NIWA provides a great tool called NIWA Solar View. Unfortunately converting this data into what a typical year might look like using an Off Grid or Grid Tied Hybrid system is quite hard. This is where this Solar Calculator helps. Simply paste in the link to your NIWA data (see below on how to do this) and experiment with the number of panels and batteries based on your daily and monthly energy needs. This will give you an idea of what is possible.

Step 1.

Open a new window/tab and go to NIWA Solar View. Once there, select planned panel tilt, panel bearing and generate your SolarView. After you create the SolarView, right click on the 'Download the Typical Meteorological Year Table' button, copy the link and then paste it below.

Step 2.

Drag bars on the charts to represent your power usage during the year and day. Use the scroll wheel if you need to zoom out or in.

Step 3.


*Calculations are based on using up to 80% of the LFP battery. Round trip losses to the battery are calculated as 5% when charging the battery and then 5% again when taking from the battery. Night rate has been calculated as between 11pm and 7am. If selecting generator, it is assumed the generator will charge the battery at the same time as powering the home. Battery is checked every hour and if above 30% then generator is turned off and home is run from solar/battery again. The number of kwhs added to the battery during this time is allocated to the solar/battery result rather than the 'from generator' result. There has been no cap put on the number of kilowatts that can exported at any given time. But inverters can have limits as well as power companies on how much you can export. These numbers are only estimates and don't take into consideration a lot of variables such as shading, panel strings facing different directions, cable losses and inverter losses.