Energy Consumption

 
 
Graphic Image for Steady
 
 
Annual kilowatt hours energy use in Rotorua district (electricity and gas)
 
 

Purpose of indicator

The production of energy from oil, coal and natural gas produces waste gases that increase greenhouse gases and have harmful effects on the environment. Energy consumption drives the demand for energy. Generally, the greater the demand and generation of energy, the greater the impact on the environment. Alternative and renewable energy resources such as hydroelectricity, solar and geothermal cause less environmental harm in general than non renewable resources.

Current information and trend

Data in figure 1 shows a small increase in energy consumption from 2009/10 to 2010/11. Likewise, greenhouse gas emissions also show an increase in figure 2, despite a trend in increasing electricity prices (figure 3).

Possible reasons for this may include more electrical devices in use globally, and new housing increasing the overall energy demand. Another contributor may be replacement of wood burners with electrical heating devices, such as heat pumps, contributing to less smoke pollution in the air, particularly in the winter. During winter time energy demand goes up as heating devices are used, and in the absence of daylight saving people tend to stay indoors more in the evening time. When a winter season is particularly cold the overall energy demand is generally higher for the year,  and similarly when a summer is particularly hot. Some Rotorua residents have an advantage in having access to geothermal heating. It is estimated that geothermal heating (via heat exchange) is available to around 1500 - 2000 households from the Rotorua geothermal field. These households are less likely to depend on electricity or gas for heating and hot water. These households are located outside an exclusion zone that is a 1.5 km radius from Whakarewarewa. This was put in place at the same time as bores were closed in the 1980s in response to evidence that the geothermal field and features were being negatively impacted on by improper and over-use of the resource. It has since recovered somewhat and reached equilibrium.

The New Zealand Energy Strategy 2011-2021 stated four priority areas; diverse resources development, environmental responsibility, efficient use of energy and secure affordable energy. Three of the 12 focus areas detailed for the priority areas that are particularly relevant to Rotorua are; develop renewable energy resources, embrace new energy technologies, and competitive energy markets.  Rotorua is well placed to progress towards these priorities and focus areas, having a range of alternative and renewable energy technology and resources available. The National Policy Statement for Renewable Electricity Generation 2011 supports the Energy Strategy and came into effect in April 2011.

Chart for Rotorua district energy use (electricity and natural goal) 

   Figure 1.
   Source: Gas Industry and Unison Networks, 2011

Chart for Rototua District greenhouse gas emissions from energy use
   Figure 2.
   Source: Gas Industry and Unison Networks, 2011

While the nation’s first hydroelectric power plant was located in Rotorua at Okere Falls from 1901 to 1936, it is now geothermal energy that is seen as having the biggest potential for development in the district. In 2010 Mighty River Power relocated its Geothermal Operations Group to Rotorua. Also in 2010 Mighty River Power and Tauhara No.2 Trust commissioned the Nga Awa Pura geothermal power station located just north of Taupo (outside of the Rotorua district). According to Mighty River Power, in 2011 this power station sold 410,000 Emissions Reduction Units (ERUs), or carbon credits to Deutsche Bank AG for NZ$9.3m at NZ$22.78 per unit.  In 2011 resource consent was granted to establish and operate a geothermal power station at Rotoma, and another two were granted in 2012 for geothermal drilling at Atiamuri and Taheke.

Chart for national average electricity prices
  Figure 3.
  Source: Ministry of Economic Development 2012

Two hydroelectric plants are located just south of the district’s boundary, however these power plants generate electricity from Lakes Ohakuri and Atiamuri, both of which are located within the southern most part of the Rotorua district. Similarly, Ohaaki geothermal power station is located just outside of the Rotorua district boundary, but draws on the Ohaaki- Broadlands geothermal field, some of which is located within the Rotorua district.

Woody biomass waste is a secondary resource to harvesting and processing by the forestry industry, one of Rotorua’s major economic drivers. Solid fuel is made from pine residues sourced from saw mills and timber product manufacturers by compressing the material into pellets or logs. This product is estimated to reduce greenhouse gas emissions to only 1/10 of that produced by old wood burners and 1/100 of open fires.

TeracTM is a joint project by council and Scion to convert sewage or wastewater into energy and other useful products using hydrothermal deconstruction technology. The pilot plant for this technology located at the Rotorua Wastewater Treatment Plant was opened in 2011. Should the pilot plant be successful it is possible this technology could be used on a commercial scale for energy production.

In summary

 
There was a small increase in energy consumption (kwh) from 2009/10 to 2010/11, despite an increase in electricity prices

Greenhouse gas emissions also increased from 2009/10 to 2011/2012
Page reviewed: 03 Jul 2019 10:12am