Solar for 600 ft cabin: - Small Cabin Forum


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Small Cabin Forum / Off-Grid Living / Solar for 600 ft cabin:

Author	Message
scrimshaw Member	# Posted: 2 Jul 2009 10:20 Reply I "want" to run five out door lights, 6 indoor lights and 3-4 electrical outlets. All will have switches so I won't be running all at the same time by any means. I only use the cabin for hunting on the weekends, am getting a wood stove and is well insulated. Any thoughts on how many solar panels and of what voltage I would need. Thanks for the helpful website. Saw what you used, but unsure how to install. Any helpful sites or posts on install/setup? Thanks so much! Eric
CabinBuilder Admin	# Posted: 3 Jul 2009 00:24 - Edited by: CabinBuilder Reply To get reasonably accurate answer, you would have to calculate the total required wattage vs. battery capacity vs. solar panel specs and how fast you need it to be re-charged. For example, a typical car battery is 70A/hr. That's @ 12V = 840W/hr --- i.e. a brand new, fully charged battery can (theoretically) power one 100W light bulb for 8.4 hrs. As a VERY ROUGH estimate, I'd say you need ~3 such batteries (or equivalent), with 30W solar panel and a 7A charge controller. That's assuming fairly conservative usage, and several days to recharge. You can use modest light bulbs, 15-40W 12V (there is an ample choice from the auto stores). If you want 110V power or bulbs, you will need an additional inverter. Hope this gives you an idea...
scrimshaw Member	# Posted: 4 Jul 2009 00:21 Reply Thanks Cabinbuilder!!! Do you have any good sites/recommendations on how to build my own? I saw and understand the basic components as listed on your website, but am not quite sure how to connect the dots.
CabinBuilder Admin	# Posted: 6 Jul 2009 10:52 - Edited by: CabinBuilder Reply Usually, solar system components (solar panel, charge controller, inverter) come with the diagram on how to connect them. Here is a typical basic solar power setup diagram, just in case:
keebler1 Member	# Posted: 6 Jul 2009 15:52 Reply Quoting: scrimshaw Do you have any good sites/recommendations on how to build my own? I saw and understand the basic components as listed on your website, but am not quite sure how to connect the dots. Skrimshaw, I ran across this site when my wife and i where tired of our outrageous power bill for our home. There is alot of good information there,it helped us out tremendously and hopfully it will help you to. www.otherpower.com
scrimshaw Member	# Posted: 12 Jul 2009 22:11 Reply Thanks for the help! On the site you have that you used the 1500 power pack with built-in inverter. What's the difference in using this versus buying a separate battery and inverter and is the power pack better...seems like it keeps everything contained well and is maybe a simpler option and if so something I would like to consider. I've got all my wiring done with the help of a friend. We have four outdoor lights, five indoor lights (all lights are 60 watts bulb rated but can also considering using fluorescentl lights), and five wall receptacles (two are outside). All lights have separate switches. Not that good with "power" so am still trying to find out what I need. As long as I keep my solar system below $1000 I will be happy. Is a 80 watt solar panel too much, or necessary or should I go with something smaller? I want 4-8 hours of use (which will probably be maybe one wall outlet for a radio for 3 hours and 3-4 hours of light (maybe 3 lights on at a time) per day. We'll probably use at most two days out of week and will only be a weekend cabin. No fridge, AC or any other electric use other than basic lighting will be needed. Recommendations on a good septup? We have breaker box, grounding rod in, etc. and am ready to get solar componenets or buy solar kit. Would like to buy best of best componsents rather than a kit but not sure if I can figure out how to put together connections...is it that hard? Thanks, Eric
Kithera	# Posted: 21 Dec 2009 17:54 Reply Hi Scrimshaw, You're asking a lot of questions, so I'm going to do my best to help. The difference between a power box and a separate battery/charger/inverter/and power panel is mostly in convenience. To assemble the separate components takes time and a certain level of education. Miss wiring can be dangerous, as can any lack of proper safety features like fuses and disconnect switches. The power box does it all for you, in a safe way, but at a cost premium. The choice is yours. Now to your question of sizing. Daily loads, time, power, energy Radio, 3hr, 20watts, 60 watt hours lights (3X60), 4hrs, 180watts, 720 watt hours total daily need: 780 watt hours Now, for my area, we average 2.2 hours a day of "Full sun" which means I would need a 400 watt rated panel for this load. At an average cost of $5 a watt, this comes to $2000. Since it sounds like you're house is already wired for 110V ac, you'll need at least a 200 watt inverter. Use a good full sign wave, and that adds about $200, you can save this all by going full 12v DC. 12V CFLs are available. Finally, you'll want to have enough battery power to smooth out your needs for a week. Each golf cart battery is good for about 500 watt hours of useful charge, so 780 watt hours a day, 7 days a week, divided by 500 watt hours of capacity, means you need 12 batteries (round up to the nearest pair) at about $70 each, so another $800. Using CFLs can drop your power needs significantly (15 watts (60 watt equivalent) *3, 4 hours, 45 watts, 180 watt hours, 110 watt panel, $600 for the panel, 4 golf cycle batteries, $240 for the batteries). Hopes this help.