New Solar Homes Partnership Calculator
Note: The Energy Commission will be revising the CECPV calculator that is used to determine an expected performance and incentive for the New Solar Homes Partnership (NSHP) program participants.
The CECPV calculator uses the time-dependent valuation (TDV) factors and weather data from the California Building Energy Efficiency Standards, Title 24, Part 6. The weather data and TDV factors were updated as part of the 2013 Building Energy Efficiency Standards code cycle. All homes participating in the NSHP program that are permitted under the 2013 Standards must use an updated CECPV calculator that is consistent with the 2013 Standards.
The updated TDV factors and weather data impact the expected performance-based incentive for a solar energy system by modifying the hourly estimated electricity generation (weather data) and the time-weighted valuation of that generation (TDV factors).
For illustration purposes, the spreadsheet at www.gosolarcalifornia.org/tools/nshpcalculator/TDV_Calculations_Results_for_Notice_2014-01-23.pdf documents the calculated incentive in all 16 climate zones for a reference system (2.64 kWdc, azimuth 180° from north, slope 22.6°) consistent with the 2008 Standards and the 2013 Standards. The impact to the incentive of a specific system will depend on the location and installation details of that system.
The NSHP program provides an incentive based on the expected performance of a solar energy system installed at a specific location. The expected performance based incentive is determined by using the CECPV Calculator. The calculator takes into account factors such as the electrical characteristics of the specific PV module and inverter, the mounting type, the orientation and tilt of the PV array, and the extent to which the system is shaded. The calculator also accounts for the available solar resource and climatic conditions in the location where the home is being constructed to determine the hourly estimated electricity generation over a year. Finally, the estimated hourly kilowatt-hour generation is multiplied by hourly TDV factors to calculate the expected production and incentive amounts.
CECPV Calculator Versions 4.1 and 5.0
Updated: January 23, 2014
This is a detailed hourly calculation tool based on the 5-parameter model developed by the Solar Energy Laboratory at the University of Wisconsin. The CECPV Calculator incorporates detailed inverter performance modeling and uses weather data from the 16 climate zones in California (as used by the Title 24 compliance calculations).
The MS Excel interface to the calculation engine is provided by the Energy Commission for download and allows the user to select PV modules and inverters from a library of eligible equipment. Please check this website periodically for updates as new equipment may be added to the NSHP eligibility lists. The CECPV Calculator generates the estimated monthly kWh production and annual TDV (kWh) production for the specified system. It also determines the appropriate incentive amount as calculated by the Expected Performance Based Incentive approach outlined in the NSHP Guidebook.
In order to provide users with future updates in a timely manner, we are asking you to "register" by entering your e-mail address below.
Registration is voluntary and will only be used to alert PV Calculator users of updates and/or other changes in the calculator. If you have previously registered, there is no need to do so again. Please use the link below the registration dialog box.
Note: If you do not register, you will not be notified of changes that may affect rebate amounts.
If you do not wish to subscribe to the list serve, you can still download the latest version of the calculator on the Download Page.Note: To qualify for an incentive, residential buildings must receive electricity distribution service at the site of installation from one of four investor-owned utilities (IOUs) in California. The IOUs are: Pacific Gas & Electric Company, Southern California Edison Company, San Diego Gas & Electric Company, and Southern California Water Company doing business as Bear Valley Electric Service. On the list within the calculator, there are cities that are not served by the above utilities. You can determine what utility serves your project by going to the page called Finding Your Utility Company.
Installation instructions, software requirements, and additional information are on the Calculator Download Page.
Related Title 24 Compliance Software
- Computer Programs to Help Meet Energy Efficiency Standards.