Thornleigh Passive House

The first quarterly bill for the house with solar fully working... As a reminder we have a solar panel system, but no battery system. On average we used 6.9kWh/day from the grid and returned 7.1 kWh/day to the grid. Between connection fees, electricity costs and rebates our electricity costs were ~ $2/day... for about half of that period all four of us were at home... every... day. While there is a real appeal to a battery system, it will be very hard to make an economic case for one when the potential savings is ~ $1.40 per day. At least until the cost for a ~7kW battery system comes down to ~$5114 (assuming a 10 year payback).

Another month of house data... The weather was mostly nice, with enough rain for almost normal moisture back in the system and enough cloud to reduce our solar generation. Of course the big news this month is still COVID-19 (2 adults + 2 children) at home... all... of... the... time... and we are not too crazy yet. As the season has changed I have moved the HRV target temperature up higher to 21 °C and then to 23 °C at the very end of the month. The need for nighttime cooling appears to be behind us, and we would have hit 100% of hours in the target range except for not quite managing the changing of target temperatures in changing weather. Percentage of hours in below, within, above the 20 - 25 °C target temperature range for the month. Inside / Outside % < 20 °C % 20 - 25 °C % > 25 °C Inside 0% 98% 2% Outside 74% 22% 4% Methods: I have taken the 5 minutely data from the wirelessTag sensors and calculated the median temperature of each ...