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Hybridising engines


OCM

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10 hours ago, OCM said:

Thanks didn't know that. Lithium is expensive.

There are lots of companies out there now that say 100%, big business recycling.

Percentage of battery that can be recycled is 5% (BBC News Business 26/4/21).

Maybe they haven't checked Google recently.

Repurposed batteries are the best way for lithium batteries as the only labour is splitting the packs apart checking them, then selling them on.

Nissan leafs often have module failures on packs as they get older it's a simple job to drop the pack and replace that faulty module with a good secondhand one. 

My mate has bought an I3 pack which we have broken down to its 8 48 volt modules to power his boat  couple of thousand for 33Kwh pack with very low mileage, a bargain and recycling. 

My batteries are from an electric bus and electric van again recycling in it best form 

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On 06/09/2021 at 11:05, IanD said:

 

Not just motor and controller, you also need a display to see what's going on with the motor and batteries, and a CANbus BMS which can manage charging and talk to the inverter/MPPT etc. They don't all have to come from the same supplier, but they do need to talk to each other, and this can be the biggest obstacle unless you're willing and able to dive in and do all the coding and integration yourself like Nick did -- and a hybrid drive system is more complex than just adding lithium batteries. It's not just a typical "marine electrician" job of connecting everything up -- there may be some who can do all the integration work, but many won't have the knowledge.

 

Some suppliers have already done this work, buying all the bits from them doesn't necessarily cost more than sourcing them separately (I looked into this), and you get support if there are any problems -- this *really* shouldn't be underestimated unless you understand these systems inside out. The attached drawing shows the kind of thing that is needed, quoted cost for this was about £30k+VAT (of which £10k was the generator, and £2k was solar).

 

The generator comment doesn't stack up with what I found, assuming you're looking for a quiet diesel generator. Unless you also mean one which doesn't use skin tanks for cooling, which means they need to be provided with huge amounts of cooling air, which is easy on a festival site but not so easy on a narrowboat. Do you have any examples in mind?

Waterworld-15_kW_Series_Hybrid–Inland_Waterways_with_Solar_(Lead_Acid)_20-1008.pdf 335.17 kB · 13 downloads

Is it possible to have it water cooled and thus get hot water as a by-product?

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There will be some heat off the motor and controller that could be captured if they are both water-cooled. However, what you would use is waste heat from the generator's diesel engine. We get all our hot water and some central heating (under-floor) from that.

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1 hour ago, David Williams said:

Is it possible to have it water cooled and thus get hot water as a by-product?

Not with that particular motor. Other motors like the Engiro ones are water-cooled but they're also very efficient, losses are only about 5% which is 750W at 15kW output, Finesse say that the cooling pump is only needed at output powers above 10kW anyway. At a typical 3kW the dissipation would only be 150W, the controller is probably similar so only about 300W total -- but even of the controller is also water-cooled (they're usually cooled by fastening to the hull) the pump won't be running at 3kW output.

 

This compares to a generator which running at 7kW output will also dump about 7kW into the cooling system, and these are normally plumbed into the calorifier. However 7kW is far too much for the calorifier to absorb (normally this is about 1kW according to Dave Jesse's measurement, similar to an immersion heater) so most of it normally goes into the skin tanks. I suppose you could add a much bigger water-water heat exchanger for hot water heating but I don't know of anyone who's done this. Or you could use ot for underfloor heating if the boat has it.

 

Don't forget that generator running times are likely to be quite short when using lithium batteries, probably no more than an hour a day in summer and a couple of hours in winter (solar makes up in summer), so this isn't going to make a big contribution to heating the water -- 1kW into a 55l calorifier (from immersion heater or heating coils) takes 1 hour to warm the water up by 15C. Ampere's generator probably runs for longer than this (an extra hour per day?)because of the losses with using lead-acid batteries, which ironically makes it more useful for water heating...

 

Using the heat from the motor and controller would only give about 5C/hour (if the pump ran all the time), but then running times are a lot longer than the generator, so you might get 25C or so from a day's cruising. Still, this is free, always a good thing.

 

Don't know how this can all be organised though, you'd still need some other way to heat the water when not travelling. An immersion heater is expensive to run if the power comes from the generator, but "free" if it comes from solar (and isn't being used for anything else). If you have heating which can also provide hot water, this will need a calorifier coil too. If the generator also needs a calorifier coil, there isn't one left for the motor/controller.

 

As usual, you need to look at the entire boat system -- motor/controller, generator, heating, hot water, calorifier -- and figure out how to make it all work together in practice...

Edited by IanD
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2 hours ago, peterboat said:

Repurposed batteries are the best way for lithium batteries as the only labour is splitting the packs apart checking them, then selling them on.

Nissan leafs often have module failures on packs as they get older it's a simple job to drop the pack and replace that faulty module with a good secondhand one. 

My mate has bought an I3 pack which we have broken down to its 8 48 volt modules to power his boat  couple of thousand for 33Kwh pack with very low mileage, a bargain and recycling. 

My batteries are from an electric bus and electric van again recycling in it best form 

 

All true, but ignoring the fact that almost all car batteries are NMC (or similar lithium-ion) not LiFePO4. The risks of catastrophic damage/battery fires are much higher with these, especially if something goes wrong.

 

Car manufacturers spend an enormous amount of time and money devising protection systems and hardware to try and stop this happening, and it's their liability if it does; if this protection is preserved when they're transplanted into boats then that's fine in theory, but if not you have a problem, especially with insurance and safety certification and who bears the liability.

 

This is not just a theoretical problem; one reason most (all?) lumpy water hybrid boats use LiFePO4 is that insurance companies won't (or are reluctant to) cover boats with NMC and similar installs. I don't know what the position of UK narrowboat insurers is but I'd be surprised it it's any different -- assuming they're aware of the issue, it might not be on their radar...

 

Which is one reason that most (all?) hybrid boat suppliers use new LiFePO4 not recycled BEV batteries, because the liability falls on them if there's a battery fire which could be shown to be a manufacture/installation problem.

 

Are your batteries (and those of your mate) LiFePO4 or NMC? What was the response of your insurance companies when you told them you were installing them? Did they ask exactly what type of batteries they were?

 

If you're using NMC and didn't tell them, in the event of a battery/boat fire they could easily refuse the claim on the grounds that you didn't disclose "significant information" to them, even if they didn't ask you for battery details. It's the "wriggle factor" that insurance companies have used on many occasions to avoid paying out.

 

If they are NMC and you told them and they agreed to cover you, you've found an unusual (or ignorant...) marine insurance company... 😉

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Again going for simplicity, the primary cooling circuit of our generator engine goes first to the domestic hot water calorifier (45 litres) and then to the underfloor c/h one (120 litres) before going through a Bowman-type heat exchanger and back to the engine. Heating the DHW cylinder from cold takes about an hour but, as it rarely gets cold and we usually run the generator for 1-2 hours morning and evening, we always have plenty of hot water. The generator runs aren't long enough to get the c/h calorifier fully up to temperature, particularly since I realised that waiting for it to get hot was simply sending more heat to the heat exchanger and thence to the canal. We now turn the heating on at the same time as the generator, getting some heat as soon as there is any to get and losing less. The c/h tank has a 3 kW immersion heater, wired so that it can only be used when we are plugged in, and the DHW one has a 1 kW one (to avoid maximum instantaneous load issues) which can be run off the inverter. We used to have an oil stove with a back-boiler which should also have heated both calorifiers but problems with its safety cut-outs rendered it incompatible with the waste heat system so we have (reluctantly) replaced it with a dry stove.

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9 minutes ago, Rishworth_Bridge said:

Again going for simplicity, the primary cooling circuit of our generator engine goes first to the domestic hot water calorifier (45 litres) and then to the underfloor c/h one (120 litres) before going through a Bowman-type heat exchanger and back to the engine. Heating the DHW cylinder from cold takes about an hour but, as it rarely gets cold and we usually run the generator for 1-2 hours morning and evening, we always have plenty of hot water. The generator runs aren't long enough to get the c/h calorifier fully up to temperature, particularly since I realised that waiting for it to get hot was simply sending more heat to the heat exchanger and thence to the canal. We now turn the heating on at the same time as the generator, getting some heat as soon as there is any to get and losing less. The c/h tank has a 3 kW immersion heater, wired so that it can only be used when we are plugged in, and the DHW one has a 1 kW one (to avoid maximum instantaneous load issues) which can be run off the inverter. We used to have an oil stove with a back-boiler which should also have heated both calorifiers but problems with its safety cut-outs rendered it incompatible with the waste heat system so we have (reluctantly) replaced it with a dry stove.

I'm surprised you have to run the generator for that long -- how big is it, and what rate does it charge the batteries at? Are you also doing this to get to 100% SoC and equalise daily to avoid sulphation?

 

Nice to see details of a working system, this does demonstrate that you need to look at everything not just one small part of it 😉

 

I did think of using a twin-coil calorifier with both coils connected to the generator cooling circuit to get it to heat up twice as fast (about 30C/hour), but then the only other way to heat the water is the immersion heater -- a bigger one (2kW or 3kW) is no problem given an 8kW inverter (Quattro 48/10000), but then the energy has to come from somewhere -- fine if you have spare solar power in summer, but in winter it means more generator running...

Edited by IanD
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It is generally accepted that a diesel-engined genny can achieve about 30% efficiency. Would anyone like to hazard a guess (or perform a calculation) as what this efficiency becomes when the hot water from the cooling system is fully utilised in the boat.

 

Going even further out on this efficiency limb, if you take my propulsion engine installed in an internal engine room, potentially how efficient is this when working hard punching a tide, heating the calorifier and putting radiated heat into the boat?

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The generator is nominally 8 kVA but we have to downrate to 5.6 for what is euphemistically called "continuous running". Current limiting is done at the Quattro and was set by the engineer who did the installation. It needs dedicated software and a very expensive cable to change it so I haven't even tried. Having said that, there is a huge discrepancy between our various instruments (another reason for not having lots of different ones). The voltmeter/ammeter in the generator line to the Quattro jumps around a bit but basically suggests about 5 KW going to the Quattro. However, the Victron Battery monitors suggest about 85A into the batteries, just over 4 kW if you assume 48V or 4.5 kW if you use the 54V charging voltage for your calculation. Some AC will be taken off directly but not enough to square that circle. However, given that we tend to use 15-20 kWh on cruising days (most of them), they're all in the "4 hours-ish" ballpark, which is what we do. As I said in an earlier post, we try not to float using the generator, arranging to plug in every 7-10 days for that if we can.

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28 minutes ago, IanD said:

 

All true, but ignoring the fact that almost all car batteries are NMC (or similar lithium-ion) not LiFePO4. The risks of catastrophic damage/battery fires are much higher with these, especially if something goes wrong.

 

Car manufacturers spend an enormous amount of time and money devising protection systems and hardware to try and stop this happening, and it's their liability if it does; if this protection is preserved when they're transplanted into boats then that's fine in theory, but if not you have a problem, especially with insurance and safety certification and who bears the liability.

 

This is not just a theoretical problem; one reason most (all?) lumpy water hybrid boats use LiFePO4 is that insurance companies won't (or are reluctant to) cover boats with NMC and similar installs. I don't know what the position of UK narrowboat insurers is but I'd be surprised it it's any different -- assuming they're aware of the issue, it might not be on their radar...

 

Which is one reason that most (all?) hybrid boat suppliers use new LiFePO4 not recycled BEV batteries, because the liability falls on them if there's a battery fire which could be shown to be a manufacture/installation problem.

 

Are your batteries (and those of your mate) LiFePO4 or NMC? What was the response of your insurance companies when you told them you were installing them? Did they ask exactly what type of batteries they were?

 

If you're using NMC and didn't tell them, in the event of a battery/boat fire they could easily refuse the claim on the grounds that you didn't disclose "significant information" to them, even if they didn't ask you for battery details. It's the "wriggle factor" that insurance companies have used on many occasions to avoid paying out.

 

If they are NMC and you told them and they agreed to cover you, you've found an unusual (or ignorant...) marine insurance company... 😉

My insurance company knows I have electric drive and LifePo4s, John I have no idea, we are using BMS'S with them and charging is pure solar for his boat (weekend cruising only).

I genny heats the heat store water which then heats the cauliflower by gravity and if it gets to hot the radiators turn on, no skin tank required. 

The lynch motor has a bulge blower on it and the controller neither of them gets hot even after an 8 hour cruise, of course the motor stops a lot because of locks 

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7 minutes ago, Up-Side-Down said:

It is generally accepted that a diesel-engined genny can achieve about 30% efficiency. Would anyone like to hazard a guess (or perform a calculation) as what this efficiency becomes when the hot water from the cooling system is fully utilised in the boat.

 

Going even further out on this efficiency limb, if you take my propulsion engine installed in an internal engine room, potentially how efficient is this when working hard punching a tide, heating the calorifier and putting radiated heat into the boat?

The generators used on boats are about 25% maximum efficiency, see the Victron generator report -- also agrees with manufacturers figures for fuel consumption.

 

If the alternator is air-cooled then a generator putting out 8kW (from 32kW fuel energy) will typically put about 2kW out into the air (which has to be vented outside), 11kW out of the exhaust, and 11kW into the cooling system -- if the alternator is water-cooled too then this means 13kW into the cooling system.

 

If you can use all this 13kW of heat (or store it and release it for slower use later, like in a big water tank) then the overall thermal efficiency goes up from 25% to 66% (59% for air-cooled alternator). It's why CHP systems are such a good thing...

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9 minutes ago, peterboat said:

My insurance company knows I have electric drive and LifePo4s, John I have no idea, we are using BMS'S with them and charging is pure solar for his boat (weekend cruising only).

I genny heats the heat store water which then heats the cauliflower by gravity and if it gets to hot the radiators turn on, no skin tank required. 

The lynch motor has a bulge blower on it and the controller neither of them gets hot even after an 8 hour cruise, of course the motor stops a lot because of locks 

If he's using batteries from i3 packs then they're NMC, so he could have a problem... 😞

 

It's interesting that your ex-bus/van batteries are LiFePO4, because I believe that nowadays most are NMC just like cars.

 

I like the idea of a big water tank heat store for when the genny is running, it seems a shame to throw all that heat away into a skin tank. How big is the heat store?

 

Motors/controllers won't get hot when cruising at 3kW or so, of course going upriver at full power is a different matter entirely...

Edited by IanD
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1 hour ago, Up-Side-Down said:

It is generally accepted that a diesel-engined genny can achieve about 30% efficiency. Would anyone like to hazard a guess (or perform a calculation) as what this efficiency becomes when the hot water from the cooling system is fully utilised in the boat.

In round terms a diesel engine puts about 1/3 of the fuel's energy into motive power, 1/3 into the cooling air or water and 1/3 up the exhaust in the form of hot gases, water vapour and unburned fuel.  So in theory if you could use all the energy from the cooling system you would up the efficiency from around 33% to 66%.  

Edited by David Mack
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54 minutes ago, IanD said:

If he's using batteries from i3 packs then they're NMC, so he could have a problem... 😞

 

It's interesting that your ex-bus/van batteries are LiFePO4, because I believe that nowadays most are NMC just like cars.

 

I like the idea of a big water tank heat store for when the genny is running, it seems a shame to throw all that heat away into a skin tank. How big is the heat store?

 

Motors/controllers won't get hot when cruising at 3kW or so, of course going upriver at full power is a different matter entirely...

140 litres Ian with multiple entry exit fittings, I have the Rayburn plumbed into it the Bubble stove and genny as feeds in for heat and the cauliflower and central heating as removers of heat. I have had the system for maybe 5 years and it works well, it was a simple solution to collect as much waste heat as possible and use it, the beauty of a widebeam is I have the space for it

Screenshot_20210909-134050_Gallery.jpg

Edited by peterboat
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58 minutes ago, David Mack said:

In round terms a diesel engine puts about 1/3 of the fuel's energy into motive power, 1/3 into the cooling air or water and 1/3 up the exhaust in the form of hot gases, water vapour and unburned fuel.  So in theory if you could use all the energy from the cooling system you would up the efficiency from around 33% to 66%.  

That stacks up roughly with the numbers I gave above, except mine were for real generators 😉 (including the 25% actual efficiency from fuel in to AC out)

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2 hours ago, Rishworth_Bridge said:

The generator is nominally 8 kVA but we have to downrate to 5.6 for what is euphemistically called "continuous running". Current limiting is done at the Quattro and was set by the engineer who did the installation. It needs dedicated software and a very expensive cable to change it so I haven't even tried. Having said that, there is a huge discrepancy between our various instruments (another reason for not having lots of different ones). The voltmeter/ammeter in the generator line to the Quattro jumps around a bit but basically suggests about 5 KW going to the Quattro. However, the Victron Battery monitors suggest about 85A into the batteries, just over 4 kW if you assume 48V or 4.5 kW if you use the 54V charging voltage for your calculation. Some AC will be taken off directly but not enough to square that circle. However, given that we tend to use 15-20 kWh on cruising days (most of them), they're all in the "4 hours-ish" ballpark, which is what we do. As I said in an earlier post, we try not to float using the generator, arranging to plug in every 7-10 days for that if we can.

So you don't have any solar panels?

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6 minutes ago, OCM said:

All depends on the definition of recycling. The main point however is, to be aware of the health risks of DIY on Lithium cells.

Not concerned as I have been using them for years with great success and safety. As for recycling primary recycling is reusing them rather than breaking them down to component parts, Nissan are building a plant just to do this 

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2 hours ago, IanD said:

So you don't have any solar panels?

No. Ours expired just after their 3 year warranty and, as has been discussed before, they work out much more expensive than using the generator so we haven't replaced them. Might ultimately put a couple of small, rigids on as top box lids. Not much power but not much cost.

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5 minutes ago, Rishworth_Bridge said:

No. Ours expired just after their 3 year warranty and, as has been discussed before, they work out much more expensive than using the generator so we haven't replaced them. Might ultimately put a couple of small, rigids on as top box lids. Not much power but not much cost.

Understood -- together with small generator and lead-acid batteries, this explains your relatively long generator running times. Good for hot water, though... 😉

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5 minutes ago, Rishworth_Bridge said:

No. Ours expired just after their 3 year warranty and, as has been discussed before, they work out much more expensive than using the generator so we haven't replaced them. Might ultimately put a couple of small, rigids on as top box lids. Not much power but not much cost.

I have always found them to be a cheap source of electricity, 400 watt panels for under 100 pounds is hardly expensive?

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Just now, peterboat said:

I have always found them to be a cheap source of electricity, 400 watt panels for under 100 pounds is hardly expensive?

Theirs were flexible -- expensive and short lifetime...

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3 minutes ago, IanD said:

Theirs were flexible -- expensive and short lifetime...

£2,000 worth of supposedly high-tech, semi-flexible panels (intricate cell linkage to reduce the effects of shade) producing about 600 kWh over 3 years is b****y expensive. Replacing them, at the reduced cost of £1,200, and assuming a life of 10 years still works out at double the marginal cost of using the generator so, despite my 'green' aspirations, that one's a no-no. As I have said before, I am not happy with the safety aspects of having large enough areas of rigid panels to make any impression on a 60 kWh battery bank on a cruising boat's roof. Fine if you don't move, or move very little, but no for me.

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40 minutes ago, Rishworth_Bridge said:

£2,000 worth of supposedly high-tech, semi-flexible panels (intricate cell linkage to reduce the effects of shade) producing about 600 kWh over 3 years is b****y expensive. Replacing them, at the reduced cost of £1,200, and assuming a life of 10 years still works out at double the marginal cost of using the generator so, despite my 'green' aspirations, that one's a no-no. As I have said before, I am not happy with the safety aspects of having large enough areas of rigid panels to make any impression on a 60 kWh battery bank on a cruising boat's roof. Fine if you don't move, or move very little, but no for me.

Agreed that rigid panels are less attractive and more of a pain to fit, even if flat mounted the edges are about 60mm above the roof. I'm not convinced about the safety problem, a line of 105cm wide panels leaves about a foot each side between them and the roof rails which is plenty to walk along, though admittedly jumping down onto the roof might be difficult if you're ever mad enough to do this...

 

If designed in from the beginning (careful placement of mushrooms etc) I reckon you can get 6 on a normal narrowboat roof, which is 2.3kW peak and would be expected to average 7kWh/day in summer -- more on a sunny day, less on a cloudy one.

 

With lithium batteries that should roughly halve the (7kW 140A) generator running time from ~2h/day to ~1h/day in summer, which I think is a decent payback since panel cost is just over £800. The reduction wouldn't be anything like as big for you, you run the generator for a lot longer and solar panel area would be much less, so it's less of an obvious choice.

 

If you read the review of the Finesse boat in the latest magazine they said that it wasn't worth installing solar panels because they only saved 15mins/day of generator time and were expensive. I talked to Ricky about this and he said the essential missing point in the article was that because of all the dogboxes and crossbeams and other stuff on the roof they could only fit 2 flexi panels in (about 600W total) which cost well over a grand, so this all adds up -- flexi panels are never worth it from a cost point of view, they're 7x more expensive per kW than rigid ones.

 

What we really need is rigid mono panels which are curved to match the roof and in a thinner frame -- no technical reason these couldn't be made (each column of cells is 175mm wide) but of course nobody would bother for such a tiny market... 😞

 

I did wonder about asking if the roof could be built with a flat-floored 35mm deep recess along the centreline to fit the panels in, but I suspect I know what the answer would be... 🙂

Edited by IanD
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1 hour ago, IanD said:

Agreed that rigid panels are less attractive and more of a pain to fit, even if flat mounted the edges are about 60mm above the roof. I'm not convinced about the safety problem, a line of 105cm wide panels leaves about a foot each side between them and the roof rails which is plenty to walk along, though admittedly jumping down onto the roof might be difficult if you're ever mad enough to do this...

 

If designed in from the beginning (careful placement of mushrooms etc) I reckon you can get 6 on a normal narrowboat roof, which is 2.3kW peak and would be expected to average 7kWh/day in summer -- more on a sunny day, less on a cloudy one.

 

With lithium batteries that should roughly halve the (7kW 140A) generator running time from ~2h/day to ~1h/day in summer, which I think is a decent payback since panel cost is just over £800. The reduction wouldn't be anything like as big for you, you run the generator for a lot longer and solar panel area would be much less, so it's less of an obvious choice.

 

If you read the review of the Finesse boat in the latest magazine they said that it wasn't worth installing solar panels because they only saved 15mins/day of generator time and were expensive. I talked to Ricky about this and he said the essential missing point in the article was that because of all the dogboxes and crossbeams and other stuff on the roof they could only fit 2 flexi panels in (about 600W total) which cost well over a grand, so this all adds up -- flexi panels are never worth it from a cost point of view, they're 7x more expensive per kW than rigid ones.

 

What we really need is rigid mono panels which are curved to match the roof and in a thinner frame -- no technical reason these couldn't be made (each column of cells is 175mm wide) but of course nobody would bother for such a tiny market... 😞

 

I did wonder about asking if the roof could be built with a flat-floored 35mm deep recess along the centreline to fit the panels in, but I suspect I know what the answer would be... 🙂

We have, as you realise, large roof lights so don't have a large area to play with. My thoughts were to stick with flexible panels but to stop them getting hot by having a double-skinned section of roof and pumping cold (canal) water through it whenever the panels were generating enough to run a pump. As to recesses, you can have what you like - at a price. And how about the fan to circulate air underneath?

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