Caring for our Environment

Siting, Design, Energy generation storage and use
 
You may notice that our roofs are almost fully covered by solar panels. 
In total we have 26kw of solar panels and 26kw of batteries. 
 
Power is created in the day while most energy usage is in the evenings after dark. 
 
The batteries are sized to get through the night in 8 months of the year but in winter of an evening we do have to buy power from the grid especially early mornings if aircons are left on overnight.  There is usually other than the coldest winter nights no need to leave aircons on as the buildings are well sealed, 6 star energy rated, double glazed, have electric blankets, sited optimally for the northerly aspect yet sheltered from the cold winter winds and also the afternoon sun with mostly large eaves and sun protection excepting early morning when we kept the ability to obtain the excellent sunrises.   More shading is planned in key areas.  Lights, aircon, TV's, fridges, bed heaters, washers, etc are all low energy use.
 
The ceiling fans plus siting of opening windows are effective to provide a good flow of fresh air in all days excepting the really hot 30Deg C hot days when the air-conditioning is used in the key location mostly of where the lounge is. Over a summer we find aircon use trends at less than 14 days as we get the benefit of an island / on the coast air movement.   Radiant heat is the area to manage with eaves and wall materials where they can achieve a benefit.
 
The water heating is achieved by using conventional electric 310 litre x 2 hot water units set with timers to only work in the max solar power creation times of the day.  This is in effect a very low cost option of storing energy overnight in the way of heated water.  This then saves use of gas to heat water but we have backup gas units if needed.
 
The end result is for an expenditure of around $50,000 just for solar, batteries and water heating we are net energy exporters and have no net power bills.   Payback is really good but it took a lot of research /work to achieve this.
 
Winter with heating is our main draw of grid power but over the year we still export 7-10+ times what we draw from the grid. That is energy efficiency in anyone's terms even if the grid may not be able to on-sell some of this.  We also limit any meaningful draw of power from the grid.   The supply charge from the grid is the factor that over time may increase significantly.   The cost of power from the grid per kw is nearly 10 times what we receive as feed in tariffs.   In time we may move over to another retailer that can access our batteries in peak use times but the math / management of that is still in its start-up stage.
 
To get this all working took some time and a lot of searching but it does prove that a comfortable all seasons residence is possible without breaking the bank to be a net power exporter, have no power/ heating bills, and only use mostly the rain that falls on the property. If I had to list in most importance first it would be site selection no1, building design no2, then power management no3, followed by water conservation / management no4.  We have a site that is tucked into the hill the side that gets the winter weather and the summer afternoon sun. We however on the other sides get the winter sun and sea/ valley views for the living and sleeping areas.   
 
Please let me know if you have a background/interest about design, energy and/or water saving as I will be all ears.  
 
Kevin