19 Mar 2018
Renewable energy has long been known as a greener alternative to fossil fuels, but that doesn’t mean that the former has no negative environmental impacts. Hydropower, for instance, has been known to reduce biodiversity in the land used for its systems.
Now, a team of Norwegian-based researchers have developed a methodology that quantifies the environmental effects of hydropower electricity production.
Martin Dorber, PhD candidate in Industrial Ecology at the Norwegian University of Science and Technology (NTNU), is part of the team that developed the analytic tool. ‘Some hydropower reservoirs may look natural at first. However, they are human-influenced and if land has been flooded for their creation, this may impact terrestrial ecosystems,’ he said,
The Life Cycle Assessment, or LCA, can be used by industry and policymakers to identify the trade-offs associated with current and future hydropower projects. Norway is one of the top hydropower producers in the world, with 95% of its domestic electricity production coming from hydropower.
Many hydropower facilities include a dam – many purpose-built for hydropower generation – which stores fresh water from lakes or rivers in a reservoir.
Reducing biodiversity in the areas where hydropower development is being considered is one of the main disadvantages of the renewable source. Reduced freshwater habitats and water quality, and land flooding are among the damaging effects – all of which are difficult to assess, says the team.
‘Land use and land use change is a key issue, as it is one of the biggest drivers of biodiversity loss, because it leads to loss and degradation of habitat for many species,’ said Dorber.
Using reservoir surface area data from the Norwegian Water Resources and Water Resources Directorate and satellite images from the NASA-USGS Global Land Survey, the team were able to create a life cycle inventory that showed the amount of land needed to produce a kilowatt-hour of electricity.
‘By dividing the inundated land area with the annual electricity production of each hydropower reservoir, we calculated site-specific net land occupation values for the life cycle inventory,’ said Dorber.
‘While it’s beyond the scope of this work, our approach is a crucial step towards quantifying impacts of hydropower electricity production on biodiversity for life cycle analysis.’
While this study is exclusive to hydropower reservoirs in Norway, the team believe this analysis could be adopted by other nations looking to extend their hydropower development and assess the potential consequences.
‘We have shown that remote sensing data can be used to quantify the land use change caused by hydropower reservoirs,’ said Dorber. ‘At the same time our results show that the land use change differs between hydropower reservoirs.’
‘More reservoir-specific land use change assessment is a key component that is needed to quantify the potential environmental impacts.’
By Georgina Hines