Ekotrope RATER Now Supports RESNET’s Carbon Index

We’re thrilled to announce that RESNET’s Carbon Rating Index is now available in Ekotrope RATER in beta. Our team has worked diligently to incorporate it into our application so that users can get Carbon Indexes for their projects.

What is the Carbon Index?

The Carbon Index shows the global warming impact of a home relative to a reference home which is very similar to the HERS reference home.

The system calculates a home’s emissions by taking the hourly energy consumption already calculated in Ekotrope and multiplying it by emissions factors for each fuel. These emissions factors are in CO2 equivalent (CO2e) which includes the impact of methane and nitrous oxides in addition to CO2. For natural gas, oil and propane, the emissions factor doesn’t change based on location or time of use. The calculation for electricity, however, is a lot more complicated.

The emissions factors used for electricity are based on data provided by the National Renewable Energy Laboratory (NREL). They vary by:

Location: Different regions have a different mix of generation sources. To account for this, the country is divided up into the 20 regions represented below which align with how the electric grid is structured. You will notice that this only includes the 48 contiguous states. Unfortunately this data is not available outside of those states and neither is the Carbon Index.

Hour: The mix of energy generation to the electric grid is constantly changing. For example, there’s no solar production at night and less during the winter. To account for this, hourly emissions factors are used for electricity.

Year: The US electric grid has been getting progressively cleaner as the share of renewable generation has increased and that trend should accelerate. To account for this, a net present value calculation is done which factors in the projected emissions rates over the next 25 years.

For more information on the index and how it works, check out our recent explainer article.

How to Use the Carbon Rating Index in Ekotrope RATER

The Carbon Rating Index does not require you to perform any additional inspections. Your index score will appear underneath the HERS score on the quick results section of RATER. If you have a HERS score, you will also have a Carbon Index score.

What if I don’t see the Carbon Index?

Unfortunately the data underlying the Carbon Index calculation is only available in the contiguous 48 states. So homes outside of those states will not be able to access the Carbon Index. We apologize for any inconvenience this causes.

How to Get the Carbon Rating Index for Your Team

If you want to start modeling homes using the Carbon Rating Index in Ekotrope RATER, please reach out to us at info@ekotrope.com. We’d be happy to provide you with more information on how it works, share a demonstration, and get your team on track to start using it today.