A new study addresses the value propositions of adding battery storage to hydropower plants.
“We believe coupling battery storage with hydroelectric plants should be studied more because water is so important, and we want to use it sustainably. Adding batteries helps with that,” said Venkat Durvasulu, a power systems engineer at INL.
Most hybrid energy systems have wind or solar as the primary generation resource, the study said. “While presently less common, there are also opportunities and value propositions to develop hydro-hybrid resources,” the study, “Rationale for adding batteries to hydropower plants and tradeoffs in hybrid system operation: A review,” said.
Hydropower represents 29 % of the total renewable energy in the United States with pumped storage hydropower comprising the most storage. “Even though the development of new, large reservoir hydropower in the U.S. is unlikely, there is a sense of growth in developing small run-of-river (ROR) by converting non-power dams.”
Battery energy storage “is among the least constrained in terms of energy source and location and the most commercially ready among the grid-level energy storage technologies,” the study said. Batteries are the most commonly used storage technology in all other commercially installed variable renewable energy hybrids too, it said.
Development of hydro-hybrids is not as common as other VRE resources, but the potential for development is significant, the report’s authors said.
“The value of hydropower can be greatly improved and can motivate the development of new hydropower projects based on hydro-hybrids.”
To understand these gaps, the paper explores value propositions for hydro-hybrids based on the lessons learned from solar and wind hybrids, existing hydropower-battery installations, and environmental and ecological literature.
“A review of the existing research and commissioned projects is conducted to establish models and tools that can be repurposed to analyze hydro-hybrids and understand the gaps to develop and deploy hydro-hybrids. A detailed quantification of each value proposition in specific regions or sites is not within the scope of this paper.”
Rather, by understanding knowledge gaps, “we aim to identify and describe the factors that impact the decision to add storage to a hydropower plant and the operation of a battery-hydropower system. This will guide future research in the field and highlight the unique benefits of hydro-hybrids,” the report’s authors said.
“The magnitude of benefit that can be captured from each value proposition will vary between plants based on value drivers such as energy prices, transmission constraints, or local aquatic species.”
Value propositions for hydro-hybrids are the types of marginal benefits that can be attained by operating the hybrid system rather than the hydropower plant alone, the study said.
“Value drivers for hydro-hybrids, on the other hand, are the local circumstances which affect the capital cost or the magnitude of value propositions at the specific plant. Essentially, value drivers determine the suitability of specific sites for pursuing different value propositions.”
Understanding the value propositions of hydro-hybrids “is important to guide techno-economic assessment studies and ensure that all potential benefits are considered. Equally important, understanding the value drivers is useful for narrowing down the set of potential hydropower plants to hybridize.”
A detailed assessment and quantification of the value drivers for hybridization is outside the scope of the paper, but the two main drivers, market structure and plant type, are used to set the scope and target audience. “These two drivers have a significant impact on which factors affecting the decision to add a battery to a hydropower plant should be considered,” it said.
The primary goal of the paper is to investigate and present the value drivers of adding a battery storage at hydropower plants by presenting a significant literature on hybrid power plants.
"This review aims to establish the difference in analyzing hydro-hybrids against other VRE-hybrids and establish the gaps in significant research to better understand the utilization of hydro-hybrids."
Although the "merits and de-merits of specific battery technologies over the other based on their cost and performance can have significant impact on the value derived, it is beyond the scope of this work to evaluate various battery technologies. We believe this article would help industry stakeholders and hydro and energy storage developers would greatly benefit from understanding the value propositions of hydro-hybrids," the study's authors said.
The paper:
- Lays out the value propositions of co-locating and/or co-optimizing solar and wind generation with batteries based on the existing literature.
- Describes the state-of-the-art and gaps in the existing literature specific to hydro-hybrids; and
- Details implications for the hydro-hybrids valuation and operation processes.
