October 19, 2008 | | Comments 57

Residential Solar – A Real World Example

I am in the process of designing and quoting a solar electrical system for a house I recently purchased.  This is a ‘Split Level’ Home of approximately 1900 sq feet.  The heating systems is electric baseboard.  I researched several local companies that provide a soup to nuts service and installation.  Some sites to find a solar installer;

Once you have selected a provider, the first step is usually a quick suitability review from the installer.  With an address, they can pull up google maps and get a view of your house, determine the orientation and roof structure.  From that initial review you get some immediate feedback about solar applicability on your house.

A site review is usually next, some firms will charge for this survey.  I imagine in their mind it is a way to determine the seriousness of customers.  The survey in my case, consisted of a 90 min review of the house.  The technician was looking at potential places for the installation, roofing and support structure, trees and shading issues, sun orientation, location of the inverters in the basement – a vented cabinet size area is needed for that and finally a review of my electric bills for the past year. This cost me $100.

About 10 days later, I received a detailed proposal.  The proposal contained pictures of the proposed installation, it’s orientation, any trees or shading that would need to be addressed, estimated energy production on my specific installation, savings and the most importantly the state and federal credits available.

A well structured ROI ( return on investment was included), and a cash flow over the life of the system were included.

The details of this installation;

Rooftop Solar Array:
Azimuth (Direction of array): 240º
Inclination: 22º (flush with roof)
Solar Access: 92%
Derate factor: 0.708
Size of solar installation: 4.94 kW DC. (26 solar panels model ES-190)

Price of Solar Installation (all costs) $35,243
Instant Savings (Commonwealth Solar Rebate) -$20,995

Upfront Cost to You $14,248

Recovered costs in year one: (Tax Credits)
State Income Tax Credit1 -$1000
Federal Income Tax Credit2 -$4274

Cost to you after rebates and tax credits $8,974

Estimated savings over 25 year life of solar panels: $85,600
Estimated increase in home value $22,500 – (based on a study by the Appraisal Institute)
Payback including increase in home value Immediate
Payback not including increase in home value 5 years
Usable life of solar panels 25+ years
Estimated annual energy production 4900 KWH
Carbon Dioxide emissions displaced per year 4510 lbs

I know that I would believe in the increase in home values in today’s economy, but the payback without that is still only 5 years.  I also don’t know if I believe the 25 year life of the panels.

I am meeting with the installer to review the proposal and get more details on what I would need to do ahead of time.  They are recommending I remove some trees, and also replace the roof prior to installing the units.

The panels are from Evergreen, which is a quality company.

Some initial questions;

Review the tax credit and or rebate process, income level qualifications, paperwork process, and timing, when does paperwork need to be submitted when would I see a check

Part guaranty and installation guaranty.

Licensing and insurance of installers

Maintenance needed

Snow and ice

What else should I be asking?

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Filed Under: Alternative EnergyGlobal WarmingHome Energy


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