|Image: Courtesy of Nanosolar|
Solar energy as cheap as grid-supplied electricity could be just a few years away, at least for large commercial facilities with flat rooftops or some acreage to spare. Six years ago the Department of Energy awarded a $42 million grant to a company called Nanosolar for the development of large-scale rooftop photovoltaic systems that cost no more per watt than conventional electricity, and earlier this month DOE certified that so far the company has passed its milestones on the way to achieving a 2015 deadline.
Cheap solar energy, with a little help
California-based Nanosolar has private investors and it has gotten clean energy tax breaks from its home state, but the real meat of its success so far comes from the kickoff grant of $42 million, which was awarded under the Bush Administration’s 2006 Solar America Initiative.
A precursor to President Obama’s 2011 SunShot Initiative, Solar America partnered the Department of Energy along with government and academic research institutions and the building industry in a drive to “make solar energy cost competitive” with fossil fuels by 2015.
The thin film solar advantage
Nanosolar specializes in printable solar cells using inks composed of nanoscale particles. These liquid solar cell inks are applied to a thin, flexible substrate in a roll-to-roll process that shares the basic characteristics of other relatively low cost, mass production printing methods.
The company’s ink-based solar technology won the Innovation of the Year award from Popular Science in 2007.
Roll-to-roll printing is less expensive than fabrication methods used to make conventional silicon solar cells, partly because it is a less energy intensive process. Thin film technology also results in reduced shipping and installation costs due to its light weight and durability.
Call out the National Guard for low cost solar power
As it turns out, if Nanosolar is ultimately successful the National Guard will have played a key role. The company achieved one of its major milestones last fall, when it completed the installation of a 538 kWp thin film array comprised of 2,750 solar panels for Camp Perry, an Ohio National Guard base (kWp refers to the peak output of a photovoltaic system).
The Camp Perry installation was designed to demonstrate how the roll-to-roll process combines with a highly efficient installation system to lower the overall cost of the array.
The installation system involved pre-assembling the solar panels into cartridges, which were fitted into prepared “piers.” According to Nanosolar, along with reduced labor and equipment costs the system also reduces the risk of breakage, which bedevils conventional silicon solar cell installations.
Low cost solar power for California National Guard
Earlier this year Nanosolar also began installing a 1 megawatt ground-mounted array at the California National Guard’s Camp Roberts, with the goal of achieving an installed cost equal to or less than the average price that the base was paying for grid-supplied electricity.
SERDP, the Department of Defense’s Strategic Environmental Research and Development Program, is the umbrella agency for that installation in partnership with the EPA and Department of Energy.
Aside from showcasing the technology for the civilian sector, that installation will serve as a template for replication across scores of U.S. military facilities, according to SERDP:
“…military installations throughout the United States can benefit from competitive electricity costs and a low carbon footprint through on-site, distributed solar generation. This demonstration will showcase that U.S.-manufactured solar technology and U.S.-generated solar power can provide energy security and independence to the U.S. military. Similar projects ranging from 1 to 20 MW enable power to be produced within distribution voltage, which avoids expensive transmission step-ups and tie-ins. This range of power plant outputs could be readily constructed at DoD installations nationwide.”
SERDP’s emphasis on cutting costs by designing projects within the 1 to 20 MW range is noteworthy in the context of the SunShot initiative. Though part of SunShot focuses on reducing the cost of solar power through new technological breakthroughs in solar cell efficiency, the initiative also takes into consideration the overall, installed cost of solar energy.
“Soft” costs including installation and permitting already account for at least half the price of a typical solar array, according to the Department of Energy, so the push is on to make those costs start trending downwards.
In addition to working on reducing soft costs at the utility-scale level, the Department of Energy also recently announced a “Plug-and-Play” solar initiative designed tolower the cost of installing small-scale solar arrays for homes and other small properties.