Since 2015, Tilia has been supporting Vietnamese municipal wastewater companies when it comes to optimising their operations, particularly with regard to improving performance and energy efficiency. In Sóc Trăng, a southern provincial city in Vietnam, Tilia and the local wastewater treatment operator have collaborated on a joint project aiming at optimising the way in which the wastewater infrastructure is managed. One of the ideas developed together with the Vietnamese partner was the concept of covering the energy needs of Sóc Trăng’s sewage treatment plant through renewable sources. After considering various approaches, the use of PV electricity appeared as the optimal solution taking into account both economic and ecological criteria. Together with the German Energy Agency (dena), Tilia planned and constructed a turnkey photovoltaic system with an output of 30 kWp. A special feature of the solution is that it integrates an electricity storage system which can be charged either via the power output of the PV system or directly from the electricity grid. The high level of flexibility of such a system enables the plant to be operated with the maximum amount of stored electricity during the times with the highest electricity purchase costs – the daily peak periods in the morning and in the evening – which has a positive effect when it comes to cost savings and efficiency. In total, a storage capacity of 20 kWh is available.

The success of this project was due to several factors: Firstly, Tilia’s comprehensive variant analysis ensured finding the best-fitting solution for Sóc Trăng’s sewage treatment plant. It was followed by the preliminary planning of the project, the energy yield estimation and the economic calculations, which answered the main feasibility questions and facilitated a successful implementation. The latter was also thoroughly organised and managed by Tilia’s team.

More information is available online on the project’s website.