City amps up energy savings with solar

Over the last five years, Tulare, Calif., has been implementing a host of energy efficiency and water conservation initiatives that are financed through a performance contract. The financing method eliminates up-front costs for the city, and instead pays for the work with the guaranteed energy and operational savings from the improvements. The most recent component of the contract is the installation of a photovoltaic system at the city’s wastewater treatment plant that will provide enough power for the facility and ultimately provide a source of revenue. As a result of the efforts, Tulare expects to save more than $13.9 million in energy costs, and avoided capital and operating costs.

In 2006, Tulare contracted with Milwaukee-based Johnson Controls to help it meet a state mandate to install water meters on all commercial and residential properties. Under a 15-year performance contract, the company developed a plan to install nearly 16,000 water meters equipped with an automated meter reading (AMR) system. Using radio transmitters, the AMR system allows city employees to drive down the street and automatically record meter readings. The meters replaced existing, less accurate meters or were installed in previously unmetered facilities. In addition to the meter upgrades, the company retrofitted lights, upgraded HVAC equipment, and replaced windows and roofs in select municipal buildings. City-owned street, roadway and intersection lighting improvements also were made.

In 2007, the company installed a 30-kilowatt solar photovoltaic (PV) system on a carport at the city’s wastewater treatment plant, resulting in more than $13,000 in annual savings. Expanding on that idea, last summer, the company installed a one-megawatt solar PV system on land adjacent to the wastewater treatment plant. The system will generate more than 1.8 million kilowatt-hours annually and is expected to save Tulare more than $6.4 million in energy and operational costs over 15 years. Power from the system will be used to operate the plant as well as select municipal buildings and some street lighting.

The company facilitated the interconnect agreement with the local electrical utility and helped the city apply for available funding. The city received more than $2.3 million from the California Solar Initiative Program and a $438,000 American Recovery and Reinvestment Act grant for the solar installation.