Kathleen Root doesn’t consider herself an activist. Sure, she has ideas and opinions about politics, the environment, and the economy. She cares about her future, the future of her children and soon-to-be grandchildren, and everyone on the planet. But she’s not the type to stand on a soapbox and preach. So why would she invest her hard-earned dollars on expensive technologies like a photovoltaic system and an electric car?
When cornered, Kathleen will admit her opinions on the environment, energy politics, and social responsibility. And since the installation of her photovoltaic system, she’s become a member of a local climate-change awareness group that has spearheaded projects like bike racks for downtown and “no-idle” zones in school turnarounds. But she’s quick to remind that it’s not to prove a political point, make an environmental statement, or convince anyone else how they “should” live. “It’s my responsibility to acknowledge my own energy use and impact, and do what I can,” says Kathleen. “I have the resources to do these things, so I’m doing them. Other people have different resources and must make their own decisions about what they can and should do.”
Kathleen blames it all on her silver station wagon. Her Audi A4 looks like a placid soccer-mom’s car. But with 217 horsepower under the hood, it would have blown the doors off the muscle cars her sons coveted in their youth. Although Kathleen wasn’t drag racing down the streets in her hometown of Anacortes, Washington, she was still getting pathetic fuel economy—sometimes as low as 14 mpg. When she complained about the wagon’s around-town mileage to the dealer, he quizzed her on her driving practices. It turned out that Kathleen’s short trips to work, the post office, and the grocery store—all less than a couple of miles from her doorstep—were not only wasting fuel, but wasting the car—and lots of her hard-earned money.
But what were her alternatives? Fifty-eight-year-old Kathleen is healthy and active—she’s fit enough that walking or riding her bike are options. But western Washington’s notoriously chilly, wet weather isn’t conducive to keeping her clothes neat and dry, necessary for her professional work as a middle-school counselor. What she wanted was an around-town vehicle that could keep her warm and dry—and sip, not guzzle, fuel. And then she found her Zenn.
Kathleen is a pretty typical American, but what frequently sets her apart is her willingness to give cutting-edge technologies a whirl. (You can blame that—at least in part—on her technophile sons, one of whom has been working with renewable energy for more than a decade.) So it wasn’t surprising when she found the Zenn—“Zero Emission, No Noise”—neighborhood electric vehicle.
With a top speed of 25 mph, a range of up to 35 miles per charge, and plenty of space for groceries in its hatchback, the Zenn is well-suited for the short trips that are typical for Kathleen. At 3 miles per KWH (about 135 mpg equivalent), the car is inexpensive to drive, costing only $0.024 per mile. Besides fuel savings, electric vehicles like the Zenn also eliminate the regular replacement and repair costs of oil changes, oil filters, exhaust system fixes, and tune-ups associated with internal combustion engines. Slower driving speeds and regenerative braking, which uses the motor to slow the vehicle and recharge the batteries, also mean reduced brake wear. To Kathleen, the Zenn’s $13,000 sticker price was a reasonable cost to pay for a reliable ride that would deliver her, warm and dry, to her destination, as well as extend the life of her Audi, which she saves for road trips.
The car’s six 12-volt sealed lead-acid batteries supply electricity to the motor, and charging is a breeze—the Zenn’s recharging dock is compatible with any typical 120 VAC household outlet. A complete charge takes about eight hours, and batteries can be 80% recharged in four hours. Kathleen simply parks her car in the driveway and plugs it into an exterior outlet every night for easy charging.
“I wanted a car that had room for another passenger, ample head and leg room, and cargo space to haul groceries and 50 pounds of dog food. I also wanted something that looked like a real car—not a glorified golf cart,” says Kathleen. But the biggest benefit, she says: “I can generate my own pollution-free fuel.”
Kathleen admits that there are a few drawbacks to driving such a unique vehicle. “It turns you into a bit of a celebrity. Little kids wave, people stare and point, everyone wants to ask you questions about it,” she says. Kathleen estimates that in the first few months of owning the Zenn, she talked with hundreds of people. “I even had a very excited man follow me into my driveway to ask me about the car.” Kathleen acknowledges that some people are disappointed when they find out the Zenn’s top speed and range. “What most people really need are plug-in hybrids,” she says. But she’s patient and usually willing to share information about her EV. And when she’s not in the mood for providing electric-vehicle education? “I go to the grocery store at night,” she says.
Little did Kathleen expect that her sage-green Zenn would take her even further down the renewable-energy road. She was already aware of the concept of photovoltaic (PV) modules generating a home’s electricity, but when it was suggested that a solar-electric system could power her car, she got really excited about the technology. “The idea that I could drive my car with energy from the sun was irresistible to me,” she says.
There are a few ways to size a photovoltaic system. In off-grid situations, the system is necessarily sized to meet all the loads on a sunny day. Typically, a small amount of backup generator time is factored in to alleviate the excessive costs that would otherwise be required to provide for total loads during extended cloudy periods. But system sizing is significantly more flexible for grid-tied systems, since utility electricity is available to make up the difference between PV production and load requirements. Usually, sizing a grid-tied system becomes a balance between budget and available mounting area for PV modules. In Kathleen’s case, the roof area of her 2,000-square-foot, two-story home was the limiting factor in sizing the PV array. It was decided to squeeze as much generating capacity onto the roof as was functionally and aesthetically reasonable.
While peak sun-hours in the area can dip below 1 per day in December and January, the summer months of June and July make up for it to contribute to an overall daily average of about 3.7 peak sun-hours. At 48 degrees north latitude, Anacortes experiences the most sunshine and highest peak sun-hours during summertime, when the sun traces a long arc through the sky, rising in the northeast and setting in the northwest. Kathleen’s grid-tied PV system would rely on these long, sunny summer days to heavily weight its net solar production for the year. To maximize PV generation capacity, it was determined that, along with a south-facing array, a west-facing array would contribute significantly to the system’s total energy production. The idea of installing an east-facing array was rejected due to shading from trees and neighboring buildings. Plus, in this coastal town, morning fog can reduce solar insolation—even in the summer months.
With maximizing the PV array output as the goal and roof area as the limiting factor, high-efficiency Sanyo HIP-195BA3 PV modules were selected. These 195-watt modules fit in two rows of five on the south-facing roof and two rows of four on the west-facing roof. The dimensions of other PV modules that were considered didn’t work well with the available roof space in portrait format, or would have required additional racking and mounting hassle in landscape format. (Savvy PV shoppers will recognize that the Sanyo HIP modules also come in 200- and 205-watt ratings with the same overall dimensions. However, at the time, these higher-rated modules were difficult to obtain.)
The other major equipment choice was the grid-tied inverters that would convert Kathleen’s solar-generated DC electricity into AC electricity. In turn, this renewable electricity would be used to power household appliances and charge the Zenn, with any excess sent to the utility grid. While there are several reputable manufacturers of grid-synchronous inverters in the market these days, two Fronius IG 2000 units were deemed a good fit. The west- and south-facing arrays would have different numbers of modules and different voltages at maximum power—221.2 and 276.5 volts, respectively. As such, one inverter would not have dealt optimally with these mismatched input voltages. Instead, two 2,000-watt inverters were installed side by side (one for each array) and paralleled on the AC output side.
Although Kathleen wasn’t a complete stranger to smart electricity use before installing a PV system, once her Fronius remote meter was spitting out the daily totals for energy production, conservation became her new hobby. Even during the winter, when a day’s total PV output can be less than 1 KWH, her new habits are making a noticeable impact.
Besides programming temperature setbacks to regulate her home heating, Kathleen has taken to drying clothes on a rack in the laundry room instead of in the dryer. “It only takes a couple of minutes to hang them up and they’re dry in a day. This is not really about sacrifice: I still throw my towels in the electric dryer because I like them soft. Instead, it’s about what we can do relatively painlessly that has a positive impact.” And those positive impacts are paying off. Kathleen’s December electricity usage was 25% lower than in 2006—even with the additional load of charging the Zenn. And that’s not even counting production from the PV system.
While Kathleen didn’t actually climb on her roof to install her PV system, she was definitely involved with the planning and paperwork of the process, especially the permitting and net metering agreements. “I was amazed and inspired,” she says, “with how patient and helpful everyone was.” Skagit County Head Electrical Inspector Dennis Patterson readily answered technical questions in advance. Jake Wade, program implementer of the Renewable Energy Advantage Program at Puget Sound Energy (PSE), Kathleen’s electrical utility, walked her through all the necessary paperwork to get her system signed up for production incentives. “His repeated friendliness and willingness to meet me on my technical level was above and beyond the call,” says Kathleen. Even the two PSE meter installers, who came to commission the system, helped fix a wiring oversight rather than reschedule the inspection. “Though there was a lot to learn, these guys all helped make the switch to state-of-the-art green energy pretty painless,” says Kathleen.
So, no, Kathleen Root doesn’t consider herself an activist. Her goal is not to tell you why solar energy is better than coal or nuclear energy—or why an electric car is better than a gas guzzler. She is not going to tell you how you should live: Her goal is to take some responsibility for how she lives, and have that responsibility be in proportion to her means. She has chosen not activism, but action.
Benjamin Root has been a graphic designer with Home Power for more than 12 years, and has been the art director since Publisher Richard Perez started giving out titles. Kathleen Root is Ben’s stepmother, and Ben was the primary system designer on her project.
Direct Power & Water • www.directpower.com • Rail mounts
Fronius • www.fronius-usa.com • Inverters
Sanyo • www.us.sanyo.com • PVs
Zenn Motor Co. • www.zenncars.com