intermittence, the supply curve for photovoltaics makes it a potentially valuable contributor to 

peak shaving. In addition, distributed power offers the prospect of increased security and grid reliability.

The relationship between the building owner and the utility is important to the success of 

grid integrated systems. Most owners want to maximize the output of their system, and they normally

have little concern about the utility's peak load. One way to benefit both the owner and the utility is by

providing time of use net metering, which values the electricity produced during the peak period higher

than that produced during off peak times. This more sensitive metering would encourage owners to orient

their systems to provide the highest value electricity and would help the utility address its peak

demand.

98

Utilities continue to have concerns about the safety, reliability and costs of net metering.

Addressing barriers to metering should be feasible with accelerated development of low cost metering

devices, along with education and demonstration activities such as DOE's Million Solar Roofs Program.

99

Thin film photovoltaic technology is the focus of current federal R&D efforts because it holds

considerable promise for cost reductions due to its need for less semiconductor material. In the long

term, research into nanocomposites offers the promise of an inexpensive and high efficiency solar energy

conversion device.

100

Currently, grid connected photovoltaic systems cost an order of magnitude more per kilowatt hour

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than do fossil, nuclear, and wind generation energy sources. However, a more appropriate comparison with

end user prices (which include transmission and distribution costs, taxes, profits, and other fees, and are

therefore much higher than generation costs) suggests that solar power is more closely competitive with

these other sources. The market for solar power is expected to grow rapidly over the next decade, due to

production tax credits, renewable portfolio standards, and buy down programs (such as California's subsi 

dies for residential and commercial photovoltaic systems), combined with anticipated cost reductions of

at least 5 percent per year.

101

Integrated Building Systems. By 2010, advances in building envelopes, equipment, and systems

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integration, may lead to 50 percent reductions in the energy requirements of new buildings relative to

2000. Incremental cost estimates for these advanced building systems run from 0 to 2 percent of the

total building cost, because most of the additional building envelope cost is offset by cost savings on the

downsized HVAC system.

102

If augmented by on site power, buildings could reduce their net energy

33

Towards a Climate Friendly  

Built Environment

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