Today, all eyes are on the potential for solar paired with storage. The combination is seen as the golden ticket to mass-market adoption, enabling customers to use electricity generated by renewables even when the sun isn't shining.
Advanced solutions hitting the market promise to alleviate intermittency, shave peak-demand prices and enable reliable off-grid electricity. Coupled with aggressive incentives and supportive policies, the U.S. solar sector is embarking on unprecedented deployment of storage solutions. Analysts have high expectations. The U.S. energy storage market is expected to grow 250% this year.
And to think that just five years ago, viable storage solutions were only a pipe dream.
To understand where storage technology is today, let's look back at where we started. One of the first storage solutions used widely in the energy industry was pumped storage for hydroelectric dams. The technology stores power by physically pushing water between reservoirs: Energy is captured when water that was pumped from a lower altitude reservoir to a higher altitude reservoir is released and flows back to the lower reservoir. Typically, this is done during the day to relieve peak load. Other traditional solutions include flywheels, which utilize a quickly spinning rotor to store energy, and compressed air, which can be heated and expanded in a turbine when electricity is required.
What all these solutions have in common is that they require a considerable amount of space and a hefty capital investment. Although these units can be economically installed for large-scale utility systems and power smoothing applications, they aren't easily coupled with distributed solar photovoltaic systems.
Lithium-ion (Li-ion) batteries are well suited for distributed solar due to their compact size. Additionally, the cost barrier with this technology has fallen with the growth of the battery-dependent electric vehicle market. The rapid drop in battery costs over recent years is not unlike the fall in solar panel prices a decade ago.
California is home to one of the largest and most dynamic energy storage markets in the U.S. This is primarily due to California's aggressive storage incentive plan Assembly Bill 2514, which requires state utilities to procure 1.3 GW of storage by 2020.
Spurred by this, California's three largest investor-owned utilities, Southern California Edison (SCE), Pacific Gas and Electric (PG&E) and San Diego Gas & Electric, are now installing cost-effective storage solutions. For example, SCE invested in a wind farm in the Mojave Desert that stores wind power in giant lLi-ion batteries. PG&E plans to integrate 74 MW of energy storage through a series of tenders.
States on the East Coast are also coming out with storage incentives to support renewables adoption. New York has budgeted $25 million to promote storage development. Moreover, PJM, a utility that serves Michigan, Maryland, New Jersey and Pennsylvania, has adopted the Federal Energy Regulatory Commission's new rules governing storage solutions.
Solar-plus-storage in action
The Alcatraz Island microgrid project, developed by Princeton Power Systems, is an example of a system that successfully unites solar and battery storage. Because the solar PV system was installed on an island, it needed to function off-grid and storage was absolutely essential.
Previously, the historic prison used diesel generators to power operations. Princeton Power Systems installed a large Li-ion battery to provide 24-hour power to the landmark facility. For its forward-thinking approach to renewables, Princeton Power Systems was awarded The North American Project of the Year at Intersolar North America 2014.
The energy storage market is dynamic. To stay up to date with the market progress, professionals need to seek out like-minded experts for insights and business partnerships. Events are a critical connection point for professionals to hear about innovation.
For the past two years, Intersolar North America has spotlighted the growing energy storage market that showcases PV energy storage systems at the annual exhibition and conference. This year, Intersolar North America (San Francisco, July 14-16) will host a new special exhibition – ees (electrical energy storage) – to extend the event's focus on the latest technologies and policies in the energy storage value chain. More than 50 of the 500 exhibitors at Intersolar North America will showcase their storage solutions in this special exhibition.
The conference will also host a number of panels focused on storage technology and policy incentives driving the market forward.
Markus Elsasser is the founder and CEO of Solar Promotion International GmbH, the organizer of Intersolar exhibitions and conferences.