In accordance with the Exceptional Calculation Method this CIR seeks confirmation of the approach indicated below in claiming energy savings on process loads. Project Description: This is a water reclamation project that takes water from a wastewater treatment plant and uses micro-filtration/ultra-filtration, reverse osmosis and finally ultraviolet radiation to treat the water. Many large motors drive pumps to move the water through the reclamation facility. The energy used by the pump motors represents greater than 90% of the energy used on the entire campus and represents the best opportunity for energy use reductions. Proposed Approach: The water treatment process runs nearly continuously throughout the year. Periodically, the membranes and filters that the water passes through get clogged, increasing the resistance that the pumps must overcome. Historically designs have used constant speed pumps to drive the water through the system coupled with resistance or bypass flow control devices to maintain constant flow volumes. It is proposed that constant speed motors be used as the basis for the baseline design. The proposed design would utilize variable frequency drives (VFD) to control the speed of the pumps to maintain flow through the system. The VFDs allow for running the pumps at lower speeds which results in lower energy use because percent of total power used at part speed is much less. Under normal conditions, when the membranes are clean, the motors will only need to operate at 80% of full speed. As the membranes begin to clog, the VFDs increase the pump speed to maintain constant flows. Please note that this baseline design and proposed design approach has been recognized and accepted (documentation can be provided) by Southern California Edison (local utility supplying power to the project) through their "Savings By Design" program. This program provides monetary incentive for projects that exceed the energy conservation requirements of California\'s Title 24 and the utility performs their own energy modeling to verify the designed savings. We seek confirmation that our proposed approach to claiming energy savings on the process loads is valid.
The project team is requesting that the project, a facility for water reclamation, be allowed to apply their energy savings from the installation of VFD\'s on the pumps operating the water reclamation system towards Energy and Atmosphere credit 1. The proposed exceptional calculation method approach described is acceptable; however documentation will need to be provided for certification. At a minimum, the applicant should provide: 1. Documentation verifying that constant flow pumping systems are an acceptable baseline or standard for water reclamation systems 2. Relevant sections of the Southern California Edison documentation referenced 3. A detailed narrative and back up data for how the baseline energy consumption was determined. 4. A detailed narrative describing the proposed processes taken credit for 5. Narratives and cutsheets of relevant equipment clearly highlighting the efficiency metric for each piece of equipment or drives credit is claimed for. The applicant should also note that if this project is process energy dominated, it will only qualify for a maximum of 4 points from the process energy efficiencies. *Please note (added 10/15/2009)*: Projects are now eligible to claim more than 4 points from process energy efficiency savings. This guidance supersedes CIR 2/9/2009 which placed 4 point maximum limit on process energy savings.