Addressing the Energy-Water Nexus

Opinion by Johannes Cilliers

Johannes Cilliers is Director of Business Development for sub-Saharan Africa at First Solar. First Solar is a leading, global solar energy company.

According to the International Energy Agency (IEA), energy production alone accounts for some 15 percent of the world’s total water withdrawal, which amounts to an estimated 580 billion cubic meters of freshwater per year. To put that number into context: global energy generation now consumes enough water per year to fill about 232 million Olympic-sized swimming pools. In fact, thermoelectric power plants already account for over a third of freshwater withdrawal in the United States, where the volume is even more than the water used for agriculture, and in Europe.

 

There is no doubt that the energy-water nexus is real and of particular concern to water-scarce countries, such as South Africa. The fact of the matter is that most energy generation technologies - including coal, nuclear and even concentrating solar power (CSP) - consume tremendous amounts of water during operations, for processes such as fuel extraction, cooling and cleaning.

 

As our energy needs continue to grow, so too will our use of water to generate it. The World Bank – which, earlier this year, launched its ‘Thirsty Energy’ initiative to highlight the energy-water nexus - predicts that while global energy consumption will increase by 35 percent by 2035, water consumption will increase by an alarming 85 percent during the same period of time.

 

Looked at in the context of energy demand in South Africa – where forecasts estimate a need for an additional 40,000MW of electricity by 2025 - the management of water resources will be critical to sustainably driving growth in the country’s generation capacity. Water is a finite resource and its use in electricity production should be managed through a diversified power generation portfolio that minimizes impacts on water usage.

 

 Sunlight, on the other hand, is an abundant resource and, if effectively harnessed, can help mitigate some of the impact on our water resources. Photovoltaic (PV) solar energy is one of only two electricity generation technologies – the other being wind – with comparatively negligible water consumption. With only 20 liters of water consumed per megawatt/hour (MWh) of electricity produced, PV power plants consume as much as 152 times less water per megawatt/hour than wet-cooled CSP technologies, 17.5 times less that dry-cooled CSP and 64 times less than coal plants. With over 8,000 MW of modules installed worldwide, First Solar alone helps displace over 14 billion liters of water per year.

First Solar PV energy systems provide a sustainable solution to the energy-water nexus by generating clean electricity for 25+ years with little to no water use. As a matter of fact, most of the water consumed at our operational power plants is used to ensure that workers onsite stay hydrated and, in regions prone to dusty and humid conditions, to occasionally clean the modules if a dry-cleaning solution isn’t suitable. Additionally, as our experience in regions such as the Middle East has shown, the superior spectral performance of our modules ensures that frequent wet cleaning isn’t necessary to maintain production efficiencies, further reducing water consumption. 

On a lifecycle basis, PV also consumes less water than most other power generation sources, including hydrocarbon-based technologies and those that use biofuels in the production process. With the smallest carbon footprint, lowest life cycle water use, and fastest energy payback time in the industry, our thin-film PV modules provide a sustainable solution to climate change, water scarcity, and energy security. First Solar has further reduced lifecycle water use by reusing water during manufacturing, implementing advanced site preparation techniques to reduce dust generation during project construction and using dry methods for module cleaning in dust-prone climates.

While a power portfolio that completely excludes thermal generation is an unrealistic expectation at this point in time, the reality is that water conservation needs to remain a priority. It will be important for the power generation sector in South Africa and around the world to recognize the importance of minimizing the use of water and to implement measures that address this very real challenge.

We pledge to continuously innovate and to contribute to our partners’ and customers’ efforts to conserve our most precious resources, while efficiently harnessing our most abundant one – sunlight.