Tools & Resources
On-site Solar


Solar project(s) built on local buildings or land at the same location that the energy is consumed.


Some on-site solar installations can produce more electricity than a building can use, in which case excess energy is sold back onto the grid using a “net metering” protocol (unless storage is deployed). States and utilities have differing policies regarding how much customers are compensated for this electricity, and the compensation rate typically has an impact on local on-site solar uptake. In states or utility territories in which net metering is offered, customers receive retail rate credit for their exported generation, which can then offset future usage. Typically, customers can roll over credit for generation not used on-site from month to month during the calendar year. In some states, compensation for energy transferred to the grid can be calculated using other methods. For example, some utilities base their compensation on a “value of solar” calculation, where in other regions a building owner only receives a very small amount set by the local utility, based on the utility’s cost of avoiding the use of other generation (this is known as an “avoided cost” rate). Some states allow municipalities to enter into third-party on-site power purchase agreements, in which they can qualify for the federal Investment Tax Credit.

Primary Considerations

  • Does my state allow for net-metering?
  • What is the state limit on the size of PV systems eligible for net metering?
  • Which types of customers are eligible for net metering?
  • How are residents compensated/credited when they generate more than they use?
  • Who owns the Renewable Energy Credits in net metering?
  • Does my state allow for third-party power purchase agreements for on-site solar?

Secondary Considerations

  • Is there a state cap on the total amount of installed PV capacity eligible for net metering?
  • What happens if I have net excess generation at the end of the year?
  • Is virtual net-metering available?


On-site Solar Tools & Resources

2018 State Solar Power Rankings Solar Power 2018 Website
3rd Party Solar PV Power Purchase Agreement (PPA) Database of State Incentives for Renewables & Efficiency (DSIRE) 2018 PPT
A State-by-State Policy Guide for Midsized Solar Customers National Renewable Energy Lab Factsheets
CURB Tool World Bank, C40, Global Covenant of Mayors 2017 Tool
DSIRE (Database of State Incentives for Renewables and Efficiency) DOE/NC Clean Energy Technology Center 2018 Website
DSIRE Glossary Database of State Incentives for Renewables & Efficiency (DSIRE) Glossary
Electric Power Markets: National Overview Federal Energy Regulatory Commission 2017 Interactive Map
GHG Emissions Calculator EPA 2017 Tool
Google Community Solar Potential Map Google Project Sunroof Interactive Map
Green Power Supply Options EPA GPP 2018 Website
IREC Glossary Interstate Renewable Energy Council (IREC) Glossary
Local Government Solar Project Portal EPA Green Power Partnership 2018 Website
Pathways to 100: An Energy Supply Transformation Primer for US Cities Meister Consultants Group / Cadmus 2017 Report
Policies and Incentives by State Database of State Incentives for Renewables & Efficiency (DSIRE) Interactive Map
Project Sunroof Google 2018 Tool
Purchasing Power: Best Practices Guide to Collaborative Solar Procurement WRI and Joint Venture Silicon Valley 2011 Report
PVWatts NREL 2018 Tool
SEIA Solar State-by-State Factsheets Solar Energy Industries Association Q3 2018 Interactive Map
SLED (State and Local Energy Data) Department of Energy 2018 Database
Solar Power Purchase Agreements: A Toolkit for Local Governments IREC (Interstate Renewable Energy Council) 2015 Templates
State-by-State Map of Energy Choice in the U.S American Coalition of Competitive Energy Suppliers Interactive Map
Toolbox for Renewable Energy Project Development EPA Green Power Partnership 2018 Website
U.S. EIA Glossary U.S. Energy Information Administration Glossary
Wholesale Electricity and Natural Gas Market Data U.S. Energy Information Administration 2019 Database