U.S. Department of Energy - Energy Efficiency and Renewable Energy
Federal Energy Management Program
FEMP Conducts Solar Technology Screening at Job Corps Centers
March 7, 2007
With funding from the Federal Energy Management Program, the National Renewable Energy Laboratory (NREL) in 2005 performed an initial assessment of solar energy opportunities at 88 Job Corps Centers across the United States and Puerto Rico. The screening considered solar water heating, solar ventilation air preheat, and photovoltaic technologies. The Job Corps program, consisting of vocational education facilities for young adults, has centers comprised of dormitories, education buildings, vocation workshops, medical facilities, gymnasiums, cafeterias, and administrative buildings, with each center ranging from 45,000 to 1 million square feet. The agency plans to install a renewable energy system at one center that will be capable of supplying 5 percent of its electricity; this assessment was the first step in identifying the most appropriate site.
The assessment examined solar resource, site-specific factors, and applicable incentives or rebates to determine which centers were most promising for a specific technology installation. Job Corps staff provided detailed site information for each of the centers for analysis, including center name; address; longitude and latitude; number of students and residents; square footage of buildings; and utility use and cost data for each fuel. The longitude and latitude data was used to extract solar resource information for each center from NREL's geographic information system database.
||Job Corps Sites with SIR >1, by Technology.|
Combining the solar resource and site-specific data, the system size and cost were calculated for each technology. Cost effectiveness was evaluated on a per-kilowatt (kW) or per-square-foot basis, but the maximum system size was also calculated to provide information to Job Corps staff on the largest potential opportunities.
Incentives and rebates offered for renewable technologies greatly impact the cost-effectiveness of various projects, and so these financial benefits need to be included in the early stages of the screening process. The relevant incentives and rebates for each center were taken from the Database for State Incentives for Renewable Energy and approximated as either a percent reduction in initial system cost, a dollar-per-watt or dollar-per-square-meter reduction in initial system cost, a dollar-per-kilowatt-hour production incentive, or a combination of the three. In this way, the initial cost estimate or the annual cost savings estimate was actually modified to reflect the applicable financial benefits for a particular site, as compared to the calculations without such benefits.
These values were then used to calculate the savings-to-investment ratio (SIR) and payback period. SIR is the life-cycle savings divided by the life-cycle cost. However, please note that this assessment did not consider the benefits or possible income to be earned from net metering; that is, the sale of excess electricity to the utility or from selling renewable energy certificates, both of which are complex to predict but would likely help the economics of using these technologies at most of the sites.
The SIR was calculated and used as the primary indicator of cost-effectiveness for the three technologies at each site. As defined according to regulation Title 10, Code of Federal Regulations, Part 436, a SIR of greater than 1.0 indicates that a project is cost effective. The higher the SIR, the better the project. According to the analysis, cost effective opportunities for solar water heating projects exist at 13 sites, for solar ventilation preheating opportunities at 18 sites, and for PV opportunities at four sites (see Figure 1 for site locations). The Job Corps staff stated that this screening has helped to develop "the foundation for the renewable technology building program" for their agency. It is likely that a project will be implemented for at least one of these promising sites with a SIR of greater than 1.0. Supporting that statement, the staff added, "After funding is approved, we will begin the engineering study and plans to complete these projects."
For more information, please contact Andy Walker of the National Renewable Energy Laboratory at firstname.lastname@example.org or 303-384-7531.