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Learning, Sharing, and Teaching => Ask a Mustachian => Topic started by: FastStache on September 23, 2014, 09:20:10 PM

Title: Evaluating Solar Quote
Post by: FastStache on September 23, 2014, 09:20:10 PM
I started my journey into getting solar for my house.

The quote is a high level breakdown and I'm asking for a more detailed quote.

Panels are from Solar World, Sun Module Plus SW 270 mono.
Water Heater is Solene 80/40 Solar Water Heater with 4 X 10 Panel.

4320 watt PV with SMA inverter - 19800
Solar Water - 5000
Solar Attic Fan - 900
Solar Pool Heater 6 Panel with Auto Controller - 4300
Total - 30K

Discounts
Paid in Full - 1500
Trade in Water Heater Credit - 1000
Utility Credit - 550
Federal Solar Tax Credit - 9000
Total Discounts - 12050

Total Cost to me - 17950

This would include all the permits, inspections, eningeering, etc.

Panels come with 30 year warranty, and hurricane rated.

I have lived in the house for a few months now, and my averages bills in July and August have been about 215. So, the assumption being my average bill will be about 150. I know there are some things I can do to make the kW requirement of this system go down which would make it cheaper to buy. But, we are thinking about more kids so having some buffer in the system is ok with me.

The hot water heater and pool heater seem a bit expensive, and I'm definitely going to continue to shop around.

I'm looking for thoughts on the quote and what should I be paying for all these components would help.
Title: Re: Evaluating Solar Quote
Post by: sol on September 23, 2014, 09:35:36 PM
Depending on where you live I expect you can do better.

The 4320W pv system for 19.8k is over $4.50/watt installed.  Some parts of the country with good competition that price is closer to $3.  I certainly wouldn't pay more than $4/watt installed before tax credits. 

900 for a solar attic fan seems dumb, unless you're installing several of them and they're all through-roof fans rather than wall mounts.  I've installed a handful of the wall mount ones, which you can buy for ~100 and do yourself in an hour or so.  Or, since you're running on PV anyway, why not just get a regular electric attic fan with a timer and add a few W to your panels?  Seems silly to have a whole separate system including a dedicated inverter just to run a single device.  PV panels on your roof always produce when the sun is shining.  An attic fan shuts off production when not in use or when the battery is full.

If your math is right, you're paying $18k to save $65/mo.  About 4.3% return but that's a deceptive number since your principal is gone, so it's not like you can compare it to a stock investment that pays 4.3%.
Title: Re: Evaluating Solar Quote
Post by: dragoncar on September 23, 2014, 10:45:28 PM
Depending on where you live I expect you can do better.

The 4320W pv system for 19.8k is over $4.50/watt installed.  Some parts of the country with good competition that price is closer to $3.  I certainly wouldn't pay more than $4/watt installed before tax credits. 


I'm assuming that price per watt installed does go up as you size the system down, but any idea how much?  For example, if I do a 2kW system, would it be more like 50% the price or 75%?
Title: Re: Evaluating Solar Quote
Post by: DarinC on September 24, 2014, 01:09:13 AM
I can't speak to the labor/permits, but there seems to be a sweet spot of ~$1.50/W for a complete system.

http://www.wholesalesolar.com/gridtie.html#SolarSkyAstronergy
Title: Re: Evaluating Solar Quote
Post by: js625 on September 24, 2014, 06:21:23 AM
I'm in NY where electricity is very expensive (about 20-22 cents per KW after fees etc), so we decided to get a system back in June.  The whole system was about 8.3kWp, and after federal, state and utility credit is will cost us about $11,000 all in.  We are really happy with the results, our electricity bill is just $10 now and we have banked energy credits even while using the AC during the summer.