According to the International Data Corp. (IDC) Energy Insights’ report, “Business Strategy: Trends to Watch as the Rate of North American Solar PV Installations Doubles in 2011,” the United States will add 2 gigawatts (GW) of solar photovoltaic (PV) power in 2011, despite the uncertainty of political changes and unsettled power markets.

Although subsidies account for much of the predicted growth, according to the report, the young solar PV industry has been rapidly innovating in ways that make systems more cost-effective, easier to install and easier to maintain.

“The conventional wisdom is that the solar industry grows at 1 GW per year, based on factors such as reduced costs, better financing mechanisms and additional government incentives,” said Ed Sappin, director, project development, Americas and Asia Pacific, BP Solar, San Francisco.

Solar power systems costs have been declining at an average rate of 4 percent per annum over the past 15 years, according to Solarbuzz. The San Francisco-based solar market research and analysis group credits progressive increases in conversion efficiencies and manufacturing economies of scale as the drivers.

Emerging technology
Over the years, the improving efficiency of wattage output per module has made them more cost-effective, while innovations in solar-panel production have improved degradation rates and mounting structures. However, the development and deployment of microinverters may be one of the market’s biggest game changers.

“Using microinverters provides an increase in energy harvest and presents interesting options in monitoring usage and generating analytics on a per-panel basis,” said James Washburn, product marketing manager for electronic circuit breakers and renewable-energy products for Siemens Industry Inc., Alpharetta, Ga.

Understanding how each individual solar module is performing enables the building owner to make real-time decisions for maintenance or uptime.

“Electrical contractors can also use these analytics to demonstrate to the building owner where maintenance or changes to the array may be required,” Washburn said.

Because each module can provide power independently, each one can be oriented to operate optimally and be used in a greater variety of applications and configurations.

Since solar cells usually operate more efficiently under concentrated light, the industry has been working on developing a range of approaches using mirrors or lenses to focus light on specially designed cells and to use heat sinks or active cooling of the cells to dissipate the large amount of heat that is generated, according to Solarbuzz.

However, these concentrator systems require clear skies and will not operate under cloudy conditions. Concentrators have not yet achieved widespread application in PV systems, but solar concentration has been widely used in solar-thermal electricity generation technology, where the generated heat is used to power a turbine.

Finally, some predict electrochemical solar cells will offer lower manufacturing costs in the future because of their simplicity and use of cheap materials. However, the challenges of scaling up manufacturing and demonstrating reliable field operations still lie ahead.

One nontechnological trend is an increased demand by users for high levels and analytics and reporting functions.

“Users need information to demonstrate return on investment, to determine if the system is performing properly, and to ensure the corresponding savings are being delivered,” Washburn said.

Cost remains a deciding factor
Solar technology is most effective at providing power during daytime’s peak-energy usage and cost, distinctly helping a building’s overall energy and cost management, Sappin said. Plus, integration of the solar-power system into the power infrastructure is improving with advancements in the smart grid, helping save money over time. However, initial cost and long return on investment periods still hinder widespread acceptance of solar energy.

“Depending on location, local utility rates and available incentives, the return on investment can be quite lengthy,” Washburn said.

Locations with cheap utility rates and little sunshine are not prime candidates for using solar power, but installing solar-power systems is a profitable business.

“These are large jobs with large profit margins. Contractors must be keenly aware, however, that some systems require a lot of engineering expertise, and depending on the system, there is a lot of direct current wiring involved, which presents a different set of safety, code and installation concerns,” Washburn said.

Even with solar’s learning curve and certification requirements, Washburn anticipates that the expansion of microinverters will drive a shift from the market being dominated by solar-specific installers toward electrical contractors.

“[Electrical] contractors’ current skill sets put them in the perfect position to partner with roofers and distributors to take advantage of the market’s potential,” Washburn said.


BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 and darbremer@comcast.net.