With climate change front and center and efforts to reduce emissions taking many forms, energy storage could be the next important player. IHS, an international research firm, expects worldwide storage to climb to 40,000 megawatts (MW) worldwide by 2023, with 43 percent of added capacity coming from the United States by 2017. It further predicts a market for storing power from solar panels to approach $19 billion in three years. In 2012, it was less than $200 million. Store clean energy, and you may have a sustainable power provider that can answer the needs of a 21st century electric grid.


“We are definitely primed for growth,” said Matt Roberts, executive director of the Energy Storage Association, Washington, D.C. “Though based on models, I do see this projected growth to be plausible here in this country. Energy storage can be an answer to many current power problems. For example, once a utility responds to increased demand, that demand may have already changed. Coal plants are slow to respond when demand is quickly needed. Though faster, gas turbines can be problematic, too. You avoid that issue by tapping into energy-storage supplies.”


Energy storage is an ancillary asset when deployed alongside various electricity delivery applications, including utility bulk storage, microgrid and distributed generation. For approximately 40 years, it has played a role as a backup source for uninterruptible power.


“Storage is no longer a singular thing,” Roberts said. “It’s conceptual to every customer. Utilities should ask what storage can do for them. Can it lower cost? Offset [transmission and distribution] investment? Reduce the running of expensive single-cycle, low-efficiency gas turbines? Managers need to strategize where to place energy storage on the grid. They are getting more engaged through their participation in the Energy Storage Integration Council.”


The more varied the scenarios, the more value energy storage seems to offer. Customers from military, industrial and commercial markets have also been turning to energy storage as part of a microgrid or standby power source. It’s also found a role in residential, healthcare and hotel marketplaces.


“If, say, a neighborhood can take itself offline, allowing the utility to catch up to peak demand and ramp up, storage becomes a tremendous asset,” Roberts said. “Right now, the people with the biggest savings are large commercial/industrial customers and utilities.”


Hitching to each other’s wagons


“Storage is a critical piece in making solar a utility-grade power resource,” said Bob Gibson, vice president of education and outreach for the Solar Electric Power Association, Washington, D.C. “To date, the intermittency of solar and wind has made it a challenging power source for utilities that need to provide steady power. Energy storage can play a role in smoothing that power out and delivering it more efficiently and on demand.”


Traditionally, utilities have been managing peaks through demand response. If ramping up power to meet peak is an issue, storage could help.


“Collecting solar energy during the day and storing it for use when a utility’s peak power hits at dusk or evening becomes a better way to manage solar power,” Gibson said.


“I definitely see clean energy as a driver that will enable energy storage to take off,” Roberts said.


The measure of storage remains a question.


“Would it be best served through smarter power inverters, power controls—perhaps syncing solar with the right amount of storage?” Gibson said. “These are important questions being explored through [research and development] and demonstration projects across the country.”


Gibson sees the storage industry today where solar was eight years ago.


“Today, solar is on a strong path,” he said. “Solar hard costs have come down, and we are seeing soft costs and the overall building and planning costs come down. Installations can now take days instead of weeks or months because of advanced interconnectivity. I see storage on a similar trajectory of market readiness and acceptance that solar has enjoyed. Right now, it’s a big add for grid management, but investment is very steep. The first tangible market is frequency regulation.”


Movement on a few fronts


If you want to look at renewable-energy storage in action, look to Arizona, California, Hawaii and New Mexico. These states are harnessing this power duo in a big way. 


The PNM Prosperity Energy Storage Project is the nation’s first solar-storage facility to be fully integrated into a utility power grid. PNM is the largest electricity provider in New Mexico. The facility uses smart-grid technology and features one of the largest combinations of battery storage and photovoltaic (PV) energy in the nation. The site uses 2,158 solar panels to produce up to 500 kilowatts (kW) of power. Eight battery containers hold 160 batteries each, for a total of 1,280 advanced lead-acid batteries that can store up to 250 kW per megawatt-hour of energy.


Arizona Public Service is tied into the Solana project, in which solar energy is captured through parabolic mirrors but doesn’t use battery storage. The captured heat is carried through pipes to huge tanks of molten salt. In the evening or early morning, heat is drawn back out of the molten salt to make steam and generate electricity. Its capacity is about six hours, with the ability to produce up to 280 megawatts (MW) (see page 28 more on Solana).


In what could be a game changer for the energy-storage market, under mandate by the California Public Utilities Commission (PUC), the state’s investor-owned utilities must acquire 1,325 MW of energy storage resources by 2020, starting with 200 MW by this year. The target would more than double the amount of nonhydro storage capacity in the United States today. This is the first energy-storage mandate in the country and could help promote economies of scale.


In Hawaii, solar is now cheaper than power from the grid. Hawaiian Electric Co. reports nearly 11 percent of utility customers now have solar (typically rooftop), compared with 0.5 percent nationwide.


“Energy storage is one of the key missing elements in integrating high levels of renewable energy from variable sources like solar and wind,” said Colton Ching, Hawaiian Electric vice president for energy delivery. 


The utility is reviewing requested proposals for large-scale energy-storage systems able to store 60–200 MW for up to 30 minutes, second in size to California’s ambitions. The utility sees multiple uses, including as an auxiliary service for grid operation through subsecond frequency response (near-instantaneous changes to keep power quality at 60-hertz) and minute-to-minute load following (power output adjustments for fluctuating demand).


“One MW of batteries for one application might be economic, but using it for multiple functions will better the economics,” Roberts said.


It’s not just the sun-drenched states looking at renewable and energy storage. Minnesota and New York are both investigating this power marriage for possible distributed generation or other utility power uses.


Advancing one breakthrough at a time


Energy storage can be driven by all sorts of methods, including flywheels, pumped-hydro storage, compressed air, thermal and flow batteries. The most commonly envisioned storage device features solid-state batteries. Battery manufacturers are working to advance battery chemistries, stack configurations and other areas to extend battery life.


Jim McDowall serves as business development manager for Saft America Inc., a worldwide battery manufacturer involved in the energy-storage market.


“There’s a growing divergence in the energy-storage market as it grows and coalesces,” he said. “Sometimes storage discharge is demanded for only two hours or less. Large-scale lithium-ion [Li-ion] works best in this situation. Discharge for energy services, such as peaking systems or shifting to renewable energy, might be up to four hours. Li-ion might not be the best choice for longer discharge applications. It’s clear we need different batteries for different uses. We’re investigating flow batteries, sodium-ion, [and] sodium-chloride batteries for longer discharge times.”


McDowall sees the energy-storage market maturing as it’s proven in demonstration projects. 


“A lot more lenders are getting involved and applying due diligence so systems operate as advertised. The future is looking bright,” he said.


ECs getting hands-on experience


In its day, the historic 1,200-acre Philadelphia Navy Yard was the nation’s largest facility for the construction, storage and repair of U.S. naval vessels. Today, this prime real estate is undergoing a massive commercial and residential redevelopment. It also is serving as an incubator and prove-out site for smart grid and green technologies within a community microgrid. Electrical contractors are part of the redevelopment team working with the GridSTAR Center, an educational and research organization operating within Pennsylvania State University’s Architectural Engineering Department.


Kenneth MacDougall, director of business development for the Penn-Del-Jersey Chapter of the National Electrical Contractors Association, said the site already has a smart home (part of the GridSTAR effort) that features solar energy storage. Serving as an educational center, the home allows the trade community and general public to learn how green technologies can work together to drive optimum efficiency.


“Working with an energy-storage unit requires training,” MacDougall said. “You have to understand how it works. For instance, how do you connect the transformer? How do you work with smart inverters? Those ECs who have worked on substation and other utility work will already know the components used in energy storage be it batteries or inverters.”


MacDougall said the Navy Yard’s microgrid electric room will soon serve as a training space, allowing electricians to see first-hand how green power and its delivery through energy storage serves the site’s infrastructure. He added that contractors involved in the site redevelopment will be poised to educate their customers and win projects that involve this burgeoning power configuration.