Has anyone got advice about the best solar (or other) solutions for indoor lighting, and some charging of gadgets in a hut? I'm interested to hear any ideas about a simple set-up to get started (including other options like using other types of rechargeable batteries like the Makita 18v).
Is this thread still active? Im about to embark on installing a simple solar system to our off grid hut and could do with a wee bit mentoring? Anyone?
Colin Bell commented on Facebook re: inverter and making sure your charge controller is capable of supplying your inverter (if you choose to use one).
My car setup uses a 30A controller (I recommend a 30A controller which has a Voc above 38V on a 12V system).
I can connect 30A to the load output. My load is my fridge (4A), some lights (1-2A). I also run my 375VA inverter but it is only really a load of around about 100VA. I know this because I know what my laptop and screen take (I measured it). 100VA to amps is 100/12 = 8A. So my total load is about 14A. This is below the controller 30A.
I disconnect my inverter when I am not using it: I use a 50A Anderson plug. Available up to 175A.
My recommend is to buy the panel, buy the controller, buy a battery. Play around safely: ask away if you need help. If it seems too complex or there is talk of fuses, disconnects then it is getting too complex. The controller comes with connection diagrams. If you overload the controller it will simply shut down.
If you short the battery the battery it can kill you.
Message me on Facebook (https://www.facebook.com/mark.robertson.33886305) if you want more help. (1) start with a panel. As large as your site and pocket permit. This 280W is GBP100. https://www.amazon.co.uk/Polycrystalline-Photovoltaic-suitable-installations-Caravan/dp/B07PZ7T3V8/ref=lp_14868283031_1_10?s=industrial&ie=UTF8&qid=1591540762&sr=1-10 (2) that panel is Voc: 37.7V; Isc: 9.7A. This is important (3) select a charge controller. Here is one that would do the job. https://www.amazon.co.uk/SolaMr-Controller-Battery-Regulator-Display/dp/B07SHGM7BH/ref=psdc_4370160031_t2_B087226LZF (4) CHECK: the controller is 30A charge current: this is MORE than the Isc of the panel (which is 9.7A). PASS (5) CHECK: the controller says the max Voc is (for 12V set up) 23V. The panel is Voc 37.7 so this is BAD. We need another controller. (6) this one is Voc 50V. PASS. https://www.amazon.co.uk/Controller-Paremeter-Adjustable-Display-Regulator/dp/B07PGYHJSJ/ref=psdc_4370160031_t2_B07SHGM7BH (7) Find a battery: https://www.amazon.co.uk/SuperBatt-Leisure-Battery-Caravan-Motorhome/dp/B07T5YYB1Y/ref=sr_1_4?dchild=1&keywords=12v+deep+cycle+battery&qid=1591541332&sr=8-4
(8) buy some 12V LED lights, some switches. (9) add an inverter if you some 240V (10) live with it for a while before wondering if another panel or another battery is the answer to why you run out of power at 9pm.... the answer to this could be panel, or battery, and sometimes both. Mostly it comes down to $ and what you find acceptable. How long will it run lights? A 100Ah battery is 1200Wh of power. Divide that in half: 600Wh. In my experience, divide it in half again: 300Wh. A 5W LED bulb will run for 60hrs. 10 such bulbs will be 6hours. How long will it take to charge? Hmm... difficult to say because of site. First, assume you need to fill half the battery: 600Wh. A 280W panel will not give 280W. Take that number and half it: 140W. Next assume you will get only 6 useful hours at this half rate. 6 * 140 = 840Wh. Your 280W panel should probably recharge your battery.
Once it is installed keep a check on the BATTERY FULL indication. If you are not getting this by around 2-3pm then you likely need to add another solar panel. If it is filling but you run out of juice too early at night then you need more battery. By adding another battery you may need more panel, too: watch for the BATTERY FULL indication when you have added #2 battery. Add a central switch or a timer relay to force lights off at night. I also force fridges off at night: the food will not spoil.
Keep your panel close to your charge controller (ie, don't put them in the field 100m away). Keep your battery very close to your charge controller. It will work across long cables but you will find that a 280W panel effectively becomes a 200W panel after losses across your cabling.
When you come to double up the battery simply add it in parallel to the first one (don't go to 24V for a simple set up). Red to red, black to black. ALWAYS replace both batteries when you need to replace 1: the dodgy battery always dominates. When you come to add more panels be careful. I'm not writing this up here and am sure the internet is full of info on it. Or message me asking "can I use this with that". I run a system like this on my Landrover: 2x90W panel + 30A controller + 105Ah battery. Separate from the primary battery. Yes, it is Africa but this is more than adequate for lights, fridge (around 40W continuous load), PC and screen for a few hours a day. I've also done new systems of 5-10kVA with arrays of solar panels. These systems are fundamentally the same, just that you end up investing in a 48V system (lots of batteries, replaced every 2-3 years) and a combo charge controller/inverter (about GBP600 for 5kW). That's my tuppence worth for the day
Very happy with this little charge controller. Over ten years of faultless service for a small solar array. https://www.morningstarcorp.com/products/sunsaver-mppt/