SPG Solar, Inc. (SPG) engineers each solar system to take advantage of California’s Net Metering law, which requires public utilities to credit renewable energy producers at the “retail rate” for the electricity they send out to the grid.

In the California Region where most of the company's systems are installed, SPG is one of PG&E's Net Energy Metering (NEM) Services top clients. In fact, for Standard NEM small business and residential installations of 10 kW and below, SPG had the second highest number of interconnections in 2004. For the Expanded NEM projects ranging from 10 kW to 1 megawatt (mW), SPG had more interconnections than any other company in the PG&E territory in 2004.

The NEM program is for customers (residential, commercial, or government entities) who install the means to generate up to 1 mW of solar, wind, or hybrid (solar and wind) power. These customers continue to purchase power from the utility and also deliver surplus generated power back to the distribution grid.

Net metering reduces the demand on the public utility grid during long hot summer days when energy demand is at its highest, and simultaneously allows solar producers to reduce or eliminate their energy bill based on annual energy credit. Under net metering, the utility company must credit solar energy producers for any surplus electricity sent back to the grid. On sunny days, the electric meter spins backwards and the solar system earns credit for the energy at the utility’s retail energy rate. Utilities are required to credit solar energy producers at the retail rate at the time of day that the energy is sent to the grid.

PG&E has a retail rate schedule that is unique in the U.S., charging more for energy at three tiered rates.

During the high energy demand months from May 1 to October 31, or “PG&E summer,” the utility charges the Off-Peak rate from 9:00 at night until 9:00 the next morning.

Between 9:00 AM and 12:00 Noon, the rate goes up to the Part-Peak rate.

Between Noon and 6:00 PM, the Peak rate period, the utility charges 3.7 times as much for energy as the Off-Peak rate.

The rate goes down to Part-Peak from 6:00 – 9:00 PM, and back down to the Off-Peak rate after 9:00 PM.

Noon to 6:00 PM is the “solar sweet spot.” This is when the sun is highest in the sky. SPG designs each solar system to collect the most sunlight during the peak demand period, and send surplus energy to the utility for credit at peak period rates.

The same solar system that produces Off-Peak rate energy for half the year nearly quadruples in value during summer peak demand periods! The Peak Rate utility credits help pay down the cost of the solar system—and add to the solar producer’s bottom line after the solar system is paid for.