TODAY’S STUDY: HOW NEW ENERGY IS CRUCIAL FOR WORLD WATER SUPPLIES
Renewable energy in the water, energy & food nexus
January 2015 (International Renewable Energy Agency)
Renewable energy technologies offer substantial opportunities in the water, energy and food nexus
The interlinkage between the water, energy and food supply systems - the nexus - is a major consideration in countries’ sustainable development strategies.
Rapid economic growth, expanding populations and increasing prosperity are driving up demand for energy, water and food, especially in developing countries. By 2050, the demand for energy will nearly double globally, with water and food demand estimated to increase by over 50%. The ability of existing water, energy and food systems to meet this growing demand, meanwhile, is constrained given the competing needs for limited resources. The challenge of meeting growing demand is further compounded by climate change impacts. From the rice fields in India to desalination plants in the Middle East, and nuclear power plants in France, the nexus is already posing a significant challenge for improving water, energy and food security, a concern for policymakers today.
The nexus affects the extent to which water, energy and food security objectives can be simultaneously achieved.
Water is required for extracting and processing fossil fuels as well as for generating electricity from various sources. Energy supply presently accounts for nearly 15% of global freshwater withdrawals annually. As a consequence, the availability and accessibility of water resources for fuel extraction, processing and power generation represent a key determinant for energy security. Conversely, disruptions in the provision of energy services, which are essential for water treatment, production and distribution, also have direct implications for water security. Vulnerabilities in water and energy supply also pose critical risks for food security, as severe droughts and fluctuations in energy prices can affect the availability, affordability, accessibility and utilisation of food over time. The agri-food supply chain accounts for 30% of the world’s energy consumption and is the largest consumer of water resources, accounting for approximately 70% of all freshwater use. Such interlinkages are compelling governments, the private sector, communities, academia and other stakeholders to explore integrated solutions to ease the pressures and formulate development pathways based on sustainable and efficient use of limited resources.
Renewable energy technologies could address some of the trade-offs between water, energy and food, bringing substantial benefits in all three sectors.
They can allay competition by providing energy services using less resource-intensive processes and technologies, compared to conventional energy technologies. The distributed nature of many renewable energy technologies also means that they can offer integrated solutions for expanding access to sustainable energy while simultaneously enhancing security of supply across the three sectors. This report analyses the key opportunities that renewable energy offers, specifically to address the key challenges posed by the water, energy and food nexus (see figure E 1).
Looking forward, an energy system with substantial shares of renewable energy could be less water-intensive
Across their life cycle, some renewable energy technologies are less water intensive than conventional options.
Renewable energy resources such as solar, wind and tidal are readily available and do not require fuel processing and associated water inputs. Bioenergy, however, could necessitate substantial water inputs depending on feedstock production. Residue-based bioenergy requires relatively less water compared to dedicated energy crops — whose water consumption in turn depends on whether irrigation is necessary and, if so, on the irrigation method adopted, the crop type, local climatic conditions and technology choices.
During the power generation stage, water needs for solar photovoltaics (PV) and wind are negligible compared to conventional thermoelectric generation where substantial quantities of water are needed for cooling. During this stage, solar PV or wind could withdraw up to 200 times less water than a coal power plant to produce the same amount of electricity. Geothermal and concentrating solar power (CSP) have higher water needs for operation. Recent projects have shown that application of dry cooling systems in CSP plants, as well as in conventional power technologies, can reduce the water use substantially. Water consumption in hydropower generation occurs primarily due to evaporation from holding reservoirs. Where water is held in reservoirs, it could be used for multiple purposes with different upstream and downstream effects. Depending on the context, attributing water consumption entirely to electricity generation may not be accurate.
Evidence of water savings from renewable energy deployment to date have been limited to specific technologies and countries/regions.
The American Wind Energy Association, for instance, estimates that during 2013 electricity from wind energy in the United States avoided the consumption of more than 130 billion litres of water, equivalent to the annual water consumption of over 320 000 U.S. households. The European Wind Energy Association found that wind energy in the European Union (EU) avoided the use of 387 billion litres of water in 2012 – equivalent to the average annual water use of 3 million EU households.
At an energy-system level, increasing the share of renewable energy can reduce water use substantially.
This report conducts a preliminary analysis on select REmap 20301 countries (the United Kingdom, the United States, Germany, Australia and India) and finds that increasing renewables penetration leads to a substantial reduction in water consumption and withdrawal in the power sector. On the back of a substantial scale-up in renewable energy deployment, in particular solar PV and wind, water withdrawals in 2030 could decline by nearly half for the United Kingdom, by more than a quarter for the United States, Germany and Australia, and over ten per cent in India (see figure E 2).
Global and regional estimations also showcase a positive impact of increased renewables deployment on water demand in the energy sector.
In its World Energy Outlook 2012, the International Energy Agency concluded that energy sector scenarios with higher shares of renewable energy require much less water.
Water withdrawals under the most aggressive low-carbon pathway (the 450 Scenario) will be 4% higher in 2035 than in 2010, compared to 20% higher in the New Policies Scenario and 35% in the Current Policies Scenario. The present report estimates that, at a regional level, realising the renewable energy plans for the Gulf Cooperation Council region (GCC) will result in a 20% reduction in water withdrawal for power generation and associated fuel extraction (see figure E 3). Analysis shows that most of this reduction will come from the largest economy in the region, Saudi Arabia, due to its heavy reliance on crude oil for electricity generation and its ambitious renewable energy plans.
Renewable energy technologies can boost water security by improving accessibility, affordability and safety…Renewable energy can provide access to sustainable, secure and cost-competitive energy along different segments of the water supply chain, thereby reducing pressure on existing energy infrastructure…Solar-based pumping solutions offer a cost-effective alternative to grid- or diesel-based irrigation pumpsets…Water utilities are looking increasingly to distributed renewable energy solutions to improve energy efficiency and the resilience of supply networks… Increasingly, renewable energy technologies are replacing electricity or fossil fuel use for water and space heating…
Integrating renewable energy within the agrifood chain could contribute to food security objectives…Renewable energy can decouple segments of the agri-food supply chain from fossil fuel use…Using renewable energy in post-harvest processing can reduce losses and enhance the sustainability and competitiveness of the industry…Substituting traditional biomass for cooking with modern fuels is imperative for social and economic development…
Bioenergy development, when sustainably and efficiency managed, can positively affect both energy and food security…Modern bioenergy could play an important role in the ongoing transformation of the energy sector…Bioenergy can provide a localised solution to transform rural economies while enhancing energy and food security…Land uses for energy and food production are closely related, and can be made compatible…Solar and onshore wind technologies offer opportunities for mixed, multipurpose land use…
Quantitative tools help to assess trade-offs and support nexus-oriented decision-making in the energy sector…Traditionally, policy making has been confined to respective sectors with limited consideration of the influence that one sector could have on another…Analytical frameworks could play a crucial role in assessing the impacts of policies on different sectors…