PCE was asked to evaluate the case for an Australian Irrigator to leave grid power and convert to Solar PV array & Diesel generation. The irrigator ran a small borehole pump continuously during the growing season to keep a holding dam full and ran a much large irrigation pump between 8 – 16 hours a day in this season.

A set of base costs such as grid electricity, PV installed costs and diesel generator installed operating costs were established based on published figures and cash discount rates. Using “Homer” software the Net Present Cost (NPC) of the grid connected base case was established as being $478,000 over 10 years.

This could be reduced to $266k by adding 93kW of Solar PV. A 300% increase in grid power costs could be offset by additional PV to arrive at an NPC of $420,000 over 10 years.

Then, a standalone PV/Diesel scheme was optimised using Homer software, to arrive at a solution of 1 x 45kW diesel generator and 120kWp of PV; at an NPC of $566k.

PCE identified the most cost-effective solution was to maintain grid connection and supplement with 93kW of Solar PV; identifying that it was not yet commercially attractive to entirely separate from the grid.