Friday, April 30, 2010

The advantages of living off grid

The advantages of living off grid

By Lorne Oja Science

No power poles, no power bill, master of your own energy destiny.

That’s living off the grid.

A popular misconception about living off grid relates to giving up most of our modern conveniences. To the contrary, modern, proven technologies, namely inverters, allow for a home not connected to the utilities to have all the conveniences of a home that is grid-tied.

The economics of off-grid living becomes viable when building a new home on a rural site and the power grid has to be brought in any distance.

The cost of an alternate energy system is comparable, and occasionally more cost effective, and it can be tailored to your budget and expanded as you can afford it.

An off-grid system has the advantage of no monthly utility bill, a bill that can and likely will increase as the demand on electrical supplies increases.

A typical new off-grid home will meet or exceed all the new building standards and have a very low to non-existent carbon footprint.

Photovoltaic cells, or solar panels as they are more commonly known, will be assembled into arrays large enough to meet the demands of the family in residence. Usually the system is supplemented with a wind turbine, to provide extra power in those low light but windy conditions.

Charge controllers will take the DC voltage from the solar array and the wind turbine and through a little technological magic; they will squeeze all sunshine’s available power into a battery bank, designed to store accumulated DC power, until power is required by the home.

The charge controller also keeps the batteries from overcharging.

DC current is fed from the battery bank into an inverter, which will provide the house with the familiar alternating current (AC).

AC is the standard type of current all household appliances are designed to run on and without it, the off-grid system would require more expensive and hard to find direct current appliances.

Using the sun is not restricted to electricity production. Heating for household needs can be supplemented by solar thermal panels.

These ingenious devices take heat from sunshine and collect it in insulated reservoirs. When heat is required, the under-floor or modern radiator system draws on this stored heat from the reservoir and distributes it where needed.

The hybrid off-grid system is backed up with a natural gas or propane generator.

This device is required by the residential insurance companies and it makes sense. For those rare fogged-in weeks, the generator will automatically start and pick up the slack when the battery bank is drawn down to a programmed set point. As long as the solar array and or wind turbine are sized correctly, the generator will rarely run.

A typical off-grid system is cost effective and can be customized to fit the owner’s needs and budget.

It goes a long way towards energy independence, a low carbon footprint and stewardship of the environment.

Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003 and is in the planning stage for his second. His column appears every second Friday in the Advocate. Oja, who lives in west Central Alberta, can be contacted at lorne@solartechnical.ca

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