Why manufacturers do not fit solar panels to hardtops?

[Deleted User YDKXO]

Mike
Yes, we will have to agree to disagree on this one.

So what next, Mike? A wind turbine? I've often thought that a wind turbine would generate an awful lot of leccy at 20kts if nailed on to the radar arch. Why bother putting alternators on the engines? Save yourself £'000s

 

[Eren]

Eren, I accept everything you and Hurricane say. I just dont think its solving a huge problem. And even if it was a problem, for the price of buying and installing the solar panels, its probably cheaper to change your batteries twice as often

And I accept that your angle of approach is different, as you already have the need of running the gennies for stabs. For me this is more for comfort on on board. The economy it brings in is just a side benefit. You are right that when we buy it from the manufacturer's option list, the ROI will be much longer.

May be I am sick but I know that I will sleep better knowing that I take good care of my batteries

 

[MapisM]

So what next, Mike? A wind turbine?

Fwiw, I must say that I'm with Hurricane on this one, M.
In fact, I can see the appeal of solar panels, depending on boat usage.
In our brief shakedown cruise to Croatia, we always overnighted at anchor, and I had the opportunity to test the (new) batteries a bit, with two fridges (one of them pretty large) and one freezer always running, plus some lights here and there, and the occasional run of the fresh water pump and of Tecma pumps (which do eat some current, albeit just briefly)
During the day, we turned on the genset for breakfast, lunch and dinner (hence also the battery charger, of course).
But after dinner, we had to leave it on for much more than we would have liked to, just to keep the batteries topped enough to handle the night without risking the big voltage drops that Hurricane mentioned - and which can kill also brand new batts.

Now, I agree that nobody is going to save the planet fitting solar panels on a 20m mobo, but for lovers of quiet (as both myself and S are, as well as most of our friends), I believe they can make a difference.
Otoh, in my usual cruising grounds, as you know it's rare to make more than a couple of nights at anchor in a row, and most of the time coming back to home port is just a matter of half an hour or so.
But if we would think of staying out for several days (or weeks), I would give solar panels a not so low priority, in my wish list for possible upgrades.

 

[Portofino]

It's a pity there is not ( yet ) some sort of solar cloth , so you could make a Bimini out of .
Run the wire down the poles , flexible to fold etc .
At the mo we optimise the geny noise n all .

 

[vas]

Yes most of the batteries last for 4-5 years, but actually the period that the batteries are having their healthy life is shorter, may be 2-3 years. Then we say OK to lower battery performance for a couple of more years and then when we see that it is not bearable any more, we change them. I expect that proper charging with the help of solar panels will extend the "healthy life" period of the batteries. But that is just an expectation, I am not technically equipped to back that up.

Spot on!

It's a well established fact that most craft fitted with properly installed/wired/setup solar panels end up changing batteries in double the time (if not more) of the others. Without serious drops in performance after the first 3-4yrs as well.

cheers

V.

 

[Hurricane]

So what next, Mike? A wind turbine? I've often thought that a wind turbine would generate an awful lot of leccy at 20kts if nailed on to the radar arch. Why bother putting alternators on the engines? Save yourself £'000s

I'm not going to fall out with you Mike but you really haven't got the point.

Actually windmills are not an option - even the yachties are binning them in favour of solar - they just don't produce enough energy.

 

[Hurricane]

Fwiw, I must say that I'm with Hurricane on this one, M.
In fact, I can see the appeal of solar panels, depending on boat usage.
In our brief shakedown cruise to Croatia, we always overnighted at anchor, and I had the opportunity to test the (new) batteries a bit, with two fridges (one of them pretty large) and one freezer always running, plus some lights here and there, and the occasional run of the fresh water pump and of Tecma pumps (which do eat some current, albeit just briefly)
During the day, we turned on the genset for breakfast, lunch and dinner (hence also the battery charger, of course).
But after dinner, we had to leave it on for much more than we would have liked to, just to keep the batteries topped enough to handle the night without risking the big voltage drops that Hurricane mentioned - and which can kill also brand new batts.

Now, I agree that nobody is going to save the planet fitting solar panels on a 20m mobo, but for lovers of quiet (as both myself and S are, as well as most of our friends), I believe they can make a difference.
Otoh, in my usual cruising grounds, as you know it's rare to make more than a couple of nights at anchor in a row, and most of the time coming back to home port is just a matter of half an hour or so.
But if we would think of staying out for several days (or weeks), I would give solar panels a not so low priority, in my wish list for possible upgrades.

Yep that last bit is the point.
If you are only out for a few days, it isn't a problem.
But if you are going to be away from shore power for more than a about 4 days, you will need to run your generator for a long period to bring the batteries back up to the level they were when you left the shore power. In fact, I spoke to a very knowledgeable guy at the end of last year who suggested just that - his words - run the generator for 8 to 10 hours every 4 days.
Look back over these forums at the posts where people think their batteries are too small.
The batteries are probably not too small - IMO, it is that they are staying away from shore power without bringing their batteries back to a fully charged state.

 

[Gentlemanracer]

In case this helps the debate. Battery charging fuel-cell technology is as good as silent and most installations are configured to supplement solar. Its not cheap but I suspect savvy builders and owners might be specking a few units as time goes by. Here's an example: http://www.fuelcellsystems.co.uk/marine/

 

[benjenbav]

My last boat was an Aquastar which - prior to my owning it - was on a permanent mooring buoy in Fowey harbour. It had a solar panel on the saloon roof in order to help keep charge in the engine-starting bank. The previous owner seemed happy with this arrangement.

 

[longjohnsilver]

I have 2 x 100W solar panels on Eos, fitted the first about 8 years ago when we moved onto our trot mooring in the Dart, obviously no shore power available. The intention was to keep the batteries pretty much fully charged when we weren't on the boat. Prior to moving there we got through 2 sets of batteries in just a few years. The current batteries are now about 6 years old and, apart from one failure, are still going strong. I have since added another panel which now enables me to leave my full size fridge freezer permanently on. Maybe a small detail for those who are marina based, but none the less it's still good to arrive down at the boat to an ice cold beer or glass of wine. It also means I have peace of mind should a bilge pump be called into action, with 6 x 225A batteries it should keep running if needed all night till the batteries start to charge again the next morning, not that it's ever happened.

Also when we go away to Scilly and anchor for 3 or 4 weeks it's quite noticeable how infrequently we have to run out genny compared to before fitting the solar panels. Overall it just makes life on board that bit easier and more relaxed, and I consider it the best improvement I've made to the boat and life on board. Even here in the U.K. I wouldn't be without them.

 

[Deleted User YDKXO]

I'm not going to fall out with you Mike but you really haven't got the point.

Actually windmills are not an option - even the yachties are binning them in favour of solar - they just don't produce enough energy.

It was said in jest Mike

 

[Hurricane]

It was said in jest Mike

Yes, I know - and thats how I took it.

 

[rustybarge]

Some interesting hi-tech solar panels...

http://sauletech.com

 

[vas]

Some interesting hi-tech solar panels...

http://sauletech.com

lots of discussion on various such tech, let's give them 3yrs and then we are talking. Would love to compliment my 600W panels with another 300W on the lower helm windscreen, nice slope and with the proper sideeffect of cutting solar gains in the helm area
Wont be able to see as well at night, no worries, go up to the f/b

let's see what's the price going to be and WHEN! Electrochromic (sp?) glass is another smart development, you don't see it used often though even a decade after launching...

cheers

V.

 

[Cheery]

Surely the OP is right in wanting a quiet anchorage, prolonging the battery life, both over his stay and the intervening years, is a welcome bonus. Or have I missed something?

I enjoyed Hurricane's original thread and would like to see some figures for the season. Unless I have missed the post.

 

[rustybarge]

lots of discussion on various such tech, let's give them 3yrs and then we are talking. Would love to compliment my 600W panels with another 300W on the lower helm windscreen, nice slope and with the proper sideeffect of cutting solar gains in the helm area
Wont be able to see as well at night, no worries, go up to the f/b

let's see what's the price going to be and WHEN! Electrochromic (sp?) glass is another smart development, you don't see it used often though even a decade after launching...

cheers

V.

Same with lithium batteries; my son tells me that you can only charge them from 30%-70% capacity if you want to get more than 500 recharges, so the usable capacity is only 40% of the quoted Max.

....not much different to lead acid bulk charge from 50%-80% except the weight and the ruinious cost of lithium. You need to very careful reading promotional leaflets that you have the technical knowledge to see through the hype.