Much of the reporting about electric vehicles focuses solely on the vehicles themselves, such as performance metrics: range, battery size, and acceleration. Other aspects are the frunk size, seating capacity, and cost. Naturally, an article about a particular EV would make such references.
However, something is missing if we don’t consider the bigger picture. Electric vehicles are connectable to other technologies in ways that fossil-fuel vehicles are not. Some EV owners have solar-power systems at home so they can charge their EVs with clean, renewable electricity. Others have solar and energy storage so they can use clean electricity to charge home batteries and charge their EVs from the batteries. Electric vehicles can also work with smart home automation to optimize charging times from utility-based electricity.
In fact, Sense and Singularity Energy, Inc. recently conducted a study of EV charging patterns and time-based carbon intensity data. According to the study, EV charging carbon emissions could be reduced 8-14% on average across the US by utilizing smart home automation and location-and time-based carbon emissions data. In California, there could be as much as a 43% reduction in carbon savings.
Mike Phillips, the CEO of Sense, and Wenbo Shi, PhD, the CEO/Co-founder of Singularity Energy, Inc., answered some questions about the study for CleanTechnica.
How can smart home automation and location- and time-based carbon emissions data from the power grid be used together when charging electric vehicles to reduce carbon emissions?
Mike Phillips: As utilities look to decarbonize and there are more renewables on the grid, it’s becoming increasingly important to influence when energy is used to better match supply and demand. While approaches like Demand Response programs and time-of-use rates have tried to address this, we think this really needs to be done through automation. Most consumers don’t want to worry about the details, but they also don’t want to give up control — the right balance between these is to use smart home automation of key energy loads in a home. The best places to use this are for things like EV charging where the consumer doesn’t really care when the car gets charged — they just need it ready by 7 am, for example. A similar approach could be taken with running dishwashers or doing laundry — applications can get schedule preferences from consumers and then automatically find the best time to clean the dishes or wash the clothes.
There are other energy intensive activities that could be automated to reduce carbon with the consent and control of consumers. For instance, HVAC systems could pre-cool a house before peak demand during a hot summer day. Smart hot water heaters could function like batteries, holding water that’s dynamically pre-heated. Pool pumps could be run to clean the water when carbon intensity is lowest.
This reality is closer than most people think. Through our relationships with Landis+Gyr and Schneider Electric, we’re building Sense’s capabilities into smart meters and smart electrical panels so they’re part of the home itself. Homeowners will use the Sense app to provide preferences and let their homes take care of interacting with smart home devices to make good decisions about when to use energy.
What is carbon intensity, and why does it matter?
Wenbo Shi: Carbon intensity of electricity is a metric to tell you how clean the electricity is based on the source of generation. When electricity is generated using fossil fuels, the carbon intensity is high as carbon dioxide is emitted in the generation. Renewable generation such as solar and wind produces almost no carbon dioxide, so their carbon intensity is very low. Lower carbon intensity means greener electricity.
The electricity that we use from the power grid is generated from a mix of sources such as natural gas, coal, oil, nuclear, hydro, solar, wind, biomass. This grid fuel mix is very different in different regions and changes in real time, so the carbon intensity of the grid power also looks very different depending where you live and the time of day. Our research paper has more technical details and a comparison of grid carbon intensity profiles across grid regions.
Knowing the grid carbon intensity is important to understand one’s carbon impact of using electricity and leverage it to help reduce carbon emissions. As the old saying goes, “you can’t manage what you don’t measure.” Even the most environmentally conscious consumers today often have no idea of their carbon footprint and how dynamic their local grid carbon intensity is. So the first step is to make carbon visible to electricity consumers. Then, we can leverage this dynamic grid carbon intensity signal and smart home automation to automatically optimize electricity consumption to reduce carbon emissions.
Can an EV owner with smart home automation manage EV charging at off-peak times to save money and reduce carbon emissions at the same time?
Mike Phillips: In our recent analysis of EV charging, we just looked at carbon emissions and found that charging to reduce carbon intensity would reduce emissions more effectively than using time of use strategies. But, yes, the right thing to do is to consider a number of factors when making the decision about when to use energy — so a combination of cost, constraints on the grid, and the carbon impact of the energy use. Some of these are quite dynamic so this is why we think this ultimately needs to be done through automation. The consumer should provide preferences about tradeoffs between cost and carbon impact, and the end results they care about — when the car should be charged, when the dishes should be clean, the acceptable temperature range of their home — and then automated systems like Sense should make the right decisions about when to use energy to make those things happen.
How does Sense work with home EV charging?
Mike Phillips: We are testing some initial capabilities around this now and plan to release a future version of the Sense application to enable EV charging automation. We are also working with our partners Schneider Electric and Landis+Gyr to figure out how this sort of functionality rolls out in the work we are doing with them in electrical panels and utility meters — both of which are running the Sense application.
Can businesses with EVs and EV chargers use Sense and Singularity to reduce their carbon emissions too?
Mike Phillips: We have been focused on residential so far, but yes, the same sort of functionality makes sense for a broader range of deployments and we will be exploring this over time.
Why was the potential California carbon emissions reduction greater at 43%?
Wenbo Shi: Greater penetration of variable renewables such as solar and wind magnifies the carbon reduction potential of load shaping. As demonstrated in our research, in California, there was a massive 43% carbon reduction opportunity. In Texas, there was an 18% carbon reduction opportunity.
Those two states have a large percentage of variable renewable energy, translating into a highly dynamic carbon intensity signal. Other regions didn’t show as much carbon reduction potential, but as more renewable energy comes onto the grid across the US, we can expect other states to look more like California and Texas. The more renewables that come online, the more carbon reduction potential a consumer can have by choosing a different time of day to use electricity.
One of the exciting things about our collaboration with Sense is the potential to automate this through smart home technology. When you automate, the customer doesn’t need to pay attention because the system will take advantage of even minor fluctuations automatically to reduce carbon emissions. Our study showed that optimizing EV charging for carbon intensity over a 24-hour period would yield 8-14% reductions in related carbon on average across 44 states.
If a homeowner has a home solar power system, an EV charger, and a home energy system, can Sense be used with such a system to monitor electricity production and consumption, including the carbon emissions reduction?
Mike: Today Sense supports solar systems, showing a real-time view of solar production, home energy consumption and how much solar energy is going back to the grid. It also detects and tracks EV charging, as well as home energy systems like HVACs and mini-splits.
On June 23, we debuted a new feature in the Sense app based on our work with Singularity. With that feature, Sense users can see their home’s carbon intensity in real time, drawing on data from the Carbona platform. Users can see their average CI and can see the current CI of the power they are using, which is based on dynamic data from the utility grid’s regional balancing authority. The Sense app also shows a projection of carbon peaks and valleys over the next 12 hours. By scheduling energy-intensive activities when the CI from the grid is lowest, Sense users can reduce their own home’s CI score and impact carbon emissions.
We also included in the app a breakdown of the fuel types that are powering the home right now. Since the energy sources on the utility grid vary widely from region to region, and regions change their fuel mix over the course of a day, creating variations in CI, we think this view of grid fuel mix will be informative for Sense users.
The new CI feature is included in the Sense app for the Sense Home Energy Monitor and Sense Solar. It’s also included in all Sense-enabled products, such as the Square D™ edition of the Sense app for the Wiser Energy™ Home Power Monitor and the Square D™ Energy Center from Schneider Electric.
Today Sense users can plan their activities proactively with the app, but in the future, smart homes will be able to take advantage of these carbon intensity fluctuations automatically by responding to real-time signals from the utility grid and guidance from the Sense user.