8. System Performance Monitoring

Section 2864 requires that SWH systems that displace over 30 kWth of natural gas be equipped with meters or other kWhth measuring devices to monitor and measure the system's performance and the quantity of energy generated or displaced by the system.

The Staff Proposal goes beyond the minimum monitoring required by the statute and recommends that all non-residential SWH systems, both electric or natural gas-displacing and regardless of size, include performance monitoring and metering equipment and make performance data available to program evaluation contractors for a minimum of five years. For residential systems, staff suggests that metering equipment be installed on a representative sample of systems for five years to verify expected performance and to provide program evaluation data.

Given the requirement in Section 2864 for monitoring equipment on systems over 30 kWth, we have little room for deviation from the Staff Proposal except for systems under 30 kWth or electric-displacing systems. PG&E comments that monitoring equipment should only be required for very large non-residential systems, but it does not define "very large." CALSEIA asks the Commission to conduct a survey of monitoring equipment availability, costs, and reliability to determine if it can be installed at a reasonable cost. The findings of this survey could help determine if metering and monitoring should be a standard feature on all SWH systems. SDG&E/SoCalGas contend it is more cost-effective to install metering on a random sample of non-residential systems, and that the appropriate sample size should be determined through the measurement and evaluation process. Environment California contends monitoring can be a financial burden for customers. Therefore, it contends monitoring equipment should not be required for smaller systems.

We will modify the Staff Proposal, in part, and require performance monitoring and metering equipment only for SWH installations with a capacity of displacing over 30 kWth that receive incentives under this program. For systems displacing 30 kWth and below, we adopt the Staff Proposal that metering and monitoring equipment should be installed for program evaluation purposes on a sample of these systems - including residential, commercial, and multifamily properties. The cost for monitoring equipment on this sample will be borne by the PAs through their measurement and evaluation (M&E) budgets. The sample size will be determined through the M&E process, in consultation with Energy Division, and discussed further in Section 13 below. The PAs should identify projects to be monitored as soon as possible in the application process, and the PAs should arrange for the installation of monitoring equipment as close as possible to the installation of the project.

SCE recommends that a meter socket should be required on every solar energy system that is installed so that the PA or utility can perform M&E at any SWH location. A meter socket might also prove useful for advanced metering capability and to comply with future renewable energy market verification standards. CALSEIA opposes SCE's meter socket proposal as complex and costly. We agree with CALSEIA and will not require this extra equipment on every installation at this time. Of course, customers who install SWH systems are free to add the meter socket at their own expense. The PAs should include information about the value of SWH system metering and monitoring in all of their customer education materials.