Production scale, not lower labor costs, drives China's current advantage in manufacturing photovoltaic (PV) solar energy systems, according to a new report released today by the Energy Department's National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT).
Solar radiation, often called the solar resource, is a general term for the electromagnetic radiation emitted by the sun. Solar radiation can be captured and turned into useful forms of energy, such as heat and electricity, using a variety of technologies.
In power tower concentrating solar power systems, numerous large, flat, sun-tracking mirrors, known as heliostats, focus sunlight onto a receiver at the top of a tall tower. A heat-transfer fluid heated in the receiver is used to generate steam, which, in turn, is used in a conventional turbine generator to produce electricity.
The dish/engine system is a concentrating solar power (CSP) technology that produces relatively small amounts of electricity compared to other CSP technologies—typically in the range of 3 to 25 kilowatts. Dish/engine systems use a parabolic dish of mirrors to direct and concentrate sunlight onto a central engine that produces electricity.
Concentrating solar power (CSP) technologies use mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat. This thermal energy can then be used to produce electricity via a steam turbine or heat engine that drives a generator.
Photovoltaic (PV) systems are usually composed of numerous solar arrays, which in turn, are composed of numerous PV cells. The performance of the system is therefore dependent on the performance of its components.
Concentrator photovoltaic (PV) systems use less solar cell material than other PV systems. PV cells are the most expensive components of a PV system, on a per-area basis. A concentrator makes use of relatively inexpensive materials such as plastic lenses and metal housings to capture the solar energy shining on a fairly large area and focus that energy onto a smaller area—the solar cell.