Extensive temperature insulation of residential structures is crucial to the efficacy of off-the-grid solar-powered living, asserts property developer Green Housing Company CEO Brett Petzer.

Petzer, who is responsible for an early-stage off-the-grid residential development in Midrand, says the capability of solar-driven energy to solely power a building is severely diminished with the threat of heat transfer in poorly insulated structures.

“Insulation in solar-powered developments is pivotal and, hence, we have created a fully sealable internal environment by employing sustainable, environment-friendly insulation and building materials from the ground up,” he notes.

The One Zero Eight development lays claim as one of South Africa’s first exclusively solar-powered residential developments, harnessing solar rays through roof-installed panels and using a solar inverter to convert direct current from the sun into alternating current.

In addition to a battery backup set, which is able to store energy for use at night or during periods of low solar activity and can operate for a maximum three-day period without sunlight, the system has a backup switching device which can alternate between the solar plant and the electricity grid if the need arises, thus ensuring a constant power supply.

Despite the development’s ability to remain fully independent of the national electricity grid, legislation prevents the transfer of property unless it is connected to municipal sewage, water and electricity infrastructure.

“This enables homeowners to decide whether to use the solar-powered system, or tap into City Power, which means they will never be without electricity,” Petzer iterates.

Cash Rebate

Further, installation of the system may activate a cash rebate from Eskom – currently in the final stages of formalisation – which will see the national electricity provider refunding homeowners for three years worth of electricity spend should they subsist independently from the national grid.

“While it is an expensive system to imple-ment, the Eskom rebate and the long-term savings on one’s electricity spend would make it worthwhile,” he enthuses.

As a member of the Green Building Council, the project offers further environment-friendly features and building components, which promotes its identity as an ecofriendly development.

An aspect of its thermally efficient building system is the presence of fully recyclable double-glazed windows for improved heat and sound insulation, as well as an energy efficient walling system developed by local construction technology company Imison.

Engineering News reported in November that this technology consisted of a walling system with embedded energy technology that promotes energy conservation, offering a thermal transfer resistance much higher than that of a double clay brick wall.

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