Researchers use the REopt web tool to optimize energy systems for buildings and communities, as well as microgrids. Users can enter site-specific data in order to determine the best size and combination for energy systems to maximize cost savings and meet resilience or energy performance goals.
The current administration has set ambitious goals to reduce the economy’s greenhouse gas (GHGs) emissions by 50% below 2005 levels by 2030. This is a great time to optimize our energy systems for tomorrow’s built environment. REopt has significantly expanded its emissions accounting functionality in response to the climate crisis. This will allow government and industry to make smart energy investments while also helping with climate change mitigation. Users can now calculate the costs of climate and health-related emission and their impacts to determine the impact of future carbon emissions costs. They can also quantify environmental justice considerations and set goals for renewable energy and emissions reduction.
Clear eyes on clear skies: Sharpening our focus on emissions for environmental and energy justice
REopt already allows users the ability to calculate the hourly impact distributed energy systems make on year one’s carbon dioxide (CO2) emissions. This can be done by offsetting grid-purchased electricity and on-site fuel burn. REopt’s latest version allows planners, engineers, energy and facility managers to model and optimize:
The health-related emissions from grid-purchased power and on-site fuel burning are important considerations for energy justice as well as the local health impacts of electricity systems.
Total lifecycle emissions, which account for future changes in grid emission intensity, are a more dynamic metric that offers insights into how a new distributed system will perform within our larger energy ecosystem in the years to come.
To estimate the social, climate, health and cost savings associated with the projects’ CO2, NOx/SO2, and PM2.5 emissions impacts, you can use optional total lifecycle emissions costs
Find the cheapest way to reach a target for renewable energy or emission reduction at a site. Also, quantify the investment and savings.
Flexible renewable energy accounting and emissions accounting methodologies that allow users to include or remove exported clean electricity as an emission offset and/or in renewable power calculations. This allows users the flexibility to adapt their analysis to different GHG policies or renewable energy research approaches.
National Renewable Energy Laboratory (NREL), engineers Kathleen Krah & Amanda Farthing, have been researching relevant policies and data sets in order to make the tool accessible for stakeholders across the United States.
Krah says it’s been fascinating to learn about the factors and rates of emissions, including where they come from and how the data is used for renewable energy and emissions modeling. The REopt team currently uses the U.S. Environmental Protection Agencys Avoided Emissions & Renewable Tool (AVERT) to generate regional hourly grid emission profiles. This allows users to project a fixed annual percentage change of emissions rates for each timestep. In the future, the team will incorporate NRELs Cambium data, which include projected long-run marginal emission rates for the contiguous United States.
Farthing claims that the team was surprised at the relative cost of health-related CO2 emissions impacts. This will be explored in a forthcoming study. While they are both important and part of the national conversation. However, health-related emissions costs are not as often discussed as the social cost of carbon. It was surprising to find that those costs were so significant. The current location-specific health cost estimates in REopt are based on the Estimating Air Pollution Social Impact Using Regression model (EASIUR), which was developed at Carnegie Mellon University. The team hopes to study the health effects of marginal power plants, as well as their proximity to communities, in the future.
Tailoring Analysis to Individual Clean Energy Goals
REopt users can customize their analyses to help them achieve different types of clean-energy goals. These include:
To help users answer a question like, “How can I achieve a 25% renewable power target at my site at the cheapest cost?”
To help users answer questions such as: How can I reduce my site’s carbon emissions by 50%?
To answer questions such as “How does the cost of the optimal system change if climate and/or health effects are considered?”
New REopt capabilities address the growing demand to assess the climate and health effects of buildings energy use and the emissions savings that can be achieved by investing in distributed energy resources.
