An experiment is underway in Illinois to answer a fundamental question about power grid modernization efforts: Does a smarter electric grid mean a cleaner one?

Utilities and grid operators across the country are equipping the nation’s power system with sensors, communications equipment and analytics software in an effort to reduce energy waste and demand. The logic is that a reduction in energy use translates to fewer greenhouse gas emissions, especially when those reductions come at times when the power supply is dominated by natural gas or carbon-heavy coal.

In other words, if Advanced Metering Infrastructure (AMI) is enabling customers to use less power during times when fossil-fuel output is high, then AMI should be getting credit for the avoided emissions.    

Proving that theory can be complicated, and there has been little effort to document the greenhouse-gas reductions associated with smart-meter deployment. That changed last March when ComEd, Illinois’ largest utility, agreed to adopt a greenhouse-gas metric it developed in partnership with the Environmental Defense Fund and Illinois-based consumer advocacy group Citizens Utility Board.

“Utilities should be recognized for putting in place more efficient, smarter energy options, but it’s impossible to know the true value of investments without a way to measure results,” Dick Munson, Environmental Defense Fund’s Midwest director of clean energy, said last year. “This metric allows ComEd to definitively show how its smart-grid initiatives are reducing pollution and clearing our air.”   

Yet questions remain over how best to measure emissions reductions in the age of the smart grid, and how directly those emissions can be linked to the deployment of smart meters.

Ameren Illinois, the state’s second-largest utility, has opposed adopting the same greenhouse gas metric. In an ongoing case before the Illinois Commerce Commission, the company says gathering the relevant data would impose an unnecessary burden on the company and, ultimately, ratepayers.

“The issue is one of causation,” James C. Blessing, Ameren Illinois’ senior director of energy supply and corporate initiatives, said in testimony before the Commission last August. “The operative question should be whether the deployment of AMI metering technology created or caused an effect on GHG output. If that causal relationship can’t be established, it wouldn’t seem to be a terribly effective use of time or resources to engage in the calculation of metrics that may or may not truly be related to AMI deployment.”

First-of-its-kind metric

Attempts to quantify the benefits of smart grids dates back to at least 2009 when the American Recovery and Reinvestment Act provided the U.S. Department of Energy with $4.5 billion to modernize the power grid and “collect an unprecedented level of data on smart grid operations and benefits.”

Two years later, the Illinois General Assembly passed the Energy Infrastructure and Modernization Act, which enabled ComEd and Ameren to make $3.2 billion in upgrades to the state’s power system. It also required both companies to develop an overall AMI plan “consistent with the goal of developing a cost-beneficial Smart Grid.”

Included in the act’s definition of “cost-beneficial” are “reductions in the emissions of harmful pollutants.” In 2013, the Illinois Commerce Commission declined to require that ComEd measure greenhouse gas reductions from smart meters because not enough of the infrastructure had yet been deployed. However, the Commission called for the eventual development of a specific greenhouse gas metric, noting that it “appear[s] to affect the very heart of the Energy Infrastructure Modernization Act, as [it concerns] the potential societal benefits associated with Smart Grid AMI deployment.

While facing pressure from CUB and EDF, ComEd agreed last March to adopt what the groups say is a first-of-its-kind metric, tying greenhouse gas reductions to smart-meter deployment. The metric aims to capture changes in emissions as a result of smart meters’ reducing customers’ energy usage when grid demands are the greatest. Central to the metric is calculating emissions based on the power system’s fuel mix at a given moment — a time-flexible capability made possible by smart meters’ frequent data collection.

Calculating the emissions saved by time-of-usage shifts is particularly important because the carbon intensity of electricity fluctuates by hour, day and month, says Andrew Barbeau, a consultant retained by EDF to work on smart-grid issues.

“The grid is not static,” Barbeau says. “Throughout the 8,760 hours in a year, there’s not a consistent average performance of greenhouse gas emissions.”

On some days there will be a higher penetration of wind or solar, while on others the power grid will lean more heavily on coal or natural gas. “Reducing a kilowatt of demand or a kilowatt-hour of energy at an hour in the summer could be a different value in terms of taking greenhouse gases off the grid than that same kilowatt and kilowatt-hour in the middle of February,” Barbeau adds.  

Aggregate estimates of greenhouse gas reductions gloss over these variations, but smart meters enable the kind of metric ComEd now uses to obtain a more granular picture of grid decarbonization.

Just one month after announcing the metric, ComEd quietly issued preliminary data from its emissions tracking efforts, showing that in 2015, residential ComEd customers with smart meters emitted roughly 161,000 fewer metric tons of carbon dioxide than residential ComEd customers without smart meters.

The company also cut transportation emissions by reducing the number of truck rolls for meter reading and by having customers participate in its Hourly Pricing and Peak-Time Savings programs. The company is expected to release updated data when it submits its annual smart-grid progress report in April.

Additional work without certainty?

CUB and EDF are now working to have Ameren Illinois use the same metric in its annual smart-grid progress reports. The utility, which is in the process of deploying smart meters to its 1.2 million customers, has opposed the effort.

“CUB/EDF’s request will impose additional work and cost on Ameren Illinois, and ultimately customers, without any certainty that the metrics in question will produce results that will be truly representative of GHG emission reductions attributable to the deployment of AMI,” Ameren’s Blessing testified last August before the Illinois Commerce Commission.

The company says variations like weather, customer mix, geography and other factors make it difficult to pin changes in greenhouse gas emissions to any one factor. Neither Ameren nor ComEd responded to requests for comment.  

The two advocacy groups say Ameren could isolate and account for variations in the data. The utility has countered that doing so is excessively burdensome and not particularly valuable to the customer.

Meanwhile, Ameren Illinois does track transportation emissions reductions due to AMI deployment. In 2015, smart meters enabled the reduction of 167,682 pounds of carbon dioxide — or the equivalent of roughly 8,500 gallons of gasoline consumed — due to fewer meter-reading trips, according to the company’s 2016 smart-grid progress report.

Barbeau says he hopes to get a final decision sometime this summer from the Illinois Commerce Commission on whether Ameren must adopt the greenhouse gas metric.

“There is an essential truth that as the grid evolves, the trend is going in the direction where people want more voice and more control and more carbon-free energy,” Barbeau says. “Tracking that and being able to have a good accounting of that is going to be key.”  

David started writing for Midwest Energy News in 2016. His work has also appeared in InsideClimate News, The Atlantic, McClatchy DC and other outlets. Previously, he was the energy editor at The Christian Science Monitor in Boston, where he wrote and edited stories about the global energy transition toward cleaner fuels.