Green energy

Answers to questions about renewable and non-renewable energy sources.

Are renewable sources used to generate electricity?

Electricity in New Zealand is generated from a variety of sources, both renewable and non-renewable.

Renewable or “green” sources are generally considered to be things that can be naturally replenished, while non-renewable sources tend to be fossil fuels such as gas or coal.

Around 73 percent of New Zealand’s electricity is generated from renewable sources. The remaining 27 percent is generated from non-renewable sources such as gas and coal. The government’s energy policy aims for 90 percent of electricity generation to come from renewable sources by 2025.

What renewable energy sources are available?

In New Zealand, current renewable energy sources include:

  • Hydro energy uses water passing through turbines at large hydro stations such as Manapouri and Clyde. Hydro power makes up around 60 percent of New Zealand’s electricity.
  • Geothermal energy uses the earth’s heat and steam such as at stations in the Taupo volcanic area. Geothermal power makes up around 10 percent of New Zealand’s electricity.
  • Wind energy converts wind into electricity through large wind turbines. Wind power makes up around 3 percent of New Zealand’s electricity.
  • Solar energy converts the sun’s radiation into power through photovoltaic (solar) panels. Solar power makes up only around 0.1 percent of New Zealand’s electricity.
  • Marine energy converts waves and tidal motion into electricity through turbines in the ocean. This is a new and developing technology that is still at a design and testing stage. However, the potential exists for significant electricity generation.

Can I guarantee the electricity to my house is from a renewable source?

If you get your power from an electricity retailer, the simple answer is no.

While most of New Zealand’s power is generated by hydro power stations, these can be affected by low levels of rainfall and melting snow. Less water means less power is produced, so the shortfall is often made up by using an alternative non-renewable source such as coal or gas.

Even if a generating company claims to produce 100 percent of its electricity from renewable sources, it does not mean that the retail electricity to your home came from 100 percent renewable sources. All of the generating companies feed the power they produce (from renewable and non-renewable sources) into the national grid. So the power in the national grid is a combination of both types – and it becomes impossible to say that your particular power is from either a renewable or non-renewable source alone.

That said, it’s possible for retailers to enter into contracts to buy power solely from companies that generate renewable energy, meaning your money is only passed on to companies generating electricity from wind, hydro or solar PV. The only retailer currently offering this kind of arrangement is Ecotricity, who also offset all their carbon emissions by purchasing carbon credits, and as a result are the only retailer of carboNZero certified electricity in the country. The catch is their rates are generally higher than average.

Another option for reducing the proportion of your power bill that goes towards non-renewable energy is switching to a retailer offering a peer-to-peer solar power platform. This allows you to purchase surplus energy from nearby homes with a grid-tied solar PV system when they’re generating surplus energy. “Peer-supplied” solar power is charged at a lower rate than for grid-power, but it’s only available during the day and depends on the number of solar installations on the network and their usage patterns. At present, only P2 Power offer a peer-to-peer solar platform, exclusively in Auckland (though there are plans to expand throughout the country next year).

The only way to ensure all your electricity is from a renewable source is to create your own power – such as from your own solar panels, mini hydro station or wind turbines.

The Energy Efficiency and Conservation Authority (EECA) provides information on renewable energy resources in New Zealand.