The 25-year-old wind turbine faithfully calls “home” with its antiquated modem five times a day to assure the Wind Surveillance Centre in Esbjerg that it is still alive, has not suffered any hot flushes and is supplying so and so much electricity. At the same time, the top modern offshore wind turbine Vattenfall has just set up in the DanTysk wind farm sends a veritable flood of data to Esbjerg that would make the old turbine breathless if it tried to keep up.
Vattenfall has a total of 48 different types of wind turbines that speak a diverse set of “languages”. Lars Højholt and his SCADA team have developed unique data systems that can read the different languages and translate them into a common language which they can present in standard reports to their colleagues in the surveillance centre as well as to service technicians, traders and management.
KEEPING TABS ON TURBINES
When Højholt completed his training as an industrial engineer specialising in high-current installations, little did he know that he would go on to create software that would bring Vattenfall to the forefront of the collection and commercial use of data from some 1,000 wind turbines.
“When I joined western Denmark’s energy company Elsam in 1999, each of its seven power plants ran several wind turbines as part of their daily operations. In 2000, it became my task to bring all these turbines under central control to provide an overview,” says Højholt. At first it took one man and 25 computers a whole day just to see whether the nearly 400 wind turbines were running at all. Together with a software developer, Højholt began to develop a system that could be superimposed onto the software from diverse turbine manufacturers – completely from scratch. Vattenfall acquired part of Elsam in 2006, and the software has played a crucial role in the company’s expansion of the wind sector in Sweden, England, the Netherlands and Germany. Højholt now leads a thirteen-man team in Denmark, England and the Netherlands that supplies millions of data to the organisation in an easy-to-read format.
The digital veneer Højholt and his team placed on the highly diverse systems allows the surveillance centre in Esbjerg to keep tabs on all of Vattenfall’s nearly 1,000 wind turbines and to receive alarm reports from five countries around the clock. In 2014, the centre restarted Vattenfall turbines 2,139 times when they had stopped outside normal working hours due to faults. Jan Jørgensen, who heads the surveillance centre, points out that restarting them “saved” the production of 15 million kWh that would otherwise have been lost while waiting for local technicians to arrive at work in the morning and take action.
Valuable input to Vattenfall’s traders
“The current discussion on the use of wind turbines to stabilise the electricity network and provide system services is a bit surprising for me. After all, way back in 2006, Horns Rev 1 was the first wind farm to be ready to provide system services to the power network under the direct control of the trading department in Stockholm,” explains Højholt.
The team’s systems now supply data from all of Vattenfall’s wind turbines to the company’s traders in Stockholm, Hamburg and Amsterdam, so that they can see live details on turbine availability, output and fault statistics. This allows them to adapt their trading activities precisely to the current situation. For example: the Thanet wind farm in England is fully integrated with the trading office in Amsterdam, which can control its output on the basis of a series of criteria including prices, demand and weather data.
To help the traders maintain an overview of this flood of information, Højholt and his team are currently developing a “traffic-light” system based on a long series of criteria to show the best times to generate power (green), carefully consider whether to produce (yellow) or shut the turbines down (red).
MAINTENANCE BECOMES AN ART
The huge quantities of data collected by the team’s systems every hour are also a goldmine for the maintenance people. This information allows them to see how the turbines are doing, and not least to notice any signs that may give prior warning of a fault.
“This extensive data gives us experience in the operation of wind turbines that is quite unique and lends us a competitive edge over many other operators. We can simply control the maintenance work much more precisely and thus save money,” says Bent Johansen, Head of O&M for wind in Denmark and Sweden.
The team is currently working together with other data statisticians to develop a self-learning system for preventive maintenance that can recognise data patterns from wind turbines and tell when it is time for an inspection or perhaps even alert the operators that the turbine is close to breaking down and should be shut down.
Højholt points out that besides all the technical aspects, the economic reporting from the system is vital to the company. “We provide both standard reports and figures in response to the specific wishes of managers and controllers, so they can monitor the economic side of the production from Vattenfall’s vast number of wind turbines,” he says.