Commentary: Waste not, want not

Molly Walton

By Molly Walton
Energy Analyst, WEO
22 March 2017

wastewater treatment plant Getty ImagesWorld Water Day this year perfectly illustrates the links between energy and water. (Photograph: Wastewater treatment plant, GettyImages)

Each year, World Water Day highlights the importance of water resources to our daily lives and wellbeing. For the International Energy Agency, it is also an opportunity to highlight the relationship between water and energy, which is set to grow in coming years.

Effectively managing the interdependence of water and energy supply is fundamental to the economic and social prospects of millions around the world. The provision of water services, such as clean drinking water and sanitation, depends on reliable supplies of energy. The ready availability of water is a key factor in the viability of many energy projects.

With both energy and water demand on the rise, and with a large share of the world’s population remaining without adequate access to reliable energy and water services, the International Energy Agency has long identified this energy-water relationship as a critical issue in need of public attention and policy action. 

The IEA first examined the water requirements of the energy sector in the World Energy Outlook 2012 report and has since provided detailed analysis on different aspects of this topic.

When it was decided that the WEO would once again have a dedicated chapter to the water-energy nexus in 2016, it became evident that to be able to identify chokepoints and propose effective solutions, the analysis must look at both sides of the equation: the water needs of the energy sector as well as the energy needs of the water sector.

For that reason, WEO-2016 provided for the first time a systematic global assessment of how much energy the water sector needs. It found that the needs and intensities of both the water and energy sectors are set to rise through 2040. Energy demand for water supply more than doubles while water consumption in the energy sector rises by more than 60% during that period.

WEO water graph

Wastewater, the theme for World Water Day this year, perfectly illustrates the links between these two sectors.

Improving wastewater management is critical to ensuring access to water and sanitation for all, which is one of the United Nations’ Sustainable Development Goals (SDG).  In many countries, a large percentage of wastewater is not collected or treated, thereby posing a threat to human health as well as being a hazard to the environment.

Tackling this problem will require energy. Today, a quarter of the electricity consumed by the water sector is for wastewater collection and treatment, and this source of demand is projected to rise steadily to 2040 as more wastewater is collected and treated. By 2040, wastewater treatment will require over 60% more electricity than in 2014.‌

There are opportunities to limit this rise in energy demand. Wastewater contains significant amounts of embedded energy that, if harnessed, could help meet some of the sector’s increased energy needs. WEO analysis finds that by 2040, under the right incentive schemes, this potential resource could cover more than half of the electricity needs of municipal wastewater utilities. Already, some wastewater utilities are able to generate all the energy needed at their plant, through a combination of energy efficiency and energy recovery.  

Technologies to save energy and water are readily available, reducing potential stresses on both resources. Taking advantage of these opportunities will require an integrated approach to energy and water issues from policymakers and industry—without it there is a risk that the development of one sector will have negative consequences for the other, undercutting the chance to reach policy and development goals effectively, or in some cases to reach them at all.

All of these challenges and opportunities are described in detail in the energy-water chapter of WEO-2016, now free to download as an e-pub or pdf. Our hope is that, by making this analysis more widely accessible for World Water Day, the IEA can contribute to the dialogue on these critical issues and raise awareness about where potential solutions may lie.