As facility owners across the country look for ways to cost-effectively deploy solar technologies throughout their entire building stock, there is an increasing need for a standardized solar rooftop optimization tool. Traditionally, photovoltaic (PV) and solar hot water (SHW) technologies have been designed with separate design tools, which can make it difficult to determine the appropriate mix of PV and SHW for a single rooftop. In the current marketplace, when a building is assessed for its potential to host a solar energy system, it tends to be an either/or analysis. 

The National Renewable Energy Laboratory has developed a new tool that uses an integrated approach based on the life cycle cost effectiveness of each system and a particular building’s characteristics—an approach that completely changes how conventional analysis is conducted. With 10 simple data inputs, a person possessing only basic knowledge of a building can simulate energy production from PV and SHW, and thereby effectively predict the optimal mix and size for a system. The user can also factor in five additional optimization criteria: Greenhouse Gas Reduction, Net-Present Value, Renewable Energy Production, Levelized Cost of Energy, and Discounted Payback Period.

The SolOpt Optimization Tool (downloadable from the Solar America Communities Resources page, under "Publications and Presentations") provides unique analysis capabilities that are not currently available in any other software program or simulation tool. Because SolOpt is built from an assessor’s standpoint, it is easy to use for anyone who is conducting solar assessments and feasibility studies. SolOpt’s comprehensive approach brings together PV and SHW technologies to analyze the combined system, including production, financial viability, and design components. This results in a comprehensive solution for using available space in the most effective manner possible (see Example Output).

Some of SolOpt’s unique characteristics complement the tool’s usability and others increase the technical integrity. Because meteorological characteristics and incentives vary significantly from one region of the country to the next, the tool is web-enabled, allowing it to pull accurate weather and incentive data for analyzing any commercial or residential building rooftop throughout the United States. The software also utilizes sophisticated hourly heat transfer and thermal storage tank calculations.

Target audiences for SolOpt include: city energy and building managers, integrated solar installers, consultants, energy service companies, solar electric power and energy industries associations, and even the general public.

To learn more about SolOpt, link to the archived webinar, Optimizing Solar Installations – Tools and Strategies. For assistance on state and local solar energy programs, please contact a Technical Assistance Provider.

Content for this Blog post courtesy of Lars Lisell, Ian Metzger, and Jesse Dean, National Renewable Energy Laboratory