As part of a wide-ranging clean energy initiative by the administration, President Obama and Energy Secretary Moniz announced at the Clean Energy Summit $24 million in innovation funding for 11 new solar technologies, as part of ARPA-E’s newest program Micro-scale Optimized Solar-cell Arrays with Integrated Concentration (MOSAIC). These MOSAIC projects seek to develop a new class of cost-effective, high-performance solar energy modules.
“The MOSAIC program demonstrates ARPA-E’s novel approach to energy innovation,” said ARPA-E Director Ellen D. Williams. “By bringing together cutting edge advances in micro-fabrication, materials science and mechanical actuation, MOSAIC will create new options for solar generation and help make clean energy technologies even more affordable.”
MOSAIC project teams will design technologies and concepts for a new class of cost-effective, high performance photovoltaic (PV) solar modules. These modules will use thousands of small lenses to concentrate light onto an array of PV cells to achieve higher solar-to-electricity conversion. These microscale concentrated PV (micro-CPV) technologies will be integrated into “flat plate” solar panels to improve their efficiency and cost.
This micro-CPV approach addresses the constraints of conventional CPV, which, while highly efficient, has not been widely adopted due to its high cost, large size, and expensive solar tracking systems. Project teams will address these limitations by developing innovative materials, micro-scale manufacturing techniques, panel architectures and tracking schemes. By exploiting micro-CPV techniques, the teams aim to reduce system costs and dramatically improve flat plate PV efficiency – and thereby expand the market and geographic areas in which these technologies can operate successfully.
MOSAIC projects are grouped into three categories: complete systems that cost-effectively integrate micro-CPV for regions, such as sunny areas of the U.S. southwest, that have high Direct Normal Incident (DNI) solar radiation; complete systems that apply to regions, such as areas of the U.S. Northeast and Midwest, that have low DNI solar radiation or high diffuse solar radiation; and concepts that seek partial solutions to technology challenges. The MOSAIC program also includes a Small Business Innovation Research (SBIR) award category.
So, these multidisciplinary teams will leverage expertise in conventional flat-plate PV, CPV, manufacturing, optical engineering, and material science to produce a new class of PV panels. If successful, these technologies could facilitate cost-effective deployment of solar power systems across a wide range of geographical locations, lowering U.S. greenhouse gas emissions and reducing dependence on imported energy.
Although it has experienced dramatic growth and cost reductions in recent years, solar PV represents only 1.1% of U.S. power generation capacity. Many roofs are too small, too shaded, or sub-optimally oriented for installation of today’s PV panel technology to be economical. Although efficiency improvements have increased solar PV’s ability to convert solar energy to electrical power, further gains will become difficult due to physical limits on their performance. Additionally, future growth of solar power systems will be limited by the cost of the systems and the space they require.
Enhanced performance and cost reductions are necessary in order to substantially increase solar penetration beyond current levels. One way to increase the efficiency of solar PV systems is by using CPV modules, which use optical devices to concentrate sunlight onto a smaller, very high efficiency solar PV receiver. This allows the system to generate more power with a much smaller footprint. However, CPV only converts direct sunlight, not diffuse solar radiation (sunlight scattered by the atmosphere and clouds), and therefore CPV is only viable in a limited geographic range, namely the southwestern U.S. where direct sunlight predominates. CPV is also currently very expensive because of the materials that are used in the receiver.
MOSAIC seeks to overcome these challenges and develop arrays of very small CPV systems (known as micro-scale CPV technology) that integrate more affordable materials and manufacturing techniques. In addition, MOSAIC seeks solutions that will utilize diffuse sunlight as well as direct sunlight in order to expand the geographic regions in which the benefits of CPV may be exploited cost-effectively.
Let’s take a look at the 11 projects in question:
— Solar Builder magazine