Kings County, NS
Gaspereau, outside Wolfville
Keywords: offgrid, passive, pv, geothermal, thermal mass
To be off-grid entirely. Home for two adults, two children and a dog. Within financial constraints, renewable energy and earth-friendly in as many ways as practical, using simple systems whenever practical.
Cold days, 3~F drop over cold nights with no fire on., The PV system supplies > 40A on cold days., Entire electrical system cost was 8000$.
VERY steep south facing WET clay slope. Open area, upon a flattened plateau with little tree obstruction to the south.
Thermal mass House-within-a-house construction to isolate the outside wall from the inside wall. Outer wall is made of cinder blocks, then 5" of foam insulation separates it from the interior wall of cinder blocks; internal thermal mass is 2000 blocks with eight cubic yards of sand packed inside, then nine cubic yards of poured concrete. Non-insulated slab.
Scissor trusses isolate the ceiling from the roof. Wood-fired range in kitchen supplies heat and its hot water side coil provides DHW.
House wiring is 12v, used for lighting and inverted at point of use.
Three 100-foot-long 4" pipes run through the ground to supply air at a constant temperature during summer and winter; the pressure to draw this air is buffered by the chimney. Designed exhaust fan not installed yet.
Water is pumped from a dug well to a surface tank whenever it's sunny; the pump is powered using two 50watt, 24V PV panels.
The electrical system for the house is charged using eight 85 watt PV panels installed vertically on the south exterior wall. The reason behind their vertical orientation is to collect radiation reflected from the winter snow. These eight panels charge 2 "Surrette deep cycle" batteries which are kept in a wooden box, vented for safety. The electricity comes from the panels and into a power optimizing unit called a "Solar Boost 50" which balances the incoming current with the voltage to output the most power in watts. The lights and appliances are mostly powered by the 12 volt supply, transmitted as Direct Current.
Hans Albarda
Four of the panels are led to one ammeter, and the other four are led into a second ammeter. The reason that this is done is to provide an effective way of determining where a problem is taking place (either at the panels or at the control board).
Phone +1 902 542-4029
Add a kitchen range insert and boiler for DHW.
