Fig 2. PLC and control panel kiosk.
With energy costs continuing to remain high and an ongoing desire for renewable energy solutions,
Total Automated Solutions developed an innovative control system to help support electricity generation taking place courtesy of an unusual renewable source â€ the power of running river water. TAS was approached by Spaans Babcock, a leading screw generator manufacturer to help design a control system that could incorporate one of their generators to produce electricity at a river location near Glastonbury. The innovative solution was the installation of a Siemens MP277 HMI running with the WinAC MP soft PLC system which helps manage the dayâ€toâ€day operation of a 11Kw Screw Generator and the solution is believed to be the first fully commissioned unit of its type in the UK. The generator uses the hydraulic power created by a head drop in the river at a weir point to operate an Archimedean screw attached to a motor which when rotated generates electricity.
With total cost a real consideration in the overall design of the control system, a number of alternative systems were examined, but in the end the flexibility and benefits offered by the WinAC MP277 proved to be the best overall combination of cost efficiency and solution benefits. It has delivered an estimated 25â€30% cost saving when compared to other such control systems. The WinAC MP277 provides a number of design benefits that include simple implementation with no added requirement for multiple systems such as data loggers or complicated communications protocol converters. The benefits also include power monitoring without the added expense of large I/O modules, downloadable historic trending easily accessed via webâ€based functionality, and remote connectivity which is extremely helpful given the river location of the generator.
The resultant generated electricity is used primarily as an energy source to power the home of the client. However, under heavy rain fall and the subsequent greater river flow, any power not consumed by the client’s home is exported onto the National Grid. All power generated by this application is monitored by the regional electricity supplier and is bought from the client per KW at a rate dependent upon the applicable tariff. With the screw generator now fully operational on site it is currently helping Total Automated Solutions are still working closely with the client refining the system to ensure maximum energy production is to produce between 1.5kw under low flow conditions, and 13kw under high flow maintained 24 /7, 365 days of the year.