Our first solar panel

[Roger Gunkel]

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week. We have a charge controller with the Rutland which allows us to plug in up to 160w of solar pv. so thought that maybe about 100w was a good starting point. A neighbour has just bought one of the Maplin 60w units at £199 and was telling us how good it is, but having looked at it, it is about a metre square, made up of 4x15w panels, which are the amorphous type, wich require a much larger area than the polycrystalline ones. Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. So we took the plunge and went over to collect one, smaller size than I expected at about 1200x670mm with waterproof connector box and built in diodes. I was also surprised that it only weighed 9.8 Kgs and had the aluminium frame already drilled for fixings. We finally plugged it into the controller at 7.00pm and immediately had a reading on our monitor of a 7.7 amp charge rate with the panel held up facing the sinking sun. I laid it flat on the roof and was still getting 5amps. Being use to getting about 2amps from the Rutland in a steady breeze, it was surprising to find 5amps of silent power from a flat panel at 7.00pm on a mid May evening. We were still getting a charge reading on the monitor right up until the the last brightness in the sky. The batteries (400 ah) were showing 80% when we went to bed. By midday the next day, with a bright overcast sky, we were showing a green and red light on the controller which meant that the charging rate was being reduced by the controller to a trickle charge and the battery state was on 92%.

 

The sun came out in the afternoon, so we switched all power to the inverter and then switched back to grid after a couple of hours having used about 25ah from the batteries. The charge rate showed up to 7.9 amps and after an hour the wind generator also kicked in with another couple of amps. We were back on trickle charge after about 3 hours. Over the 3 days since, we haven't used the inverter, but pretty heavy use of the water pumps, for baths, 3 washing machine loads and the usual washing up etc, plus lights. There has been nothing from the wind generator and mainly overcast apart from today, Sunday, but the batteries are showing 98%. The figures will fluctuate of course depending on varying factors and I only see them as a general indication based on my everyday view of the readings.

 

I'm certainly not an electrician, but so far I am impressed with the 'laying flat' output and will shortly be adding a second panel plus a new mppt controller, before switching our power use to to the inverter for all our daytime use. A tilting mount will also be added to get the best output from the panels. I estimate up to £2.00 per week Summer saving with the 2 panels and wind generator and of course plenty of power when away from the mooring. Not total independence, thats for sure, but a step in the right direction.

 

Roger

[Scooby]

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week. We have a charge controller with the Rutland which allows us to plug in up to 160w of solar pv. so thought that maybe about 100w was a good starting point. A neighbour has just bought one of the Maplin 60w units at £199 and was telling us how good it is, but having looked at it, it is about a metre square, made up of 4x15w panels, which are the amorphous type, wich require a much larger area than the polycrystalline ones. Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. So we took the plunge and went over to collect one, smaller size than I expected at about 1200x670mm with waterproof connector box and built in diodes. I was also surprised that it only weighed 9.8 Kgs and had the aluminium frame already drilled for fixings. We finally plugged it into the controller at 7.00pm and immediately had a reading on our monitor of a 7.7 amp charge rate with the panel held up facing the sinking sun. I laid it flat on the roof and was still getting 5amps. Being use to getting about 2amps from the Rutland in a steady breeze, it was surprising to find 5amps of silent power from a flat panel at 7.00pm on a mid May evening. We were still getting a charge reading on the monitor right up until the the last brightness in the sky. The batteries (400 ah) were showing 80% when we went to bed. By midday the next day, with a bright overcast sky, we were showing a green and red light on the controller which meant that the charging rate was being reduced by the controller to a trickle charge and the battery state was on 92%.

 

 

 

 

The sun came out in the afternoon, so we switched all power to the inverter and then switched back to grid after a couple of hours having used about 25ah from the batteries. The charge rate showed up to 7.9 amps and after an hour the wind generator also kicked in with another couple of amps. We were back on trickle charge after about 3 hours. Over the 3 days since, we haven't used the inverter, but pretty heavy use of the water pumps, for baths, 3 washing machine loads and the usual washing up etc, plus lights. There has been nothing from the wind generator and mainly overcast apart from today, Sunday, but the batteries are showing 98%. The figures will fluctuate of course depending on varying factors and I only see them as a general indication based on my everyday view of the readings.

 

I'm certainly not an electrician, but so far I am impressed with the 'laying flat' output and will shortly be adding a second panel plus a new mppt controller, before switching our power use to to the inverter for all our daytime use. A tilting mount will also be added to get the best output from the panels. I estimate up to £2.00 per week Summer saving with the 2 panels and wind generator and of course plenty of power when away from the mooring. Not total independence, thats for sure, but a step in the right direction.

 

Roger

 

 

Do you have a website address for where you bought it from, might have to get one myself, we are liveaboards but only about 7 months now..

Edited May 17, 2010 by Scooby

[luctor et emergo]

Why, oh why, do people have to quote an entire post, if all they want is ask a generic question? Have some thought for those browsing on their phones, or dial up connections.....

 

 

:lol:

[Grace and Favour]

Roger - - Thank you - -

 

As we have 'come to expect of you' - your post was well researched, clearly described and rather helpful!

 

Very useful - - Cheers!

[Scotty]

Do you have a website address for where you bought it from, might have to get one myself, we are liveaboards but only about 7 months now..

 

I suspect it's Midsummer Energy

[dor]

I looked at Midsummer Energy and their panels do look quite promising on paper. Can you confirm if that is your supplier Roger?

 

I looked at Midsummer Energy and their panels do look quite promising on paper. Can you confirm if that is your supplier Roger?

[Grace and Favour]

I looked at Midsummer Energy and their panels do look quite promising on paper. Can you confirm if that is your supplier Roger?

 

I looked at Midsummer Energy and their panels do look quite promising on paper. Can you confirm if that is your supplier Roger?

 

That's one hell of a stutter you have there, Dor!

[Roger Gunkel]

Sorry for delay in replying, but I posted at 2.35am and didn't wake up 'til 9.30 this morning.

 

Thanks for the comments Grace & Favour, and well spotted Dor and Scotty, yes it was Midsummer Energy. They are a very small online business working from a small industrial unit, but Andy who runs it, was very happy for me to come and collect one even though they are not a retail premises. I'll have no hesitation using them again and recommending. The panel I bought was an XM100. They also supply Kyrocera and BP Solar panels and the flexible self adhesive ones, plus controllers, cable etc.

 

When I connected the panel, I checked the output on the terminals before going through the controller, expecting to get a reading of about 17.5 volts, but my meter only showed a '1'. Not knowing what that was about, I took a reading from a central terminal between the two main connections and that showed nearly 11 volts. Never having wired a panel before and being a bit concerned, I rang the office at Midsummer Energy at 5.35 and a lady in the office said that Andy had left and was off for a few days break, she took my numbers though, saying she would see if she could get hold of him. Ten minutes later my mobile rang and it was Andy, who was travelling but was extremely helpful. It seems that in bright sunlight, the panels can give voltages into the mid 20s and he guessed that I had set my meter in the 0-20v range. He was absolutely right and I immediately got a reading of 26v at the panel on the 100v range. I see that as help above and beyond the call of duty and well worth a mention! It's also worth mentioning that Andy lives on a narrowboat in Cambridge.

 

The panel this morning in mixed sun and cloud, has fully charged the batteries again-98%, and the controller is restricting it to a 1.5amp trickle charge.

 

Roger

[nb Innisfree]

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week.

Roger

 

In our experience that figure sounds a bit low, we run a w/machine and fridge and use about 60-70ah (@24v) per day, or for you 120-140ah @12v. A more realistic figure IMO

[FadeToScarlet]

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Good to hear the success, Roger! We're very pleased with our 135w solar panel, also from Andy- it's made us fully self-sufficient, no need to run the generator unlesss we plan on watching more than a couple of hours worth of television, which is rare...

 

The MPPT controller should be good too, even on cloudy, overcast days we still get output from the panel.

[Roger Gunkel]

Good to hear the success, Roger! We're very pleased with our 135w solar panel, also from Andy- it's made us fully self-sufficient, no need to run the generator unlesss we plan on watching more than a couple of hours worth of television, which is rare...

 

The MPPT controller should be good too, even on cloudy, overcast days we still get output from the panel.

 

Hi James and Amy, nice to hear you're fine, and another satisfied customer from Misummer Energy!

 

NB Innisfree - My figure was a general estimate for when we are off the mooring, but we don't use our washing machine at all while we are cruising, or our computers, hi-fi and very little TV. Our fridge/freezer is also a high efficiency unit which we turn off overnight when cruising. I don't think I am far out in the estimate, although if we were cruising for longer, rather than the typical 3-4 day trips we do now, I am sure you would be right with your higher estimate.

 

Roger

[blackrose]

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week. We have a charge controller with the Rutland which allows us to plug in up to 160w of solar pv. so thought that maybe about 100w was a good starting point. A neighbour has just bought one of the Maplin 60w units at £199 and was telling us how good it is, but having looked at it, it is about a metre square, made up of 4x15w panels, which are the amorphous type, wich require a much larger area than the polycrystalline ones. Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. So we took the plunge and went over to collect one, smaller size than I expected at about 1200x670mm with waterproof connector box and built in diodes. I was also surprised that it only weighed 9.8 Kgs and had the aluminium frame already drilled for fixings. We finally plugged it into the controller at 7.00pm and immediately had a reading on our monitor of a 7.7 amp charge rate with the panel held up facing the sinking sun. I laid it flat on the roof and was still getting 5amps. Being use to getting about 2amps from the Rutland in a steady breeze, it was surprising to find 5amps of silent power from a flat panel at 7.00pm on a mid May evening. We were still getting a charge reading on the monitor right up until the the last brightness in the sky. The batteries (400 ah) were showing 80% when we went to bed. By midday the next day, with a bright overcast sky, we were showing a green and red light on the controller which meant that the charging rate was being reduced by the controller to a trickle charge and the battery state was on 92%.

 

The sun came out in the afternoon, so we switched all power to the inverter and then switched back to grid after a couple of hours having used about 25ah from the batteries. The charge rate showed up to 7.9 amps and after an hour the wind generator also kicked in with another couple of amps. We were back on trickle charge after about 3 hours. Over the 3 days since, we haven't used the inverter, but pretty heavy use of the water pumps, for baths, 3 washing machine loads and the usual washing up etc, plus lights. There has been nothing from the wind generator and mainly overcast apart from today, Sunday, but the batteries are showing 98%. The figures will fluctuate of course depending on varying factors and I only see them as a general indication based on my everyday view of the readings.

 

I'm certainly not an electrician, but so far I am impressed with the 'laying flat' output and will shortly be adding a second panel plus a new mppt controller, before switching our power use to to the inverter for all our daytime use. A tilting mount will also be added to get the best output from the panels. I estimate up to £2.00 per week Summer saving with the 2 panels and wind generator and of course plenty of power when away from the mooring. Not total independence, thats for sure, but a step in the right direction.

 

Roger

 

Er...

 

Why, oh why, do people have to quote an entire post, if all they want is ask a generic question? Have some thought for those browsing on their phones, or dial up connections.....

 

 

:lol:

 

What was that?

Edited May 17, 2010 by blackrose

[Scooby]

QUOTE (Roger Gunkel @ May 17 2010, 02:56 AM)

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week. We have a charge controller with the Rutland which allows us to plug in up to 160w of solar pv. so thought that maybe about 100w was a good starting point. A neighbour has just bought one of the Maplin 60w units at £199 and was telling us how good it is, but having looked at it, it is about a metre square, made up of 4x15w panels, which are the amorphous type, wich require a much larger area than the polycrystalline ones. Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. So we took the plunge and went over to collect one, smaller size than I expected at about 1200x670mm with waterproof connector box and built in diodes. I was also surprised that it only weighed 9.8 Kgs and had the aluminium frame already drilled for fixings. We finally plugged it into the controller at 7.00pm and immediately had a reading on our monitor of a 7.7 amp charge rate with the panel held up facing the sinking sun. I laid it flat on the roof and was still getting 5amps. Being use to getting about 2amps from the Rutland in a steady breeze, it was surprising to find 5amps of silent power from a flat panel at 7.00pm on a mid May evening. We were still getting a charge reading on the monitor right up until the the last brightness in the sky. The batteries (400 ah) were showing 80% when we went to bed. By midday the next day, with a bright overcast sky, we were showing a green and red light on the controller which meant that the charging rate was being reduced by the controller to a trickle charge and the battery state was on 92%.

 

The sun came out in the afternoon, so we switched all power to the inverter and then switched back to grid after a couple of hours having used about 25ah from the batteries. The charge rate showed up to 7.9 amps and after an hour the wind generator also kicked in with another couple of amps. We were back on trickle charge after about 3 hours. Over the 3 days since, we haven't used the inverter, but pretty heavy use of the water pumps, for baths, 3 washing machine loads and the usual washing up etc, plus lights. There has been nothing from the wind generator and mainly overcast apart from today, Sunday, but the batteries are showing 98%. The figures will fluctuate of course depending on varying factors and I only see them as a general indication based on my everyday view of the readings.

 

I'm certainly not an electrician, but so far I am impressed with the 'laying flat' output and will shortly be adding a second panel plus a new mppt controller, before switching our power use to to the inverter for all our daytime use. A tilting mount will also be added to get the best output from the panels. I estimate up to £2.00 per week Summer saving with the 2 panels and wind generator and of course plenty of power when away from the mooring. Not total independence, thats for sure, but a step in the right direction.

 

Roger

 

 

Er...

 

 

QUOTE (luctor et emergo @ May 17 2010, 06:29 AM)

Why, oh why, do people have to quote an entire post, if all they want is ask a generic question? Have some thought for those browsing on their phones, or dial up connections.....

 

 

 

 

 

What was that?

 

This post has been edited by blackrose: Today, 06:57 PM

 

Can you repeat that??????????????????????????????

 

QUOTE (Roger Gunkel @ May 17 2010, 02:56 AM)

Nearly six years since we bought our boat and fitted it out, but only just bought our first solar panel. We have a permanent residential mooring and mains hookup, but at 25p per unit, decided we should finally install a solar PV panel to be a little more flexible with our power, and able to generate more when away from the home mooring. We have had a Rutland wind generator for a couple of years, but although it's been great for helping to keep the batteries up, we felt that we would like to use the inverter more and the grid less.

 

Our 12 volt use has generally been quite low, just water pumps and lights, whereas our 240v consumption is normally about 30Kw per week. We work from home using computers, and run a washing machine and fridge/freezer, plus TV and hi-fi. When we move off the mooring, we would use about 25-30% of that or about 700 -800 ah over a week. We have a charge controller with the Rutland which allows us to plug in up to 160w of solar pv. so thought that maybe about 100w was a good starting point. A neighbour has just bought one of the Maplin 60w units at £199 and was telling us how good it is, but having looked at it, it is about a metre square, made up of 4x15w panels, which are the amorphous type, wich require a much larger area than the polycrystalline ones. Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. So we took the plunge and went over to collect one, smaller size than I expected at about 1200x670mm with waterproof connector box and built in diodes. I was also surprised that it only weighed 9.8 Kgs and had the aluminium frame already drilled for fixings. We finally plugged it into the controller at 7.00pm and immediately had a reading on our monitor of a 7.7 amp charge rate with the panel held up facing the sinking sun. I laid it flat on the roof and was still getting 5amps. Being use to getting about 2amps from the Rutland in a steady breeze, it was surprising to find 5amps of silent power from a flat panel at 7.00pm on a mid May evening. We were still getting a charge reading on the monitor right up until the the last brightness in the sky. The batteries (400 ah) were showing 80% when we went to bed. By midday the next day, with a bright overcast sky, we were showing a green and red light on the controller which meant that the charging rate was being reduced by the controller to a trickle charge and the battery state was on 92%.

 

The sun came out in the afternoon, so we switched all power to the inverter and then switched back to grid after a couple of hours having used about 25ah from the batteries. The charge rate showed up to 7.9 amps and after an hour the wind generator also kicked in with another couple of amps. We were back on trickle charge after about 3 hours. Over the 3 days since, we haven't used the inverter, but pretty heavy use of the water pumps, for baths, 3 washing machine loads and the usual washing up etc, plus lights. There has been nothing from the wind generator and mainly overcast apart from today, Sunday, but the batteries are showing 98%. The figures will fluctuate of course depending on varying factors and I only see them as a general indication based on my everyday view of the readings.

 

I'm certainly not an electrician, but so far I am impressed with the 'laying flat' output and will shortly be adding a second panel plus a new mppt controller, before switching our power use to to the inverter for all our daytime use. A tilting mount will also be added to get the best output from the panels. I estimate up to £2.00 per week Summer saving with the 2 panels and wind generator and of course plenty of power when away from the mooring. Not total independence, thats for sure, but a step in the right direction.

 

Roger

 

 

Er...

 

 

QUOTE (luctor et emergo @ May 17 2010, 06:29 AM)

Why, oh why, do people have to quote an entire post, if all they want is ask a generic question? Have some thought for those browsing on their phones, or dial up connections.....

 

 

 

 

 

What was that?

 

This post has been edited by blackrose: Today, 06:57 PM

 

Can you repeat that??????????????????????????????

 

whats generic mean?

[Roger Gunkel]

:lol:

 

Roger

[Scooby]

:lol:

 

Roger

 

Hi roger, i am a total newbie when it comes to power stuff, if i get the 120w solar panel like you did does it come with everything i need to install it and instructions, we are struggling with power at the moment as our batteries are ready for replacing, hoping to get some from vince in a few months, thought it might be a good idea to get solar panel now to help us out for a bit longer..dont understand regulators and volt metres lol..thx for any help..

[Roger Gunkel]

Hi Scooby, I am neither an electrician or a solar expert, I just listen and read then put into practice what seems to be the best solution for me. I'll gladly pass on what I have picked up though if you feel it may help you.

 

There are various types of solar panel of varying efficiencies. The amorphous type, such as the £199 60w Maplin ones, seem to work best in bright sunshine, with performance dropping off quite rapidly in overcast conditions. They also seem to require about 50% more area of panel for the same output as The Polycrystalline ones. The Polycrystalline are probably the most common, having a mottled blueish look to the panel. They apparently work better in our climate as they still produce useable power in overcast conditions. Mine was still giving a small reading even after the sun had gone down, as long as the sky was light. There are also variations by different manufacturers including self adhesive flexible ones that you can walk on, although at a higher price.

 

As your batteries are 12v and the panels give out varying voltages depending on conditions and efficiency, you need a solar controller or regulator that will convert the output to a charging voltage for the batteries. They will also sense the charge condition of the batteries, to prevent overcharge. Most panels have diodes built in, to prevent the panel draining power back out of the batteries at night. Some regulators have additional connections to allow not only a charging output to the batteries, but also a direct feed to an appliance that may be in constant use such as a 12v fridge. It is also important to ensure that the controller/regulator can take the maximum output from the panel. That is slightly confusing to a non electrician like myself, as the panels are normally sold on Wattage, and the controllers by amps. A rough calculation would be to divide the Watts by 12 for a 12v system i.e. a 120w panel gives a 10ah maximum output. One final point on controllers, is that there are two main types I believe, the standard ones and the MPPT type, which use sohisticated circuitry to optimise the balance between panel and batteries to give the best output at all times. They can make an improvement of up to 15% in the summer and considerably more under low light conditions.

 

The wattage quoted for the panels, is always based on maximum output at midday, midsummer, in full sunshine, with the panel inclined directly towards the sun. So it is important to realise that only under ideal conditions will the quoted output be reached. It will help if you work out the ammount of ah you would like to be able to generate over a 24 hour period, then you can relate that to the size of panel you need. There are tables readily available on the internet that will tell you the average amount of panel output you can expect during different times of the year, but expect to get a very small percentage of the panel output during winter months.

 

If you are serious about solar energy, then you will need to have a battery bank that is able to continue to give output even on cloudy days when the panels are not giving much power, usually at least 3 times the ammount of your daily consumption. Some people allow a lot more, not forgetting that you should never use more than 50% of your batteries full rating.

 

We have no intention of trying to be fully reliant on solar as it would cost us thousands, but rather we want to reduce our reliance on grid power and increase our power generation when we are cruising. At the moment we have a Rutlad 913 wind generator with a Rutland wind/solar controller and 1x100w PV panel. We will be adding a second 100w panel soon and putting both through a seperate MPPT controller.

 

Hope some of this helps,

 

Roger

[nb Innisfree]

usually at least 3 times the ammount of your daily consumption. Some people allow a lot more, not forgetting that you should never use more than 50% of your batteries full rating.

 

 

Roger

 

Not forgetting of course that batteries lose their capacity over a period of time, ours are less than 50% of capacity and still functioning well, so maybe 6 to 8 times daily usage?

Edited May 18, 2010 by nb Innisfree

[Roger Gunkel]

Not forgetting of course that batteries lose their capacity over a period of time, ours are less than 50% of capacity and still functioning well, so maybe 6 to 8 times daily usage?

 

Yes I was making the assumption that the battery bank can maintain the daily consumption over 3 days or so, which may be so when they are new, but as you rightly say, when the batteries maximum capacity gradually diminishes to only 50% of their new state, then you will only have 25% of the original capacity still available. Another reason why its always useful to be aware of what your battery condition is.

 

Roger

[barge sara]

Recent googling suggests that the Maplin ones are a fairly good price per watt at about £3.20 pw, but are huge for the output. Polycrystalline are a lot smaller but seem to vary from about £3.80 to as much as £5 pw.

 

I eventually found a company advertising 100w Polycrystalline for £280, which seemed an excellent price and they turned out to be in Cambridge about 7 miles from us. .....

 

With a bit of shopping around you should be able to get close to or under £2 per watt now.

I've just added five 100W polycrystaline panels and got them for £910 delivered. There was some discount for buying five, but not that much....

Edited May 18, 2010 by barge sara

[Phoenix_V]

With a bit of shopping around you should be able to get close to or under £2 per watt now.

I've just added five 100W polycrystaline panels and got them for £910 delivered. There was some discount for buying five, but not that much....

 

Do tell where?

[barge sara]

Phoenix_V said:

Do tell where?

 

Thousand Suns Ltd

81 Furzehill Road

Borehamwood, HERTS WD6 2DL

United Kingdom

[Phone number removed] 

 

I have to say they're not the easiest company to deal with, but they appear to be good panels at a good price.

Edited September 2, 2017 by magpie patrick
Phone number removed at request of the owner of the number

[Scooby]

Hi Scooby, I am neither an electrician or a solar expert, I just listen and read then put into practice what seems to be the best solution for me. I'll gladly pass on what I have picked up though if you feel it may help you.

 

There are various types of solar panel of varying efficiencies. The amorphous type, such as the £199 60w Maplin ones, seem to work best in bright sunshine, with performance dropping off quite rapidly in overcast conditions. They also seem to require about 50% more area of panel for the same output as The Polycrystalline ones. The Polycrystalline are probably the most common, having a mottled blueish look to the panel. They apparently work better in our climate as they still produce useable power in overcast conditions. Mine was still giving a small reading even after the sun had gone down, as long as the sky was light. There are also variations by different manufacturers including self adhesive flexible ones that you can walk on, although at a higher price.

 

As your batteries are 12v and the panels give out varying voltages depending on conditions and efficiency, you need a solar controller or regulator that will convert the output to a charging voltage for the batteries. They will also sense the charge condition of the batteries, to prevent overcharge. Most panels have diodes built in, to prevent the panel draining power back out of the batteries at night. Some regulators have additional connections to allow not only a charging output to the batteries, but also a direct feed to an appliance that may be in constant use such as a 12v fridge. It is also important to ensure that the controller/regulator can take the maximum output from the panel. That is slightly confusing to a non electrician like myself, as the panels are normally sold on Wattage, and the controllers by amps. A rough calculation would be to divide the Watts by 12 for a 12v system i.e. a 120w panel gives a 10ah maximum output. One final point on controllers, is that there are two main types I believe, the standard ones and the MPPT type, which use sohisticated circuitry to optimise the balance between panel and batteries to give the best output at all times. They can make an improvement of up to 15% in the summer and considerably more under low light conditions.

 

 

 

The wattage quoted for the panels, is always based on maximum output at midday, midsummer, in full sunshine, with the panel inclined directly towards the sun. So it is important to realise that only under ideal conditions will the quoted output be reached. It will help if you work out the ammount of ah you would like to be able to generate over a 24 hour period, then you can relate that to the size of panel you need. There are tables readily available on the internet that will tell you the average amount of panel output you can expect during different times of the year, but expect to get a very small percentage of the panel output during winter months.

 

If you are serious about solar energy, then you will need to have a battery bank that is able to continue to give output even on cloudy days when the panels are not giving much power, usually at least 3 times the ammount of your daily consumption. Some people allow a lot more, not forgetting that you should never use more than 50% of your batteries full rating.

 

We have no intention of trying to be fully reliant on solar as it would cost us thousands, but rather we want to reduce our reliance on grid power and increase our power generation when we are cruising. At the moment we have a Rutlad 913 wind generator with a Rutland wind/solar controller and 1x100w PV panel. We will be adding a second 100w panel soon and putting both through a seperate MPPT controller.

 

Hope some of this helps,

 

Roger

 

 

Thx for putting the time and effort into that, it was a really good read, i might take the plunge and buy one shortly, we have 8 batteries at the moment 135amp each, trouble is they all ruined, the original first four we didnt know there state so replaced them, but we have damaged the new four cos of the large telly that was onboard when we bought it, due to lack of knowledge really and the boat being more of a shoreline conection type, since then we added the old four to the bank to try and make some use of the new damaged ones, we been liveaboards 7 months so the new four batteries are 7 months old, they charge upto 12.7 volts but drop very quick and seen them many times in a morning at 11.5 and lots lower,

 

we have done a few changes and got rid of the 240volt telly and dvd seperate,(boat even had a sub woofer omg) so now got 12v telly with built in dvd running straight from batteries and works fine and has done for many months, the fridge is pretty big same as you get in a house like a washing machine size, we use a pc but only when engine running cos not enough power otherwise, and at same time we can charge phones and laptops up, halogen lights in roof approx 15 of them in total were 20w bulbs so i swapped them for 10watts, i like it dark lol, we also have a few battery powered led lights we use to help out, overall we are managing with the batteries but ready for new ones, we spent nearly £500 on the last 4 numax 135amp ones so dont want to do that again, gunna ask vince for 6 and pick them up when we pass oxford in a few months, we can see us living on our boat for many many years so a solar panel will get its use in that time i suppose..

[Phoenix_V]

Thousand Suns Ltd

81 Furzehill Road

Borehamwood, HERTS WD6 2DL

United Kingdom

020 7193 6531

 

07771778011 (Jean)

 

I have to say they're not the easiest company to deal with, but they appear to be good panels at a good price.

 

Ah better still that's near me though i gather Borehamwood is the warehouse and the offices are elsewhere, may pay them a visit if possible.

[Smelly]

You may well have inspired me to another 60 watts Roger...

 

That'll take us up to 230 which is about as much as the controller will handle and about as much space as I can afford on the roof...

 

Hmmm...

[Gibbo]

We have a permanent residential mooring and mains hookup, but at 25p per unit

 

Don't people keep telling us that's illegal?