Flexible solar panels are junk

[geem]

We have a huge area of cabin roof that is ideal for the location of solar panels - one of the advantages of a multihull. If we filled the roof with rigid panels we would not have access to the boom. We could leave a space to walk on but inevitably when you want to access the boom in a hurry (45 knots, lump seas) the space would be located in the wrong place

I do agree flexible panels don't last, some delaminate, some simply corrode under the top layer (so the top layer is insufficiently robust) - but you can walk on them (for 5 - 10 years) - and then replace. Ours a fixed to a rigid base, the cabin roof and to instal have been bent, slightly. We don't run around on the cabin roof - only needing visit to tidy the sail. Treat them as an, expensive, consumable - a bit like red wine, a black sail, exhaust elbow or antifouling. Just change your thinking.

There is another problem. You start off with a matching set of flexible panels. They start to fail, Initially you live with the loss of one - then you start to replace. You cannot replace with the same panel, its gone out of fashion or the manufacturer is no more. You end up with an untidy mess of different sizes and visually appearance of panels. It all looks like a bit of a pigs breakfast.

Its at this point a WattnSea and a wind gen looks attractive

But I am interested in your final sentence - how are you making a tank full of hot water?

Do you also mean desalination and heat, or just heating and is heating: battery, convert to AC, immersion heater in tank - or has technology passed me by (again)

Thanks

Jonathan

Our immersion heater is 1200w at 220v. If you buy a cheap 110v inverter, a 'break before you make' changeover switch, and a mechanical 1 HR timer, you can turn on the inverter once your batteries have gone to float and feed 110v into your 1200w immersion heater. The reduced voltage turns the immersion heater into a 300w heater. This keeps our batteries on float. No load on the batteries and after 2 hrs we have enough hot water for a couple of showers and washing up. 3 hrs run time gives us a full tank of hot water. Since arriving in the Caribbean at the beginning of Jan, we have made almost all of our hot water this way

 

[Neeves]

Thanks Geem,

Interesting

It is most annoying when the batteries go to float and you have no use for the extra power. We have a bread maker which fills the need - but often we don't need bread! I need to investigate

We don't have a calorifier, is that the word?. as we wanted hot water at anchor without the need to run the engine. We have an instant hot water gas heater which works for hot water , washing up and showers for 2, twice a day. We carry 2x 8kg gas cylinders. The big issue is not HOT water but water - desalination uses a lot of power. You soon learn what a Navy shower is.

Jonathan

 

[geem]

Thanks Geem,

Interesting

It is most annoying when the batteries go to float and you have no use for the extra power. We have a bread maker which fills the need - but often we don't need bread! I need to investigate

We don't have a calorifier, is that the word?. as we wanted hot water at anchor without the need to run the engine. We have an instant hot water gas heater which works for hot water , washing up and showers for 2, twice a day. We carry 2x 8kg gas cylinders. The big issue is not HOT water but water - desalination uses a lot of power. You soon learn what a Navy shower is.

Jonathan

Ah, ok. I built my watermaker using a Cat247 pump and three membranes. We make 200 litres per hour. We run the diesel generator for 15 mins per day for all our water requirements.
We also have an ice machine. That uses 100w and makes 26 lbs per 24 hrs.

 

[Neeves]

Ah, ok. I built my watermaker using a Cat247 pump and three membranes. We make 200 litres per hour. We run the diesel generator for 15 mins per day for all our water requirements.
We also have an ice machine. That uses 100w and makes 26 lbs per 24 hrs.

Ice is decadent

and malt whisky is ruined with ice

I am (very) envious of your water maker but resisted the generator - too heavy. The sacrifice imposed the Navy showers.

Jonathan

 

[ryanroberts]

They were certainly crappy 10 years ago, so I went for amorphous panels as I had space in spades on a narrowboat roof. I am considering modern semi flex to replace / upgrade the blown out old semiflex on my pilothouse roof as finding someone to do the steelwork to mount panels is a nightmare. I can easily get 3-400w of new EFTE panels on with homebrew mountings.

 

[thinwater]

Our immersion heater is 1200w at 220v. If you buy a cheap 110v inverter, a 'break before you make' changeover switch, and a mechanical 1 HR timer, you can turn on the inverter once your batteries have gone to float and feed 110v into your 1200w immersion heater. The reduced voltage turns the immersion heater into a 300w heater. This keeps our batteries on float. No load on the batteries and after 2 hrs we have enough hot water for a couple of showers and washing up. 3 hrs run time gives us a full tank of hot water. Since arriving in the Caribbean at the beginning of Jan, we have made almost all of our hot water this way

Neat.

The only concern would be not to do this every day, because I'm guessing the batteries are not really at 100% and will start to sulfate. The acceptance rate really drops off near full.

The problem for me, at least, is that in the summer I don't have much desire for hot showers, and in the shoulder seasons the sun isn't high enough for long enough for the math to work.

But neat.

 

[geem]

Neat.

The only concern would be not to do this every day, because I'm guessing the batteries are not really at 100% and will start to sulfate. The acceptance rate really drops off near full.

The problem for me, at least, is that in the summer I don't have much desire for hot showers, and in the shoulder seasons the sun isn't high enough for long enough for the math to work.

But neat.

That's not correct. They have gone through a bulk and absorption charge of about 5 or 6 hours combined before going to float.
We kite surf. The sea cools you down. A nice warm shower is a must even though the air temperature is 29 degC. It's the same if you go diving for an hour. A warm shower feels great

 

[thinwater]

That's not correct. They have gone through a bulk and absorption charge of about 5 or 6 hours combined before going to float.
We kite surf. The sea cools you down. A nice warm shower is a must even though the air temperature is 29 degC. It's the same if you go diving for an hour. A warm shower feels great

Well, there you go. I figured you had lots of solar and had thought this through. The comments were for others.

I have a vented propane water heater that sees heavy use in the shoulder seasons and winter.

 

[geem]

Well, there you go. I figured you had lots of solar and had thought this through. The comments were for others.

I have a vented propane water heater that sees heavy use in the shoulder seasons and winter.

We don't have a cold season here. It's either hot or very hot ?
We also use a solar hot water system. A 20 litre plastic dark green water can with a 3 metre hose and shower head. Hoist up mizzen mast and get a warm shower direct from the sun

 

[Neeves]

Its the 21st century, Grandfathers were unaware previously but warm or hot showers, twice a day with fresh water, are a birthright and that birthright is not restricted to granddaughters.

Cold showers should be restricted to memories of camping in the 50s and 60s. I have found that my tolerance of cold water has decreased with increasing maturity (though the mods here might suggest my maturity has not extended to tolerance ). Water I would have once swum in now feels near freezing.

Jonathan

 

[geem]

Its the 21st century, Grandfathers were unaware previously but warm or hot showers, twice a day with fresh water, are a birthright and that birthright is not restricted to granddaughters.

Cold showers should be restricted to memories of camping in the 50s and 60s. I have found that my tolerance of cold water has decreased with increasing maturity (though the mods here might suggest my maturity has not extended to tolerance ). Water I would have once swum in now feels near freezing.

Jonathan

I am not sure if my intolerance to cold water is age or genetic. I have never liked cold water but now hot water feels like an essential in life?

 

[thinwater]

Its the 21st century, Grandfathers were unaware previously but warm or hot showers, twice a day with fresh water, are a birthright and that birthright is not restricted to granddaughters.

Cold showers should be restricted to memories of camping in the 50s and 60s. I have found that my tolerance of cold water has decreased with increasing maturity (though the mods here might suggest my maturity has not extended to tolerance ). Water I would have once swum in now feels near freezing.

Jonathan

I guess I should add that my water tank is in the bridge deck, in a section that gets sun, and thus in the summer a cold shower is slightly greater than the average daily air temperature, probably at least 80F.

And I guess I've never been that hung up on hot showers if the air is warm. Most of those days a little cool is refreshing... to me. I also dislike bringing all that dampness into the cabin, and thus most often shower on the swim platform.

 

[Stemar]

finding someone to do the steelwork to mount panels is a nightmare.

Go to Metal Supermarket and get some aluminium angle. Pop rivet exactly what you need together.



It may look like a trap for lines, but it never gave me any problems