Where Batteries Should Be Installed to Modernize Power Grids
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- Jul 24, 2020 8:49 pm GMTJul 21, 2020 4:14 pm GMT
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This item is part of the Special Issue - 2020-07 - Energy Storage, click here for more
It was the first week of July 2018, and I was preparing a presentation on electricity infrastructure vulnerabilities to heatwaves, when I heard the news that a heatwave struck Southern California. Thousands of people were left without power for days. My presentation notes had read, “This is a map of where and by how much substations in Southern California could be overloaded if the region has a heatwave today.” But given the timing of events, my notes were revised to read, “This is a map of where and by how much substations in Southern California were overloaded...”
Historically, batteries may have been too expensive to supplement substation capacity to avoid situations like the 2003 US Northeastern or 2011 Southwestern heatwave-related blackouts, but technology has improved since then. Would batteries have been too expensive to prevent the 2018 outages in Southern California? What research has been conducted to prioritize battery placement and answer those types of questions?
Over the past few years, researchers have made effective advancements in visualizing grid constraints and simplifying long-term planning collaboration between utilities and other organizations. Electricity grids can be comprised of tens of thousands of miles of power lines and supporting components networked in multi-layered multi-dimensional parallel- and series-configured webs. The combinations of scenarios to analyze can be burdensome for even the fastest modern supercomputers. Fortunately, the analytical capabilities of geographic mapping software have matured exponentially over recent years as has personal computing power. Thanks to recent developments in digital infrastructure data and artificial intelligence software, there are now efficient ways of mapping reliability issues at various scales — from cross-country transmission lines to neighborhood distribution circuits to individual buildings. With sufficient data, knowledge, and skills, one engineer on one laptop can design and run planning scenarios in one minute that would have taken years to do with previous tools and techniques. These new modeling tools can be used to pre-screen neighborhoods for good circuits to install batteries on.
When most of us think about batteries, we are more inclined to think about powering cellphones, or maybe cars, than we are about batteries powering buildings. Nevertheless, many buildings have had batteries and/or other types of on-site back-up generators for years, including hospitals, banks, and data centers. These organizations’ operations are so critical that they have invested funds to avoid even a blip in their electricity supply. Most residential and other types of electricity customers do not have the kinds of critical loads that make the case for installing on-site storage and/or generators, but some do. And as battery technologies keep improving, more choices are becoming sensible to pursue, including utilities using batteries to improve their own operations and provide higher levels of resilience to their customers.
Maintaining continuous and reliable electric power throughout cities is not a simple task. Unlike other commodities, electricity supply and demand must always be balanced. Failure to balance power means that either someone’s lights go out, or another’s hardware gets damaged. On one side of the equation, electricity demand varies daily and seasonally in a relatively predictable pattern around weather. It also varies in relatively predictable patterns around economic and social/behavioral factors. The predictabilities are statistical, and the uncertainties increase with both granularity and the further into the future we forecast. On the other side of the equation, the supply of electricity has uncertainty due to the availability of generators and the capacity of delivery equipment, including power lines, substations, and transformers. All these generation and delivery assets are subject to their own maintenance requirements and lifespans, in addition to weather and/or other outage hazards. The result is a complex system with moving targets on both sides of the equation. And now, with new intermittent generation resources being added to the grid, mostly in the form of wind and solar, there is even more statistical uncertainty to manage.
Statistical uncertainty in electric power grids is the reason circuit breakers and other protection devices were invented. Still, too many coincident spikes in power-flow can initiate a chain reaction that escalates into a blackout. And as history has repeatedly shown, low-probability, high-impact events do in-fact happen. The economic impacts of a blackout can be several billions of dollars. Those impacts, as well as the intangible effects on human health, living conditions, and security, are all worth accounting for when evaluating our risk-tolerances and assessing the costs and benefits of our options. Therefore, as we work to answer questions of where to install batteries to modernize our electricity grids, we must consider more factors than just the changing of the winds and the movement of the clouds. We must consider the grid system itself, and should as much as possible, consider interdependencies with other systems that affect urban planning too, like population growth, building efficiencies, land-use, electric vehicles, industrial water systems, the internet of things, etc.
Cities are growing, delivery infrastructure is aging, and congested assets are being pushed beyond limits. These are not new challenges for the utility industry, and thanks to recent advancements, we now have more tools and techniques for understanding problems and creating solutions. When located optimally, batteries can smooth the curves from wind and solar energy sources, relieve congestion in electricity grids, enable more reliable services at lower prices, and unlock potential for new urban development in areas that would otherwise be constrained.
Now that we have the information, tools, and strategies to add more clean renewables to our power grids while improving system reliability and lowering costs for ratepayers, the question is not so much what to do, but how soon can we do it? For those who consider energy security a higher priority than either environmental or economic impact, how long are we going to wait to make our infrastructure more resilient against known threats from extreme weather events, physical sabotage, and cyber-attacks? Since progress towards each set of questions yields progress towards all the questions, how long will it take for recent research and development advancements to be implemented in practice? Once a pilot program is in place, what other lessons will be learned, what new capabilities will be developed, and how quickly will they be applied throughout the industry?