Grow Your Own Green Power Plant

#113, March 19th, 2003

 

There’s a big green plant on my roof. Its broad shiny leaves stretch from eave to ridge, tilted to the southern sky. The leaves gather sunlight, transform it, and push it down a long slender stem. A network of roots connects to the stem, delivering juice to every room in my house.

 

This plant is a solar power plant. It generates electricity for my family (and sometimes for some of my neighbors.) Unlike the solar power plants in my garden, which produce food fuel by photosynthesis, my rooftop plant employs the photovoltaic (PV) method, converting light directly into electrical current. The panels – I’ve got twenty, each two by four feet, and about four inches thick – are made of silicon wafers and copper wire. As they bask motionless beneath the sun, they send up to three thousand watts of direct current down to my “Sunny Boy” (actual name), the briefcase-sized inverter that converts direct current into the alternating current that powers homes.

 

Here’s comes the good part: when the output of the plant exceeds my household demand, the electricity flows out to the neighbors, turning my meter backwards. Of course it doesn’t always turn backwards (like, when it’s dark.) But I’ve had my system sized so that over the course of a year, the meter will turn backwards a bit more than it turns forward. And since I’m on annual billing now, I expect to never again pay an electricity bill (these panels have long life expectancies.)

 

Good part #2: my power plant is truly a green plant, because the power is produced without pollution – no carbon dioxide to cook the climate, no sulfur emissions to acidify the rain. It generates no nuclear isotopes to cause cancer and birth defects for centuries; no butchered mountaintops, radioactive rivers, or drowned canyons. It’s energy we can live with, for millennia.

 

Good part #3: I emailed a digital photo of the installation-in-progress to my friends, with the caption, “Take *that* Osama Saddama!” My plant is striking a blow against Saddam’s well-oiled despotism (without killing anyone) by reducing the demand for his “cash crop”. And it contributes to the decentralization of our energy supply, making it harder for a well-placed Osama-bomb to render us powerless.

 

The State of California, recognizing the benefits of clean, terror-proof electricity, has made it more attractive for homeowners to invest in PV power. They offer a combination of direct rebates and tax credits that reduce the initial costs by half. If you finance the job with a line of credit against your home, especially with interest rates at an all-time low, savings on the PG&E bill pay back the balance in five to ten years (depending on what happens to electricity prices.) After that it’s free energy.

 

The finances are even better if you get on a time-of-use (TOU) electric rate, which charges (and pays) several times more for electricity during the noon-to-six “peak” period when the demand is high. Since this is when your solar plant is generating at *its* peak, your billing credit is magnified, shortening the payback period.

 

Petaluma can help, without spending a dime. Policy 30 in the Energy Section of Petaluma’s 1987 General Plan says, “Domestic solar energy use shall be encouraged.” I remember helping draft that policy with former Council Member Michael Davis. We envisioned new subdivision homes aligned to the sun, making it easy for them to “go solar.” But little was done until the City Council, with Matt Maguire’s leadership, recently required 10% of the homes in a large subdivision to install PV.

 

Our new General Plan should require that a steeply increasing percentage of all new homes be PV powered, and all be pre-wired for solar. We should support the development of solar utility districts (SUDs), where neighborhood coops would get more favorable buy-back rates from PG&E.

 

My green power plant and I are enjoying solar living, but we would like some company. I invite you to grow a plant of your own. Write me at thehman@pacbell.net if you want more information.