How Austin Energy is looking to manage solar-plus-storage on its grid
The Texas municipal utility is the biggest winner of a DOE program that aims to integrate solar with storage
As utilities increasingly integrate distributed energy resources onto their grids, new technological advances are necessary to manage DERs in concert.
Distributed energy resource management systems (DERMS) are an area of promise. They could be used by utilities to flatten demand curves, integrate a wide array of distributed technologies, and even control prices. But the technology is still in its early stages and the market has not reached the point where there is a standardized solution.
Austin Energy is one utility looking into the promise of this technology. The Texas municipal utility is implementing new energy storage and software tools to help integrate a big increase in solar power on its system as the utility moves toward its target of deriving 55% of its energy from renewable sources by 2025.
The key component of those tools are software applications that will be used to control and integrate distributed energy resources, including energy storage systems, into the city’s grid and enable the grid to interact economically with the surrounding grid of the Electric Reliability Council of Texas (ERCOT) region.
The test program is being implemented under a $4.3 million award from the Department of Energy’s SunShot Initiative under which Austin Energy will pilot a platform to enable and promote integrated distributed energy resources, including solar, storage, and smart inverter technologies.
The Austin project is part of a wider initiative at the DOE called SHINES (Sustainable and Holistic Integration of Energy Storage and Solar PV) that is part of the Grid Modernization Initiative that aims to improve the resiliency, reliability and security of the nation’s power grid. In January, the DOE awarded $18 million in funding for six projects under the SHINES program. The $4.3 million award to Austin Energy was the largest of the six.
How SHINES works
SHINES is the first DOE funding program focusing exclusively on connecting renewable power to storage. The objective of the program is to enable the widespread deployment and integration of solar PV generation at a system levelized cost of energy (LCOE) of less than 14 cent/kWh.
“As part of the Austin SHINES project we will develop use cases and business models during the initial phase of the project,” says Karl Popham, manager of electric vehicles and emerging technologies at Austin Energy. “Ideally, we want to drive increased value of DERs for the customer, utility, and ERCOT to find that ‘win-win.’”
Popham says being able to monitor that cost data should increase the value of renewables, especially distributed resources, on its system and that could lead to increased investment in distributed energy resources.
The muni aims to hit is 55% renewable target mainly through power purchase agreements for wind and solar generation. Popham also notes that Austin Energy’s generation plan includes storage targets. The muni is developing a plan for distribution connected local storage of at least 10 MW complemented by as much as 20 MW of thermal storage.
Austin Energy’s current generation breakdown is 602 MW of coal-fired generation, 436 MW of nuclear power, 1,497 MW fired by natural gas, 112 MW of biomass, 63 MW of local solar, 1,041 MW of wind power. In all, renewable resources equals 28% of the mix. But the muni’s generation plan calls for 950 MW of solar capacity to be installed by 2025.
Recurrent Energy is building a 150-MW solar farm for Austin Energy, and the Austin city council has authorized a 450-MW solar farm and another 150 MW of solar power that would be added either by building new capacity or singing power purchase agreements.
And as more utilities raise their renewable targets, Popham says storage is going to be a “critical component” of the solution for the grid.
Austin's management strategy
Austin Energy’s partner in the SHINES program is 1Energy Systems, which is deploying two levels of software to control Austin’s grid. Over the course of the 39-month SHINES program, the Seattle based company will integrate up to 4 MW of solar power, more than 3 MW of distributed energy storage, as well as smart inverters and a variety of forecasting and communications applications. Those storage resources will be the first on Austin’s system.
A key component of the project will be the creation and use of a new cost metric that reflects the all-in costs of serving customer load with a combination of solar, energy storage, demand response, and existing grid assets in order to get below the 14 cents/kWh target.
Under the project, 1Energy Systems will deploy two of its products, its Intelligent Controller (IC) and its Distributed Energy Resource Optimized (DERO) system, which will serve as the project’s distributed energy resource management system (DERMS).
The IC software will control two energy storage devices that will be installed. One is a 1.5-MW, 3-MWh device at a substation. The size of the other storage system has yet t be determined, but will likely be roughly the same size, Dan Sowder, vice president of power systems integration at 1Energy, says.
The IC system will work at the distribution level to monitor and control the energy storage systems. The software also has an interface to communicate between the storage system and the DERO system.
The DERO system will provide the interface between the DERs on Austin’s system and the wider, bulk power system. The DERO platform also will host several applications that will enable it to pick assets and to send signals to resources while bringing a level of economic “thinking” into the process.
“Treating new resources like solar and storage as silos doesn’t make sense,” Sowder says. “One of the aims is to make solar storage not just a bolt-on component, but integral to the system.”
The Austin project is the second deployment of 1Energy System’s DERO system. The first deployment was for the Snohomish Public Utility District in Washington. That project is adding scalable storage and control technology that uses Modular Energy Storage Architecture (MESA) standards.
When the 39-month term of the Austin project is up, Popham says the muni plans to continue to utilize all assets for their life cycle and continue to keep them in production. The SHINES project is the “first step towards a much larger goal,” he says.
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