AD Operators and water companies can reduce the energy usage of their digester pumps and mixers by up to 50%, according to leading manufacturer, Landia. “It is somewhat ironic that in an industry trying to create and save energy there is so much energy being wasted”, said Landia’s Paul Davies. “Poorly designed mixing systems located inside a digester, which are difficult to service, are typically using 7.5kW motors running flat out 24/7, using up 180 kW hours per day. “Motors on externally-mounted systems that are also far easier to maintain, may be bigger at 18.5 kW, but only have to run for 10-15 minutes per hour to achieve the same or often better results. Even at 15 minutes per hour, the energy usage is just 110 kW hours per day, compared to 180 kW. This is on just one mixer/pump, so the energy savings are substantial”.