Solar energy is far and away the largest of the world’s six significant energy sources—the ones with the potential to deliver at least 1 terawatt (TW) of electric power, according to IEEE Senior Member B.J. Stanbery. The others are fission, fusion, oil, gas, and coal.
“It takes that much to make a meaningful contribution to the world’s power needs, currently 13 TW but projected to be 15 TW by 2020,” Stanbery says. Solar-generated power also adds no carbon or other pollutants to the air, nor does it leave radioactive waste.
Abundant and green though it may be, very little solar energy now gets turned into electricity. Solar’s contribution is dwarfed even by sources not on Stanbery’s list, such as hydropower, wind, geothermal, and biofuel generation. The organizers and attendees of the 38th Photovoltaic Specialists Conference (PVSC), which Stanbery chairs, are working to change that.
The conference, to be held from 3 to 8 June in Austin, Texas, covers all aspects of solar-cell technology, from basic material science to installed system performance. Scheduled presentations include 63 oral sessions and 26 individual posters in four sessions, covering 10 technical areas. The organizers expect about 1900 scientists, engineers, and academics, as well as students, from around the world, according to Angus Rockett, the program chair.
The opening day, Rockett says, will be devoted to three special events: tutorials for those new to the photovoltaic field; a public Solar Day, an event (first held last year) that incorporates the conference’s long-established high school science fair; and the Solar Energy for Bright Minds Golf Classic, which will raise money to install a solar-powered system for the high school whose students enter the most innovative project in the science fair. “Our goal,” Stanbery says, “is to leave a legacy behind in Austin and every city we go to in the future.”
This year’s PVSC is sponsored by the IEEE Electron Devices, IEEE Photonics, and IEEE Power & Energy societies. “The cosponsorship has been in place for two years,” Stanbery says, “but this is the first time we’ve made an effort to intentionally leverage it in our technical program plan. Bringing together the IEEE Power & Energy Society’s research on the smart grid and the advances from the IEEE Electron Devices Society’s photovoltaic segment could really lead to greater penetration of distributed photovoltaic generation.
“Some people think the claimed synergies between PV and smart grids are a myth; others think they’re an inevitability," Stanbery continues. "We don’t really know yet, so we’re making it a focus topic for the tech community to see if we can get clarity.”
COST A CONCERN
Adoption of any power source is dependent on its cost. Solar power has long been cost-effective in remote areas—including space satellites—where running power lines, hauling fuel, or performing maintenance would be prohibitive. It’s now competitive in other markets, too, “where there is a lot of sunshine, a lot of demand, high power costs, and subsidies—for example, Southern California,” Rockett says. “That’s driving the construction of a lot of solar farms.”
The per-watt cost of solar-cell technology continues to fall, a trend temporarily accelerating in the past few years “as Chinese manufacturers experienced overcapacity,” according to IEEE Member John Benner, who chaired the 2007 PVSC. “With federal tax incentives factored in, you can now buy a silicon solar module for under $1 per watt, and the installed price for large-scale systems is about $3 per watt. In Southern California, such a system would deliver electricity for well under 15 cents per kilowatt during the time of day when rates are well over 20 cents per kilowatt.”
Other factors affect solar power’s competitiveness. Subsidies are a complication, rising and falling in different countries as the political winds shift. “And who would have thought two years ago that the cost of natural gas in the United States would drop in half?” Benner says.
Solar power’s cost structure differs from that of other sources. “lt’s the only major resource that needs no fuel, and solar installations require almost no maintenance; operating costs are 2.5 percent of the installed system capital cost per year,” Stanbery says. “So almost all the cost is making and installing the equipment—capital costs that must be paid up front. The cost of solar thus depends critically on your cost of capital.”
Asked what areas of photovoltaics are showing the fastest advances, Rockett answers, “All of them—there’s something exciting in pretty much every area right now.”
Stanbery adds, “I doubt any of us would hazard a more specific answer now. Part of our job is to create an open and unbiased platform for people to present the data. We’ll know better after the conference.”