Muntanui goes solar

On 2 April 2013, the Muntanui 5kW Solar Power Station was officially commissioned and came on line. It is now supplying power, not only to Muntanui, but also the surrounding properties and anyone else connected to the New Zealand power grid.

It was a long time in the planning and execution. We placed orders for equipment back in October 2012. The solar panels arrived in late November and the inverter and cabling in January. Installation of the panels and inverter took a couple of days in late January and then there was a wait for the power company to supply the new import/export meter. In the meantime, we arranged for power cables to be run through a trench from the shed to the house.

Here are a few technical details:

22 x 230W PV-TJ230GA6 Mitsubishi Solar Panels
1 x SMA SB5000TL Solarworld 5kW Inverter

Our average power consumption at this time of year is around 13kWh per day. Working on the basis of approximately six hours of useful daylight, this gives a required system size of 2.2kW. We decided to go for the most we could afford now and sell excess power to the grid, hence the 5.0kW installed. It was not cheap and certainly nowhere near as cheap as systems being offered for sale in Australia these days. But, as with most things, you get what you pay for. We have Japanese manufactured panels and the inverter is from Solarworld in Germany, both good quality and reliable suppliers.

We missed out on all of the great weather in Feb/Mar and, as you can see from the graph below, production is already slowing down as we get into winter. Our second day of production was a satisfying 27.55kWh.  We have already produced a total of 400kWh and look forward to celebrating our first 1MWh in about seven weeks time -- depending upon the weather, of course.

We haven't yet received our first power bill to confirm import/export prices. It will be interesting to see how that works out.

Now we shall be looking at ways of reducing our existing usage to enable us to export as much as possible back to the grid.

Muntanui power production from 02/04/13 to 04/05/13 (the red dashed line is calculated average usage)

Posted by Farmer Wan