Alameda County's Santa Rita Jail
A Solar Photovoltaic Project - California

Project Summary

By integrating the largest rooftop solar photovoltaic (PV) system in the US with energy efficiency upgrades and state-of-the-art energy management software, PowerLight and CMS Viron Energy Services have designed a project for Alameda County that can serve as a model for other large public and private sector consumers. Building upon a legacy of innovation in efficiency that already saved the county between $3 and $4 million annually, Alameda County was able to access an array of financial incentives offered by state agencies and utilities. The County is able to reduce peak power consumption by 20% without any expenditure from its general fund. Annual energy savings from the solar system and new efficiency investments are estimated to be $190,000 at a minimum and may exceed $400,000 given recently approved retail electricity rate hikes. Finally, this marriage between solar PV and intelligent energy efficiency provides public benefits to the community-at-large in the form of significant reductions in demand upon the grid in a region where existing transmission line constraints pose reliability challenges.

Rooftop View of the New Solar Panels at Santa Rita Jail

Size of the Purchase

The 6,000 solar photovoltaic (PV) tiles being installed on six medium and minimum-security housing units at the Santa Rita Jail in Dublin, California will generate 500 kilowatts of clean peak power. This system, which features PowerLight Corporation's unique PowerGuard roofing materials, is the largest solar rooftop system in the U.S. By linking the clean solar generation of PV technology with a patented R-11 rigid polystyrene foam roofing insulation, PowerLight has developed a clean distributed generation system that will add 675,000 kilowatt hours of clean summer peak electricity to this project's benefit profile while simultaneously reducing heating and cooling requirements. In addition, PowerGuard tiles do not require any perforations of the roof. They protect the roof membrane from weather and ultra-violet radiation, which delivers additional economic benefits to the county.

CMS Viron Energy Services will deliver an additional 975,000 KWh in electricity savings primarily from replacing an old inefficient chiller with a new 850 ton high efficiency, variable speed, chiller that does not rely upon the CFCs that contribute to the alarming ozone hole in the southern Hemisphere. The existing chilled water-pumping system pushed water through both chillers regardless of cooling needs. The new variable speed drive will respond directly to the precise real-time cooling requirements needed to deliver chilled water instead of operating at 100% capacity all of the time.

A new computerized energy management system, which has been dubbed UtilityVision, will automatically reduce power consumption during peaks in response to short-term fluctuations in solar fuel caused by weather conditions such as cloud cover. For example, if clouds block the sun for 5 minutes on a summer afternoon, UtilityVision will automatically reduce power consumption proportionately so that no additional purchases of expensive peak priced electricity are necessary. Once the cloud passes, and solar electricity generation is resumed at maximum levels, the energy management software will automatically make corresponding adjustments to power consumption.

These kinds of sophisticated smart energy controls benefits all state consumers by reducing purchases of grid power during times of the tightest supply and highest demand. This is an especially critical concern in the so-called Tri-Valley Transmission Line area, a region that includes the City of Dublin.

The environmental benefits linked to this solar PV and energy efficiency improvements is 200,000 lbs. of carbon dioxide, a global climate change gas, and 850 lbs. of the nitrogen oxides that contribute to urban smog, a primary cause of asthma and other respiratory diseases.

Impact

The total electricity peak demand for Alameda County is approximately 15 MW, of which Santa Rita Jail represents about 3 MW. Due to the synergy between solar and efficiency, Alameda County now hopes to more than double its solar PV capacity by covering all 18 Santa Rita Jail housing units with PowerGuard. It is also investigating installing solar PV on three buildings it owns in Oakland. All told, Alameda County's solar PV commitment could expand to 1.2 MW. Including additional energy efficiency measures will provide additional economic and environmental benefits to the county and further reduce peak electricity demand in the region.

Alameda County already saves between $3 and $4 million annually from energy efficiency upgrades to lighting and HVAC systems and additional efficiency measures that commenced in 1989. Matt Muniz, Alameda County's Energy Manager for the past eight years, first implemented energy efficiency measures at the Santa Rita Jail back in 1993. Alameda County secured $3 million in financial incentives from Pacific Gas & Electric (PG&E) for lighting upgrades and controls. Energy costs at the Santa Rita Jail were reduced by a third. Over the next several years, Muniz monitored available funding sources of energy efficiency retrofits that led to a series of initiatives at the county's courthouse, administration buildings, jails, hospitals, social service structures and other public buildings.

The fresh efforts of Viron and PowerLight will save Alameda County almost $200,000 annually under previously frozen retail electricity rates. Given the fact that prices for purchased grid power for customers the size of Alameda County are likely to rise by as much as 50 percent - from the current 6.5 cents per kWh to 9.5 cents per kWh -- these savings figures could easily double.

Accountability is a key feature of this project. The project's performance data will be posted on the Internet so that other local governments and commercial customers can review and analyze the performance of both solar PV system and energy efficiency measures. A series of public outreach and education efforts are underway, including a groundbreaking ceremony planned for early June and a major public tour once the solar PV system and energy efficiency upgrades are fully installed and fully operational later this summer.

Several local governments, among them the cities of San Jose, Santa Rosa, Livermore and Santa Clara County, have already approached Alameda County to find out more information about both how solar PV and energy efficiency work together and how the county was able to pay for these innovations without tapping into its general fund.

Innovation

Much of the innovation of the Santa Rita Jail project stems from integrating solar PV with energy efficiency and smart energy management systems. Yet another compelling aspect of this project was the purchasing and installation strategy. By re-reroofing, buying and installing PowerGuard tiles, and incorporating energy efficiency upgrades all at the same time, administrative costs were lower than if the projects had been done separately. This streamlined approach - relying upon one comprehensive contract instead of three discreet contracts - greatly reduced the complexity of negotiations. It also provided a platform of related services that are easier to manage. By aggregating financing requests to the California Energy Commission, for example, a single prime contractor approach employed at the Santa Rita Jail facilitated a successful campaign on the part of Alameda County to secure a variety of state financial incentives based on both the solar generation component and the energy efficiency components.

Perhaps the most impressive accomplishment by Alameda County, at least from a consumer's point-of-view, has been the high level of public goods funding that Alameda County was able to capture to support this project financially. Since this project provides substantial public benefits in the form of reduced peak electricity consumption in a region hampered by severe transmission constraints, these substantial public goods funds appear to be justified. Though the total project cost for Alameda County was approximately $4 million on paper, the following financial incentives were awarded to this innovative project: 

• $1 million from the California Energy Commission Emerging Renewable Buy-Down Rebates Program. Alameda County was able to secure this funding at the rate of 2.50 per watt. However, the Energy Commission recently raised this rebate amount to $4.50 per watt. Since this increase is retroactive to February 2001, Alameda County will receive additional funding under this program.
• $1 million fixed 6% interest loan from the California Energy Commission Energy Efficiency Financing Program (which will be paid off by avoided electricity cost savings over the next 11 years);
• $300,000 from the California Energy Commission's AB 970 funds. This legislation authorized the spending of $50 million for energy projects that reduce the state's demand for electricity this summer. 
• CMS Viron Energy Services secured $250,000 from PG&E under its "cross-cutting demand" program.

Contact
Bret P. Hunter
CMS Viron Energy Services
(801)290-4411 
bhunter@Viron.com