So far, solar panels have mostly been used as stand-alone systems for energy. These systems are now being deployed throughout the industrialized and developing world on a commercial scale. Today the global market demand for PV (photovoltaic) exceeds USD 5 billion annually. The market for PV has developed in both industrialized countries and in the developing countries where off-grid and hybrid village grid electrical services are now becoming available to thousands of remote villages. Such rural populations of developing countries without the benefits of grid connections can enjoy an electrical supply from stand-alone PV systems with their inherent advantages of modularity and independence from imported fuels.
It is now technically possible to connect solar panels to the electricity grid, meaning those who own them could sell excess energy back to their power company. Three developments show how important this branch is becoming:
- The world’s largest solar PV power plant, a 10 megawatt facility in Bavaria, Germany, became fully operational at the beginning of 2005.
- The world’s largest roof-top PV installation, a 5 MW roof-integrated design, is now operating in South Hessen, Germany.
- Also during 2005, a leading American manufacturer started marketing a 3 kW Grid Tie Solar Inverter for home use.
PV grid-connected systems are rapidly increasing in numbers supported by government sponsored programmes in Australia, Europe, Japan and the USA. Most of these systems are located on residences and public/commercial/industrial applications. Installations of large scale centralized PV power stations, typically owned by utilities, continue at a very slow rate.
IEC Technical Committee 82 prepares International Standards for systems of photovoltaic conversion of solar energy into electrical energy and for all the elements in the entire photovoltaic energy system. In this context, the concept "photovoltaic energy system" includes the entire field from light input to a solar cell to, and including, the interface with the electrical system(s) to which energy is supplied. TC 82 has prepared standards for terms and symbols, salt mist corrosion testing, design qualification and type approval of crystalline silicon and thin-film modules, and characteristic parameters of stand-alone systems, among others.
In the future, TC 82 work will include:
- System commissioning, maintenance and disposal.
- Characterization and measurement of new thin film photovoltaic module technologies such as CdTe, CIS, CuInSe2, and so forth.
- New technology storage systems.
- Applications with special site conditions, such as tropical zone, northern latitudes and marine areas.
TC 82 also expects to address several system and component safety issues including grid-connected systems on buildings and utility-connected inverters, as well as various aspects of environmental protection. This includes safeguarding the natural environment from such things as radio frequency and electromagnetic pollution, disposal of toxic PV materials and atmospheric contamination from PV manufacturing processes, among other topics.