Knowledge Partner: Gas + batteries: Driving efficiencies together
Beyond ‘storage’ and adjusting erratic wind and solar output, battery solutions can enhance overall grid efficiency, thereby expanding the capabilities of the electricity value network
In the bold new era of power generation, there is a heightened focus on the integration of traditional resources and renewable energy. The continuous growth of natural gas alongside renewables is pretty straightforward, as the goal is to guarantee reliability when there is an abundance of wind and sunlight.
Modern gas turbines, like GE’s HA technology, feature ramp-up times as short as 10 minutes from start command to full load, and more than 80 MW per minute ramping capability. This gives plant operators great flexibility to adjust the load to changing grid conditions caused by intermittent sources.
In this evolving energy ecosystem, battery storage is widely recognized as an additional component that brings value by bridging between traditional and renewable, as it helps to maintain the load while the gas turbine starts up when the wind abates or the sun goes down.
“Touted for its rapid discharge rate, modern battery storage technology ensures the stability of the grid upon any unexpected change in demand or supply,” says Otmane Benamar, Executive Leader Customer Application Engineering, Gas Power Systems, GE Power.
“When combined with adjacent digital technologies, such as artificial intelligence and predictive analytics, the uses and benefits of battery deployment are manifold.”
For all these good reasons, storage solutions top the agenda for energy producers that are desirous to establish a robust energy network. According to a report commissioned by Deloitte, the storage market could reach more than $26bn in annual sales by 2022 at a compound annual growth rate of 46.5%. Having said that, there are vast possibilities in the battery storage space that remain untapped.
Beyond ‘storage’ and adjusting erratic wind and solar output, battery solutions can enhance overall grid efficiency—thereby expanding the capabilities of the electricity value network. Besides providing base load and flexible ramping capabilities, gas turbines also play a role as backup technologies to cover for demand peaks or dips, as caused by sudden consumption increases, planned and unplanned outages, or failures of other gas turbine units.
These backup units are called “peakers”, and even the fastest of them take several minutes to reach full power, forcing operators to run them at minimum load to keep them ready, burn gas and put more wear on the machines.
This is where battery storage can unfold additional potential, says Benamar. A viable antidote to overcome this challenge, is a gas turbine and battery storage hybrid. “It enables power producers to keep backup units completely switched off until they are really needed; the battery ensures consistent load during the entire start-up period.”
“This helps to ensure grid stability while lowering fuel consumption, which makes a combination of gas turbines with battery storage relevant for almost any power producer, even if renewables do not play a significant role in their particular power generation network,” adds Benamar.
And the advantages of this technology combination don’t stop here, Benamar points out. He says that utilities need to keep a certain percentage of the overall capacity to cover for peaks during the day, which is a regulatory requirement in many countries.
“This requires to keep some units running below full load, which is affecting efficiency. Battery storage can be used to deliver the additional power needed during peak hours, so all gas turbines can operate at full load, at the best of their efficiency; the so called “peak shaving.”
Frequency containment is a similar challenge that battery storage can help to address. As a precautionary measure, Benamar says that utilities need to keep capacity to cover for unexpected variation in grid frequency, which requires very fast reaction. With its rapid discharge rates, battery storage can provide the extra power needed, releasing power producers from the need to run gas turbines at partial load as a backup.
The value of such hybrid solution is being demonstrated in the world’s first battery-gas turbine hybrid system in Norwalk, California, at Southern California Edison (SCE). This system, called the LM6000 Hybrid Electric Gas Turbine (Hybrid EGT)* integrates a 10 MW/ 4.3 MWh battery energy storage system capable of immediately providing power with GE’s proven 50MW LM6000 aeroderivative gas turbine.
With the Hybrid EGT, SCE units are expected to generate up to $1.4mn per year in additional revenue by using integrated battery storage to serve traditional spinning reserve needs. While SCE does use their hybrid to balance intermittence of renewable sources, this solution is also viable for utilities that just want backup power at their fingertips without having to keep backup gas turbines running on low load.
The flexibility this model offers is particularly relevant to energy producers in this region that are expected to cater to the burgeoning demand for energy, which is expected to increase by 49% by 2035.
“The energy landscape in the Middle East is no doubt undergoing a paradigm shift in every aspect and dimension of creation and consumption. It is imperative for governments and industry leaders to identify the energy solutions that best fit their individual needs,” says Benamar.
Innovative technology is available today to support growing energy consumption and sustainability requirements alike, and gas-battery hybrid power plants appear to be a natural fit. While it is evident that natural gas is here to stay, it is indisputable that storage technology is the steady undercurrent that fuels grid stability, flexibly and scalability in the long run. The economic and environmental potential of innovative hybrid solutions has just started to be explored.