Product Breakdown for Adelaide Airport 1.17MW Solar Project

Publish on August 31, 2016

The recently completed Adelaide Airport solar power system is one of the first few Australian rooftop installations to exceed a megawatt in size. Large projects like this demand even more attention to the ongoing operation and maintenance of the project. Panel level control, power production optimisation, system monitoring and overall system durability are the main reasons TrinaSmart panels and SMA Tripower 60 inverters were selected. They provide the safest and most efficient solution for the project.

TrinaSmart panels come with a Tigo optimiser that allows the panel to operate at its own maximum power point but alters the current and voltage output of the panel through impedance matching. This function would remove mismatching losses and prevent shaded panels from affecting the entire string, which would improve the energy yield of the PV system.

The optimisers enable panel-level monitoring, panel shutdown and open-circuit voltage clipping that would greatly reduce the maintenance and balance of systems (BOS) costs of the entire PV system. For example, if a material defect has reduced the performance of a panel out of a system composed of 4496 panels, it would be near impossible for a normal string monitoring system to identify the issue and help the installer locate the defected panel. This issue would be easily spotted using the panel level monitoring capability of the Trina Smart panels.

The Tigo optimisiers embedded in the Trinasmart panels can reduce the open circuit voltage of the panel by 30 per cent through impedance matching. A reduced open circuit voltage would allow longer strings for the installation. As a result, less strings are needed and significant savings on the BOS component of the system was accomplished.

To further improve the cost-effectiveness and installation safety of the project, the larger SMA Tripower 60 inverters were used to reduce the amount of space needed for the inverter room and total weight of the products that needed to be handled.

This was possible because the SMA Tripower 60 inverter has a much higher power density compared to most sub 30kW inverters that are usually used for commercial-scale PV systems. For example, the inverter has 60kW of power output with a weight of only 75kg and dimensions of 540mm×740mm×300mm. Comparing these figures to the Tripower 25000, the Tripower 60 doubled the power density using either weight or volume as the denominator. In terms of accessories, the Tripower 60 uses a unique monitoring unit called the SMA Inverter Manager that can connect up to 42 inverters. This makes the entire solution much more cost-effective for larger projects. As a result, the scalability of the Tripower 60 inverters greatly reduced the BOS costs of the entire project.

Overall, the combination of Trina Smart panels and SMA Tripower 60 inverters allowed significant savings in the installation and BOS component of the project’s capital expenditure. As a result, the levelised cost of electricity for the PV system was far more competitive than the airport’s current electricity tariff. Making solar an attractive long term investment to manage the Airport’s energy costs.