Solar Does Work !

[Robbo]

its a 240v immersion and runs directly through the inverter to the batteries.

 

we do it when batts are at 100% it takes about 45 mins to heat the tank and usually takes the batts down to 84%, if done early enough batts will be back at 100% before the sun goes in.

It may be better to heat the water when the sun us at its highest. Depending on how much solar you have and how fully charged the batteries are you may have more solar amps than the batteries can take.

[Alan de Enfield]

"Solar Does Work"

 

Not this week it doesn't.

 

8/8 th's very black clouds.

 

Had torrential rain for the last week, every time I look at the 'meter' its showing around 0.1 Amp.

 

River gone up by over 2 feet this week and with another 1/2" of rain forecast for today, and a further 3/4" tomorrow it will soon be back up to Winter levels and I won't get under the bridges.

[Guest]

its a 240v immersion and runs directly through the inverter to the batteries.

 

we do it when batts are at 100% it takes about 45 mins to heat the tank and usually takes the batts down to 84%, if done early enough batts will be back at 100% before the sun goes in.

Cheers, will give it a go, especially as we hope to double the solar up soon. Also noticed that there are 12V immersion elements available these days.

[MtB]

"Solar Does Work"

 

Not this week it doesn't.

 

8/8 th's very black clouds.

 

Had torrential rain for the last week, every time I look at the 'meter' its showing around 0.1 Amp.

 

 

I get this too.

 

Again and again I see people write on here that solar output drops to about 10% when light conditions ae poor. 10% would at least still be slightly useful, if it were true.

 

My own experience is the same as yours, that it falls to about 1% or even nothing at all.

[Guest]

 

 

I get this too.

 

Again and again I see people write on here that solar output drops to about 10% when light conditions ae poor. 10% would at least still be slightly useful, if it were true.

 

My own experience is the same as yours, that it falls to about 1% or even nothing at all.

Can't comment because I haven't connected the ammeter in yet

We are using solar for the first time this summer and very pleased we are, though of course it works better in't sun.

 

As an aside, may I ask how mot people connect the panels via the roof? Some kind of waterproof junction box perhaps?

Cheers.

Edited June 15, 2016 by Guest

[MtB]

Can't comment because I haven't connected the ammeter in yet

We are using solar for the first time this summer and very pleased we are, though of course it works better in't sun.

 

As an aside, may I ask how mot people connect the panels via the roof? Some kind of waterproof junction box perhaps?

Cheers.

 

 

Yes. Traditionally termed a 'mushroom'

 

Although my solar wires come in through the pigeon box.

[Guest]

 

 

Yes. Traditionally termed a 'mushroom'

 

Although my solar wires come in through the pigeon box.

As I have been looking I have seen a lot as you describe and it makes perfect sense.

I have been considering a slightly different approach by using an IP rated input socket of some sort on the deck above the batteries (NOT a blue 240V one !!) so that I can input the little 12V Honda genny (superb for desulphating goes to 15V), the solars, and use it as a 15 amp output for me big 12V drill.

[MtB]

On my other boat there is an ordinary plastic cable gland carrying the cables through the roof, fitted underneath the panel so shielded from direct rain.

[Guest]

On my other boat there is an ordinary plastic cable gland carrying the cables through the roof, fitted underneath the panel so shielded from direct rain.

Cheers for that Mike. May I ask what size of cable you used? Thanks.

[Alan de Enfield]

Changed my mind, 14:00 hours the sun has come out for a couple of minutes.

 

14.6v

10.8 amps

 

= 157 watts.

 

Not bad from a 170w panel

[MtB]

Cheers for that Mike. May I ask what size of cable you used? Thanks.

 

Can't remember exactly. The cables that came with the solar kit! They are about 6mm in diameter each I'd say...

 

As there are two separate cables a single cable gland wouldn't have a prayer of being fully waterproof. One gland per cable would be best.

[Alan de Enfield]

 

 

As an aside, may I ask how mot people connect the panels via the roof? Some kind of waterproof junction box perhaps?

Cheers.

 

Standard deck-gland.

This one is a bit big but it was left over after installing the radar, GPS, nav lights etc.

 

OK - who has nicked the picture ?

 

 

Edited June 15, 2016 by Alan de Enfield

[Guest]

 

Can't remember exactly. The cables that came with the solar kit! They are about 6mm in diameter each I'd say...

 

As there are two separate cables a single cable gland wouldn't have a prayer of being fully waterproof. One gland per cable would be best.

Cheers

 

Standard deck-gland.

This one is a bit big but it was left over after installing the radar, GPS, nav lights etc.

Cheers again

[canals are us?]

I have certainly been surprised that I have been getting between 6.5-7.1A from my 380 watt solar panels mounted flat on the roof today in cloudy and rainy Staffordshire. I have yet to wire them into a junction box on the roof as at the moment all 8 cables come through the sliding hatch to the PWM controller.

 

James

Edited June 15, 2016 by canals are us?

[Guest]

Talking of controllers....

I understand there are different types, ours being a very basic one that came as a "kit." It appears to work well, though I intend to increase the solar and put a more advanced controller on in time to come. Any recommendations for an efficient controller? Cheers

[canals are us?]

Talking of controllers....

I understand there are different types, ours being a very basic one that came as a "kit." It appears to work well, though I intend to increase the solar and put a more advanced controller on in time to come. Any recommendations for an efficient controller? Cheers

 

If I was looking to upgrade the controller, I would buy one of these tracer series.

http://www.bimblesolar.com/offgrid/mppt Not sure if they are top notch but I have bought a panel from them and pleased with their service etc

[rusty69]

Talking of controllers....

I understand there are different types, ours being a very basic one that came as a "kit." It appears to work well, though I intend to increase the solar and put a more advanced controller on in time to come. Any recommendations for an efficient controller? Cheers

Outback and Morningstar get good reviews if you are after an MPPT type. Not cheap though

[jenevers]

Outback and Morningstar get good reviews if you are after an MPPT type. Not cheap though

I wonder how much better they are, compared to the Tracer MPPT. Do they charge better or do they just give lots more accurate info?

[rusty69]

I wonder how much better they are, compared to the Tracer MPPT. Do they charge better or do they just give lots more accurate info?

I wonder that myself. I assume they may just be better quality units. I have had a Tracer controller, which was replaced with a larger chinese MPPT type, but when that eventually fails will get an Outback or Morningstar unit.

[Murflynn]

I am looking at installing 200W solar in my new boat which has 4 x 110AH batteries and an electric auxiliary outboard (which I actually hope to use most of the time). I also have a small Honda genny and will try to plan my journeys to make best use of charging points (e.g. at certain locks on the Thames).

 

The Victron Blue Solar 75 15 MPPT controller looks interesting and at less than £80 appears to be excellent value for money; it includes 'full battery management'.

 

 

 

PS there are many cheap Chinese controllers on ebay which purport to be MPPT but are nothing of the sort.

Edited June 17, 2016 by Murflynn

[Alan de Enfield]

Article - "Difference between PWM & MPPT Controllers"

 

http://solarcraft.net/articles/comparing-pwm-and-mppt-charge-controllers/

 

My basic summary is that for boat applications (150w +) the its MPPT every time.

[MtB]

I have a Tracer MPPT of one boat and a cheapo no-name PWM on the other. Frankly, the PWM seems to work better than the Tracer, although it's hard to judge as the two electrical systems are so different.

[Jambo]

Regarding Outback and Morningstar, we have an Outback which has performed faultlessly but I'd probably switch to Morningstar because they have an open comms port which allows you to stream data to the internet. Outback have a proprietary protocol that means you have to fork out another few hundred quid for a Mate whereas you can stream data straight from the Morningstar which is a big plus in my book.

 

See e.g.

Edited June 17, 2016 by Jambo

[Guest]

Thanks for replies re. controllers, will have a look around

[jenevers]

I wonder that myself. I assume they may just be better quality units. I have had a Tracer controller, which was replaced with a larger chinese MPPT type, but when that eventually fails will get an Outback or Morningstar unit.

Apparently Tracers (which are made in China) also made MPPTs for Outback. They looked identical but were black instead of silver. Don't know what the price difference was.