Investment analysis of solar energy in a hybrid diesel irrigation pumping system in New South Wales, Australia

Off-grid groundwater cotton irrigators using traditional technologies have had few options to reduce water extraction costs. New options of blending of Alternating Current and Direct Current through an all-in-one soft start converter/controller offer opportunities to lower costs, diversify fuel sources and continuous off-grid power in remote locations. Diesel energy can be replaced by renewable fuel sources through installing an electric submersible pump powered by solar photovoltaic in combination with a diesel generator. An investment analysis using a discounted cashflow over 25 years showed a 23% internal rate of return and payback over 5 years. Benefits of installing a renewable fuel source included lower greenhouse gas emissions per bale of cotton produced and less labour to monitor and service traditional diesel irrigation plant. Emissions calculations reveal a reduction of 26%, or 35 kg CO2e per cotton lint bale, and an abatement of 2665 t/CO2e for the life of the project. The cost of emissions abatement under the Renewable Energy Target to displace almost one million litres of diesel was found to be $31 t CO2e.