Solar Array Installed at Wellington Head Office

Black Diamond Technologies Limited were looking for an efficient and affordable energy solution for their head office in Wellington. The install of a solar array was identified as the most effective opportunity to reduce overall energy consumption, while also being cost effective.

The Challenge

For many commercial businesses in New Zealand the real cost of electricity can be tens of thousands of dollars every year. With an annual energy usage of over 392MW (392,000kWh) Black Diamond Technologies Limited (BDT) was no different.

Electricity is, of course, vital to any business however BDT noticed that the price of electricity was fluctuating and there was a need to explore other electricity options. The ability to operate with lower ongoing energy costs would ensure the business as a whole runs more efficiently.

BDT’s annual energy consumption is spread across four facilities nationwide, and BDT’s Head Office based in Lower Hutt, Wellington, was identified as the most effective opportunity to reduce overall energy consumption. With over 50 staff, the BDT Head Office contributes to 64% of the company’s annual energy consumption.

The Solution

As exclusive distributors of Mitsubishi Electric product, BDT was already distributing premium quality Mitsubishi Electric Solar Panels to the New Zealand Solar Photovoltaic (PV) market, so did not need to look far to find a solution. As solar PV is now more affordable than ever it was concluded that BDT’s return on investment (ROI), and overall reduction in ongoing electricity costs would benefit from installing this new technology.

BDT understood that the principles applicable to residential solar PV remain fundamental to commercial installations. Any energy generated by solar panels installed on the BDT Head Office would automatically be directed for use within the company first before surplus power is exported to the grid and credited against BDT’s electricity bill.

The advantage of installing PV was due to the amount of energy BDT consumes across the day (load profile). As is the case with many commercial businesses, BDT consumes a majority of their power during the day, which is well suited to PV. With energy consumption occurring at the same time that energy is generated BDT is able to get the maximum return per kWh. When more energy is generated than used, e.g. on the weekend, the excess units are credited against their electricity bill.

It was vital any solar array installed would see a significant reduction in BDT’s overall energy usage but also ensure maximum ROI was achieved. With this in mind the decision on size was one based not solely on roof space available, but also took into consideration the way BDT uses electricity. A system was designed which ensures any energy generated during office hours is self-consumed, ensuring maximum ROI.

After BDT’s requirements were fully assessed, the decision was made to choose a 30.68kWp array. In total 118 x Mitsubishi Electric Premium PV-MLE260HD Solar Panels were installed.

The final layout and installation at BDT’s head office was unique. BDT places high importance on industry leading technical training and support for their nationwide specialists and consumers. With this in mind BDT placed great emphasis on incorporating this 30.68kWp array into their National Technical Training Facility based at head office.

It was decided to install the PV inverters (which convert the energy generated from the array into energy suitable for consumption) as a display which can be used to explain PV. It was decided that inverter technology common in both commercial and residential scale projects would be used in order to add value to those attending training courses.

In total BDT’s Head Office solar array is estimated to generate 34,270kWh per year. The system is designed for maximum self-consumption and has the potential to provide 25.12% estimated savings on the daily operational energy requirements. As is the case with any commercial solar PV array, BDT’s Head Office array can also be depreciated across its life cycle creating a tax benefit, and increasing the return on investment. BDT is also proud to report an estimated annual CO² reduction of 16.4 tonne.

Solar PV panels

118 x PV-MLE260HD Premium Monocrystalline 260W Solar PV Panels

Solar Inverters

2 x SMASTP10000TL – SMA Sunny Tripower 10000TL Inverters
2 x ES-5.0kWGT - Enasolar 5kW Grid-tied Inverters

Energy Generation

30.68kWh peak output


Hoskins Energy Systems Ltd, assisted by BDT Technical Support Engineers.

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Watch as Solar PV panels are installed.

Published: Monday, 23 June 2014

Solar Array Installed at Wellington Head Office