Impacts of Non-Revenue Water on Energy Efficiency and Carbon Footprint: A National- Scale Case Study of Thailand’s Provincial Waterworks Authority
This national-scale case study of Thailand's Provincial Waterworks Authority demonstrates that Non-Revenue Water (NRW) causes significant energy waste and carbon emissions, revealing that reducing NRW from 27.47% to 15% could cut associated energy losses and emissions by approximately 53.4%.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Water is often thought of as a resource that simply flows from a source to a tap, but the journey it takes is powered by electricity. Before a drop of water reaches a home, it must be pulled from a river or aquifer, cleaned at a treatment plant, and pushed through miles of pipes to overcome gravity and distance. Every step of this process consumes energy. In many parts of the world, this energy comes from burning fossil fuels, which releases carbon dioxide into the atmosphere. When water is lost along the way—leaking from broken pipes or slipping through faulty meters—the electricity used to move and treat that water is wasted too. This wasted energy creates a hidden carbon footprint, a burden on the climate that is often invisible in standard water reports. For decades, water utilities have focused on the volume of water lost, but a new perspective is emerging that links these losses directly to energy efficiency and climate change.
A team of researchers at King Mongkut's Institute of Technology Ladkrabang in Thailand decided to investigate this hidden connection on a national scale. They turned their attention to the Provincial Waterworks Authority, the organization responsible for supplying water to most of the country's provinces. Instead of just counting how much water was lost, they asked a different question: how much energy and carbon emissions are wasted every year because that water never reaches a customer? By analyzing operational data from 2020 to 2024, the researchers built a picture of the entire system, tracking how much water was produced, how much was billed to customers, and how much disappeared as non-revenue water. They then calculated the electricity required to produce that lost water and converted that energy use into carbon emissions, using the specific mix of power sources that Thailand relies on.
The results revealed a massive, ongoing waste of resources. Over the five-year period, the system lost an average of about 27 to 29 percent of all the water it produced. While this percentage is high compared to well-managed systems in developed nations, the true cost was found in the energy behind the water. The researchers estimated that the electricity wasted on this lost water amounted to more than 200 million kilowatt-hours every year. To put this in perspective, that is enough electricity to power hundreds of thousands of homes for a year. Because Thailand's electricity grid still relies heavily on fossil fuels, this energy waste translates directly into a significant carbon footprint. The study calculated that these water losses generate between 122.7 and 132.2 million kilograms of carbon dioxide equivalent annually. This means that a substantial portion of the country's water sector emissions comes not from the water that is used, but from the water that is lost.
The study also looked at what would happen if the utility could fix these leaks and improve its management. The researchers ran scenarios to see how much energy and carbon could be saved if the loss rate was reduced from the current level of roughly 27 percent down to 15 percent, a target seen in many efficient systems. The findings were clear: cutting the loss rate to 15 percent would slash the wasted energy and associated carbon emissions by more than half. Even a modest reduction in water loss would yield a dramatic drop in the carbon footprint, proving that fixing leaks is not just about saving water, but also about saving energy and protecting the climate. The researchers found that for every single percentage point the loss rate drops, the system saves millions of kilowatt-hours of electricity and prevents millions of kilograms of carbon emissions.
This work challenges the way water utilities and policymakers usually think about their systems. Traditionally, reducing water loss is seen as an operational goal to save money or conserve a resource. This study suggests that it should also be viewed as a critical climate strategy. In countries where the electricity supply is still carbon-intensive, every drop of water lost is a double failure: it wastes a precious resource and it burns unnecessary fuel. The researchers noted that while the exact amount of energy wasted might vary slightly depending on local conditions like terrain or pipe length, the overall trend is undeniable. The connection between water loss and carbon emissions is strong and consistent. By treating non-revenue water as a source of energy inefficiency, Thailand and other nations with similar challenges can find a powerful, low-cost way to meet their climate goals. The path to a carbon-neutral water supply does not just require cleaner power plants; it requires stopping the leaks that make the current power usage unnecessary.
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