Enlarge: Soc Trang - where Solar energy meets water treatment facilities

The wastewater treatment plant for a provincial capital in the Mekong delta has been given a surprising high-tech upgrade, thanks to the innovative management of the Soc Trang Public Works Company and Leipzig based company Tilia GmbH, which implemented this project within the framework of the Renewable Energy Solutions Programme of Deutsche Energie-Agentur (dena) – the German Energy Agency.
Water management consultancy is one of Tilia’s strengths – the German experts have been helping the Soc Trang Public Works Company, headed by Lam Huu Tung, to optimise of the various cleaning stages of the wastewater treatment plant since 2015. Their initial cooperation revealed an interesting challenge: how could the Vietnamese plant operate at lower costs while being more climate friendly? Photovoltaic energy seemed to be the obvious answer, but a little tinkering was required to arrive at the best possible solution.

Bespoke power supply concept

The goal was to meet around 50 percent of the wastewater treatment plant’s power requirements with solar energy from a rooftop installation, while reducing electricity costs by far more than half. This was to be achieved via a smart energy management system which not only reduced electricity consumption from the public grid but also the average costs per kilowatt-hour of that electricity. The Tilia experts eventually settled on battery storage that can be charged in two ways: when solar radiation is high and demand for electricity is low, the batteries are charged with solar power. Thus during the day when the wastewater treatment plant is in full swing, a large portion of the required electricity is drawn both from the photovoltaic system and from the battery, while at night when electricity prices are low electricity from the grid is stored for the next day's operations.

A first for Vietnam

Tilia hasn't just created a reference project for energy efficiency and smart partial self-sufficiency in an interesting market: they have also established the very first installation of its kind in a water management operation in Vietnam. Shortly after the opening ceremony on 6 November 2018, Tilia was able to present the project to potential interested parties at the Vietwater trade fair in Ho Chi Minh City.

Lam Huu Tung, Soc Trang Public Works Company: “Combining a wastewater treatment plant with solar electricity was totally new for me. We gained a lot of valuable experience from the project.”
Stefan Böttger, Tilia: “Our participation in the RES programme enabled us to implement this project. We would like to thank dena for the excellent cooperation, particularly for its support in marketing.”

Tilia GmbH is a European services company with over 50 employees. Tilia helps public companies, cities, utility and industrial companies and other institutions to develop and implement strategies in the fields of energy, water, environment and mobility. Tilia aims to promote innovation, secure change and improve long-term performance in a rapidly changing environment. This is partly achieved through a new form of equal partnership – the Impulspartnerschaft®. Tilia operates internationally and has its main offices in Leipzig, Berlin and Paris.