What we did
We are on the mains grid in Melbourne. While we wanted to go with
something more environmentally sustainable than brown coal, the payback
times were very long and we didn't think we could justify it. Instead,
we made sure we purchased 100% Green Power from our retailer to ensure
that what we did consume was produced from renewable sources (more
accurately: the equivalent from renewable sources was pumped into the
Once reasonable rebates for photo-voltaic systems became available, we
went ahead and fitted a 1.5KW system. The most cost-effective approach
at the time was to only fit a 1 KW system, but we were looking ahead to
when better feedin tariffs would become available. This has now
happened in Victoria, and we are getting paid 0.66 $/KWh for energy we produce
that is surplus to our needs, while paying only 0.22 $/KWh for energy that
we pull in from the grid.
One annoying gotcha with our system that we didn't realise sufficiently
at the time is that the inverter unit (which converts DC coming off the
roof to AC for use by us) doesn't operate when the mains supply cuts
out. This is a safety measure to prevent the electricity coming off our
roof potentially electrocuting linesmen who are working to repair a
fault elsewhere in the neighbourhood, but it is still frustrating not
to be able to use our own electricity during an outage. The only way
around this would be to fit a battery-system (rather than a
grid-connected system) and that would have cost much more.
At the same time that we were looking to improve our drain on the grid
(and particularly on coal-sourced electricity) we also undertook a
gradual program to wind back our consumption. This involved replacing
appliances as they came due with the most energy efficient options
available at the time. We considered replacing appliances before they
failed, but felt on balance that we couldn't justify junking somethat
worked perfectly well. It's a tricky balancing act, and I'm not sure we
always got it right.
We also did the obvious things like replacing our incandescent light
globes with compact fluorescent ones, and leaving nothing in standby
mode that didn't need to be. One particular challenge was the network
backup server. If power cost nothing, I would use an old PC running Linux,
but this would consume 150-160 Watts. So instead, we use a Buffalo
Linkstation, which only consumes 17 W when running.
We all use laptops (which draw a maximum of 65W each) so the
number of computers in the house is less of an issue than it would be
if we all used desktops.
We have currently got the electricity consumption for the entire house down to 8 KWh/day.
What we should have doneAs (somewhat) early adopters of
photo-voltaics we didn't get the best possible rebate, but we did start
reducing our demands on the grid earlier so it balances out.
What we are considering now
We are waiting for LED lights to get cheaper (and also to have
provide a warmer light) before we start moving to use them throughout
the house. I am also looking for a lower power-draw backup unit to
©Andrew Treloar, 2015. W: http://andrew.treloar.net/ E: email@example.com
Last modified:Monday, 18-Sep-2017 03:25:29 AEST