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Tash and Bex

"outside the box" thinkers only please!!!

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16 minutes ago, Tash and Bex said:

do you know (unrelated to the bath) I was just looking into the use of a heat pump for heating an all electric (hybrid I guess) boat.

It's tempting, but for any reasonable heat output the electrical consumption (assuming that you go the more conventional route) gets a bit scary. A CoP of 4 would be good in practice even if the theoretical maximum is higher, you might be able to do better with a reliable heat sink like a canal and by keeping the output temperature low. Gas-fired absorption heat pumps are available, but you said somewhere that you don't want gas and you'll still need some electric for running mechanical pumps. (I'm looking at heat pumps for domestic use. Glad that I kept my old thermodynamics text book!)

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14 minutes ago, peterboat said:

By the way you will be shot at dawn for saying such things like electric boats on here 🤣

Good!!! 

 

Thinking of maybe converting Helena at some point, and hopefully going gasless at the same time, be interested to hear your thoughts on it.

 

If I do actually build myself a widebeam (more pistols drawn) it will certainly be all electric (open the armoury, we need more guns). ATM though we are knocking Helena round a bit to make her more suited to live aboard by a couple.

3 minutes ago, Onewheeler said:

It's tempting, but for any reasonable heat output the electrical consumption (assuming that you go the more conventional route) gets a bit scary. A CoP of 4 would be good in practice even if the theoretical maximum is higher, you might be able to do better with a reliable heat sink like a canal and by keeping the output temperature low. Gas-fired absorption heat pumps are available, but you said somewhere that you don't want gas and you'll still need some electric for running mechanical pumps. (I'm looking at heat pumps for domestic use. Glad that I kept my old thermodynamics text book!)

well I wouldn't exactly be all electric, and a decent cocooned generator should keep up with a heat pump I would have thought, particularly if i were to use ballast as a thermal store.....early days and depends on whether I take the plunge and go wide beam. but between a generator and 4kw of solar I think it's worth looking into 

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22 minutes ago, peterboat said:

By the way you will be shot at dawn for saying such things like electric boats on here 🤣

Nah, I think she may have already blocked the nay-sayers :)

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29 minutes ago, peterboat said:

By the way you will be shot at dawn for saying such things like electric boats on here

Only if you accompany the suggestion with the assertion that two hours of cruising during summer months is all that anyone requires...

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9 minutes ago, jradley said:

Nah, I think she may have already blocked the nay-sayers :)

Lol, I haven't blocked anyone, I live by the mantra "don't block, just mock" Seems to work!

3 minutes ago, WotEver said:

Only if you accompany the suggestion with the assertion that two hours of cruising during summer months is all that anyone requires...

Seems to work for most CCers!

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1 minute ago, WotEver said:

Only if you accompany the suggestion with the assertion that two hours of cruising during summer months is all that anyone requires...

Given that I have over 30KWHs of batteries on board and at 3mph in uses 3kws I might have a lot more than 2 hours cruising available,especially with the amount of solar I have, I continuously say 2hours suits me because I get bored! But no one ever reads what I type!!

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13 minutes ago, Tash and Bex said:

well I wouldn't exactly be all electric, and a decent cocooned generator should keep up with a heat pump I would have thought, particularly if i were to use ballast as a thermal store.....early days and depends on whether I take the plunge and go wide beam. but between a generator and 4kw of solar I think it's worth looking into 

If you've got that much electrical power then no problem! You'll have a large bath tank as a thermal store! Water has the highest thermal capacity of anything readily available, although it would be interesting to do a conceptual design using parafin wax as a thermal store using its latent heat of fusion.

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4 minutes ago, Tash and Bex said:

Lol, I haven't blocked anyone, I live by the mantra "don't block, just mock" Seems to work!

Seems to work for most CCers!

See what I mean? Its like this all the time, people dont want to give up their diesel engines, even though for most of the ones that cruise electric would work. At Tullys I am still the boat that goes out the most even though its electric, I would suspect on most marinas it would be the same. If I was you i would forget altering Helena and just go the wide route like I did, 4.5 KW of solar powers a lot of things including heating water in the summer via immersion heater

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42 minutes ago, Tash and Bex said:

Good!!! 

 

Thinking of maybe converting Helena at some point, and hopefully going gasless at the same time, be interested to hear your thoughts on it.

 

If I do actually build myself a widebeam (more pistols drawn) it will certainly be all electric (open the armoury, we need more guns). ATM though we are knocking Helena round a bit to make her more suited to live aboard by a couple.

well I wouldn't exactly be all electric, and a decent cocooned generator should keep up with a heat pump I would have thought, particularly if i were to use ballast as a thermal store.....early days and depends on whether I take the plunge and go wide beam. but between a generator and 4kw of solar I think it's worth looking into 

Now that does sound an interesting subject, better than the tank of hot water IMO

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20 minutes ago, peterboat said:

See what I mean? Its like this all the time, people dont want to give up their diesel engines, even though for most of the ones that cruise electric would work. At Tullys I am still the boat that goes out the most even though its electric, I would suspect on most marinas it would be the same. If I was you i would forget altering Helena and just go the wide route like I did, 4.5 KW of solar powers a lot of things including heating water in the summer via immersion heater

I'd love to do that, but there are just over 100,000 reasons stopping me! 

 

As far as electric propulsion is concerned, I guess if you have a holiday boat, then it might not be for you, but If you are a liveaboard, a huge amount of electricity available is considerably more useful than having a huge amount of diesel in the boot on a day to day basis.

 

Interested that you didn't consider solar thermal hot water though?

 

Bex

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30 minutes ago, Onewheeler said:

If you've got that much electrical power then no problem! You'll have a large bath tank as a thermal store! Water has the highest thermal capacity of anything readily available, although it would be interesting to do a conceptual design using parafin wax as a thermal store using its latent heat of fusion.

what about a collector network directly on the baseplate, a given amount of reflective insulation on top to create a thermal barrier, then run the heating matrix through those bricks with holes in them in lieu of a more conventional frog?  Always good to make stuff work for a living on a boat, and it would make my ballast less "passive"!

 

That is the idea that's doing the rounds of the old grey matter atm, but I haven't even started adding numbers to it!

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6 minutes ago, Tash and Bex said:

what about a collector network directly on the baseplate, a given amount of reflective insulation on top to create a thermal barrier, then run the heating matrix through those bricks with holes in them in lieu of a more conventional frog?  Always good to make stuff work for a living on a boat, and it would make my ballast less "passive"!

 

That is the idea that's doing the rounds of the old grey matter atm, but I haven't even started adding numbers to it!

Might work if you've got enough space under the floor. However (without doing any sums) you would need a thick insulation layer as the area used over the baseplate would be large. Otherwise you'll be circulating heat from one side to t'other.

 

Molten salt storage? 🙄

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33 minutes ago, Tash and Bex said:

I'd love to do that, but there are just over 100,000 reasons stopping me! 

 

As far as electric propulsion is concerned, I guess if you have a holiday boat, then it might not be for you, but If you are a liveaboard, a huge amount of electricity available is considerably more useful than having a huge amount of diesel in the boot on a day to day basis.

 

Interested that you didn't consider solar thermal hot water though?

 

Bex

Because in the summer I have more solar than I need so its used for hot water as well as drive, in the winter though I have only just enough solar and just enough roof space to have the solar on so PV is the best use of the space available

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2 hours ago, Tash and Bex said:

 

well I wouldn't exactly be all electric, and a decent cocooned generator should keep up with a heat pump I would have thought, particularly if i were to use ballast as a thermal store.....early days and depends on whether I take the plunge and go wide beam. but between a generator and 4kw of solar I think it's worth looking into 

I wonder how the figures stack up for a diesel generator driving a heat pump Vs a diesel engined combined heat and power unit? 

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5 hours ago, peterboat said:

Because in the summer I have more solar than I need so its used for hot water as well as drive, in the winter though I have only just enough solar and just enough roof space to have the solar on so PV is the best use of the space available

makes perfect sense, do you manage entirely on solar?

 

4 hours ago, Eeyore said:

I wonder how the figures stack up for a diesel generator driving a heat pump Vs a diesel engined combined heat and power unit? 

so do I.

 

I do, however, know that i would likely use the generator much more than the heating, and I usually take the boat off the mooring only for bunkers.

 

I don't think there is a "one size fits all" solution

 

Edited by Tash and Bex
stupidity on my part
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5 hours ago, Onewheeler said:

Might work if you've got enough space under the floor. However (without doing any sums) you would need a thick insulation layer as the area used over the baseplate would be large. Otherwise you'll be circulating heat from one side to t'other.

 

Molten salt storage? 🙄

hmm, I take your point about heat transfer, but the transfer would be minimised by the relatively low temperature needed for underfloor I would have thought. maybe foil backed kingspan (other insulations are available) double layered so the foil is facing down and up? Anyhoo, much as I would love to do it I am not ripping out all my interior to try!

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7 minutes ago, Tash and Bex said:

makes perfect sense, do you manage entirely on solar?

 

so do I.

 

I do, however, know that i would likely use the generator much more than the heating, and I usually take the boat off the mooring only for bunkers.

 

I don't think there is a "one size fits all" solution

 

Mostly yes I have a LifePo4 battery bank so can extract and charge far faster than other batteries, for backup and instant heat I have a 24 volt whispergen which provides 35 amps DC and 5 KW of hot water works well and would get you your bath full of hot water quickly

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1 minute ago, peterboat said:

Mostly yes I have a LifePo4 battery bank so can extract and charge far faster than other batteries, for backup and instant heat I have a 24 volt whispergen which provides 35 amps DC and 5 KW of hot water works well and would get you your bath full of hot water quickly

do you know I was just looking at one of those yesterday, but as stirling engines are essentially witchcraft I ignored it and it went away!

 

Are your lipo's repurposed car jobs, I have been looking into them but I am struggling to work them out!

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Latest electrical power source. Becoming  all the rage. Can deliver between 600 and 800volts. Electric eel.

eel-me-2.jpg

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52 minutes ago, Tash and Bex said:

do you know I was just looking at one of those yesterday, but as stirling engines are essentially witchcraft I ignored it and it went away!

 

Are your lipo's repurposed car jobs, I have been looking into them but I am struggling to work them out!

They are great machines my last one clocked up 6000 hours before it was sold on, this one is brand new ex MOD I bought a number of them made them into working kits and sold them on.

I have two different types of LifePo4s both are made by Valence the 12 volt ones are out of a van the 36 volt ones out of buses, lots of threads on here about them, a few of us have gone that way

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1 hour ago, peterboat said:

They are great machines my last one clocked up 6000 hours before it was sold on, this one is brand new ex MOD I bought a number of them made them into working kits and sold them on.

I have two different types of LifePo4s both are made by Valence the 12 volt ones are out of a van the 36 volt ones out of buses, lots of threads on here about them, a few of us have gone that way

oooh so the MOD use them, I shall look out! I presume you can't really hear them in operation?

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2 hours ago, bizzard said:

Latest electrical power source. Becoming  all the rage. Can deliver between 600 and 800volts. Electric eel.

eel-me-2.jpg

how many Ah ?    can it be discharged below 50% ?  

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49 minutes ago, Tash and Bex said:

oooh so the MOD use them, I shall look out! I presume you can't really hear them in operation?

Totally silent,  the MOD used them in mobile showers,  worked well, the ones I bought came of bidspotter and the UK dealer is a mate of mine in rotherham, not that they make them anymore, but they still come up for sale 

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15 hours ago, bizzard said:

Latest electrical power source. Becoming  all the rage. Can deliver between 600 and 800volts. Electric eel.

eel-me-2.jpg

 

13 hours ago, Murflynn said:

how many Ah ?    can it be discharged below 50% ?  

 

You just strap them together into a harness connected to your boat, drop a trail of currants (sultanas at a push) in front of them and off you go. 😁

  • Greenie 1

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1 minute ago, cuthound said:

 

 

You just strap them together into a harness connected to your boat, drop a trail of currants (sultanas at a push) in front of them and off you go. 😁

I always wondered what 'tail currant' meant. 

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