The array

The thin film solar photovoltaic (PV) panels on the Hubbards dry foods warehouse are capable of generating 20 kilowatts (kW) during peak sunlight hours. They will produce approximately 29,000 kW hours of electricity per year.

The energy generated from this solar system will be used immediately rather than stored, and will be used for lighting the finished goods warehouse at Hubbards Foods, which has an annual average power usage of 14,300 kW hours. The amount of energy generated is the equivalent of that used to produce 169,000 packets of cereal.

Environmental impact

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The system will produce enough electricity to displace 6.5 tonnes of CO2 that would have been otherwise produced from grid-generated electricity. This is equivalent to the amount of greenhouse gas an average vehicle produces in travelling 60,000 kilometres.

The technology – thin film solar PV

Thin film solar PV is lower cost per watt than crystalline solar cells. It has also been shown to perform better in both shade and very hot temperatures.

If part of a crystalline cell is shaded, the whole cell won’t produce energy, but with thin film the output will only be reduced by the amount shaded. Certainly if there is damage to either technology they may not work, however thin film solar panels will continue to operate at a lower output if only a part of the solar panel is damaged.

Another advantage is that it takes less energy to manufacture a kilowatt of thin film solar, and thin film panel production requires less use of raw material (eg. glass and aluminium) than crystalline panels.

For thin film solar PV it takes approximately two years for the energy produced by the panels to exceed the amount of energy it took to manufacture them. The expected life of the panels is greater than 25 years, so they will contribute to reduction in greenhouse gas emissions for a significant time.

Hubbards Foods Solar Array is the largest thin film solar PV installation in New Zealand.