The nexus of water and energy, by Liew Yien Phin

Did you know a single query on Google consumes a tenth of a teaspoon of water? Multiply that by 293 million searches, and more than one million litres of water is consumed through Google searches every day.

And Google is already one of the most energy-efficient search engines in the world, using only half the energy of a typical data centre for each search query.

There is a relationship between the water we drink and energy we consume, and it is much deeper than we can imagine. Using one inflicts a cost on the other. It takes energy to produce water, and water to produce energy. This is the nexus of water and energy – and it must quickly rise on the agendas of government planners and utility providers.

 

Water for energy; energy for water

 

Water is a key resource in power generation.

For instance, China, the world’s largest producer and consumer of coal, relies so heavily on water to extract coal that there are fears the water will run out before the coal. Water plays a key part in each stage of the coal supply chain – from coal mining to final conversion into power. And China is facing serious water shortage and water quality issues.

Coal is not the only fossil fuel industry threatened by water availability. Water is routinely forced into oil and gas fields at high pressure to drive fossil fuels out.

Harnessing renewable energy also requires the use of water. For example, water is used to cultivate biofuel crops, which are the most water-intensive source of fuel in the United States due to the heavy irrigation used in corn production. It also takes water to keep solar energy operational.

When fuels are burnt for energy, water is the most common way to cool plants. Whether the cooling process is done by water drawn from a nearby water source, or by recirculating cooling water, the heat causes water to evaporate.

Similarly, water production is highly dependent on energy. Desalination and water recycling, on which a country with no natural aquifers such as Singapore relies heavily, require energy to power, as do wastewater treatment processes. Energy is also needed to pump water from the source or treatment plants to customers downstream – a necessary daily process for public consumption.

Since desalination has proven effective, why doesn’t a country like Singapore have multiple desalination plants? The reason is cost – both in economics and energy-use. On average, it takes more than ten times the amount of energy to desalinate water, compared to using lake or river sources.

A packed planet

This nexus of water and energy has serious implications that could limit economic development in Asia in the coming years. Increased demand for both water and energy will be the critical issue of the next decade. This is due to several driving forces:

• Global population growth
• Continued expansion of the global economy
• Improved standard of living in emerging countries
• Increased urbanization

The world’s population is increasing at an alarming pace. From 6 billion people at the turn of the century, it reached 7 billion just a little more than a decade later. And it looks like the world will surpass the estimate of 9 billion people by 2045 – in the blink of an eye.

This impacts energy use, which is projected to increase by 50 per cent by 2035, while water withdrawals are expected to increase by 50 per cent by 2025. The UN states that most population growth is in developing countries and these are most at risk of dwindling water supplies to meet the rise in demand required to improve their quality of lives. In addition, the expected increase in urbanisation, from 50 per cent of the current world population living in urban areas to 70 per cent by 2050, will contribute to a higher concentrated demand for utility services.

The combination of these forces results in growing concerns about the availability of water to support energy, and vice versa. This increased demand on water and energy inflicts urgency on the global community – policy makers, water and energy providers, industry leaders, and consumers – to rethink the way water and energy needs are addressed going forward. A mindset change is necessary. Government and industry alike must recognise the interdependence of water and energy to manage competing priorities more effectively. Streamlined and cost-effective techniques must constantly be developed to keep global water and energy supply chains sustainable.

To achieve this, a greater understanding of the value of these precious resources is needed.

Solutions?

 

Start viewing water as a fuel. Save water by saving energy.

Governments and business leaders have started identifying alternatives to save water and energy. For instance, the Water Supplies Department (WSD) in Hong Kong has implemented measures to reduce its energy consumption while developing viable renewable energy options. WSD works closely with business partners to ensure “green housekeeping” in water treatment facilities with infrastructure that consumes less energy and has a lower carbon footprint. Alternative energy sources such as hydro-power, wind and solar energy are also heavily utilised. These measures have helped the WSD, a water utility, reduce energy use by more than 10 per cent over the past decade.

Using alternative technologies, such as air cooling systems instead of recirculating water systems, to cool power generators can also aid in water conservation. This approach is being deployed by Eskom, the state owned utility in South Africa, at its Kusile Power Station. In addition, governments have begun viewing wastewater as a resource. Treated wastewater can be put towards industrial or agriculture use in countries heavily involved in both.

Innovation is a powerful tool in conserving our precious resources. Energy-efficient desalination and water treatment technologies are constantly being developed and improved upon in resource-scarce countries such as Singapore to ensure minimal wastage. Largely driven by the private sector, innovation has grown at such a rapid pace that effective water treatment technologies are now more attainable than before.

Ultimately, despite all that is done, it falls to each individual to play their part in protecting the resources we need. It is simple – water fuels life. The sooner we understand that, the better position we are in to do more with less and conserve for our future generations.