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Solar hot water

locostmike

By locostmike
in Boat Equipment

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Jambo Proficient

Jambo

Posted
Posted

 

The latter must be a very innefficient prospect.

 

But better than not generating when batteries are full.

 

I've seen a widebeam in London with a ~10 tube evacuated tube collector. I think if I was going to do it I'd go for a flat plate collector because roof space isn't really at a premium in a widebeam and it would be cheaper and more robust. It's a tempting idea but I don't have it on the cards for now.

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LEO Influencer

LEODonate to Canal World

Posted
Posted

Hi,

 

Not sure if this helps - I have just had a 4Kw system installed on our house, this installation includes a unit made by Solarimmersion.co.uk.

 

This allows for any unused power to be diverted to the immersion heater, and away from the immersion when power as required and when water is hot and no power required diverts the power back to the grid.

 

Brilliant, might be possible to incorporate it in a boat system, obviously with a smaller system and not diverting power back to the grid.

 

Works well with my installation - so far tank full of hot water, 10 units generated on a sunny day, average power generation over 11 days 6.5 units and my wife can run her beloved tumble drier at no cost!.

 

L.

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DaveR Proficient

DaveRDonate to Canal World

Posted
Posted

We have solar hot water heaters on the roof of the house. On good days, our system takes the 350ltr stainless steel tank to 95 deg C. There is a mixer valve on the outlet to take this down to 40 deg C.

 

Throughout this summer we used no gas at all for hot water, in fact in 3 months just the total gas usage was £3.50 on a little heating on occassional nights when it got cold.

 

The solar panel uses a special fluid (no idea what it is but it is pink and rather thick) that conveys the heat via a pump to the coil in the calorifier. Everything - pipes, pump and tank are insulated to the highest degree. We have two panels because the house is East / West facing. The whole system cost just less than £4k

 

How the system would work on a narrow boat, I dont know - certainly will have to be a scaled down version, but from the domestic point - very much worth it.

 

Dave R

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ditchcrawler Veteran II

ditchcrawlerDonate to Canal World

Posted
Posted

I saw a boat between Branston and Napton last week with one on the roof, it was connected by flexible pipes and was on a wheeled tripod base so could be turned and tilted to face the sun, They also and solar panels for electricity mounted the same way but separate units.

The tripod bases were advertised in October Canal Boat page 80

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peterboat Veteran II

peterboatDonate to Canal World

Posted
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I built one on to the side of my old boat it worked well in the summer providing all my hot water needs. The boat at its moorings nearly always had the sun on that side so it wasnt a problem being static. I removed it when I sold it as the broker thought it would detract from the boat :)

 

Peter

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smileypete Veteran II

smileypete

Posted
Posted (edited)

Do many narrow boats use solar panels for generating hot water or at least pre-heating it? Are there any tech reasons why you shouldn't? I have a calorifier with an Eberspacher already fitted.

 

Most of the cheap evacuated tube collectors only work when inclined, not too handy for a cruising boat.

 

There are ones that don't care about angle but the cost could probably buy a lot of gas for a Morco!

 

I built one on to the side of my old boat it worked well in the summer providing all my hot water needs. The boat at its moorings nearly always had the sun on that side so it wasnt a problem being static. I removed it when I sold it as the broker thought it would detract from the boat smile.png

 

Peter

 

How did you make it?

 

cheers, Pete.

~smpt~

Edited by smileypete
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Rod a mod from Tod Proficient

Rod a mod from Tod

Posted
Posted
DaveR, on 31 Oct 2013 - 10:13 AM, said:

 

 

The solar panel uses a special fluid (no idea what it is but it is pink and rather thick) that conveys the heat via a pump to the coil in the calorifier. Everything - pipes, pump and tank are insulated to the highest degree. We have two panels because the house is East / West facing. The whole system cost just less than £4k

 

 

Dave R

 

Anti-freeze as a rule.

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Ex- Member Veteran II

Ex- Member

Posted
Posted

There are a couple of threads on this where some members were in the process or planning to make a solar hot water collector. This is on our to do list as well and I have gleaned nearly all the parts to make one. I think I now just need some alloy sheet which will be the back plate to coiled copper pipe which is all painted Black.

 

The one we're planning is based on this one http://www.bigginhill.co.uk/solar.htm

 

It'll be a sealed system using fluid so doesn't need emptying in winter. There's some thermostatic electronics you can use to ensure only the hottest water goes to the calorifier. Just requires a 12v pump to circulate.

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MtB Veteran II

MtBDonate to Canal World

Posted
Posted

Do many narrow boats use solar panels for generating hot water or at least pre-heating it? Are there any tech reasons why you shouldn't? I have a calorifier with an Eberspacher already fitted.

 

1) No.

 

2) Yes.

 

Well can't, rather than shouldn't.

 

MtB

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peterboat Veteran II

peterboatDonate to Canal World

Posted
Posted

 

Most of the cheap evacuated tube collectors only work when inclined, not too handy for a cruising boat.

 

There are ones that don't care about angle but the cost could probably buy a lot of gas for a Morco!

 

 

How did you make it?

 

cheers, Pete.

~smpt~

It was simple I created a box on the side of the boat the inside of which had copper pipe going from bottom to top in 8mm micro bore off a 15mm pipe at the bottom and top. it was all painted matt black and was clipped and glued to the cabin side. It was covered by a double glazed unit the reverse side of the cabin was insulated so it kept the heat in. The pipe at the top had a thermo switch which controlled a 12v pump the immersion was removed from the calorifier and a coil from ebay was put in and it had a small header tank above it. It was filled with pink antifreeze and worked well

 

Peter

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Top cat Rising Star

Top cat

Posted
Posted

We also divert excess power from our domestic solar panels to the hot water tank and it works very well. But we have 4 kW on the house roof , our boat on the other hand has just 130w . So while in theory you should be able to use surplus power to heat water once the batteries are changed I suspected that unless you have a lot more panels than most people want to fit then the amount of hot water you get would be very small.

I estimate that our £300 domestic system will pay for itself in about 3 -4 years, a low power boat system would need to be seriously cheap to have a realistic payback.

 

TC

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peterboat Veteran II

peterboatDonate to Canal World

Posted
Posted

That sounds great Peter, how much hot water produced in a typical day,& @ what temp ?.

Would you do it again,& what improvements would you make. Its something that would interest me,If they are effective.

I would if I could but my new boat has a calorifier on the floor and not behind the panel so I cant do it on sunny days it provided all my hot water needs. The only improvement I would do would have been when I had the calorifier made. I would have had a 3rd coil put in instead of the one I put in via the immersion heater. It was ideal for me as my boat had sun on that side for hours both summer and winter, If I did it again I would weld a frame on rather than using wood.

 

Peter

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Grace and Favour Veteran II

Grace and Favour

Posted
Posted

We also divert excess power from our domestic solar panels to the hot water tank and it works very well. But we have 4 kW on the house roof , our boat on the other hand has just 130w . So while in theory you should be able to use surplus power to heat water once the batteries are changed I suspected that unless you have a lot more panels than most people want to fit then the amount of hot water you get would be very small.

I estimate that our £300 domestic system will pay for itself in about 3 -4 years, a low power boat system would need to be seriously cheap to have a realistic payback.

 

TC

That's cheap!!

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sassan Collaborator

sassan

Posted
Posted (edited)

I built one this summer, old car radiator painted black, small barrel, cheap (£4) 12V pump and some garden hose and fittings.

 

Saved a lot of complexity by not connecting it to my existing hot water system, You just fill it with water using a valve, leave it half an hour, turn the pump on, leave it another ten minutes and then the garden hose spray nozzle delivers water to shower or sink (hose through window).

 

Works well in summer, but I'd like to encase the radiator in glass and insulate the barrel to increase the number of days where I can use it.

 

Redneck engineering at its finest.

Edited by sassan
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