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#214118 - 10/06/14 06:56 PM Small off grid solar job
ChrisCrawford Offline
New Member
Registered: 09/12/14
Posts: 2
Loc: Molokai Hawaii USA
We have been electrical contractors for a long time in Hawaii and are just getting into solar voltaic (this is our first job). I have a customer with a 1 bedroom house, all gas appliances, that wants solar voltaic + a 600W windmill to power lights and plugs via a battery bank and invertor off the grid. He already bought a SunForce 600W wind turbine and built his own little shed for the batteries that is about 4' x 8' with an 8' x 12' roof, located about 140' from the house. He wants us to put solar panels on the roof of the shed and install a battery bank and invertor to supply power for his house. I am thinking we could at best get 4 panels on the roof of the shed to produce about 1200 watts + the 600 from the windmill would be 1800W. Is that enough for his situation (it is a windy area with lots of direct sun) and what brand of equipment would you recommend (panels, invertor, and batteries)? Your input would be appreciated. Thanks
Chris Crawford, Space Options, Molokai Hawaii
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#214119 - 10/06/14 08:33 PM Re: Small off grid solar job [Re: ChrisCrawford]
sparkyinak Offline
Registered: 07/08/07
Posts: 1307
Loc: Alaska
Sad to say that you are not even close to having all the needed data. First, unless real estate is a premium, I'd never put panels on a roof because you will likely need an engineer to sign off the roof loading. Do you have the isolation hours for the particular site? How is your southerly view?

As for the turbine, how's the wind conditions at the proposed site? If the turbine is close to the house, how is it's noise level rating? Is the neighbors to the north of the properly going to get "shadowed" by the "flickering" turbine? Will be high enough to get favorable winds? Does local ordinances have a height restriction? Is the turbine a suitable match for the wind conditions?

As for the equipment, who will be maintaining it? What is their aptitude as for taking care of it? What is the actual estimated electrical load as it each load and it's anticipated length of use, per day? How much is the customer willing to spend now? How much is the customer willing to spend later? Is the system bring connected to a utility? What does the local ordanaces have to say? Will there be a backup generator that will automatically or manually start when needed?

You may want to find a local advisor like a reputable supplier. Maybe take some courses and read read read on the subject. There's plant of good and not so good equipment out there. Too big or too small of a system will cost your customer needlessly. For get the customer being a minimalist. One light will lead to two lights. Two lights will lead to a coffee maker. The coffee maker will lead to a microwave. It will happen. I have dealt with many off gridders...

"Live Awesome!" - Kevin Carosa

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