Another Solar Experience in Lafayette!
Submitted By: Bart Carr (bart_carr@yahoo.com)

Challenge
I’ve been interested in solar power for many years. Early on, the expense and effort of setting up an “off-grid” solar power system was a real obstacle. An off-grid system relies on batteries to store whatever power is generated. Since off-grid systems are totally isolated from PG&E’s electrical distribution system (normally called the “grid”), a home is completely reliant on the power generated by the off-grid system. This can be a risky situation during prolonged periods of limited sunlight. Conversely, the newer “grid-connected” systems maintain full connection with the grid. When the sun is shining, the solar system supplies the electrical needs of the home. Excess energy is fed back into the grid and the household is credited for this “excess” energy. When the sun goes down, the home draws electricity from the grid assuring necessary energy whenever it is needed.

So with the advent of the grid connected system, reduced installation pricing thanks to recent legislation (see the California Solar Initiative), and a recent solar installation by a friend, the time seemed right to explore a grid-connected solar system for my home in Lafayette.


Solution Details
Shopping for a solar system in this area is easy because so many vendors are available to choose from. Go to the California Solar Initiative’s website (www.gosolarcalifornia.ca.gov) and visit the “web links” section to find various vendor/installers. The go solar website also provides important information on solar systems and incentives, including rebates and tax credits, available in California.

I decided to get proposals from three large, well established installers that were active in central Contra Costa County. These included Sun, Light & Power, Borrego Solar, and Cooperative Community Energy. Each company’s sales rep visited my home to analyze our power needs and describe their services. An important component of the initial visit is to determine whether the home is a good candidate for solar power. Most homes are but the sales rep will take measurements that will include the tracking the sun’s movement and the amount of shading that might be expected from neighboring trees, if any exist. This analysis will determine the location and configuration of the solar panels on or around your home (in some cases, the panels might be mounted on the ground), and the number and power generating capacity of the solar panels that will be used. There are a wide variety of panels made by different manufacturers including Sharp, Kyocera, and Sun Power. Your annual electric power requirement, roof space, potential panel array orientation, and the amount of money you are willing to spend generally determines the number and power generating ability of the panels that will be used.

Sizing the system is an extremely important step in the process. The system should be built to meet, but not exceed, the electric power requirements of your home on an annual basis. This is because in a grid-tied system, any excess energy that you generate, and do not use during low or no sun light periods, goes back into the grid without compensation. As already stated, the current system in California is set up to allow a home with a grid-tied system to send excess energy back into the grid. PG&E tracks the amount of excess energy sent back into the grid along with the amount of energy drawn from the grid during periods of no or low solar generation. This is known as “net metering”. In net metering, the amount generated vs. the amount used is “trued” up annually by PG&E and any excess energy not used by the home is uncompensated. Environmentally, this may be a good thing but from a cost perspective, you will not make any money to offset your costs. Most, including myself, will size the solar system so that it will generate the energy your home will need on an annual basis. This still carries great environmental benefit because not only are you supplying your own energy needs but also putting electricity back into the grid during peak electricity demand periods during summer months when the energy is most needed!

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After having received three excellent proposals from each company, I selected a 3.3 Kilowatt system from Borrego Solar. It took less then a week for the Borrego crew to install my system. I have 20 solar panels mounted on the rear roof area of my home, facing in a south-southwest direction. Wiring from the panels runs outside my home under the eaves of my roof to my garage where my inverter and electrical box are mounted. The inverter converts the DC current coming off the panels to AC current, which can be used in my home. Additionally, the inverter has a digital meter that records real-time power generation, power generated for the 24-hour period, and total amount of power generated by the system. I like having the inverter in an accessible location because it is fun to monitor the power that is generated. Of course, the real fun is in watching the meter spin backward. Actually, PG&E installed a new meter box designed for net metering that has digital readouts and symbols. So instead of watching the meter spin backwards, you watch the little arrow symbol point backwards, indicating power going back into the grid. It is exciting to know that my home has become an electric power producer (albeit a small one) in California!

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A minor word of warning. As I said earlier, it took the Borrego crew less then a week to get the system up and tested. However, it couldn’t be turned on until PG&E performed a final inspection. For whatever reason, PG&E will take anywhere from 2 weeks to over a month to do the inspection and sign-off on the system. In my case, I had to wait three weeks!


Benefits & Payback
Regarding system cost, solar is not cheap. My system cost over $25,000. However, this cost was reduced by a $5,500 solar rebate from the State, $450 in discounts offered by Borrego, and a $2,000 federal tax credit. So my net cost was around $17,000. A cost/benefit analysis performed by Borrego indicates that the system will pay for itself in 8-10 years, depending on the cost of electricity and anticipated increases. The system will operate for 30 plus years (the panels are warrantied for 25 years and inverter for 10) so we expect many years of free electricity from our system!

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Once the PG&E inspection was complete, we were free to use our new solar system. We started using it the last week of July, so we had plenty of sun to generate electricity. During the summer, we generally use 12-16 kilowatts (Kwh) of power per day. Our solar system immediately began to generate over 20 Kwh per day, so we were putting excess power back into the grid. Each month, we receive a PG&E bill that only has a small grid connection fee required by PG&E (because we are still using the “grid”). This connection fee will be my only electric charge until the first anniversary of my system’s connection in July 2008. PG&E also sends me a statement each month showing the amount of energy that we are placing back into the grid versus the amount taken from the grid. A credit for the excess amount sent in the grid for the month is also shown. Instead of paying hundreds of dollars for electricity, we are on track to pay only $40-$50 for the first year.

So, it feels absolutely great to generate our own electricity, help the environment, and reduce our electric bill through the installation and use of our new solar electricity system!


Informational Links

Borrego Solar – www.borregosolar.com
Sun, Light & Power – www.sunlightanpower.com
Cooperative Community Energy – www.ccenergy.com
CA Go Solar - www.gosolarcalifornia.ca.gov



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