Climate change’s impact on rainfall patterns, runoff, snowmelt, and temperature is unavoidable, leaving a host of challenges and opportunities for the hydropower sector in its wake. Recent headlines show that this is already happening – the US Energy Information Administration reported in March 2024 that hydropower generation in the western US had fallen to its lowest levels for 22 years, while Indian hydropower output also plunged to a four-decade low. And this is why research projects such as ReAdapt play an important role, giving more of an insight into how hydropower production will fare in the face of climate change and extreme weather events, as well as understanding how systems can be adapted for future conditions.
Led by SINTEF, one of Europe’s largest research institutes based in Norway, ReAdapt will run until 2027 and is being funded by the Norwegian Research Council, with collaboration from hydropower producers such as Statkraft, Eviny and Å Energi AS.
The project is looking at how hydropower operations can adapt to floods, droughts, and high temperatures, while maintaining or increasing production and preserving biodiversity. It will study three locations across Norway and consider multiple factors including how hydropower can continue to serve as both a source of energy and a means of flood control. There is also a special focus on salmon due to the species’ ability to adapt quickly to changes in its physical surroundings.
Studies to be undertaken at one of the Norwegian Institute for Nature Research’s experimental stations will examine how salmon react to different water flows and temperatures. Models developed from these findings will be used alongside models for climate, hydrology, and power generation, helping to estimate the impacts of climate change and identify mitigating measures to ensure both power production and salmon survival can continue to thrive in the climate of the future.
Ten scenarios showing how climate change and extreme weather events may evolve will be studied and, as Sintef researcher and ReAdapt Project Manager, Ana Adeva-Bustos adds, power system models will be used to predict future energy production, electricity prices, and the operations of reservoirs and power plants.
Small hydropower and climate change
New research published in the Journal of Hydrology has shown how developing small hydropower plants can provide a new direction for alleviating energy shortages in regions of Central Asia which do have abundant hydropower potential.
The Upper Amu Darya (UAD) is the longest river in Central Asia but since 1960 its discharge has been declining due to the expansion of agricultural land and the construction of large reservoirs, while conflicting water demands have been exacerbated by worsening political and economic conflicts that have hindered reservoir management.
Apart from determining potential site selection of small hydro in the UAD, the main purpose of this study by Guoqing Yang, Miao Zhang and Geping Luo was to analyse the impact of future climate change on discharge and hydropower potential, thus providing research results to support water resources management and hydropower development in the region.
The study comprehensively determined ten potential small hydro sites in the UAD based on hydrological simulation and a geographic information decision-making method. Based on future climate data, modelling found that future precipitation and temperature are projected to increase, with precipitation increasing mainly in spring and winter. The average discharge will increase by 19.1~36.6% in the near-term (2031–2050) and by 29.7~106.8% in the long-term (2071–2090). In addition, there will also be an increased risk of extreme discharge, with a peak flow increase in relatively low altitudes and a base flow increase in relatively high altitude areas.
Further development of small hydropower in the UAD, the study recommends, needs to assess the risk of extreme discharge and melting glaciers, as well as the consideration of the ecological environment, geopolitics and socio-economic factors.
Climate change and Brazilian storage
Recent research in Brazil has demonstrated how seasonal pumped hydropower storage (SPHAS) can help to mitigate the challenges of climate change. As the authors of a paper published in the Journal of Energy Storage claim, given Brazil’s high hydropower storage capacity and the strong seasonal patterns of its renewable resources, SPHS technology can play a critical role in enabling the country to transition to a more resilient energy system.
The study, called Seasonal Pumped Hydropower Storage Role in Responding to Climate Change Impacts on the Brazilian Electrical Sector by de Assis Brasil Weber et al, highlights the potential benefits of SPHS over conventional hydropower storage. These include reduced GHG emissions, inter-basin transfer, and higher energy storage capacity. The research also demonstrated that the integration of SPHS with other renewable energy sources can significantly reduce CO2 emissions by up to 68% and contribute to achieving a 100% renewable matrix by 2100.
However, the authors caution, the additional investment costs associated with SPHS technology need to be taken into account when considering its economic viability, but nonetheless these results are important for decision-makers and policymakers to understand the potential role of SPHS in addressing the challenges faced by the power sector in Brazil and other countries in similar situations.
Warming potential
Closed-loop pumped storage hydropower has been shown to be the smallest emitter of greenhouse gases, and so ranks as having the lowest potential to add to the problem of global warming for energy storage when accounting for the full impacts of materials and construction.
Recent analysis conducted at the US Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL) was reported in the journal Environmental Science and Technology, and provides previously unknown insight into how closed-loop pumped storage hydropower compares to other grid-scale storage technologies.
In the paper, “Life Cycle Assessment of Closed-Loop Pumped Storage Hydropower in the United States,” pumped storage is compared against four other technologies: compressed-air energy storage, utility-scale lithium-ion batteries, utility-scale lead-acid batteries, and vanadium redox flow batteries. Pumped storage hydropower and CAES are designed for long-duration storage.
The researchers modelled their findings based on 39 preliminary designs from 35 proposed sites in the contiguous US. The average closed-loop pump storage facility was assumed to have storage capacity of 835MW and an average estimated 2060GWh of stored energy delivered annually. The base scenario also assumed the electricity mix would entirely come from renewable technologies.
Hydropower offered the lowest global warming potential on a functional unit basis, followed by lithium-ion batteries, vanadium redox flow batteries, compressed-air energy storage, and utility-scale lead-acid batteries. The research also found that certain decisions can have a substantive impact, such as building on a brownfield rather than a greenfield site can reduce the global warming potential by 20%.
Decarbonising
Open Hydro, a leader in modelling, reporting, and tracking emissions from reservoirs, has secured significant investment to propel its efforts in decarbonising freshwater systems. This infusion of capital marks a pivotal moment for the company as it seeks to help water and electric utilities become leaders in emissions reduction, while supporting their claims for good water quality and clean hydropower electricity.
The funds will be instrumental in helping reshape how emissions are managed in freshwater systems globally and in solving the looming problem of methane emissions lurking in electricity production used by the world’s largest corporate energy consumers. Open Hydro said its solution holds significance in accurately representing and accrediting low-carbon electricity production, particularly from renewable sources like hydropower.
By modelling, reporting, and accrediting low-carbon electricity production, the company said it empowers hydropower operators to differentiate themselves in the electric market and meet the growing demand for green energy solutions.
