Climate change and hydropower

Climate change and melting glaciers have been creating inflow challenges for hydropower producers over recent years. In Norway, the Folgefonna glaciers are among the largest in the country and meltwater travels down into the hydropower system of Sunnhordland Kraftlag AS (SKL). For over 75 years, SKL has been supplying the region with sustainable electricity and, with precipitation of up to 4000mm per year, already deals with some of the wettest weather in Norway. In a nominal year SKL produces about 2700GWh of hydropower and 60% of this comes from the Blåfalli hydropower plant in Kvinnherad municipality. Here, around 30% of the catchment area is covered by the Folgefonna glaciers.

SKL’s hydro reservoirs are highly flexible and can store huge amounts of water. However, inflow forecasting to optimise energy production is becoming ever more important due to melting glaciers. To help extract the full value of its flexible portfolio, the hydropower producer is set to use software from Norwegian technology supplier Volue. 

Volue’s Smart Generation software will enable SKL to will find out how much water is expected to come into the reservoir system on an hourly basis over a two-week period and help improve seasonal planning of hydropower generation. Previously SKL had handled this by almost emptying reservoirs before the heavy inflow season, and by refilling to the allowed maximum during wet periods before the dry winter season.

Volue says its software will change this. The solution will prepare long-term inflow forecasts by using a mix of weather forecasts and historical weather data as input. Combined with the long-term price forecast from Volue Insight, which provides real-time data, forecasts and market analysis on a scalable platform for the next 15 minutes or 30 years or more, it will suggest how reservoir storage should be best-utilised week-by-week throughout the year. It is said that such a planning cycle will help SKL get greater value out of the water on a yearly basis. 

Critical data

US-based company SensorLogic is also helping to optimise hydropower production in Norway and bring critical water availability data across the Nordic region.

Doug Roberts, Founder of SensorLogic, claims that climate change has rendered existing technologies and networks unreliable when tracking and analysing water availability. 

“We have invested significant time and capital to develop SNOdar and the cloud computing platform needed to combine public data, our sensor data, and proprietary algorithms to offer water availability analytics to the US$7billion private climate data industry,” he said.

In September 2022, Where2O, a Norwegian IoT company and part of the Telenor group, announced it is to deploy SNOdar sensors from US-based SensorLogic Inc to provide critical water availability data to allow hydropower plants to optimise power production.

SNOdar is a snow-depth sensor which can accurately measure snow depth in real-time. They are currently deployed across US and European environmental agencies, hydropwer plants and ski resorts.

"We are excited about being able to offer products from SensorLogic to our customers,” said Eivind Trondsen, CEO of Where2O AS. “Knowing the amount of snow accumulating in the watersheds above hydropower plants is one of the greatest challenges to hydrologists in the power industry.”

Hydro losses

In its 2021-22 annual report, Manitoba Hydro says that last year’s drought led to losses of C$248million for the fiscal year ending 31 March 2022.

“Obviously, the impact of last year’s drought is significant,” said Jay Grewal, President and CEO of Manitoba Hydro. “The drought was one of the worst on record. It not only weakened our ability to generate and sell surplus energy on spot markets in the US and Canada, but we also had to import energy to serve our customers.

“The financial results of record high water flows this year show how much the corporation’s net income is subject to water flow conditions as well as weather, interest rates and export prices,” Grewal added. “All of these factors can be unpredictable and out of our control.”

High water levels on Lake Winnipeg were due to this year’s unprecedented spring flows into the lake across southern Manitoba, Northwest Ontario, and the northern US states, representing the highest volumes of water since records began in 1913. Last year, a large part of the same region was in drought.

At the end of May 2022 all the rivers flowing into Lake Winnipeg contributed to a peak inflow of over 450,000cfs, primarily from the Winnipeg and Red rivers, both in flood stage. These exceptional inflows caused the level of Lake Winnipeg to rise more quickly than it has in recorded history – a full 5.5 feet in the six months between January and mid-July.

“The change from the drought last year to high water conditions this year is extraordinary,” Grewal said. “Any time we have above-average water flows, we run as much water as we can through our turbines and sell that excess energy on the opportunity market. That helps keep rates for our customers here in Manitoba lower than they would be otherwise, while providing needed revenue to reinvest in our existing electric system to ensure reliability into the future.”

Grewal said the unpredictability of export market prices and the impact of precipitation and water flow on Manitoba Hydro’s revenues highlight the need for moderate, steady, and predictable rate increases. For example, in a first quarter forecast last year – a drought year – predicted net income was approximately C$120 million but that turned into a net loss, with a variance of almost C$370 million, as water conditions did not improve.

Slave Falls generating station passing high water on the Winnipeg River in Canada.  High water levels were experienced due to this year’s unprecedented spring flows. Last year, a large part of the same region was in drought. Photo courtesy of Manitoba Hydro.

Facing drought

Even in the face of drought, Gia Schneider, CEO and Co-Founder of Natel Energy, believes that hydropower is still key to the energy transition. Writing for the National Hydropower Association in the US, Schneider says that although the “predominant media narrative has been sowing seeds of doubt about hydropower’s reliability as the western US states continue to face historic drought”, data shared by the US Energy Information Administration “tells a different story.”

Over the course of a 12-day heat wave during September 2022, described as the hottest and longest on record, hydropower in the northwest region (which includes Oregon, Washington, Idaho, Wyoming, Montana, northern Nevada, Utah, and Colorado) continued to far outpace other renewable energy sources across western states. It delivered 26% of total electricity generated, demonstrating that even with reduced water levels due to drought, hydropower remains a cornerstone of the existing grid and a necessary building block for the transition to a low-carbon grid.

Acknowledging that hydropower is, and should remain, a pillar of the clean energy transition does not mean simply carrying on with business as usual, Schneider cautions. 

“While climate models differ on the predicted frequency of droughts or periods of increased precipitation, it is clear that climate change is water change,” she adds, “and we must adopt new strategies to ensure that the hydropower of the future is responsive and resilient in the face of an evolving climate.”

Schneider believes that it is clear that the effects of climate change are ongoing and that “through these extreme and varied weather conditions, hydropower remains a critical means to a stable grid”. 

“What’s more,” she concluded, “when thoughtfully deployed in tandem with natural infrastructure, hydro soars well above many other renewables as a leading solution for building a resilient future.”

Postponed renovation

Back in Europe, Axpo has announced that extensive renovation work at the Gigerwald Dam in Switzerland, is to be postponed for two years, due to the imminent power shortage expected this winter.

Although the work is critical for the long-term operation of the plant, due to the forthcoming extreme energy situation, priority will be placed on ensuring the production of up to 160GWh of energy from the water in the reservoir and recirculation operation, the company said. Extensive renovation scheduled for this winter would have required full drainage of the reservoir. Construction preparations that began in the spring of 2022 have been suspended immediately and renovation work has been postponed until the winter of 2024/25. 

"The danger of a power shortage in the upcoming winter has intensified over the last few weeks,” explained Christoph Brand, Axpo’s CEO. “As a result we have decided to suspend work immediately in order to save every possible kilowatt-hour that can be produced from the reservoir and ensure recirculation operation during the winter months. In doing so, we want to continue boosting our contribution to the security of supply.”

The Gigerwald reservoir will now be fully drained in the winter of 2024/25 to ensure that renovation work can be carried out smoothly. The plant is expected to go back into operation in early summer of 2025.

Power shortages

Extreme droughts and the lack of water in hydroelectric systems across Europe could be contributory factors to insufficient energy supplies across the UK this winter. 

Professional advisory firm Lane Clark & Peacock (LCP) has shared its analysis highlighting that coal could be playing a crucial role in providing energy security over the coldest months of the year, but even with this emergency support, the country could still be facing ten hours of power cuts throughout the winter.

Furthermore, LCP looked at the very possible scenario of the UK energy system receiving no imports through its interconnectors from Europe (due to continued nuclear shortages in France and low hydroelectric levels in Norway) and concluded that the UK could experience a loss of load expectation of 29 hours. This level would be reduced to ten hours if the country was to tap into its winter contingency reserve and prop up the energy system with coal.

“The irony is that as Europe baked during this summer’s heatwave, it was simultaneously sowing the seeds for further pain this winter,” Chris Matson, Partner at LCP, explains. “As a result of the extreme droughts and the lack of water that is hitting hydroelectric systems in key interconnector markets like Norway, coupled by the issues we are seeing in France with their nuclear reactors, there are significant doubts about the availability of electricity coming into the UK from the continent which is critical to its security of supply.”

REFERENCES:

Glaciers and Fjords: How SKL Will Extract the Full Value of Its Hydro Flexibility by Olga Apostolova. Published on Jul 07, 2022 

Why Hydro is Key to the Energy Transition, Even in the Face of Drought by Gia Schneider, CEO and Co-Founder of Natel Energy. October 3, 2022. NHA Powerhouse.