Sense Blog

How to Clean Up Your Home’s Carbon Emissions

Sense has introduced an exciting, new feature in the Sense app that tells you when the electricity coming into your house is the cleanest (or dirtiest). You can use this new Carbon Intensity feature to minimize the carbon emissions of the electricity you use every day. Even if you don’t have solar panels on your roof, you can use cleaner energy at home.

Now in the Sense app, you can see the carbon intensity of the electricity coming into your home and compare it to your energy usage. You can also see a forecast of carbon intensity so you can plan high energy tasks such as laundry, dishwashing or charging electric vehicles when carbon emissions are lowest. If you take this approach, you’ll see your average CI score declining. You’ll actually be contributing to lower carbon emissions from the power grid!

What is carbon intensity?

There’s more to learn about using the Carbon Intensity feature, but first, what is carbon intensity? Carbon intensity is a measure of carbon emissions. It’s the amount of carbon dioxide emitted to generate a specific unit of power and it’s described in pounds of CO2 per kilowatt hour of energy produced.

The carbon intensity of your electricity changes dynamically as the power grid taps different energy sources. When you reduce your home’s carbon intensity, you’re also reducing carbon emissions from the utility grid.

Sense has partnered with Singularity Energy whose Carbonara platform tracks and analyzes carbon intensity from

the utility grid. Their data is now integrated with Sense to bring this capability into the app.

Insights and Actions from the Carbon Intensity feature

You can find the Carbon Intensity feature in the Trends menu. When you open the Carbon Intensity screen, you’ll see your energy usage as green bars and a red line that shows the carbon intensity (CI) of electricity coming into your house from the utility grid.

You’ll also see your average carbon intensity score. You can choose the time periods to view your score and the CI trend line.

Carbon intensity is measured in the Sense app on a scale from 0 to 2 pounds per kWh. The average CI across the country is 1 (the gray line), which happens to be just above the CI of natural gas. Renewable energy sources like hydro, wind and solar have CI

scores that are below 1. Conventional power sources like oil and coal have CI scores above 1.

Notice, also, that the CI trend line extends into the future, showing you the peaks and valleys over the coming hours. If you schedule your activities to align the peaks of your energy usage (the green bars) with the valleys of CI, you’ll be reducing carbon emissions.

Why the utility grid’s fuel mix matters

The Carbon Intensity screen also shows a breakdown of the fuel mix that is powering the home right now. Each region taps its own mix of power sources to deliver electricity to homes. Those energy sources vary widely from region to region. Your CI may be lower or higher than other Sense users simply based on the fuel sources used by your regional grid.

Above: This map shows the average annual carbon intensity for regional balancing authorities around the country. Some regional authorities don’t report carbon intensity frequently enough to help you plan daily activities, so it’s not included in the app for Sense users in those regions at this time

But no matter where you live, there’s an opportunity to reduce your carbon. Here’s why. The regional balancing authorities that manage the power grid are continually changing their fuel mix over the course of a day, adjusting to demand and available energy supplies, creating variations in CI. When you use energy during higher CI periods, you’re contributing to more carbon emissions. When you use energy during lower CI periods, you’re helping to reduce emissions.

Some regions have wider ranges of CI on a daily basis than others. If you live in California, for instance, you’ll see more daily variability in your CI as clean energy sources like wind and solar peak and wane. On the other hand if you live in New England, you’ll see low variability in CI daily since the region relies heavily on conventional fuels that supply power steadily.

Above: These graphs show the carbon intensity in several regions over the course of one week. Notice that some regions have higher variability than others because they depend on a fuel mix that has a wider range of carbon intensities. For instance, CAISO, the California ISO, has a lot of variability because of its reliance on renewable energy sources that vary over the course of a day, whereas ISONE, the New England ISO, has low variability because of its heavy reliance on natural gas and nuclear power.

The Carbon Intensity feature is only available on the mobile version of the Sense app initially. You need to enter your zip code in order to access this feature. If you don’t see CI data for your home, it’s most likely that you live in a region where the utility industry doesn’t supply their carbon intensity data in the 5-minute intervals used in the Sense app.

Carbon intensity vs carbon footprint

The CI data in the Sense app tells you a simple fact: how much CO2 is released when power sources are turned into energy. It doesn’t reflect the carbon footprint of that fuel mix, which would include the cost of manufacturing, extracting and transporting the fuel or power source. It also doesn’t reflect your home’s overall carbon impact. You can have a low CI score but if you’re using a lot of electricity on an ongoing basis, then your contribution to carbon emissions could be higher than someone with a high CI score who uses very little electricity. Your home’s carbon footprint is an even more complex number to calculate since it takes into account the home’s construction as well as all the fuel sources it uses, not just electricity.

So we’re keeping it simple. Your CI score is another way to learn about your home’s electricity and to use the Sense app to live responsibly on the planet.