New Zealand’s energy production comes from both renewable and non-renewable sources. In 2016, about 85% of electricity generation came from renewable sources, marking the country’s highest production level in 35 years.
Renewable energy comes from sources that replenish naturally in a considerably short period of time. The country’s renewable energy supply particularly comes from geothermal, hydro (24%), biomass (17%), wind and solar power.
Aspiring for a future with a secure and resilient renewable energy supply, the NZ government has put into place research and development initiatives to economically grow its renewables supply. Electricity renewable percentage is trending up since the mid-2000s due to the continual market development, declining costs of renewable technologies and the downgrading of Maui natural gas reserves.
The country has significant advantages in electricity generation, given its vast renewable resources from windswept landscapes to volcanic features and generous sunlight hours. Currently, NZ has the third highest renewables percentage of total primary energy supply (TPES) in the OECD, next to Norway and Iceland.
Below are the types of renewable energy sources that make up the country’s supply:
New Zealand is located strategically between two tectonic plates, meaning it has vast potential for geothermal power generation. The Earth’s crust is thinner along faults, so the hot mantle is much closer to the surface. The heat generated and stored in the ground is what we call geothermal energy, which supplies 17 percent of the country’s electricity and 22 percent of our TPES.
Geothermal fluid, which is a mixture of high pressure water and steam, is piped from deep wells to a central generation power plant where it is turned into steam. The steam is what drives turbine generators to produce electricity.
Since it’s not weather dependent, geothermal energy supply is consistent and reliable. However, careful monitoring and management of water and pressure levels in the power station are necessary to prevent land subsidence and depletion. This generation method does produce greenhouse gas emissions, but still at a relatively lower amount than the cleanest natural gas plants.
Hydro power generation is the backbone of New Zealand’s electricity system, contributing more than half of our electricity supply.
Hydroelectricity plants rely on gravity to drive water from nearby streams, rivers or dams through turbines, which drive power generators. The process is fast and gives off no greenhouse gases, however there are environmental repercussions to building dams.
The challenge with hydro schemes is New Zealand’s lack of water storage capacity and variable water supplies. Fortunately, the growing wind farms and solar power systems are easing these concerns.
Wind turbines harness wind power and convert it into electricity. With the country’s vast landscapes, wind-powered generation is a very promising form of electricity generation. It is one of the most environmentally friendly methods as well, given that wind turbines don’t produce greenhouse gas emissions during operation. That being said, wind energy only accounts to two percent of New Zealand’s total renewable energy supply.
Three quarters of Kiwis support wind farms, but there are objections to the sight of them and the noise they create. This has led to stricter building codes for farms as well as noise standards for turbines to ensure quieter operation.
We use either passive or active solar power systems to harness the sun’s energy. Passive systems use architecture and engineering to design homes to absorb solar radiation for heating spaces. Active systems use photovoltaic (PV) solar panels to generate electricity as well as solar water heating devices. Solar panels consist of light-sensitive cells that absorb sunlight and irradiance to produce electricity.
Solar electricity is silent, unobtrusive and sustainable. It is the underdog among all of New Zealand’s renewable resources. While it’s totally free and can be used all around the country, it currently amounts to only 2 percent of the total primary renewable supply.
The benefits are definitely there, but there are apprehensions to its uptake primarily due to the high capital cost of solar power systems. Another hindrance to its utilisation is that solar PV is branded as a ‘disruptive technology’ because it challenges the conventional model of electricity provision. However, newer technologies and price reductions in solar PV equipment are making solar power more efficient and affordable to own. And the ever-increasing prices of electricity are pushing more Kiwis to adopt solar as an alternative power generation method.
In fact, there are a number of island resorts that installed their own off-grid solar power plants to cut costs and gain energy independence. On the other hand, householders and property owners prefer grid-tied systems as they need backup power from the grid when the solar panels aren’t generating power at night.
Bioenergy is fuel made from biomass feedstocks, which are renewable organic materials such as trees, residue wood, crops and by-products like straw, manure, sewage, etc. This type of energy contributed to 7 percent of our TPES in 2015.
Biomass can be burned to provide process heat, which can be used directly or used to generate electricity. Residue wood can be burned to produce heat for domestic use, although this practice is used primarily in the timber industry.
Alternatively, biomass can be turned into liquid biofuels for use in transport. The most common types of biofuels are bioethanol (a type of alcohol fuel processed from waste and organic by-products) and biodiesel (made from animal fats and vegetable oils). Biofuels help make our vehicles cleaner and gentler on the environment.
The current issues with bioenergy are the costs of gathering and transporting biomass feedstocks. Nevertheless, recent innovations are making it easier and cheaper to produce biofuels on a mass scale.