North Ridge Pump as Turbine

The North Ridge Pump as Turbine (XAT) system is an innovation in pump technology. It allows the pump to run in reverse as a turbine to harness any wasted energy in the system to generate electricity. When not operating normally as a pump, the new design allows for any excess flow and pressure to pass through the pump in reverse. The reverse flow spins the impeller and therefore transfers power through the pump shaft to a turbine, generating electricity.

Efficiency

Even though the pump has undergone design changes to accommodate reverse operation, it is only 2-3% less efficient than running a standard type of pump. Our PAT systems are designed on a case by case basis depending on the system requirements. They are flexible as we can install them with either multistage pumps, centrifugal pumps or split casing pumps depending on the flow rate and pressure requirements. We can accommodate flow rates up to 4000m³/hr and pressures up to 20 bar.

Pump vs Turbine

Typical power harnessing systems involve large turbines up to 10,000 megawatts in size. They can be up to 95% efficient, however the investments costs are high, and it takes around 4-5 years to recover those costs. In addition to the large investment costs, the designs are extremely complex and expensive to install. Highly skilled labour is required to install and maintain the equipment. However, our pump as turbine system does not involve powers higher than 1000 megawatts. The investments costs are low, and these can be recovered in around 6-12 months. They are 85% efficient and the simple design means they can be installed and maintained by relatively low skilled labour at far lower costs.

Applications

Typical PAT applications are; water supply systems, water distribution systems, wastewater systems, reverse osmosis, geothermal power plants, irrigation systems, clean water treatment systems and industrial facilities where pressure regulation is required. Also, any installations currently using pressure reducing valves are wasting excess pressure that could otherwise be harnessed for energy recovery. PAT is the ideal solution for developing countries and remote installations where it is difficult to obtain skilled labour and difficult to source the necessary machinery for traditional complex turbine systems.

PAT can be installed in two modes, either; off-grid or on-grid.

Off Grid

For Off-Grid installations, any generated electricity must be used immediately and locally for powering other systems. The power cannot be stored and therefore any electricity not used is lost, this system is not as efficient as on-grid installations. Off-grid systems are viable for smaller motor powers, typically between 0.1 and 15Kw. An alternator is installed that generates the electricity, the frequency of the generated electricity is either 50 or 60Hz.

ELECTRICITY GENERATION FOR AN OFF-GRID SYSTEM

EXAMPLE OFF-GRID APPLICATION

On Grid

On-Grid installations are the most efficient as the generated power is transferred into an interconnected system. The generated electricity can then either be sold to the power generation company or stored for later use. An on-grid system is recommended for larger motor powers, typically larger than 15Kw. Instead of an alternator, an asynchronous electric motor is installed for generating the electricity. The frequency of the generated electricity is not required to be regulated as it is sent directly to the grid.

EXAMPLE ON-GRID APPLICATION

Read more about Pump as Turbine in our guide