Saving Diesel at Llanwern – Timed Running & Solar Charging

To reduce both our running costs and environmental impact of the water treatment system at Llanwern, Engineering have completed upgrades to the system to enable timed operation of the generators whilst maintaining full system control.

The principal objective was to reduce diesel usage by automatically turning off the generator at times of low flow of water into the pre-treatment lagoon on site. To achieve this, several changes were needed, namely:

  • Installation of a ‘generator off’ output from our control panel PLC.
  • Upgrade control panel UPS batteries to 120Ah, to maintain control panel power for long periods.
  • Installation of solar panels to provide additional charging of system batteries whilst the generator is off.
  • Programming of the PLC to allow timed or situation-based switching of the generator.


These upgrades were completed in April, in time for the uplift in diesel costs but also coinciding with a period of low influent flow to the system, allowing for trial of timed running. As such, the system has been automatically switching off for 3 no. three hour periods per day, thereby reducing diesel consumption by 38%. The upgrades were all carried out using in-house resources, keeping the cost to a minimum.

10,000 to 15,000
litres of diesel per year will be saved.

This will help reducing not only operational cost, but the site’s carbon footprint by up to 40 tonnes of CO2 per annum.

In-house CCTV Installation

Tony Webster’s experience as a CCTV installer has come in useful at the Llanwern site, having now installed a new CCTV tower and transmitter. Following the relocation of the main site security hut from the entrance adjacent to Englobe’s system to a location several hundred metres away, several break-ins occurred through the entrance near Englobe. Although no entry was gained to Englobe’s compound, it was clear that site security had to be stepped up. A tower with two remote swivel cameras and a third fixed unit were installed, along with transmitter, to transmit to the relocated site security hut, providing CCTV coverage of Englobe’s system and nearby site entrance. Each camera has night vision, motion detection and remote operability. This system is also being backed up with a UPS battery and inverter kit, to provide power during generator off periods. The total cost of the CCTV and transmitter installation was approximately one third of the price of a third-party installation.


Englobe is one of Canada’s premier firms specializing in professional engineering services, environmental sciences, and soil and biomass treatment.