Identifying, protecting and developing our geothermal potential
Using low temperature geothermal to decarbonise and electrify Aotearoa New Zealand
GeoExchange NZ Limited is a multidisciplinary team of scientists, engineers and social scientists that provides independent design and advisory services to the public and private sector on geoheat systems.
Our advantage lies in our unique capability to integrate the disciplines of mechanical engineering, environmental sciences, systems thinking, social sciences and some design philosophy. Combined with over seventy years of local and international experience we identify simple and elegant system solutions that solve multiple problems.
A good solution is never just a matter of swapping out a boiler for an equivalent-sized heat pump!
GeoHeat and Aotearoa New Zealand
New Zealand is blessed with abundant high temperature geothermal resources that provide low carbon and renewable electrical energy.
New Zealand is also blessed with abundant low temperature (10°C to 150°C) groundwater and geothermal resources that can provide low carbon and renewable thermal energy.
Less well known, these low temperature, or geoheat sources, are everywhere and can be used either directly (e.g. geothermal pools) or indirectly with a heat pump.
The result is low carbon, energy efficient heating, cooling and hot water to homes, offices, health and educational facilities, aquatic centres as well as district heating and industrial applications such as process heat and greenhouses.
Green buildings
Geoheat, in particular the indirect systems that utilise ground source heat pumps (GSHPs), is present in many of the most efficient and greenest buildings in the world. The high efficiencies and thermal storage capabilities of these systems can often double the efficiency of conventional HVAC, while removing the aesthetic and acoustic issues associated with outdoor heat pump units.
Industrial process heat
Geoheat systems can replace carbon intensive fossil fuel boilers in a number of industrial applications. Direct heat examples, often cascaded from geothermal power plants, are already in use in New Zealand within the Taupo Volcanic Zone and Northland. The development of high temperature heat pumps that can utilise low temperature geothermal systems now makes such applications available to the rest of the country.
District heating and cooling
Whereas the original district systems were heating only, often from a geothermal source, modern fifth generation systems provide both heating and cooling. They can utilise a central energy plant or each building can have their own heat pump(s) as best suits the individual application. In either case, each building benefits from an efficient and sustainable operating system. Geoheat enables both types of systems depending on the underlying geological conditions.
The energy transition
The global energy transition is an opportunity to reimagine how and why we use energy. By prioritising our use of thermal energy (heating, cooling and hot water) a more equitable future energy system is possible.
Equitable outcomes include:
Lower energy costs;
Lower CO₂ emissions;
Healthier buildings;
Cleaner industry; and
A more stable power grid where the scale and cost of required upgrades to the power grid are reduced by smart management.
Heating accounts for half of global energy consumption and is predominantly done using fossil fuel boilers. To decarbonise our energy sector by replacing these fossil fuel boilers we need wholistic technology solutions that:
Prioritise efficiency and demand management;
Are optimised on a site-specific basis;
Substantially reduce carbon emissions;
Consider the full thermal energy system (e.g. heating, cooling, hot water, pools etc); and
Consider integration with the electrical energy system (e.g. annual usage, peak loads, more renewables).
