Solar energy and the global water-energy-climate nexus

29 MAR 2020

As water scarcity and the climate crisis worsen, solar energy will become the ultimate solution to sustainability. The Middle East should play a leading role as a solar energy superpower. 
In the past few years, we unwillingly witnessed previously unfathomable water rationing in Cape Town, South Africa, Sydney, Australia, and Chennai, India. The term “day-zero”, which was first used in Cape Town, indicates how easily human society can be pushed into a primitive living state when the water supply is not secure. 

While rapid population growth and steadily improving living standards, among others, continue to put enormous pressure on already very stressed water systems, climate change is increasing air temperatures along with the frequency and intensity of extreme droughts, which together lead to increased water use for crop irrigation and livestock. Predictions indicate that more than 60 percent of the world’s population could experience severe water scarcity by 2040. Ensuring water security is a daunting challenge and, in many countries, tantamount to national security. 

Desalination of seawater, an energy-intensive process, provides water to many parts of the globe. The Middle East, with limited freshwater sources, is heavily dependent on desalination. It accounts for 45 percent of the world’s total seawater desalination capacity. Consequently, water and energy are closely intertwined in the Middle East. In Saudi Arabia, around 10 percent of the electricity is used for seawater desalination. In Abu Dhabi, the desalination sector contributes more than 22 percent of the emirate’s total CO2 emissions. Climate change is already leading to environmental changes in our seas and oceans. Phytoplankton productivity may be a casualty of climate change, which may increase the energy intensity of seawater desalination processes. 

Water, energy and the climate are inextricably interconnected in the Middle East and beyond. Solar energy must sit at the center of this nexus for the following four reasons.

First, solar energy is clean with a minimal carbon footprint. Studies have projected life-cycle emissions from solar power to be 4–12 gCO2eq/kWh (note: grams of CO2 equivalent per kilowatt hour electricity generated), compared with 80–110 and 400–1000 gCO2eq/kWh of fossil fuel burning plants with and without carbon capture and sequestration, respectively.1 

More often than not, the complaint against solar energy is for its low areal energy intensity, which necessitates the use of large land areas in any form of its utilisation. However, Japan is third in the world in total photovoltaics (PV) installation capacity and Singapore is on its way to producing 4 percent of its total electricity from solar energy by 2030. These two land-scarce countries should inspire the rest of the world. Our will and determination can always overcome physical land constraints.

Second, solar energy is abundantly available in most parts of the world where there are human activities. The often-quoted statement that the solar energy that the Earth receives in one single hour is enough to power the entire world for one year communicates the vast abundance of solar energy available for energy production and its unmatched potential.

Third, solar power has a very low barrier-of-entry, which is especially true with PV. The cost of PV has been drastically reduced. Depending on available capital, PV can be used at any scale, from household panels to massive industrial-scale solar farms. Nowadays, regular households can afford small-scale PV systems even without governmental subsidies. Affordability leads to a virtuous cycle in PV development. A very recent study reports that the cost of solar power is lower than local grid power in 344 cities in China, even without subsidies. And in 76 of those cities, the price of solar power was equal to or less than that of coal-fired power.2 

Fourth, solar power generation consumes minimal amounts of water. To generate 1 MWh of electricity, PV consumes only 2 gallons of water whereas thermal power plants using coal and nuclear fuel as energy sources consume 692 and 572 gallons of water, respectively.3  Technologies now being developed can even turn conventional PV farms into net freshwater production facilities while also producing electricity.4  

The Middle East is blessed with stable and reliable solar irradiation; arguably, it is the best quality solar irradiation in the world. In addition, there are vast areas of land in the Middle East that remain undeveloped and unused. The annual average solar irradiance in Saudi Arabia (2300 kWh/m2) is more than 1.4 times that in Japan (1600 kWh/m2). By a simple calculation, if 5  percent of the land area in Saudi Arabia were covered with state-of-the-art PV panels, more electricity than needed by the entire world could be produced. However, solar energy has been considerably underutilised in the Middle East. At status quo, solar electricity in Saudi Arabia and the United Arab Emirates accounts for less than 0.1 percent and 1 percent of the total domestic electricity generation, respectively.

Fortunately, giant solar projects in both Saudi Arabia and the United Arab Emirates currently being planned demonstrate the region’s ambitions to rightfully lead the world in solar power generation. 
As the world is moving into a decarbonised and circular economy, solar energy must sit at the center of the water-energy-climate nexus. 

1. Pehl, M.;  Arvesen, A.;  Humpenöder, F.;  Popp, A.;  Hertwich, E. G.; Luderer, G., Understanding future emissions from low-carbon power systems by integration of life-cycle assessment and integrated energy modelling. Nature Energy 2017, 2 (12), 939.
2. China brings solar home. Nature Energy 2019, 4 (8), 623-623.
3. Wilson, W.;  Leipzig, T.; Griffiths-Sattenspiel, B., Burning our rivers: The water footprint of electricity. River Network (Austin, TX: Comptroller of Public Accounts, Data Division Services) Publication 2012,  (96-1704), 62.
4. Wang, W.;  Shi, Y.;  Zhang, C.;  Hong, S.;  Shi, L.;  Chang, J.;  Li, R.;  Jin, Y.;  Ong, C.; Zhuo, S., Simultaneous production of fresh water and electricity via multistage solar photovoltaic membrane distillation. Nature communications 2019, 10 (1), 1-9.

By Professor Peng Wang / King Abdullah University of Science and Technology The Hong Kong Polytechnic University


20 MAY 2020

Need to know: top 10 facts about World Bee Day

  1. World Bee Day, which was approved by the United Nations General Assembly in 2017, is held on May 20 each year to mark the birth of Anton Janša, a pioneer of modern apiculture, or beekeeping.
  2. There are a variety of pollinator species in the world, which include bees, butterflies, birds and bats.
  3. The most popular pollinator is the bee, which has between 25,000 and 30,000 species.
  4. Nearly 90 per cent of all wild flowering plants depend on animal pollination.
  5. Caring for bees and other pollinators is part of the fight against world hunger.
  6. Ensuring biodiversity among pollinators is crucial to build resilience in agroecosystems and adapt to climate change.
  7. Over 80 per cent of human food is supplied by plants. The loss of pollinators would, therefore, lead to an exponential loss of biodiversity, endangering our ecosystems and our diet.
  8. Nearly three quarters of the world’s crops depend, at least in part, on bees and other pollinators.
  9. In economic terms, natural pollinators contribute up to US$577 billion to the global economy.
  10. The goal of World Bee Day is to strengthen measures aimed at protecting bees and other pollinators, which would significantly contribute to solving problems related to the global food supply and eliminate hunger in developing countries.


Sources: United Nations & the Food and Agriculture Organization




22 APR 2020

Need to know: top 10 facts about Earth Day

  1. The first Earth Day was held on April 22, 1970, in the United States, marking the birth of the modern environmental movement;
  2. Earth Day was founded by Gaylord Nelson, a US senator from Wisconsin, after witnessing the fallout from an oil spill in California in 1969;
  3. The date of April 22 was chosen to maximize the greatest college student participation as it fell between Spring Break and Final Exams;
  4. The first Earth Day inspired 20 million Americans to take to the streets to demonstrate against the impact of 150 years of industrial development, which left a growing legacy of serious human health impacts;
  5. Earth Day went global in 1990, mobilizing 200 million people in 141 countries;
  6. Today, Earth Day Network, the organizer of Earth Day, say that 1 billion people mark Earth Day each year, while more than 190 countries have joined the movement;
  7. Earth Day was renamed officially by the UN in 2009 as International Mother Earth Day
  8. The aim of Earth Day is to empower people with information, the tools, the messages and the communities needed to make an impact and drive change to protect the planet and mitigate climate change;
  9. The theme of Earth Day 2020 was climate change;
  10. Earth Day 2020 marked the first time it was celebrated virtually, with many of the world’s population in lockdown because of COVID-19.

Top 10 facts about Earth Day


Source: Earth Day Network –


01 SEP 2020

10 key facts around International Day of clean air for blue skies

The UN has designated September 7 as the International Day of clean air for blue skies, with short-lived climate pollutants (SLCPs) among those pollutants most linked with both adverse health effects and near-term warming of the planet. 

SLCPs can persist in the atmosphere for a few days or a few decades, so reducing them can have an almost immediate health and climate benefits for those living in places where levels fall. 

These pollutants are responsible for about one-third of deaths from stroke, chronic respiratory disease, and lung cancer, as well as one quarter of heart attack deaths. Ground-level ozone, produced from the interaction of many different pollutants in sunlight, can also cause asthma and chronic respiratory illnesses.

Аir pollution is the single greatest environmental risk to human health and one of the main avoidable causes of death and disease globally, with an estimated 6.5 million premature deaths across the world in 2016 attributed to indoor and outdoor air pollution. 

Air pollution disproportionately affects women, children and the elderly, especially in low-income populations as they are often exposed to high levels of ambient air pollution and indoor air pollution from cooking and heating with wood fuel and kerosene.

Society bears a high cost of air pollution due to the negative impacts on the economy, work productivity, healthcare costs and tourism, among others. 

In the absence of aggressive intervention, the number of premature deaths resulting from ambient air pollution is estimated to increase by more than 50 percent by 2050.

UN Member States recognize the need to substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination by 2030, as well as to reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management by 2030.

The 2030 Agenda for Sustainable Development, which outlines a road map to achieving sustainable development, environmental protection and prosperity for all, recognizes that air pollution abatement is important to the attainment of the Sustainable Development Goals.

Countries have committed to promoting sustainable development policies that support healthy air quality in the context of sustainable cities and human settlements