling as are many other sources, of course you can use something lower if you want to ?

I can Ian because I have been on 4 boats that are electric not parallel hybrids and your figure is wrong the loss at the gearbox is a fairly fixed amount that doesn't change a lot by speed , I am halving the normal gearbox loss which is over 2 hp

My boat at 3mph uses 3.3kw Finesses boat when I had a go in it was nearly 2kw at 3 mph. James boat 70 x 13 is over 4 kwh. The bathtub uses next to nothing as its light and has a boat shape.  You are guessing I have seen the figures with my own eyes. Ok we are in deep water, but the boats have slow spinning big props which are correct for efficient propulsion 

[IanD]

45 minutes ago, peterboat said:

I can Ian because I have been on 4 boats that are electric not parallel hybrids and your figure is wrong the loss at the gearbox is a fairly fixed amount that doesn't change a lot by speed , I am halving the normal gearbox loss which is over 2 hp

My boat at 3mph uses 3.3kw Finesses boat when I had a go in it was nearly 2kw at 3 mph. James boat 70 x 13 is over 4 kwh. The bathtub uses next to nothing as its light and has a boat shape.  You are guessing I have seen the figures with my own eyes. Ok we are in deep water, but the boats have slow spinning big props which are correct for efficient propulsion 

Gearbox loss "fixed with speed" makes no sense -- 2bhp is 4% at max power (fine) but 1bhp is 25% at 3kW according to you -- where does this data come from, and where do you think this power is going? (especially since most electric boats don't have a gearbox...)

 

I'm not guessing about propeller power absorbed vs. rpm, there's plenty of data to back this up -- a Beta 43 at 1400rpm will be putting 3kw/4bhp into the prop, and that's how fast I've always travelled, it's normally about 3mph (GPS tracked) on a normal depth/width canal, less (2.5mph?) on a narrow/shallow one, more (3.5mph?) on a deep/wide one. I've seen these numbers on at least a dozen different boats with this engine.

 

If you or Finesse go slower or in deep water (which I know you do where you are) you use less power -- 2kW on Finesse will give 3.7mph in deep water according to Vicprop, so 3mph on a deep UK canal is reasonable. 3kW would give 4.2mph in deep water, so maybe 3.5mph on a deep UK canal -- which is exactly the number I gave above. That extra 0.5mph costs an extra kW...

 

[ just to remind you, IIRC you previously claimed Finesse did 4mph on 1kW... ? ]

 

But as I keep saying I don't want to get into yet another argument with you about the numbers; I've given a set that I think are correct using data from reliable marine engineering sources, if you don't agree then feel free to use your own ?

Edited January 15, 2021 by IanD

[Alan de Enfield]

Germany looks to use Gas pipelines to ship Hydrogen.

 

 

Repurposing gas infrastructure for hydrogen | 2020 | Siemens Energy Global (siemens-energy.com)

 

 

A growing interest in hydrogen is prompting planners to consider the reuse of existing gas pipelines and other infrastructure for transportation and storage. In Germany, a key region of Europe’s energy system, experts are testing the parameters for safe operation of an integrated hydrogen grid.

 

 

The EU’s “Hydrogen Strategy for a Climate-Neutral Europe” of July 2020 is only the latest in a series of programs designed to foster the use of hydrogen to decarbonize and integrate the energy system. The G20, Germany, and Japan have also indicated interest in developing this technology. And more recently, a white paper jointly produced by German pipeline operators Nowega and Gascade and Siemens Energy studied practical aspects of converting natural gas pipelines as pillars of a future hydrogen-based energy transition.

Beside decarbonized hydrogen produced from natural gas, green hydrogen produced with an electrolyzer powered by sustainable electricity can be used for sector coupling (“Power-to-X”) and for the large-scale storage of renewable energy.

Green hydrogen is becoming economically more viable due to the declining costs of renewable energy as well as of electrolyzers. Linking up all elements of the energy system with hydrogen promises to deliver efficiencies, cut carbon emissions, and increase the robustness of energy systems while ensuring security of supply. In this context, one often-cited advantage is that the natural gas infrastructure could be reused with minor modifications for transportation and storage of hydrogen.

[IanD]

46 minutes ago, Alan de Enfield said:

Germany looks to use Gas pipelines to ship Hydrogen.

 

 

Repurposing gas infrastructure for hydrogen | 2020 | Siemens Energy Global (siemens-energy.com)

 

 

A growing interest in hydrogen is prompting planners to consider the reuse of existing gas pipelines and other infrastructure for transportation and storage. In Germany, a key region of Europe’s energy system, experts are testing the parameters for safe operation of an integrated hydrogen grid.

 

 

The EU’s “Hydrogen Strategy for a Climate-Neutral Europe” of July 2020 is only the latest in a series of programs designed to foster the use of hydrogen to decarbonize and integrate the energy system. The G20, Germany, and Japan have also indicated interest in developing this technology. And more recently, a white paper jointly produced by German pipeline operators Nowega and Gascade and Siemens Energy studied practical aspects of converting natural gas pipelines as pillars of a future hydrogen-based energy transition.

Beside decarbonized hydrogen produced from natural gas, green hydrogen produced with an electrolyzer powered by sustainable electricity can be used for sector coupling (“Power-to-X”) and for the large-scale storage of renewable energy.

Green hydrogen is becoming economically more viable due to the declining costs of renewable energy as well as of electrolyzers. Linking up all elements of the energy system with hydrogen promises to deliver efficiencies, cut carbon emissions, and increase the robustness of energy systems while ensuring security of supply. In this context, one often-cited advantage is that the natural gas infrastructure could be reused with minor modifications for transportation and storage of hydrogen.

Doesn't seem likely to get to the canals though -- given the objections to the cost of getting a power cable to electric charging points, just think what the cost of running a pipe (and a leak-safe refuelling station) for hydrogen will be... ?

 

Hydrogen may well have infrastructure uses (including energy storage), but it's pretty unlikely to make it to the end user because it's horrible to deal with -- it leaks through practically anything including absolutely tiny gaps and pores and a lot of materials that natural gas doesn't have a problem with, and to get any usable energy density it needs high-pressure tanks (5000-10000psi) or absorptive materials (still being worked on) -- and it still needs 10x the storage volume of diesel.

Edited January 15, 2021 by IanD

[peterboat]

1 hour ago, IanD said:

Gearbox loss "fixed with speed" makes no sense -- 2bhp is 4% at max power (fine) but 1bhp is 25% at 3kW according to you -- where does this data come from, and where do you think this power is going? (especially since most electric boats don't have a gearbox...)

 

I'm not guessing about propeller power absorbed vs. rpm, there's plenty of data to back this up -- a Beta 43 at 1400rpm will be putting 3kw/4bhp into the prop, and that's how fast I've always travelled, it's normally about 3mph (GPS tracked) on a normal depth/width canal, less (2.5mph?) on a narrow/shallow one, more (3.5mph?) on a deep/wide one. I've seen these numbers on at least a dozen different boats with this engine.

 

If you or Finesse go slower or in deep water (which I know you do where you are) you use less power -- 2kW on Finesse will give 3.7mph in deep water according to Vicprop, so 3mph on a deep UK canal is reasonable. 3kW would give 4.2mph in deep water, so maybe 3.5mph on a deep UK canal -- which is exactly the number I gave above. That extra 0.5mph costs an extra kW...

 

[ just to remind you, IIRC you previously claimed Finesse did 4mph on 1kW... ? ]

 

But as I keep saying I don't want to get into yet another argument with you about the numbers; I've given a set that I think are correct using data from reliable marine engineering sources, if you don't agree then feel free to use your own ?

The point I am making and you know it, is that you have taken the 3kw figures from a parallel hybrid, this where the electric motor also drives the gearbox, which means that you lose 1 hp or more off your figures, so a real figure for an electric boat is 2kw, which is 33 % better than yours. Another poster with an electric boat earlier in this thread confirmed this, so has Finesse and myself.  We all have practical experience of this you don't.

[IanD]

39 minutes ago, peterboat said:

The point I am making and you know it, is that you have taken the 3kw figures from a parallel hybrid, this where the electric motor also drives the gearbox, which means that you lose 1 hp or more off your figures, so a real figure for an electric boat is 2kw, which is 33 % better than yours. Another poster with an electric boat earlier in this thread confirmed this, so has Finesse and myself.  We all have practical experience of this you don't.

No Peter, I'm using figures for 3kW/4bhp power at the propellor for the diesel, which you keep ignoring. And please explain how any gearbox can lose 1kW from 3kW in, because this is utterly ridiculous -- no hand-waving, show some actual measured numbers or stop waffling like Boris ?

 

Don't forget that most of the power losses in a gearbox are when it's transmitting power through the gears, and (in a hydraulic box) driving the oil pump, which is driven off the input (engine) shaft. In a parallel hybrid under electric power the diesel engine is off (no power through the gears), the oil pump isn't running (no power), the clutches are disengaged (no power), so the only loss is turning the output shaft...

 

I don't see what the point you're trying to make is, the power vs. speed figures you gave for Finesse agree with what I came up with. All you're arguing about now is absolute power levels, and as I said if you go a bit more slowly it takes a lot less power. Some (deep-water) numbers from Vicprop to show this:

 

bhp     knots

1        2.3

2        2.9

3        3.3

4        3.7

6        4.2

8        4.6

10      5.0

 

2kW for Finesse to do 3mph on a canal agrees with my 3.5mph on 3kW at the prop (1400rpm Beta 43) -- or 3kW on the hybrid I proposed.

 

I'm agreeing with you, so what's your big problem?

 

[and you might as well stop focusing on the parallel hybrid, we both agree they're obsolete and the numbers -- as a I said -- were an example]

Edited January 15, 2021 by IanD