Which solar systems should I consider?
November 3, 2012 7:50 AM   Subscribe

We're building a new house and have a roof with plenty of space for number of solar panels, most likely photo-voltaic electric ones. But I'm hard-pressed to find a thorough *current* analysis discussing the pros and cons of various schemes for the systems.

Buy myself, lease, tax breaks, etc. Are there any online resources that really break it all down? Not just websites for the vendors themselves that focus on just their products. Or the various energy conservation nuts trying live off the grid. I can respect those viewpoints, but they don't usually tell the whole story.

I'm looking to make use of my roof area for creating power and I expect to feed that back into the grid during daylight hours. I'm not looking to store it locally. I do not need nor expect to have this take me off the grid. I'm just looking to make use of an otherwise wasted space on my roof to do something to offset energy consumption.

So where can I find some truly objective reviews of what's available today?
posted by wkearney99 to Technology (5 answers total) 6 users marked this as a favorite
 
I'd begin with DSIRE (Database of State Incentives for Renewables & Efficiency put together by the US Department of Energy) to check which incentives are available to you. Click on your state for a full list that further breaks it down based on county and utility. DSIRE also details the federal incentives.
posted by snez at 9:13 AM on November 3, 2012 [1 favorite]


Just get some bids from local solar power companies. They do all of the analysis you need so that they can show you what the payback period will be. They will include local grid buy back rates, all available tax breaks, lease vs buy etc.
posted by monotreme at 11:34 AM on November 3, 2012


A person that might have some useful info for you:
http://www.stsci.edu/~pmcc/sustainability/index.html
See, for example, the powerpoint slides (last link).
posted by spbmp at 1:30 PM on November 3, 2012


I don't know a specific web site that has what you're asking for and in any case the answer is quite location specific. I'll assume you're in the USA and give you the top level view for there.

You have 3 basic choices ranked in order of how much work you want to do.
1) Lease a system
2) Buy a system from an installer
3) Buy the components and build you own system.

Option 1) is the simplest, it requires no money down. You will still pay a monthly bill but in this case it's for the solar power you use and will be lower than you current utility bill assuming that you have a moderate to expensive electric utility bill (more that $100/month). You're doing you bit for global warming and it's a pretty painless way to get a solar system. But make no mistake the company selling you the lease is making a profit on the deal - so you're paying for the convenience and not having to invest the money upfront. Good companies in this space are Solar City, Sunrun, Solar Universe and Sunpower.

Option 2) is very reasonable as long as you have the cash to pay upfront for the system. The cost of solar has dropped dramatically in the last 2 years thanks to the Chinese. Right now the cheapest solar panels are selling wholesale for about $0.70/Watt. Just 4 years ago they were closer to $5/Watt. Once you factor in the other items needed (grid tie inverter, racking, wiring and labor) you should pay about $4/Watt. So for a typical 4kW residential system you look to pay around $16~18k. There are still some rebates and tax credits available (30% federal ITC would knock off around $1.7K if you are in the 28% tax band) but it depends what state you live in. (I paid $42K for a similar system in 2006 - that was still $28K after all rebates & tax credits). The main decision point here is how big a system you want - in general you should size the system to zero out your electric utility bill. The range is 3kW for a small family house to 7kW for a McMansion. Select an installer like you would any contractor, pay for the permits and get the inspections done - a poorly installed system won't generate the promised power and could cause a fire.

Option 3) may only be open to you in some states unless you have a contractors license and in any case IMHO you really need a qualified electrician to do the wiring. But as you're already building a house you might have all the contractors you need. Frankly I don't recommend going this route unless you have somebody in the business to help you or you really want to educate yourself about solar. The system design is non-trivial and critical. At the end of the day you pay higher (retail) prices for the components compared to what an installer would pay so the savings over option 2) may not be that great. (In May this year I built a 6kW system and even with very favorable prices still paid $4/Watt by the time I was done).

My recommendation is go with option 2) if you have the cash, if you live in a sunny location with high utility rates it should be the financial winner over the mid to long term. Go with option 1) otherwise unless you want to learn a lot about solar and make a project out of option 3).
posted by Long Way To Go at 4:38 PM on November 3, 2012


Also, the last commenter had a good point: "if you live in a sunny location".

Odds are that your entire roof is not going to see peak sun all day, all year. For example, I live in the soggy part of Oregon. Solar water heating costs out pretty fast, even here. Solar electric can take a long, long time.

Even if its a hobby/long-term investment, take a good look at your neighbors' trees before you put in PV that might get shaded out in a few years.
posted by ivan ivanych samovar at 7:48 PM on November 3, 2012


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