The first step to choosing a technology is to identify the objectives for undertaking an energy efficiency project, installing a solar system or any other energy system on municipal properties. This could include getting the best return on investment, optimizing greenhouse gas emissions reduction, or raising public awareness of a new technology. After clearly identifying objectives, it will be easier to list locations in order of priority based on these objectives.
There are many different energy efficiency and renewable technologies that should be considered when evaluating potential options for a project. Tools such as RETScreen are useful for evaluating a wide range of renewable technologies. Mapping software and solar resource calculators are available to identify the most feasible potential installation site for solar. Consider ground-mounted as well as roof-mounted systems. NREL’s tool SolOpt is also useful for optimizing the sizes of solar PV and solar thermal systems.
Identify buildings with other renovations planned such as an upcoming roof replacement and consider combining the projects. It’s best not to install solar systems on roofs that need to be replaced in the near future. To do major roof work, solar panels must be removed and reinstalled on the new roof, increasing costs. An ideal approach for installations where roof penetrations are required is to integrate the technology into the structure during roof replacement instead of penetrating an existing roof. This is one example of how effective planning can save money and lead to better results.
It is important to include facilities managers and other staff in the on-site assessment early on to integrate them into the process and use their knowledge of the building’s energy use and schematics. Utilize the site assessment and project evaluation as an opportunity for hands-on training of additional in-house facilities personnel and site assessors.
Section heavily draws on Solar Powering Your Community: A Guide for Local Governments (January 2011)
The U.S. Department of Energy developed this comprehensive resource to assist local governments and stakeholders in building sustainable local solar markets. This second edition of the guide was updated to include new market developments and innovations for advancing local solar markets that have emerged since the first edition was released in 2009. This updated edition also contains the most recent lessons and successes from the original 25 Solar America Cities and other communities promoting solar energy. The guide introduces a range of policy and program options that have been successfully field tested in cities and counties around the country. Chapter 7, Leading by Example with Installations on Government, is particularly relevant to local governments that want to go solar on their own facilities.
Created by the University of Minnesota West Central Research and Outreach Center, this is a comprehensive guide on both solar thermal and PV. It explains the technologies, offers advice for evaluating projects, and includes performance case studies.
This guide to assessing, investigating, and contracting for solar energy systems for small commercial businesses is adapted from Renewable Energy and Schools: A step-by-step guide for evaluating, acquiring, installing, promoting, and using renewable energy systems in K-12 schools. The original document is published by the State of Minnesota Department of Commerce, Division of Energy Resources.
A PV mapping tool visually represents a specific site and calculates PV system size and projected electricity production. This report identifies the commercially available solar mapping tools and gives a thorough summary of the source data type and resolution, the visualization software program used, user inputs, calculation methodology and algorithms, map outputs, and development costs for each map.
RETScreen 4 is an Excel-based clean energy project analysis software tool that helps decision makers quickly and inexpensively determine the technical and financial viability of potential renewable energy, energy efficiency and cogeneration projects.
SolOpt is a tool for optimizing and sizing rooftop photovoltaic and solar hot water system installations. The tool is currently in beta version and can be tested using the attached Excel spreadsheet. Note: When prompted to ‘Open,’ ‘Save,’ or ‘Cancel,’ select the ‘Save’ option for proper operation.
The In My Backyard (IMBY) tool estimates PV array and wind turbine electricity production based on specifications of system size, location, and other variables.
NREL’s PVWatts calculator determines the energy production and cost savings of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, installers, manufacturers, and researchers to easily develop estimates of the performance of hypothetical PV installations.
The Federal Energy Management Program (FEMP) has worked with the Geographic Information System (GIS) staff at the NREL to create federal energy management program maps showing the market potential for various solar technologies throughout the country.
OpenEI is an open-data platform for energy information–specifically analyses on renewable energy and energy efficiency. The platform is a Wiki and users can view, edit, and add data, – and download data for free to make informed decisions on energy, market investment, and technology development. In addition to the Wiki, OpenEI provides a platform for sharing datasets.