hydropower projects look for reliable climate change projections to prepare for the future
Three Gorges Dam, China
Hydropower is being heralded as a way to combat climate change by reducing the world’s reliance on fossil fuels.
Large hydropower capacity is expected to grow by 52 percent and provide 10 percent of new global electricity energy capacity between 2013 and 2030, according to a 2015 report by the Pew Charitable Trusts.
But in an odd twist of fate, climate change is also altering the supply of water needed to run these projects. Prolonged droughts and changing river flows have project teams looking to research initiatives to help them maximize long-term benefits in the face of unpredictable weather patterns.
“Hydropower is entirely dependent on fuel [in the form of water] coming from the river,” says Vincent Mercier, PMP, hydropower project manager, Hatch, Montreal, Quebec, Canada. His organization provides engineering, project and construction management services to the Canadian hydropower industry. “Mother Nature decides how much fuel we have at our disposal, and climate change adds another layer of variability on top of that,” he says.
Too little rainfall can mean a reduction in power output and decreased revenues over time. In California, USA, for instance, record drought conditions have decreased hydropower generation to about 50 percent of average annual levels. And a key reservoir in Brazil dropped below 10 percent of its capacity in January 2015, leading to power outages in its most populous city, São Paulo.
In the case of Three Gorges Dam, over 360 million people live within the watershed. If unprecedented amounts of rain inundate the dam’s spillway, the results for the country could be disastrous.
Too much water poses new risks, as well. “Depending on the region, climate change can, and probably will, affect the severity, duration and time of year of extreme [rainfall] events,” says Mr. Mercier.
From a strategic perspective, that means sponsor organizations may want to assess the benefits of upgrading facilities or installing new turbines to capture additional capacity. For example, Mr. Mercier manages the Mactaquac Hydroelectric Generating Station project, based in New Brunswick, Canada. Portions of the station will reach the end of their life span in 2030, so Mactaquac has identified three options for the future of the station. Because each potential project plan has its own implications for the community and the environment, the company is including a broad range of stakeholders, from expert climatologists to First Nations communities, in the decision-making process.
Climate change is increasing risk on the technical side of things. Maximum precipitation values determine the size and operating parameters of a dam’s spillway, for example. So better forecasting tools are needed to make the right engineering decisions, says Mr. Mercier. “It’s important because it affects the risk profile of the investment as well as the safety of the public in some cases.”
Hydropower megaprojects like the Three Gorges Dam in China prove just how serious that risk can be. Historically, dams were built in remote locations away from large population centers. But in the case of Three Gorges Dam, over 360 million people live within the watershed. If unprecedented amounts of rain inundate the dam’s spillway, the results for the country could be disastrous.
“Against the backdrop of the global warming, the risks faced by our large engineering projects have increased,” Zheng Guoguang, head of China’s Meteorological Administration, told state newspaper Study Times, according to Reuters. “Global warming affects the safety and stability of these big projects, as well as their operations and economic effectiveness, technological standards and engineering methods.”
The Water Cycle
Despite these warnings, some hydropower sponsors are reluctant to include climate change models in their project plans. With climate change hydrology still in its infancy, tools are currently being developed to adequately capture the effects of global warming on hydropower projects. “It’s easier for designers and sponsors of much larger projects to include refinement of climate change effects forecasting tools in their design, which is why you usually see public owners with more resources taking the lead on this,” says Mr. Mercier.
With the support of large utility companies, organizations like Ouranos, based in Montreal, Quebec, Canada, are trying to improve the quality of the available data. Ouranos conducts climate monitoring projects and hydropower adaptation studies for Canada’s energy sector. One of its current research projects studies recent historical rainfall patterns for use in simulation models for several watersheds in Canada where large dams are located. The project aims to determine maximum precipitation amounts and flood levels under changing climate conditions, which will make it easier for hydropower project planners to take climate change into account during the decision-making processes.
“Against the backdrop of the global warming, the risks faced by our large engineering projects have increased.”
—Zheng Guoguang, China’s Meteorological Administration, to Study Times
Still, normal annual variability may mask long-term trends. “We may not see the effects of climate change for 20-30 years,” says Mr. Mercier. Since large hydropower projects typically expect to recoup the bulk of their costs within the first 15 years of operation, some sponsors are reluctant to invest money into projects without a clear ROI, Mr. Mercier says. “Owners who decide to trust the science may not know if their investment paid off for many years.” —Tegan Jones
PM NETWORK SEPTEMBER 2015 WWW.PMI.ORG
SEPTEMBER 2015 PM NETWORK