The environmental engineering client was tasked with preventing the migration of juvenile fish through the water intake for a power plant. This is to be done by an electrical barrier consisting of several electrodes with different voltages. It is designed to produce an approximately linear increase in the electric field in the direction of flow in the water intake. Fish are thus deterred from swimming into the water intake. Since the fish are to escape against the flow, they must not fall into galvanic anaesthesia, as is common with electrical barriers.

It had to be clarified whether the electrical barrier at the water intake could be realized and safely operated. In the first step, I created a realistic model of the water intake. In the process, I first had to digitize old plans.

An approximately equal electric field strength in the water over the entire cross-sectional area of the water intake was required. I then optimized the electrode configuration as well as the voltages at the individual electrodes in several iteration steps. Thus, the desired fields could be achieved. Measures in the design have succeeded in preventing the fish from swimming to the superelevated fields directly at the electrodes.

By using the AC solver, I calculated the electrical resistances and capacitances at each electrode. These values were the basis for a network model that combined electrodes and generator. This allowed me to calculate the required generator power for various operating parameters.

All the requirements for the electrical barrier at the water intake I have met by the elaborated concept.

This study should also examine whether there are any aspects regarding safety that make it impossible to install the electric fish barrier. I found nothing in the investigation that could not be solved by appropriate measures.

I estimated the investment costs for the proposed concept through quotations and price lists. I also analyzed the possible maintenance of the electrical barrier and the amount of running costs. The results of this study are the basis for the decision to implement the electric fish barrier at the water intake.

Targets and key figures

Water intake digitized from old plans

Configuration and geometry of the electrodes optimized

Voltages at the electrodes calculated and generator designed accordingly

Safety aspects analyzed and possible measures to reduce risks developed

Investment and operating costs estimated

Maintenance effort analyzed

July – December 2022

Budget 30’000 CHF

Independent project work

Environmental Technology

Testimonial