Energy from waves: Data analysis withSQL4automation on the sea
CorPower has introduced a totally new type of wave energy converters, located off-shore.
TwinCAT-control systems by Beckhoff are used for controlling and permanent optimization of
the systems. Data are sampled and analysed in SQL-databases. The SQL4automation
connector transfers data from the control unit to the database in a simple way. Jakob
Sagatowski from CorPower explains the solution.
Inspired by the pump-principle of the human heart, the wave power plants or wave energy converters
engineered by CorPower AB make use of undulations of the sea and transform them into electrical
energy using phase-controlled oscillation. Thus, an energy density is achieved which is up to five times
higher than generated by conventional wave-energy-converters working without phase control. Using the
new technology, a remarkable amount of energy is generated. "Actually we work on a plant, achieving
the same effect of power generation by using a tenth of the volume, compared to conventional buoys,"
Jakob Sagatowski, Senior Software Engineer Control & Communications at CorPower Ocean AB in
Stockholm/Sweden, explains.
Clean energy from waves
The converters, integrated in buoys, could generate 2.000 TWh up to 4.000 TWh energy per year. At
least 10 % up to 20 % of the energy consumption worldwide could be produced more cleanly, more
efficiently, and more economically, thus conserving our resources. J. Sagatowski underlines that it is the
major challenge to develop a device, which is resilient to extreme weather conditions whereas it has to
be overly efficient at the same time. "Our new converters combine both", J. Sagatowski proudly reports.
"We aim at creating a new generation of devices to efficiently use wave energy for energy generation,
which can compete with conventional sources of energy."
PC Control based on TwinCAT 3 by Beckhoff Automation is used for control technology. Two of those
control units are integrated within the Wave Energy Converter"One TwinCAT PLC collects all sensor
data, the other one is used for computing", explains J. Sagatowski. The sampled information is delivered
to a SQL-database via the SQL4automation Connector, which is also integrated, so the data can be
used for system optimization. "A lot of measured data must be observed and gathered in order to
analyze and optimize the system", the automation specialist continues. "Values measured by pressure
and humidity sensors, values of temperature and flow velocity are correlated, for example. Last but not
least the amount of electricity generated is gathered in order to make detailed predictions with regard to
efficiency." The motion of the buoy is also recorded by motion- and vibration sensors.
Up to three times more efficient by analyzing data
The SQL4automation Connector is used "for several reasons", J. Sagatowski explains. "On the one
hand a huge amount of sensor data must be sampled to ensure perfect functioning." For efficient
application a lot of tests are required. This also includes tests on the mechanical components: For
example, the temperature in the cylinders is controlled. On the other hand the technology itself has to be
optimized continuously. We work on a permanent-self-optimizing model, to maximize the energy
efficiency."
According to the specialist, using data analysis, the efficiency of the system is increased threefold.
"Permanent monitoring of system parameters is inevitable for carrying out the continuous Build-in tests.
Thus the system is not only optimized but it is also less failure prone," the automation specialist
concludes. Hence, the customer can rely on a system operating smoothly.
"Needless to say, the buoys are also controlled and observed visually but to optimize the whole system
with all its functionalities and various influences it is exposed to, the permanent processing and
acquisition of all data is essential. SQL4automation allows the most practicable way for this. We acquire
nearly 3 GByte to 4 GByte of data per day," Sagatowski further explains. Accordingly, we deploy the
standard version with up to ten connections.
The data ensure the permanent continuous optimization of the system and maximize its performance.
In addition, the plant itself is controlled, because it is exposed to significant influences of temperature
and environment. "The combination of control technology by Beckhoffand Inasoft-data-technologies fits
our needs perfectly," J. Sagatowski continues. "The SQL-accessibility by Inasoft is both: simple as well
as comfortable. So far, it has operated brilliantly for the last two years."