# Off Grid Solar Power System **URL:** \ **Category:** Factual Questions\ **Created:** [July 24, 2013, 6:10pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401 "2013-07-24T18:10:46Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [July 24, 2013, 6:10pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/1 "2013-07-24T18:10:46Z")
OK, so I’m finally gonna install a off-grid solar power system for our cottage on an remote island in Georgian Bay. I have used smaller portable 12v systems and have designed and built my own wind generator so I’m familiar with how it all works. I know the math and am tired of reading tables so I’d appreciate some practical experience from someone whose not a salesman. At this point, I’m doing the research on the size and requirements we may have in the future as well as designs, brands, upgrades, etc. As far as demand goes, I’m calculating for: 12 light fixtures (LED) a hood fan a DC water pump for 2 faucets, a toilet, and a shower a UV purification system a radio 12 - AC outlets 6 - 12v DC outlets We’re also hoping to run: a TV and satellite receiver Chargers for various electronics such as iPads, cell phones, etc… a toaster (I know, I know) My 2 fridges and stove are propane and I will add a tankless heater at some point. Inverters? 2800W and 4000W but will probably go with the bigger one. PV Panels?- how big of an array? Any brands better than others? Batteries?- I’ll be running 24v DC to the inverter - probably 6v 530W Charge controllers? I have one that cost about $50, do I really need the $600 one? Anyone have a system running that would like to discuss/brag about it? ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [September 1, 2013, 4:18pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/4 "2013-09-01T16:18:00Z")
Do you have an estimate of how many kilowatt hours you will use in a month? ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [September 1, 2013, 9:43pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/5 "2013-09-01T21:43:48Z")
> [@Sparky812](#): > > a DC water pump for 2 faucets, a toilet, and a shower Might I recommend actually getting one of the lovely and fairly inexpensive pressurized tanks to pump your water into? You do not want to pump direct into your house plumbing - tanks allow sediments to settle out, to use the plumbing at night without running down the battery system and they even out your water pressure [so the water doesn’t go flup flup flup along with the water pump.] You do not need a tanked water heater, but life will be much better with a pressurized tank. ---
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [September 1, 2013, 11:47pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/6 "2013-09-01T23:47:31Z")
> [@aruvqan](#): > > Might I recommend actually getting one of the lovely and fairly inexpensive pressurized tanks to pump your water into? You do not want to pump direct into your house plumbing - tanks allow sediments to settle out, to use the plumbing at night without running down the battery system and they even out your water pressure [so the water doesn’t go flup flup flup along with the water pump.] > > You do not need a tanked water heater, but life will be much better with a pressurized tank. Yes, I’m already running a gravity feed tank but I will use a 12v pump to fill it instead of a Honda gas pump. I wil be installing a propane tankless water heater for hot water on demand. ---
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [September 1, 2013, 11:49pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/7 "2013-09-01T23:49:09Z")
> [@PastTense](#): > > Do you have an estimate of how many kilowatt hours you will use in a month? A month? No. Systems are rated by daily kilowatt usage, usually over a 3-5 day charging period. ---
**Author:** ![neilzero](https://avatars.discourse-cdn.com/v4/letter/n/fbc32d/32.png) [@neilzero](https://boards.straightdope.com/u/neilzero)\ **Post date:** [October 15, 2013, 1:19pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/8 "2013-10-15T13:19:25Z")
> [@Sparky812](#): > > OK, so I’m finally gonna install a off-grid solar power system for our cottage on an remote island in Georgian Bay. > > I have used smaller portable 12v systems and have designed and built my own wind generator so I’m familiar with how it all works. I know the math and am tired of reading tables so I’d appreciate some practical experience from someone whose not a salesman. > > At this point, I’m doing the research on the size and requirements we may have in the future as well as designs, brands, upgrades, etc. > > As far as demand goes, I’m calculating for: > 12 light fixtures (LED) > a hood fan > a DC water pump for 2 faucets, a toilet, and a shower > a UV purification system > a radio > 12 - AC outlets > 6 - 12v DC outlets > > We’re also hoping to run: > a TV and satellite receiver > Chargers for various electronics such as iPads, cell phones, etc… > a toaster (I know, I know) > > My 2 fridges and stove are propane and I will add a tankless heater at some point. > > Inverters? 2800W and 4000W but will probably go with the bigger one. > PV Panels?- how big of an array? Any brands better than others? > Batteries?- I’ll be running 24v DC to the inverter - probably 6v 530W > Charge controllers? I have one that cost about $50, do I really need the $600 one? > > Anyone have a system running that would like to discuss/brag about it? I’ve thought about such a system a lot, so I probably know some things that aren’t so. You will be disappointed if some of your panels are shaded between 9 am and 3 pm, especially late December and if you are farther North than 45 degrees latitude. Worse you need a steep South facing roof, to keep the number of panels reasonable. You need to cover all your sunny South facing roof to avoid damaging your batteries near the end of a week long stay at your cabin. Likely a cheap 300 watt gasoline generator is best for the rare need to catch up the battery charging. Lots of batteries mean you rarely need to run the generator, and the batteries will last longer, however you can start small and expand later. Do consider the possibility of thieves and vandals. The 2800 watt inverter is adequate for near term except you may need to shut off a high watt something to run the toaster. Neil ---
**Author:** ![Sparky812](https://avatars.discourse-cdn.com/v4/letter/s/eb9ed0/32.png) [@Sparky812](https://boards.straightdope.com/u/Sparky812)\ **Post date:** [October 15, 2013, 3:06pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/9 "2013-10-15T15:06:16Z")
> [@neilzero](#): > > I’ve thought about such a system a lot, so I probably know some things that aren’t so. > You will be disappointed if some of your panels are shaded between 9 am and 3 pm, especially late December and if you are farther North than 45 degrees latitude. Worse you need a steep South facing roof, to keep the number of panels reasonable. You need to cover all your sunny South facing roof to avoid damaging your batteries near the end of a week long stay at your cabin. Likely a cheap 300 watt gasoline generator is best for the rare need to catch up the battery charging. Lots of batteries mean you rarely need to run the generator, and the batteries will last longer, however you can start small and expand later. Do consider the possibility of thieves and vandals. > The 2800 watt inverter is adequate for near term except you may need to shut off a high watt something to run the toaster. Neil I’m actually looking for people who have some practical experience, so I can gauge the initial size of my system and what obviously I can expand on components later. But I will address some of your comments. Shade will not be a problem since we are on a large rocky island. We only access the cottage between late May and late September/early October and we are just below the 45th. We have alot of room and the panels will not be on the roof so I can face them any direction I want. I can also add as many panels as I want but will probably start with 4 panels in the 1000-1200W range. I’m assuming you mean a 3000W generator? Already have one which I use for power tools, etc. Thieves and vandals don’t really concern me. We are on a remote island in a large grouping of family owned islands. If someone could actually get way out there and steal stuff without the marina and all the friends and neighbours noticing, what could I do to prevent it? Besides, there’s way, way richer neighbours all around us. You’re right on one thing, a 2800W inverter may be too small at some high demand periods which is why I’m looking for others with similar systems already installed. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [October 15, 2013, 5:31pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/10 "2013-10-15T17:31:04Z")
> [@Sparky812](#): > > You’re right on one thing, a 2800W inverter may be too small at some high demand periods which is why I’m looking for others with similar systems already installed. At least go with the 4000W inverter so that if you start with a lower amount of panels you can add more without needing another inverter or changing out the one you have. It is a lot simpler. I went up from my original install and wish I had better inverters to start. My system is on grid so I don’t have any other good information. One bonus though, the power output from the inverters is usually much cleaner than any portable generator. This is important for charging electronics and even seems to make a difference to CFL & LED lighting. Toasters are a fairly big draw, so are coffee makers don’t forget. I just picked up an [18w LED that puts out about 100w equivalence for $25](http://www.amazon.com/dp/B009EU82PW/ref=pe_385040_30332190_pe_175190_21431760_M3T1_ST1_dp_1). I am really impressed by the light it puts out. The wattage of a small LED or LCD TV can be really low. I understand that Suntech, Kyocera and Grape are all excellent brands for panels. I’m friendly with the guy that installed my system and he really likes the Kyocera panels. He has a mobile system that he helps runs small outdoor stages with and uses Kyocera for that. My panels are a mix of I forget what and the newer ones are Kyocera. Panel prices are finally begin to drop quickly now. That should be good news, so shop around. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [October 15, 2013, 5:42pm UTC](https://boards.straightdope.com/t/off-grid-solar-power-system/664401/11 "2013-10-15T17:42:52Z")
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