Water and energy are closely related, particularly in the current electricity generation based on thermal coal, gas, oil and nuclear power. The so-called water-energy nexus is a significant sustainability concern. However, a recent LUT study published in Nature Energy shows that the nexus can be resolved for thermal power plants worldwide as a consequence of the energy transition towards a system based on renewable energy, dominated by wind energy and solar photovoltaics.
Currently used electricity generation technologies depend to a large extent on water availability. In particular, thermal power generation comprised of coal, gas, oil, and nuclear power plants requires considerable amounts of water for cooling purposes. In turn, water extraction and distribution typically consume energy.
This link between water and energy, which is commonly referred to as water-energy nexus, is increasingly highlighted as a sustainability concern for achieving water and energy security worldwide and for future planning.
The LUT University research team, led by Solar Economy professor Christian Breyer, carries outworld leading research on modelling the energy transition towards a carbon neutral global energy system by the year 2050. In a recent scientific article published in Nature Energy, the highest ranked scientific journal focused on energy research, Breyer’s team projects a dramatic reduction of water use in power generation as a consequence of the energy transition.
This study connects research on water demand of power plants with mitigation strategies for energy-based water use to provide new solutions enabling a more sustainable use of water and energy.
“Energy transition towards highly renewable electricity generation leads to energy systems mainly based on solar photovoltaics and wind energy and thus substituting existing thermal power plants. This reduces dramatically the cooling water demand of thermal power plants which has a strong impact on the withdrawal and consumption of water from rivers for thermal power plants. The water-energy nexus at rivers can be resolved worldwide as a consequence of the energy transition”, Breyer explains.
“In the study, for a total of 13,863 thermal power plants, which corresponds to 95.8% of the global thermal power plant fleet, the exact location and cooling technology were identified using satellite imagery. Subsequently, they were linked to water bodies using the method of Geographic Information System (GIS) analysis, and the water footprint of each of them was estimated”, explains Alena Lohrmann, LUT researcher and first author of the article.
The study estimates the current and future water demand of thermal power generation on several distributions: global, regional, country and river-based.
“Our work presents an impact analysis for 354 major rivers globally carried out in a high temporal and spatial resolution. This river analysis is of high relevance since thermal power plants affect mainly local aquatic ecosystems due to thermal pollution and increased water discharge”, Lohrmann continues.
“The research provides the assessment of the water use reduction potential in global thermal power plants from 2015 (base year) to 2050. Results show that the transition towards a 100% renewable electricity system can potentially reduce the global water consumption of thermal power plants by up to 97.7%”, Breyer concludes.