700 kW grid-connected pv plant has been commissioned, and a 425 kW capacity is under installation in Madhya Pradesh. The state of West Bengal has decided to convert the Sagar Island into a pv island. The island has 150,000 inhabitants in 16 villages spread out in an area of about 300 square kilometers. The main source of electricity at present is diesel, which is expensive and is causing severe environmental problems on the island.

The state of Rajasthan has initialed a policy to purchase pv electricity at an attractive rate of $0.08 per kWh. In response, a consortium of Enron and Amoco has proposed installing a 50 MW plant using thin film cells. When completed, this will be the largest pv power plant in the world.

The studies at the Arid Zone Research Institute, Jodhpur, indicate significant solar energy reaching the earth surface in India. About 30 percent of the electrical energy used in India is for agricultural needs. Since the availability of solar power for agricultural need is not time critical (within a few days), India is expected to lead the world in pv installations in near future.

3.2Building Integrated pv Systems

In new markets, the near-term potentially large application of the pv technology is for cladding buildings to power air-conditioning and lighting loads. One of the attractive features of the pv system is that its power output matches very well with the peak load demand. It produces more power on a sunny summer day when the air-conditioning load strains the grid lines (Figure 3-10). The use of pv installations in buildings has risen from a mere 3 MW in 1984 to 16 MW in 1994, at a rate of 18 percent per year.

In the mid 1990s, the DOE launched a 5-year cost-sharing program with Solarex Corporation of Maryland to develop and manufacture low cost, easy to install, pre-engineered Building Integrated Photovoltaic (BIPV) modules. Such modules made in shingles and panels can replace traditional roofs and walls. The building owners have to pay only the incremental cost of these components. The land is paid for, the support structure is already in there, the building is already wired, and developers may finance the BIPV as part of their overall project. The major advantage of the BIPV system is that it produces power at the point of consumption. The BIPV, therefore, offers the first potentially widespread commercial implementation of the pv technology in the industrialized countries. The existing programs in the U.S.A., Europe, and Japan could add 200 MW of BIPV installations by the year 2010. Worldwide, the Netherlands plans to install 250 MW by 2010, and Japan has plans to add 185 MW between 1993 and 2000.

Figure 3-11 shows a building-integrated and grid-connected pv power system recently installed and operating in Germany.

In August 1997, The DOE announced that it will lead an effort to place one million solar-power systems on home and building roofs across the

© 1999 by CRC Press LLC

FIGURE 3-10

Power usage in commercial building on a typical summer day.

FIGURE 3-11

Building-integrated pv systems in Germany. (Source: Professional Engineering, Publication of the Institution of Mechanical Engineers, April 1997, U.K.. With permission.)

U.S.A. by the year 2010. This “Million Solar Roof Initiative” is expected to increase the momentum for more widespread use of solar power, lowering the cost of photovoltaic technologies.

© 1999 by CRC Press LLC