One of Going Solar's long time solar dealers, John Morgan, recounts his experiences with building sustainable houses and living off the grid:
"Woodrising [pictured below] was built as a reverse masonry veneer house with an attic storey. The external timber structure – clad with ‘board and batten’ from the local forest – was heavily insulated as was the roof and the periphery of the slab. The internal masonry walls were in effect a ‘heat bank’ or thermal battery. There was no masonry in the upper storey as we did not wish to retain heat there which could be an issue in summer. The upper floor was comfortably warm in winter just from waste heat from downstairs. At the peak of the roof structure there were large vents at each end of the house. These were used to vent air from the building if things got too hot. The house was ventilated using the 'stack effect'. ... We had many delightful low cost years at Woodrising but there came a time when a single storey house was needed.
"The successor to Woodrising is Galaxy Hill [pictured above], a very different construct altogether. ... The house has no architectural merit but is simple and basic, and so, is easily built.
"As I expected to be an elderly retiree at Galaxy Hill, there would be no firewood to carry, cut or even purchase. The idea was that the sun was readily available all day – for most of the year – and at 1kw per square metre, there should be more than enough direct radiant energy available to power a low energy home (or even a high energy one). I like to think of this house as being powered by a thermo-nuclear fusion reactor located at a safe distance from the nearest population centre.
"Again, as the daily electrical demand was around 4 or 5 kwh, we didn’t need a very large power plant so a twelve module PV array was set up and a small wind turbine was added as a conversation piece (it doesn’t offer much in comparison to the PV). ...
"The reverse masonry veneer design feature of the house – similar to Woodrising – has the effect of keeping internal temperatures down in the hot weather as heat is absorbed into the walls. Thus the internal temperature is always lower than outdoors in summer and there is no need to open windows for ventilation. The heat in the walls thus remains there until the cooler weather comes and thus helps with thermal comfort in winter. As the house windows are not opened, ventilation is provided by warm, fresh, oxygenated air from an attached greenhouse. ...
"Off grid living is potentially very expensive at the installation stage unless the domestic electricity demand is very small. This proviso can be achieved by ensuring that the architecture is highly energy efficient. So we made sure that both Woodrising and Galaxy Hill were very energy efficient, as buildings. People thinking of going ‘off grid’ need first of all to deal with the energy demand of the building."
Read John's full article at: http://onestepoffthegrid.com.au/the-off-grid-experience-and-how-its-chan...
Incidently John's previous property, Woodrising, at Musk, near Daylesford was the site of the first Sustainable Living Fair which was organised primarily by then team at Going Solar.
With the Galaxy Hill house, note the steep angle of the PV panels. As John has an off-grid system the steeper angle improves the energy production in winter when there are less hours of sunlight. Some of his panels are facing east to catch the early morning sun.
More information about off-grid systems can be found at: http://www.goingsolar.com.au/what-we-do/solar-electricity-off-grid