We’ve heard about the value of energy storage for integrating renewables, shaving peak demand and regulating frequency, but there’s another service it can provide: combating air pollution.
When sited and deployed according to air quality data, energy storage can strategically replace more polluting energy services in the areas most susceptible to poor air quality, researchers at UC Berkeley and nonprofit research institute PSE Healthy Energy found. In this way, storage can address decades-old discrepancies in environmental justice, whereby poor neighborhoods have been more likely to sit near the dirtiest power plants.
This public health case for storage won’t displace the economic arguments for calculating the value of storage, but it could join them. The main obstacle will be convincing state regulatory bodies to price the negative externality of localized air pollution from energy production, which is a different beast than the more commonly recognized greenhouse gas emissions. Now may be the best time to pursue that, as states drastically overhaul the ways they assign value to distributed energy.
This study, published in the journal Energy Policy, joins a growing body of literature that aims to figure out how society should value new distributed energy resources like rooftopsolar wind, demand response and storage. The authors argue that the conventional approaches focus too much on immediate monetary value for the grid without looking at the bigger picture.
They home in on the local air-quality effects of energy production. Fossil fuel combustion releases a slew of deleterious substances into the air besides greenhouse gases. Ozone exposure has been connected to increased mortality from lung disease, and fine particulate matter is linked to higher rates of heart disease and asthma. Unlike greenhouse gases, the effects of these hazardous emissions are highly location- and time-specific, so remedies must be similarly sensitive.
The study suggests a framework for targeting both deployment and dispatch of distributed clean energy, namely storage and demand response, at the times and places where they could optimally avoid hazardous power plant emissions. Then they test the framework on data from California’s grid, with a particular focus on their peaker plants.
The peaker plants California turns to for quickly meeting demand surges run on simple cycle gas turbines; they cost more and emit more per megawatt-hour than baseload gas plants there. They also disproportionately fire up on poor air quality days, compounding the air pollution.
The authors recognize that states probably won’t retire particular plants just because of their contributions to air pollution. But, they note, the rules are still being written for procuring and dispatching clean, distributed energy.
For instance, the public utility commission could factor in time and place air-quality metrics in their analysis for locating new storage assets. That would send a signal to developers and utilities to focus their efforts, where possible, on putting storage in the communities that stand to benefit most from deferring peaker plant use on smoggy days.
The authors also propose that guidelines for meeting peak surges prioritize the use of demand response and storage over peaker plants if air quality has already reached a dangerous threshold.
This paradigm would expand the spectrum of factors considered relevant to grid improvements, which lead author Elena Krieger, renewable energy program director at PSE Healthy Energy, acknowledged is a challenge.
“Pricing externalities has never been an easy thing,” she said. “You can see that it’s hard enough to price CO2. That doesn’t mean we shouldn’t do it, though.”
California has some precedents for this type of action, she added. In fact, California has put a price on NOx and SOx emissions for years under a Regional Clean Air Incentives Market, so pricing this particular externality isn’t new. On the operational side, a model already exists in the state’s “Spare the Air” days, when poor air quality prompts the local Air Quality Management District to request residents avoid driving and other smog-producing activities. “Why not extend that to power generation as well?” Krieger asked.
The California Public Utilities Commission has already made greenhouse gas reductions a priority for distributed energy planning. CPUC President Michael Picker, speaking at an event in 2015, went so far as to say, “We’ve increasingly started to pay attention to the role of greenhouse gases in the electric system, both as a source and as a solution.” The question remains whether that emphasis can extend to the emissions that have a more localized effect.