The latent power of rivers has been harnessed to generate electricity for over 150 years, with one of the technology’s pioneers being Gilbert Gilkes. The company he founded in Kendal UK, Gilkes & Gordon, is still a leader in the field and has installations all over the world.

Internationalisation and modernisation creates need for remote monitoring 

Lead Electrical Engineer, Joe Hacker, explains: “We concentrate on small and medium sized installations, in the range from 50kW to 30MW, leaving the mega projects to governments and international consortia. Our field is very active and there is worldwide interest in new projects for rural electrification, renewable green energy and powering remote facilities. There is also a steady requirement to modernise existing plants.”
 
One of the issues faced by operators of hydroelectric plants is that they are often sited in distant locations, making regular maintenance visits both difficult and expensive. Aware of this, Gilkes began to look for solutions, hoping to develop an idea that that would be scalable from one or two individual generators up to 50 or more, which would typically be providing a power grid for multiple communities. 

Netbiter - a powerful but cost-effective solution

Joe again: “We initially looked at SCADA (Supervisory Control And Data Acquisition) and while it was very attractive it was over-complicated and costly. So we drew up a list of our needs and soon identified Netbiter as a possible candidate.”

Netbiter is a remote communications gateway technology that can collect live data from plant or machinery and transmit it back to a central control station for automatic analysis. The result of the analysis can then be reviewed and used to assess the condition of the plant. If measured parameters appear to be trending out of tolerance 
pre-emptive actions can be initiated, either manually or automatically, to resolve the pending problem. 

This means unscheduled downtime, typically due to failure of a minor part, can be avoided allowing the plant or machinery to continue operating productively until the next scheduled maintenance shutdown.  

Long distance between sites

Joe explains some of the details of the Scottish job: “The total generating capacity of the 17 Highland sites is 23MW, the largest plant being 5MW. However, the sites are up to 150 miles (225km) apart and are not easily accessible.

In most cases a single Netbiter unit is mounted on the single PLC (Programmable Logic Controller) that is controlling the entire plant and taps into its data stream. The PLC is also connected to a number of different sensors monitoring various functions, conditions and parameters, such as temperature in key locations, speed of the turbine, water flowrate, power generated, vibration and the status of various valves. It may also be taking readings from rain gauges, wind speed anemometers and other environmental instruments.  

Connects to anything

“The plants use different types of PLC and in some the architecture of the control system is a bit more complicated,” says Joe. “One of the attractions of Netbiter is that it can work with control equipment from all the main manufacturers, so we have been able to standardise our kit.”

Overall, a lot of data is collected and sent using Ethernet to the control centre where it is automatically analysed to produce high-level. real-time information and trend reports. One of Gilkes’ design objectives was to present the information in a clear and easily understood manner. 

Access via computer or smartphone

It does this through a number of different screens. The top screen shows key parameters such as temperature and power output for each site in an ‘OK/not OK’ format. From here it is simple to drill down through other screens to see more live data and to access time-based logs and quick overview reports. The managers often access the Netbiter screens via their smartphones, so they are designed to be clear and easy to read even at small sizes. 

Alarms whenever certain thresholds are reached

Alarms are set to alert managers if parameters go out of tolerance or if readings start changing quickly. The Netbiter system can also be used to stop/start individual generators and to reset functions.

“The Highland job has been running for a few months now and we are already seeing a significant reduction in downtime and increase in output,” says Joe. Plus the managers have fewer call-outs so they are able to use their time more productively.”