2006. Reverse-cycle air conditioners were subsequently installed in the
large and small halls although gas space heating was retained in the
halls as well.
As the cost of natural gas became increasingly greater and ACT’s pro-
portion of renewable energy grew, it became evident that reverse cycle
air conditioning was better than gas from both an environmental and an
economic perspective.
Although Ross Walker Lodge was designed to be energy efficient (with
a 6-star energy rating), the long sequence of hot nights in 2018 con-
vinced the residents and the Management Committee that air condi-
tioning of the bedrooms and living area was desirable to provide a level
of comfort to community standards. Individual room air conditioners
were installed, resulting in some increase in electricity consumption,
and although gas heating was retained its use has been significantly
reduced.
In 2019 the operating budget of Ross Walker Lodge allowed installation
of a solar PV system to be considered to enable electricity consumption
to be markedly reduced. Due to their reasonably favourable orientation,
the 13kW of solar panels have been able to fully offset electrical con-
sumption in the house for most daylight hours, and export as much or
more than is being used.
It’s too early to be accurate about the impact, but payback is expected
to be less than 5 years, while ongoing electricity costs are halved. Mon-
itoring over a full cycle of seasons will enable us to judge whether bat-
teries should be added to extend the self-sufficiency and get better val-
ue from the excess solar generation that is presently exported.
The cumulative effect of 20kW of solar panels on the St Margaret’s
property is to reduce greenhouse emissions by some 22 tonnes a year
if the electricity produced displaces that from coal fired power stations
in NSW. Although the ACT has now achieved 100% renewable electrici-
ty, largely by commissioning wind and solar farms outside the Territory,
the contribution of our 20kW enables more of that renewable energy to
be available in the East Coast Network to displace the burning of coal.
The following table gives an indication of numbers concerned. As both
generation and consumption vary from year to year, typical results have
been used.
Carbon Action Project
5
1 March 2020