Minister of Fire
- Jul 11, 2008
I only use around 200 KWh of electricity a month for 9 months of the year and around 280 the other 3 months, in the summer. But I am in the north where the sun isn’t strong in the winter.... it’d be neat to put a system in and I have done quite a bit of DIY project like building my own 3 level home here and electrical work here and in my past job in facilities maintenance.... huh... I don’t know... maybe someday.
Regular forum readers probably can skip this as its my standard plug for solar that I do when people express interest
First thing is go outside and look at your roof and make sure you have sun from 9 AM to 3PM. Your roof should face south for optimum production but some angle away from south may mean you just need another panel or two. There can be no significant shade or shadows. For a 2 KW array my guess is roughly 8 panels totally roughly 16' by 16'. You most likely need to leave open roof 2' from the ridge pole and two feet from the edge of the roof but that varies with locality. Best time to look for shading is winter but remember if you have tall trees in front of the spot factor them in.
Go to this website http://www.dsireusa.org/, look up your state and see what incentives and policies are in place for your area. You may not have winter sun but most production is spring fall and summer. Now go to this site http://pvwatts.nrel.gov/ and you can plug in your local data and it will calculate your array size based on annual electric usage (it assumes you have net metering available). If you dont,its gets a bit trickier as you end up with a smaller system to try to match your monthly loads so you are not throwing away power.
As long as you have a good net metering option, you are probably a candidate. Unless your building inspector or state requires it, a small PV installation like this is within the skills of homeowner comfortable with basic electrical. The microinverter based systems are pretty well plug and play and unless you have an odd roof, there are several on line companies that can design a system including the roof racking. The biggest hassle for most is working on the roof and finding the roof joists to screw into. The racking that holds the panels is attached to the roof with special flashing systems, dotn go cheap on them as that is the biggest spot where you could have a leak in the future, usually its lift up the shingle, slide in the special flashing and screw in a special lag screw to the joist centerline). The microinverters are either integrated with the panel or just need to be screwed on the back and then the panel leads are plugged into the microinverter. The manufacturer supplies a standard cable with special connectors on it at intervals. The microinverters are then plugged into this cable (usually limited to around 16 panels per cable whihc wont be a issue for you) and then the cable is run to your main panel. If you have 200 Amp panel its pretty simple, just install a new double pole breaker on the opposite end of the panel from the main breaker and you are good to go except for putting up a bunch of warning stickers which the supply house should be able to supply you and getting it inspected.
The biggest hassle is the paperwork, some inspectors and utilities dont like solar or their brother in law is an electrician so they can throw some hurdles in front of you.
There is book called Solar Power your Home for Dummies, there is an older version on line but you can buy the newer version for less than $15 bucks, its highly recommended to get you up to speed..