THE SUN IS ONE OF OUR MOST POWERFUL SUPPORT !

Depending on roof size, shading, orientation, and location, the solar rooftop potential for the entire country is the number of rooftops suitable for solar power. Rooftop potential is not equivalent to rooftop solar's economic or market potential, as it does not account for availability or cost. Instead, it is the maximum solar rooftop deployment across the United States.

 

Solar rooftop potential is the quantity of solar that could be installed on a specific rooftop based on its size, shading, tilt, location, and construction. Installers incorporate satellite maps, irradiance data, equipment specifications, and other factors into the bids they present to customers to help them comprehend the potential costs and benefits of installing solar panels on their roofs.

 

Rooftop Potential On A National Scale ​

 

In 2016, the National Renewable Energy Laboratory (NREL) estimated that there are over 8 billion square meters of rooftops in the United States where solar panels could be installed, indicating over one terawatt of potential solar power. With improvements in solar conversion efficiency, the country's rooftop potential could be even higher. Residential and other small rooftops account for approximately 65% of the total national rooftop capacity, with low-to-moderate-income families accounting for 42% of residential rooftops.

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NREL estimates that an average of 3.3 million homes are built or need roof replacement each year, representing a potential of approximately 30 gigatonnes (GW) of solar capacity per year. If even a tiny percentage of these new roofs included solar panels, it could significantly affect solar power generation in the United States.

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Individual Rooftop Capability 

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National laboratories and private companies have developed various tools for estimating the number of solar panels that can be installed on a specific rooftop. The tools described below were partially funded by the Solar Energy Technologies Office (SETO) of the U.S. Department of Energy to assist consumers in determining the solar potential of their homes or enterprises.

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EnergySage​

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EnergySage, a previous Incubator awardee, estimates solar energy savings for homeowners, businesses, and non-profit organizations and connects them with pre-screened installers who can provide estimates unique to the user's location. Users can compare systems and choose the one that best meets their requirements. Electricity bills are used to calculate the possible savings from solar energy, and Energy Sage has been found to provide customers with significant savings over more traditional products.

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PVWatts​

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PVWatts is an online tool from the NREL that estimates the energy production and expense of electricity for photovoltaic (PV) solar power systems connected to the power grid around the globe. It enables homeowners, business proprietors, and non-profit organizations to quickly estimate the performance of potential PV installations based on an online map or data supplied by the user. The System Advisor Model (SAM) is free software that enables detailed performance and financial analysis for renewable energy systems.

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Sun Number​

 

Sun Number, a former Incubator awardee, provides a numerical score representing the solar viability of a building's rooftop on a scale from 1 to 100, with 100 representing the optimal rooftop for solar. Inputting a genuine address in a region where the analysis has been performed provides access to the scores. The Sun Number score is derived from aerial imagery that has been processed with proprietary algorithms to analyze individual rooftops accurately and is based on various factors, each uniquely weighted to provide an accurate analysis of a rooftop. Factors include roof form, surrounding buildings and vegetation, regional variation, and atmospheric conditions. Additionally, the company partnered with Zillow, an online home-listing service, including a potential solar listing to the descriptions of more than 40 million homes.

 

 

Business Tools

 

Aurora Solar

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Aurora Solar Inc., a former Incubator grantee, created a web application that calculates the rooftop solar potential of a building in a flash. The application evaluates and compares numerous potential sites using image recognition and computer vision algorithms.

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dGen: Distributed Generation Market Demand

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This instrument simulates the 2050 customer adoption of distributed energy resources for residential, commercial, and industrial entities in the United States and other nations. It can analyze the main factors that will influence the future demand for distributed energy resources on the market. dGen will be an open-source instrument in the future.

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Folsom Labs

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Former Incubator grantee Folsom Labs created a solar permit generator, a software engine that autonomously generates standard documents for inspectors and authorities with jurisdiction. (AHJs). These documents are required for AHJs to authorize solar arrays in their jurisdiction. Helioscope, a design and engineering product offered by Folsom Labs, is utilized by the software to rapidly generate permit documents, single-line diagrams, site plans, and design details.

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National Database For Solar Radiation 

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This tool provides a compilation of hourly and half-hourly meteorological data values and the three most common measurements of solar radiation: global horizontal, direct normal, and diffuse horizontal irradiance.

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PVLib

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PVLib is an open-source software application that enables users to simulate photovoltaic energy system performance. Two versions (pvlib-python and PVILB for Matlab) have grown substantially due to contributions from an active user community.

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Regional Energy Deployment System (ReEDS)

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ReEDS simulates investment decisions in the electricity sector based on system constraints and energy and ancillary service demands. Its advanced algorithms and high spatial resolution enable it to represent the cost, value, and technical characteristics of integrating renewable energy technologies.

 

REopt Lite: Integration and Optimization Of Renewable Energy

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REopt Lite recommends the optimal mix of renewable energy, conventional generation, and energy storage technologies to meet cost savings, resilience, and energy performance goals

 

reV: Model Of Renewable Energy 

reV is the first spatiotemporal modelling assessment tool that enables users to calculate renewable energy capacity, generation, and cost based on geospatial intersection with grid infrastructure and land-use characteristics.

 

System Advisory Model

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This free, techno-economic software model, SAM, facilitates the simulation of renewable energy projects' technical performance and financial analysis. SAM combines time series weather data and system specifications to calculate potential electricity production and uses system cost, compensation, financing, and incentive data in an annual cash flow to calculate the levelized cost of energy, net present value, payback period, and internal rate of return of a potential project.

 

Additional Material 

• Technical Potential for Rooftop Photovoltaics in the United States

•  Guide to the Federal Tax Credit for Solar Photovoltaics for Homeowners

•  Federal Investment Tax Credit for Commercial Solar Photovoltaics: A Guide

•  Technical Potential for Rooftop Photovoltaics in the United States (Dataset) 

 

Learn more about the DOE's solar energy research and the available solar energy resources.