There are tens of millions of smart meters deployed across the United States. While a precise number is difficult to pin down, roughly half of electricity customers have advanced metering infrastructure (AMI) installed. And their prevalence has grown steadily in the last decade, despite debate over the technology's effectiveness.

The devices are foundational to grid modernization efforts, allowing two-way flows of information between the utility and customer. New meters mean utilities can offer dynamic rates and a range of demand management programs, as well as integrate more distributed renewable resources.

A recent report from the Federal Energy Regulatory Commission concluded advanced meters are the most common type of meter deployed in the United States, "accounting for nearly half of all meters installed and operational" in the country.

According to FERC, there were 70.8 million advanced meters operating in 2016, out of 151.3 million meters in the U.S., giving them a penetration rate of 46.8%.

But a look at data from the last decade shows the rate of AMI deployments may be slowing. And two utility AMI proposals were rejected by state regulators this year, bolstering arguments that they are not cost effective.

Shifting controversies

Smart meters have always been controversial, though not always for the same reasons. It's only been a decade since the Wall Street Journal ran the story, "Smart Meter, Dumb Idea?"

While debate over health impacts has quieted, in 2011, protestors took over a California Public Utilities Commission meeting and forced regulators to allow customers to opt out of Pacific Gas & Electric's rollout.​

More recently, privacy concerns have grown as the amount and type of data the devices can collect has broadened. Smart meter issues wound up in front of the United States Court of Appeals for the Seventh Circuit this year, with a panel of judges concluding readings from smart meters constitute a "warrantless search."

There have long been arguments that the savings smart meters generate do not justify the cost. Regulators in Kentucky and Massachusetts were not so blunt, but they did reject proposals this year over concerns that utilities did not sufficiently make the business case. AMI deployments are expensive: Kentucky Utilities and Louisville Gas & Electric had proposed to install AMI for 1.3 million customers over the next five years, but the plan carried a $350 million price tag.

Despite the costs and controversy, the number of smart meters has grown ten-fold in a decade: from about 6.7 million in 2007, to north of 70 million today.

How many meters are out there?

The FERC staff report estimates 70.8 million smart meters installed across the country, a figure based on 2016 responses to the U.S. Energy Information Administration's Form EIA-861. But estimates vary: In the same report, the commission noted that the Institute for Electric Innovation (IEI) concluded 72 million AMI were installed in 2016.

EIA also maintains a smart meter count on its website, which says the total number of AMI installed as of 2017 was 78.9 million — of which almost 70 million are residential.

The growth of AMI has been impressive, but it also may be slowing.

FERC staff told Utility Dive in a statement that the number of smart meters "grew quickly over the period from 2007-2011, partially due to American Recovery and Reinvestment Act funds." Since then, deployment has been "fairly steady," with the number of AMI meters increasing by about 13% per year on average.

The Smart Grid Investment Grant (SGIG) program was authorized by the Energy Independence and Security Act (EISA) of 2007, which called for federal matching funding for smart grid investment costs. And The Recovery Act built on EISA to deliver $4.5 billion for grid upgrades, including about $3.4 billion for SGIG projects

AMI growth tapering?

A Congressional Research Service report in April described the introduction of AMI as "problematic."

"Smart meters have run into cost and performance issues and resistance to the technology (generally from concerns of some customers over potential health impacts of radio wave emissions)," the report said. 

Despite the issues, tens of millions more AMI meters are expected to be deployed in the coming years as utilities continue with grid modernization efforts. According to IEI, smart meter installations will hit 90 million by 2020.

But penetration rates have been mired between 40% and 50% over the last few years, according to FERC data. 

"AMI penetration sits around 50%, and it seems that's just where it's at," Brenda Chew, an analyst at the Smart Electric Power Alliance, told Utility Dive. "Part of me wonders if those that have a lot of changing customer needs and a lot more demand response resources have already got AMI installed."

Despite the pair of state rejections this year, AMI proposals also notched wins. Regulators in Minnesota and Mississippi authorized rollouts; ConEdison plans to deploy 5 million smart meters by 2022 in New York; and Hawaiian Electric received authorization to launch its grid modernization strategy.

FERC concluded in its analysis that both regulators and utilities alike "appear to be past the early adoption stage of advanced meter deployment. ... Over the past year, electric utilities in a number of states received approval for, or proposed, large-scale deployment of advanced meters, in some cases as part of grid modernization efforts."

But other regulators and utilities "are taking more targeted or cautious approaches to advanced meter deployment," FERC's report added, "while other states are seeking to get more benefits out of their existing advanced meters by leveraging those investments through, for example, data sharing mechanisms."

As the technology evolves, experts say the meters' capabilities will expand.

"Going forward, the computing power in each smart meter opens the door to applications beyond traditional metering services," IEI wrote in its report. That could include using smart meters as platforms for distributed analytics, decision making and communication across devices.

Looking ahead, the group said smart meter "applications are under development to predict the behavior of customer-sited energy resources so that these resources can be utilized more efficiently."