Energy IQ: What is stationary energy storage and how energy storage works

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Last year, solar installations across the world were over 100 GW1 and covered an area equivalent to one tenth the size of Puerto Rico in just one year. Similarly, the installation of on-shore and off-shore wind turbines are speeding up.

This is great news, yet introduces an unexpected challenge. In a given geographical area, newly installed solar and wind capacity will likely be producing electricity at the same time with the existing solar capacity. This can result in excess electricity from renewable sources during a certain time of the day, and no energy being produced when the sun isn’t shining, and the wind isn’t blowing. So, the challenge becomes how to capture and store this excess energy for future use.

This is where stationary energy storage technologies comes to play and become an instrumental component of the future of energy infrastructure. Let’s answer four common questions about energy storage technologies to boost your energy IQ.

No. #1: Why do we need stationary energy storage technologies?

Sources of power system flexibilityThe daily pattern of when and how much electricity we produce differs from when and how much electricity we consume. Moreover, renewable energy sources aren’t flexible, meaning they can’t be dispatched when needed to meet the ever-changing requirements of energy consumers.

While traditional power plants and interconnections will continue to be key levers to address this challenge, energy storage systems are projected to be the rising star in solving this flexibility challenge.

Advancements in battery technologies and decreasing costs are the enablers behind the rise of stationary energy storage technologies. 

No. #2: What is a stationary energy storage system?

A stationary energy storage system can store energy and release it in the form of electricity when it is needed. 

In most cases, a stationary energy storage system will include an array of batteries, an electronic control system, inverter and thermal management system within an enclosure. 

Unlike a fuel cell that generates electricity without the need for charging, energy storage systems need to be charged to provide electricity when needed.

No. #3: How does a stationary energy storage unit work?

Batteries and an electronic control system are at the heart of how stationary energy storage systems work. Batteries are where the energy is stored within the system in the form of chemical energy, and lithium is the most popular element used to store the chemical energy within batteries. 

Here is a simplified overview of how batteries work during discharging and charging.

  • Discharging energy in the form of electricity: Lithium is stored on one end of the battery with its electrons. Electrons get separated from lithium and move through a circuit to provide electricity to the loads. Meanwhile, lithium ions, now positively charged since they lost negatively charged electrons, move from one side of the battery to the other side. This movement continues until all the lithium ions move to the other end; this is when the battery is discharged.
  • Charging the batteries and storing the chemical energy: A source external to the battery starts to provide electricity, providing an influx of electrons to the battery. These negatively charged electrons start to merge with the positively charged lithium ions, and the lithium elements, now neutrally charged, move from one side of the battery to the other side. Once all the lithium elements move, the battery is now fully charged. 

An electronic control system is the brain orchestrating the operation of the energy storage system. It controls when the batteries need to charge, when the loads need the energy from the batteries, and the operation of the thermal management system. This control system also interacts with devices outside the energy storage system to coordinate the operation. 

An inverter is where the electricity produced by the batteries is converted from direct current (DC) to alternating current (AC). Most of our homes and offices are wired for AC, and the utility grid carries electricity in AC. With the help of the inverter, the electricity provided by the batteries can be used to power loads.

The thermal management system manages the temperature of the overall system and prevents the heat generated through the chemical reactions within the batteries to be harmful for the system operations. 

No. #4: Where will I see stationary energy storage solutions?

Economic feasibility is one of the key drivers of where stationary storage solutions will be adopted more rapidly. A high local price of electricity, low resiliency of existing power infrastructure and criticality of business operations all play a role in this, yet two types of customers likely leverage energy storage solutions ahead of others.

  • Utilities, power producers and grid operators: Already an area where an increasing amount of installed capacity exists. Energy storage solutions address a range of customer challenges including intermittent renewables, peak demand and short outages.
  • Commercial buildings: Within this large group, energy storage solutions will likely become more common for businesses where the cost of energy is significant, or the continuity of operations is extremely critical. 

Another use case for stationary energy solution systems is to provide an uninterrupted supply of power in the event of an outage, while backup power generators are starting up. This is where the immediate dispatch capability of these solutions comes into play; in reacting to loads that have significant voltage and frequency fluctuation, for which some generating assets aren’t capable of reacting to without causing interruptions.

Cummins involvement in stationary energy storage systems

Cummins Inc. is a leading provider of diesel and natural gas power generators, digital solutions and control systems; and has recently developed Tactical Energy Storage Systems (TESS). The TESS provides an integrated power solution when used in a tactical microgrid to increase resilience, improve power quality and provide silent power. 

Microgrids and fuel cells  to energy storage devices, our energy future includes a diverse set of technologies and fuels, and Cummins is committed to innovating and delivering a variety of solutions to meet these diverse needs of customers. 

Sign up below for Energy IQ to periodically receive relevant insights and trends about energy markets. To learn more about the distributed generation solutions Cummins offers, visit our webpage.

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References: 

1 International Energy Agency. (Nov 2019). World Energy Outlook 2019 [PDF file]. Retrieved from https://www.iea.org/
 

Aytek Yuksel - Cummins Inc

Aytek Yuksel

Aytek Yuksel is the Content Marketing Leader for Cummins Inc., with a focus on Power Systems markets. Aytek joined the Company in 2008. Since then, he has worked in several marketing roles and now brings you the learnings from our key markets ranging from industrial to residential markets. Aytek lives in Minneapolis, Minnesota with his wife and two kids.

Cummins Custompaks are being used for water management as Thailand struggles with its water crisis

CustomPak on site

Water crisis

Sixty Cummins Inc. CustomPaks are in service in Thailand as part of a critical water management plan aimed at easing the country’s water crisis – a crisis that has caused enormous economic and social damage and stirred conflict among communities.

Over the past several decades, Thailand has continually faced water problems caused by severe drought. Water reserves in dams and reservoirs are insufficient while water resources are often contaminated with toxins caused by urban communities and the industrial and agricultural sectors.

Severe flooding is a threat, too, at a time when the realities of climate change are hanging over the country.

As a result, the allocation of precious water resources, which must be shared among various stakeholders including new and existing industry, large and small agriculture, and cities and villages has become a flashpoint.

Kittithanapat Engineering Co. (KTP), has been involved in the water management system since 1996, working closely with authorities such as the Royal Irrigation Department, Department of Water Resources, Bangkok Metropolitan Authority and others.

CustomPaks on site

600 hp CustomPaks

To help KTP meet its often urgent requirements, Cummins DKSH (Thailand) has recently supplied 60 Australian-built CustomPaks – 45 powered by Cummins’ X15 engine rated at 600 hp, and 15 powered by the QSL9 rated at 325 hp. These fully self-contained powerpacks are emissions certified to Tier 3.

The CustomPaks are coupled to hydraulically-driven, large-volume submersible water pumps sourced by KTP from US company Moving Water Industries (MWI); KTP is the exclusive distributor in Thailand for these MWI Hydroflo pumps.

Prior to Cummins’ involvement, KTP was using another diesel engine brand but service support wasn’t up to the standard required.

Long-serving KTP engineer Kittisak Thanasoot says Cummins DKSH’s reputation for technical and aftersales support along with the reliability of the Cummins product were a key reason behind KTP’s decision to specify the CustomPaks for the Royal Irrigation Department.

The ability of Cummins DKSH to respond to short delivery times was also important.

“Supplying large quantities of high horsepower diesel engines for emergency situations such as flash flooding can be a challenge for KTP,” says Kittisak Thanasoot.

“Responding to the needs of the government agencies to manage such problems in a timely manner and with least impact on communities, KTP has found the answer in our partnership with Cummins DKSH.”

Power, pride and passion

Parked semi truck

The switch back to Cummins power has been beneficial for iconic New Zealand company Uhlenberg Haulage. It's all about whole-of-life costs.

Uhlenberg Haulage is closing in on 60 years in business, having been founded in 1966 by Mike and Carol Uhlenberg.

Based in Eltham, Taranaki, in New Zealand’s North Island, the operation is today owned and operated by their sons Chris, Daryl and Tony Uhlenberg.

Describing the Uhlenbergs as “old school family truckies”, Daryl talks about the company’s time-honored journey with a definite tone of pride, especially the work of his parents in laying the foundations for what is today an iconic fleet in its own right.

Cummins Inc. made its debut in the Uhlenberg fleet in 1971 with an NH250 powering a second-hand Kenworth K923 used in logging. A second Kenworth, a new W924 with a Cummins NTC335, followed soon after hauling an LPG tanker.

The Uhlenberg operation today comprises 40 prime movers and a variety of trailing gear to cater for the myriad of a jobs the fleet is involved in.

A number of Peterbilts feature in the fleet although Kenworth is now the brand of choice with six new units to be delivered over the next 12 months to cater for business growth.

Cummins’ X15 Euro 5 engine rated at 550 or 600 hp is the preferred power specification, with 18 red engines currently in the fleet.

Uhlenberg family in front of truck

Whole-of-life support

“The switch to Cummins has been a very good experience for us. We have nothing but praise for the Cummins organization,” says Daryl.

“The whole-of-life picture is the key thing for us and we’ve got that nailed with the support we get from Cummins – parts availability, scheduled maintenance, life expectancy and in-frame rebuilds.

“So the red engines turn up, we run them to life, which is 900,000 to 1.2 million kilometers, and then Cummins does an in-frame overhaul in a timely manner. If there’s an issue, parts and support are close by.

“The support we get from Cummins Palmerston North is fantastic, second to none.”

Daryl recently looked under a Kenworth that was in the workshop for a service and was surprised to see no oil leaking from the one-million-kilometer X15. “I remember when I was a fitter we had to wear a raincoat when working under a truck,” he jokes.

Fuel agnostic

Acknowledging that the push to decarbonize is now “very real”, Daryl likes the idea of Cummins’ fuel agnostic concept where one base internal combustion engine, optimized to run on diesel, can also be customized to run on ultra-low and zero-carbon fuels like renewable natural gas and hydrogen.

“My father was a pioneer of linehaul trucking in New Zealand and he always embraced new technology. He was never scared of it,” he says.

“I tend to be a little more cautious but I can see where a 500 hp natural gas or hydrogen engine would work for us in short haul applications,” he admits. “We’re certainly willing to look closely at these alternative fuel technologies when suitable infrastructure is in place.”

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