useful solar panel explanations

[smileyt]

For the quintessentially thick, like me, here is a really good website explaining what you need in a solar power set-up. I feel much more confident now and am ready to start saving up my pennies!

http://www.cleversolar.co.uk/shop/help-advice-faq.html

Takes a bit to read through each section but it really does help. I'm still a bit woolly on amps, volts and watts but I get the gist of it!

[Ferricks]

thanks for this - it's exactly what I was needing!

[Orange5]

Solar panels are very good for lighting and 12 volt applications. However for mains type use the can be e
Very costly.

[preppingsu]

Solar panels are very good for lighting and 12 volt applications. However for mains type use the can be e
Very costly.

Any change, when you are able to, could you put together a tutorial about solar usage based around a 12v system, please.
Thank you

[bazonbeleza]

My main source of battery charging aboard Beleza is by 240 watts of solar power, in three 80w panels, dumping the load into a main bank of 300Ah domestic battery and a second bank of 300ah engine starting battery. That drives all my lighting needs and no all of it is LED there are Halogen lights in the boat, too. It runs the telly, the dvd, the and the sound system which really does drink the power (4 x 40 watts, meaning at full chat its using twice that power) it also runs the fridge. Ice for a GnT an imperative. All on a 12v sysytem

I usually start the day with a big deficit that is made up during the day, If i'm a bit too profligate with the power then I turn the generator on for an hour for 240v to drive the microwave, toaster and kettle,etc plus a bit of charging.

My newly repaired Aerogen wind genny, will be going on shortly that will help reduce the need to turn the genny on at all.....hopefully. I could add another Solar panel but that would need another 300Ah battery to store the extra juice.

it is all a very delicate balancing act but once batteries, panels etc are installed there is no ned for shore connection at all. I'm now debating wether the new watermaker will be genny driven (240v) or 12v or 240v driven from my inverter.

Houses are not too disimilar to boats other than you have bigger loads, but with the advent of lcd tv's, low energy lights and fridges, a solar array and big inverter it seems to be the way to go, I'm not talking of the flog leccy back to the grid schemes but a low key system of solar/ battery that generates most of what you need. Besides should anything happen do you want your electricity vanishing into a grid? Costs to me? 3 solar panels off ebay £300, Domestic 300ah battery £300, Aerogen £750, inverter £250 so a total £1600 but then I've had no electricity bills for seven years

You can also build it all up gradually, say a couple of panels and a big batttery and smaller inverter.

My wind gen is an expensive american marine one and could easily be replaced with a home fabricated unit for land based application, for a fraction of the cost, whatever you are told its not brain surgery.

Hope this helps

[C4tch]

That's a very interesting read. Thanks for taking the time to put that together for us!


C

[bazonbeleza]

For small scale Solar panel application, the way its calculated is quite simple, basically you just add up the loads, in Amps, multiply the loads by the hours per day you use them. So you have say 3 20w bulbs that are on for four hours a night, 25 watts divided by the voltage give you the Amps it uses so approx 2 Amps if you have those three on for four hours a night then in one night you will have used 3 x 2 amps x 4 hours =24 Amp hours (Ah) similarly if your 12v fridge (awful users of the precious amps, believe me!) uses an average of 4 amps then over 24 hours it will use nearly 100 Ah

If you like music and you have a car stereo with a 25w per channel output you can guestimate it will use twice that to produce music so its using 100w divide that by 12 to get amps and it will be using 8 amps for every hour its on, so 4 x 8A =24 Ah so if musics your thing and its on for four hours while you read with your cabin lights on and drinking cold beer from your fridge over the day that will consume a grand total of 148 Ah

So now you have an idea of what you need in terms of Amp Hours for a basic simple system and you can add other items to your list to suit your particular needs.

Now you Know the Ah you use, you need to think battery size, Your average Leisure battery have an Ah rating, heres the trick, HALVE IT, most important this because if you let your battery discharge more than half it will have a very very short life indeed, trust me! So for a rough 150Ah use a 300Ah battery is needed if you are not to wreck it in a short space of time.

If you are using 150Ah and you have usable sun for say 10 hours a day (I am in Portugal after all. lol) and you need to put back 150A for an hour or 15 amps for ten hours then you need a minimum of

15a x 12v = 180w of solar panel to achieve this, hence my 240w array, as a bit of spare is always nice.

Over the years I have found that

1. you can never have enough battery capacity

2. you can never have enough solar panel to fill the above

3 wind power is expensive troublesome intrusive and noisy, but can give useful power when the sun don't shine,

4. Never, ever, discharge your battery below 50%

5. Big Batteries are heavy and wreck your back, big banks of 100ah batteries are much easier.

6. Caravan absorption type fridges are Voracious eaters of leccy,

7. Marine 12v compressor fridges use a quarter of the leccy of the above but are expensive. worth though.

8. Backup your power with a genny of some description.

9 order of preference, Solar its cheap, effective and quiet, then wind, its noisy, dangerous and expensive but automatic when its windy, then the genny as an oil guzzling backup, but at least its reliable in an emergency.

10. A good battery monitor such as a Smart Guage pays for itself in unwrecked batteries in no time at all.


For further reading I would recommend the 12v Bible for Boats as great source of info, boat related yes but still true for any low voltage system.

Any Questions class? lol

Hope this helps