Opening of Proposals - WWTP Solar Guaranteed Energy Savings Contract Proj. No. 124-015 - Ameresco

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“Page content is subject to Confidentiality Restrictions” City of Arvada, Colorado | Project #37213 | M&V Report – Year 2 | Page 26 City of Arvada, Colorado In order to verify proper installation during construction, Ameresco performed a submittal review, installation checkout, functional testing, and PV system commissioning report review. Installation of the new PV systems were inspected and found to be acceptable by Ameresco. The inverters at City Hall were replaced, as specified in the scope of services; however, additional existing conditions were revealed that continue to cause ongoing issues with production from the existing solar PV system. Each PV system is controlled by their inverter’s internal control system. All inverters were confirmed to have the required grid interconnection controls during Xcel Energy’s interconnection review process. Two rounds of functional performance tests (FPTs) were performed, as data from round 1 was found to have issues, due to an uncalibrated insolation meter, which was later determined to have read approximately 5% higher, compared to the calibrated meter used in round 2. The round 1 measurements for the string voltage and current tests were deemed accurate and were approved by Ameresco; therefore, those performance testes were not repeated during round 2. The round 2 measurements focused solely on the functional efficiency of the PV systems, all of which demonstrated acceptable system performance, based on the following measurements: • Plane of array insolation (W/m2) • PV cell temperature (°C) • PV system output (kW AC) Measurement & Verification The M&V Plan for this ECM was based on IPMVP Option A – Retrofit Isolation Using a Key-Parameter Measurement. Savings for this ECM were determined using a HelioScope model, which is a solar PV design software tool. When key metrics – such as array location, specific PV module to be installed, tilt of the modules, module spacing, and specific inverter to be installed – are entered into the HelioScope program, an annual production report is generated that shows how much energy is expected to be provided by the solar PV system. For this ECM, the key parameter being measured is PV system power output. Instantaneous power measurements were taken for each PV system, as well as the corresponding insolation measurements, which allows for the system performance to be evaluated. The solar PV measurements are shown in Appendix H. This value was measured for each of the installed arrays, and it was compared to the expected power output to determine the expected savings for the Post Install Report. For this Year 2 Report, Ameresco utilized the actual production data from the monitoring systems to be as accurate as possible. The data and relevant notes can be seen in Appendix I. Note 2: During preparation of the Post Install Report, it was discovered that the value of the Xcel Energy renewable energy credits (RECs) for City Hall were counted twice when calculating project savings. Ameresco has removed the incorrectly applied additional REC savings from the verified savings.