Impact of Distributed Energy-Efficiency with Solar on SMUD’s Peak Load

Mike Keesee, Sacramento Municipal Utility District
Rob Hammon, ConSol

Keywords

Abstract

One of the advertised benefits of distributed solar energy is its ability to produce power during summertime peak periods. This is particularly true in Southwestern states, where summer peaks can be over twice the capacity of winter peaks. To date, however, a limited base of empirical data has been developed to quantify the peak shaving benefit.

The Sacramento Municipal Utility District (SMUD) has been working with the Building America Research Alliance (BIRA), one of the U.S. Department of Energy’s (DOE) Building America teams to encourage local production-home builders to build and sell homes that are designed to produce nearly as much electricity as they consume. These homes combine state-ofthe art, energy-efficient construction and appliances with commercially-available solarelectricity systems. The near-term goal is to reduce a new home’s total energy bill (electric and gas) by at least 60%.

In 2004, SMUD and BIRA worked with Premier Homes to develop a subdivision-scale zero electricity home (ZEH) project called Premier Gardens. By coincidence, Premier Gardens was built adjacent to an almost identical, but non-ZEH subdivision of similar size, affording an unprecedented opportunity to compare the effectiveness of the ZEH design in reducing customer’s energy use, utility bills, and, more importantly, peak demand. Both projects were completed and fully occupied in 2005.

This paper provides the results of monitoring of the Premier Gardens ZEH project for more than 1 year of occupancy, including the impact a new ZEH has on annual energy bills and use and peak demand compared to the neighboring control homes.