Going ‘off grid’ creates contrasting imagery. The romantic image is a remote house or log cabin in the woods, a wood fire and candlelight. The hardship image is a remote house or log cabin in the woods, a wood fire and candlelight. The fear in the second image is an absence of modern comforts, having to choose when various electrical items can be used and general sacrifice. As in most instances when two extremes are present, neither is completely accurate. The good thing for homeowners considering ‘off-grid’ living is that you can now pretty much choose where your house and lifestyle sits on this scale.
Aside from a remote location, the drivers behind off-grid living could be a desire for self-sufficiency, a statement to utility companies or an economic decision based on rising power and network prices. The barriers are ready access to the grid, upfront system cost and comfort.
The practicalities of off-grid living are now such that you can be effectively off-grid in the suburbs, while having the grid as a back-up in case of emergency (insert first world jokes about coffee machines and spa baths). Producing your own power is also now significantly easier with rapid reductions in the cost of solar PV over the past decade or so. No longer does an off-grid home work off 1-2 kW of solar PV and with the onset of mass market home energy storage systems, no longer is use restricted to the hours when power is available.
So what about the comfort element? Sustainable or passive home design and construction is now mandatory in many areas. The value of this to your comfort and future living costs cannot be stressed sufficiently. The final element is the home heating and cooling system. Depending on your location, heating and cooling systems are a significant contributor to both the household energy bill and the required capacity of the power system to be installed.
In accordance with the US EPA, the most energy efficient system for heating and cooling a home is a geoexchange or geothermal heating and cooling system. In the off-grid context, it is important to address energy efficiency in terms of both annual energy consumption as well as efficiency during the peak heating and cooling periods (ie cold winter mornings and heatwaves through summer). The efficiency during peak periods impacts upon the electrical maximum demand and is especially important with off-grid systems as it determines the overall capacity of the power generation system (typically solar PV) to be installed.
The high efficiencies of geoexchange systems are achieved by utilising solar energy (technically not geothermal heat) stored in the ground as a heat source (heating), heat sink (cooling) or for thermal energy storage. The Ground Heat Exchanger (GHX) delivers the constant ground temperatures (think cave or wine cellar) via water circulated through PE pipes into the ground source heat pump that provides the home with heating, cooling or hot water as required.
To further assist with reducing energy consumption in the off-grid setting, geoexchange systems are able to generate thermal energy when power is in abundance and store it for when heating/cooling is required. It can do this by either using the ground itself or in buffer or storage tanks such as are typical on hydronic heating systems.
To this end, off-grid living is no longer about remote woods and sacrifices. Effective off-grid living can occur in the suburbs and can include a home with all the creature comforts of a grid connected energy guzzling house. The reduced cost in solar PV, the onset of home energy storage and the efficiency of geoexchange systems can provide off-grid living to even the most fussy of family members.
To find out how a geoexchange system can assist you with off-grid living or just to reduce your power costs contact us.
