Your Guide to Commercial & Residential Geothermal Energy
One of the biggest advantages to calling British Columbia home is access to various renewable sources for geothermal heating and cooling. ‘Geoexchange’ or geothermal systems (also called geothermal heat pumps, earth coupled heat pumps or ground source heat pumps) use clean energy to heat and cool buildings and homes.
As a homeowner or business owner, tapping into this green energy could save you a substantial amount on electricity bills.
Let’s dig deeper into how geothermal heating and cooling works, its benefits and why geothermal systems are worth the investment.
What is Geothermal Energy?
Geothermal energy generates power from the heat within the earth. Similar to solar energy, another form of thermal energy, this resource is renewable. The stable temperature underneath the ground provides a constant supply of thermal energy that can be tapped into.
This type of energy is capable of:
- Generating electricity
- Producing hot water
- Transferring heat to or from individual buildings
Unlike fossil fuels, geothermal energy has a minimal impact on the environment. A geothermal field produces nowhere near the amount of carbon emissions as gas or oil.
So how does geothermal energy work? And why are geothermal heating and cooling systems an increasingly popular choice among homeowners and business owners?
How Do Geothermal Heat Pumps Work?
Although there are several applications for geoexchange technology, replacing conventional heating and cooling systems is the most common use.
In essence, a geothermal heat pump transfers heat to or from the ground depending on the season. It harnesses heat from the heat source and deposits it in the heat sink.
During the winter months, the heat source is the ground and your home or commercial building is the heat sink. Heat pumps extract heat from the ground and disperse it indoors.
In the summer months, the opposite process occurs. The geothermal heat pump absorbs heat from inside the building and releases it underneath the earth. Due to the relatively constant temperature within the earth’s crust, adding more heat this way makes no difference.
A ground source heat pump typically uses either the earth itself or ground water for thermal energy. The geothermal heat pumps are available as water to water or water to air:
- Water to water heat pumps harvest geothermal energy from a water source. Afterwards, they distribute it throughout residential or commercial buildings using in-floor heating or fan coils.
- Water-to-air heat pumps capture energy from the same source as water-to-water heat pumps. However, in these systems, the energy is distributed using forced air.
In terms of design, geoexchange systems can be installed as an open or closed loop:
- Open loop systems extract thermal energy by pumping groundwater into a heat exchanger. Afterwards, the slightly warmer or colder water is released back to the earth through an aquifer or rejection well.
- Closed loop systems derive thermal energy from the earth itself. Antifreeze or refrigerant circulates a closed loop of piping buried beneath the ground. Heat is transferred inside residential and commercial buildings through an indoor heat pump connected to the buried pipe.
Facts About Geothermal Energy
If you want to learn more about this resource, here are some additional facts about geothermal energy:
- Despite modern advancements in geothermal heating and cooling systems, humans have used this energy for ages. Its earliest use in North America dates back to 10,000 years ago. Indigenous Peoples used hot springs powered directly by geothermal energy.
- The word ‘geothermal’ literally translates into “earth heat”. It originates from the Greek words ‘geo’ which means earth and ‘therme’ meaning heat.
- Geothermal resources are classified by temperature. Heat pump systems use low-temperature geothermal resources. Any resource above 80°C is regulated by the Geothermal Resources Act.
- According to Natural Resources Canada, Canada’s emissions would decrease by 400,000 tonnes of carbon dioxide if 100,000 homes switched from conventional heating and cooling systems to geoexchange systems.
Geothermal Energy Pros and Cons
There are numerous benefits to installing a geothermal heat pump in residential and commercial buildings. However, there are cases when a certain type or design may not be an ideal choice.
To determine whether a ground source heat pump is the right solution for your home or commercial building, consider the following benefits:
- Energy Efficiency: Heat pumps redirect heat rather than generate it. As a result, their energy consumption is a lot less than conventional systems. According to BC Hydro, a geothermal heat pump system is 300% more energy efficient than baseboard heating. It is also 50% more efficient than a window air conditioning unit.
- Minimal Climate Impact: Geothermal systems use minimal electricity and rely mostly on renewable energy. Moreover, the process of depositing or absorbing heat from the ground has little effect on ground temperature. Switching to a geothermal heat pump means lower carbon emissions and less impact on the environment.
- Lower Electricity Bills: The operating costs of a geothermal heat pump is significantly less than electric heating. Since geoexchange systems are powered mostly by renewable geothermal energy, they operate almost entirely for free.
- Long Lifespan: Ground source heat pump systems last longer than other alternative heating and cooling systems. They have a lifespan of 20 years or more.
- Low Maintenance: Similar to other heating and cooling systems, proper maintenance is key to your heat pump’s longevity and efficiency. However, heat pumps tend to be easier to maintain than other systems. They only require an annual maintenance and a filter change every three months.
While all homes and commercial buildings can benefit from installing a geothermal heating and cooling unit, there are a few drawbacks to keep in mind. Some reasons why homeowners and business owners may hesitate to switch to geothermal energy include:
- Installation Costs: In comparison to more traditional HVAC systems, geothermal heat pumps have a higher installation cost. Fortunately, there are several provincial rebates and federal grants that help to cover this expense. Additionally, savings in hydro costs over time will ultimately offset the initial costs of installation.
- Extreme Temperatures: The mild winters and summers in BC are perfect for geoexchange systems. However, some places in Canada are not as lucky. Heat pumps may not be able to provide enough heat in the extreme cold of provinces such as Alberta.
- Poor Water Quality: In areas with poor water quality, an open loop heat pump system is not a good idea. Dirt and debris from the water source could ruin your geoexchange system.
Is Geothermal Heating and Cooling Worth It?
As fossil fuels deplete in the coming years, humanity must transition to a world powered by renewable energy. Investing in geoexchange systems for your home or business means moving one step closer to a green energy future.
If you’re considering switching to geothermal heating and cooling systems, our team of geoexchange experts can help. At South Island Mechanical, we are proud to be a leading provider of exceptional HVAC services to homes and businesses across Vancouver Island for over 20 years.
Our certified technicians can install, maintain and repair all types of geothermal systems. If you have any questions about geothermal heating and cooling or want to make the switch to a greener future, contact us today.