Seb's Solar System

On August 30th 2011 we turned on our grid-tied 3.3kW solar electric system, installed by Independent Power Systems, from Boulder, CO. It's an array of 14 high efficiency (19%), black SunPower E19 238W monocrystalline solar panels (PDF), located on the south facing slope of our roof. All electric cables are going through the roof, the attic, and exit on the side of the house where the inverter and electric meters are located. As it is grid-tied there are no batteries, it directly feeds the electric grid like any other power plant. More panels could be added in the future thanks to the high-efficiency (95%) SunPower 4000m 4kW inverter (PDF), transforming the DC current produced by the panels into AC.

The system is capable of producing 14x238 = 3332 Watts of power at peak efficiency. In northern Colorado, this translates to an estimated energy production of 5 MWh/year (megawatt-hours per year). When we produce more energy than we consume, the meter's disc spins backward and decreases the recorded number of consumed kWh. The Utility pays each produced kWh at the same rate we, the customer, pay for each consumed kWh. Since our electric energy consumption is around 3.6MWh a year, the Utility will send us checks.

The monitor (an optional component of the system) continuously transmits its data to a panel inside the house and is wirelessly accessible from the internet at http://sunpowermonitor.com/, smart phone or iPad, secured by user and password authentication. Click here to see the actual monitor (note that the link may have expired) .

Incentives are in place to drastically reduce the cost of the system.

The initial cost includes the panels, the inverter, the monitor (optional), and the system installation. From that deduct:

- $1.50 per W up to 3kW (so $4500) from the Colorado's Governor's Energy Office (GEO)

- $1.25 per W up to 3kW (so $3750) from the City of Fort Collins Utilities

- $0.45 per W (so $1500) thanks to a deal between SunPower and Hewlett-Packard

- 30% of the total above from the government as a Federal Tax Credit for this year's taxes.

All the incentives end up refunding about 2/3rd of the initial cost. The initial cost must be paid in full, the rebates checks and tax credits come in later.

All necessary permits and rebate paperwork were done by the installer IPS. The home owner association (HOA) has fully approved the architectural improvement. Note that Colorado law C.R.S. 38-30-168 prevents the HOAs from stopping any solar system installation. The installation took 5 hours.