Engineers at Traffic.com Inc. faced an interesting dilemma in the late 1990s. They had devised a way to save fuel by monitoring traffic flows with sensors stationed along roadsides. But before drivers could reduce energy usage by avoiding jam-ups, the company had to figure out how to power its roadside monitoring stations.
"As the wireless world exploded, cellular technology gave us a way to send data. But if we still had to dig trenches for power lines, there was no benefit to going wireless," says Chris Rothey, COO at Traffic.com Inc.
The company opted for solar panels, which can provide the 5W requirements during the day and charge batteries that last through the night. In this application, solar is a huge money saver. "We can do installations at a tenth the cost of connecting sensors with power lines and fiber optic communication links," Rothey says.
Traffic.com has installed more than 3,000 solar-powered traffic sensors, with another 10,000 or so scheduled. That underscores the success of solar power, which has been growing at double-digit rates for the past few years.
But the company's finely-focused application also points up solar's struggle to become a viable competitor in the power arena: Its costs and output are generally limited to special requirements or a simple desire to use renewable energy sources.
"The photovoltaic market has been growing at 30 percent per year for five years or so. But what it needs is more integrated products like photovoltaic roof tile systems," says Shawn Fitzpatrick, a solar engineer at the North Carolina Solar Center, well known for its Web database of solar incentives and tax breaks.
†Solar power provided big savings for Traffic.com's highway sensors
Worldwide, solar output jumped from 574 MW in 2003 to 927 MW last year, according to Solarbuzz Inc. of San Francisco. Solarbuzz analysts estimate that the U.S. accounts for only about 10 percent of that output, trailing Germany and Japan, which together have more than two thirds of the solar installations.
The pricing declines of electronic products are being watched closely as fuel prices soar. "For the last 10 years, we've seen the price of solar come down about 6 percent per year. At the same time, we've seen fossil fuel prices continue to rise," says Rhone Resch, president of the Solar Energy Industries Association (SEIA), headquartered in Washington, DC.
In the U.S., much of the focus for solar is on simplification. Home owners who want to use solar face many challenges. "Now one of the biggest problems is that every job is a one, with a big learning curve by the installer and the home owner," says Abby Nessa, project manager at Solar Roofing Systems of Philadelphia.
SRS is one of a handful of companies designing solar panels that mesh with existing roofing techniques. The startup is competing with the likes of BP Solar and GE Solar, which are both attacking the market with integrated roofing materials.
More solar vendors are teaming up with roofing suppliers to create modules that can be interchanged, greatly simplifying installation. "We're getting closer to plug and play," says John Benner, manager of electronic materials and technology at the National Renewable Energy Lab in Golden, CO.
Cypress Semiconductor is currently spinning out its SunPower Corp. division, which also focuses on roofing materials. The Sunnyvale, CA, company touts efficiency of 18 percent, compared to 13-15 percent energy conversion for most photovoltaic cells on the market. "We put the wiring grid on the backside so the electrical contacts don't prevent light from coming in. We also have an all-black appearance, which blends better with roofing materials than the bluish hue of many panels," a SunPower spokesperson says.
SunPower and most others now produce crystalline silicon cells, which aren't overly efficient but are extremely reliable. For example, Traffic.com has had good luck with the two or three solar panels on each of its thousands of stations. "They've performed flawlessly, though we had one blown down by a hurricane and two knocked down by cars," Rothey says.
There's a push to shift to thin film technologies, which hold the promise of lower costs. But manufacturing has proven complex, so usage is still below 10 percent of the output, according to Solarbuzz.
Many observers note that the regulatory environment in the U.S. also plays a significant role. "Now, it's a combination of roofing and electrical, and each locality licenses it independently. That's not conducive to volume usage," Benner says.
He also notes that utilities typically monitor installations closely, since adding in systems that tie into the power grid hold the potential to damage key equipment if it's not properly installed.
Others note that government incentives were a key factor driving growth in Germany and Japan. In the U.S., the recently signed National Energy Policy Act of 2005 provides 30 percent federal tax breaks for the next two years. That's augmented by state incentives.
"We're going to continue seeing states take the lead for their own economic reasons. That will proceed faster if the federal government continues to support solar with tax breaks," says Colin Murchie, director of government affairs at the SEIA.
Extending federal tax breaks for more than two years will provide more certainty for those making capital expenditure decisions, he adds. California, New Jersey, Massachusetts, and Pennsylvania are among the states that have the best incentives for solar energy, he says.
Though solar has been criticized for relying on tax incentives, proponents note that the oil industry also receives substantial tax credits. They often cite a 2000 General Accounting Office report that estimates tax incentives for the petroleum industry were $82 billion from 1968 to 2000. Resch notes that under the current two-year federal tax program, solar will receive only a portion of the $14 billion that will be shared by wind power, ethanol, and other alternative energy sources.