In addition to water supply, wastewater treatment and waste disposal, basic services also include the reliable provision of clean, easily usable energy and mobility as well as information and communication networks. In the Austrian state of Salzburg, Salzburg AG was formed in 2000 from the merger of the Salzburg municipal utilities and the state energy supplier SAFE. The company offers digitalized solutions - from public transport, telecommunications, internet and cable TV to district heating, water, gas and electricity supply. Salzburg AG generates around 30% of its electrical energy in its 30 hydropower plants, which have been built over a period of more than 100 years. Their control and instrumentation equipment is correspondingly different. Previously, two completely different central control systems were in use. With the aim of standardizing this heterogeneous system landscape, the company developed a general control technology strategy. The strategy process resulted in the creation of a specification sheet for the control systems of the company's own hydropower plants. The choice fell on the zenon software platform from Copa-Data.

Resilience provides security

The zenon-based control system for all Salzburg AG hydropower plants with customer-specific templates was implemented by Rittmeyer Austria with support from Copa-Data.

© Salzburg AG

One of the decisive factors in this decision was zenon's compatibility properties. The software platform can connect all components and subsystems commonly used in energy systems via more than 300 drivers, regardless of their make. To do this, it uses the standardized transmission protocols commonly used in the energy industry. In addition to the clean implementation of IEC 60870-1-104, the accelerated engineering through energy-specific application sets was also convincing.

The high level of resilience provided by geo-redundant servers also spoke in favor of zenon. In addition to protection against cybersecurity risks, the possibility of autonomous operation of the normally unmanned power plants in the event of a server failure was particularly important. These are always equipped with the option of local operation and monitoring. While other software products are based on a client-server architecture, zenon is a distributed system and masters bumpless ring redundancy, which makes it easier to set up fail-safe systems with geographically distributed and redundant servers.

First implementation in the hydropower plant

Salzburg AG was the first power plant to equip the Rotgülden hydropower plant in the south of Salzburg with a control system based on zenon Energy Edition.

© ZeK Hydro/Roland Gruber

Salzburg AG's first power plant with a control system based on zenon Energy Edition is the Rotgülden hydropower plant on the upper reaches of the River Mur. The power plant in the high alpine Lungau district of Tamsweg was rebuilt around two kilometers downstream from its original location. The additional head resulted in a 66% increase in output. Equipped with a six-nozzle Pelton turbine and a generator with a nominal output of 6.3 MW, the power plant supplies 10 GWh of electrical energy in a standard year. The increase compared to the replaced power plant alone corresponds to the average consumption of 1,300 households. The plant planned by the experts at Salzburg AG is suitable for island operation and can be black-started. This means that in the event of a grid failure, for example after storm damage to the 30 kV spur line, it can independently maintain the power supply to the nearby village of Muhr.