Would power grid interconnections protect the Mekong’s wetlands?

Abstract:

The Mekong’s wetlands are a major biodiversity hotspot and home to a large inland fishery, upon which the lives of millions depend. These delicate ecosystems are threatened by hydropower dams, which limit the transport of sediment, block or delay fish migration, and alter hydrological regimes. Considering the economic interests at stake and expected life-span of dams, the removal of these infrastructures may not be a feasible option. On the other hand, the reoperation of existing infrastructures may be a more practical strategy for balancing, at least partially, hydropower and ecological outcomes. Yet, many challenges prevent dam reoperation from being immediately deployable. First, a decrease in hydropower production would affect the returns on investments for private and public investors. Second, dams are often locally managed, while their effects are perceived across economic sectors and political borders. Third, the presence of multiple decision-makers, typically responsible for individual sectors, hinders the governance of transnational water and energy resources. Here, we hypothesize that these challenges could be addressed by harnessing power grid interconnections. The rationale is that a large-scale infrastructure connecting multiple production and load centers should be able to dampen local variations in hydropower production caused by more sustainable dam operations. To verify our hypothesis, we rely on a high-resolution, semi-distributed water-energy model that simulates the Mekong’s hydrological processes—including the operations of all major dams—as well as the production and trade of electricity between Laos, Cambodia, and Thailand. We then proceed to modify the dam operations, so as to explore the trade-offs between hydropower production in the Lower Mekong’s countries and hydrological regimes at Stung Treng—a gauging station located upstream of the Mekong’s wetlands. We show that favoring natural-flow regimes decreases the amount of hydropower dispatched into the grid; the loss, however, could be offset by transferring electricity across multiple production sites. With minimal investments, we may thus have tangible opportunities for coordinating regional hydropower systems while protecting the Mekong’s wetlands.