Solar Electricity

Solar electricity generating (Photovoltaic or "PV") systems have a number of advantages; however they can be expensive to install.

Advantages

The advantages of PV systems include:

Roof-top installation.
Minimal maintenance is required, other than periodic cleaning of the panels.
Silent operation.
Fuel-less operation.
Produce no CO2 emissions.
Unused electricity can be sold back to your electricity retailer.

Costs

PV systems can be expensive to install and, as a consequence, the electricity produced can be more costly than the electricity delivered to your home or business through Aurora’s distribution network. The cost of PV systems, however, is declining. In 2008, The Energy Efficiency and Conservation Authority (EECA) reported that the installation of a 2kW PV system had dropped to around $18,000 to $26,000; down from $40,000 in 2004 - a decline of 35%.

Stand Alone or Connected to Aurora's Network?

If you are installing a PV system, you have two choices for connection. You can install the system so that it is isolated from Aurora’s network, or you can configure the system so that unused electricity is exported.

If you choose to export surplus electricity into Aurora’s network, there are specific technical requirements that must be met. To learn more about these requirements, click here (PDF).

Installation Tips

If you considering installing a PV system, whether stand-alone or connected to Aurora’s network, here are a few tips:

Purchase the equipment from a reputable supplier.
Unless you are a competent do-it-yourselfer, get the supplier to include installation - they will ensure all building and electrical regulations are complied with and will give a guarantee on the final installation. Note that connection of PV system is prescribed electrical work, and you must engage a registered electrician to do this.
We recommend that you obtain quotes from several suppliers, for full installation, with a guaranteed electrical output in Watts. If the inverter offered does not have an output meter that you can check, we recommend that you insist on a certificate from an independent testing authority of the 230V AC output of the installation - otherwise it is possible that a faulty cell or incorrect installation will go undetected.
A permit may be required from the local building control authority if the array is to be mounted on a building. An electrical permit will always be required for 230V applications. For safety reasons in cases of on-grid generation, the inverter must be approved by the local electricity distributor - your supplier or electrician will check this.
If the inverter does not have an output meter that you can check, we recommend a 5-yearly test of electrical output - to discover any failed cell or other problem.

Frequently Asked Questions

Isn't Otago too far south for solar energy?
No. While the average yearly insolation (light energy) is 11% lower in Invercargill than in Auckland, photovoltaic cells operate more efficiently at lower temperatures. As a result, the electricity generated in Invercargill is only 9% less than in Auckland.

My roof doesn't face north (or "We get a lot of cloud on the coast"). Will that affect solar power?
Yes, but not much. The difference between expected generation from our two coastal and inland Solar Homes is only 25 kWh per annum. Up to 40% output is achieved on a fully overcast day! Your supplier will need to know where your house is, which way the roof faces and its slope - they will then be able to give you a good estimate of the generation you can expect per square meter of array. Obviously any shading of the array by trees, other buildings or hills will dramatically reduce output.

To learn more about Aurora’s Solar Home project, click here (PDF).

Other Resources

To access more information on solar and renewable energy, click here.