The cliffhanger in the last post was… How does my fridge’s performance compare with when it was brand spanking new?
This is a really important question if you are going to make an informed decision about reducing your electric bill, so we’ve been busy developing a database backend for sokitt that pulls historic energy performance figures for appliances from the energyrating.gov.au site. Yes that’s right, pick yourself off the floor, there is a government website out there that actually contains really valuable data! Data input by men in white suits who spend their Canberra days torture testing fridges, dishwashers, dryers and clothes washers to decide how many stars to put on their energy rating sticker.
So I can put my fridges make and model: Fisher & Paykel E249T into sokitt and it shows me the ‘as new’ performance of my fridge:
1.5 Stars - Oh Dear!
So, when new, my fridge was guzzling 691kWh per year costing $1300 bucks over 10 years in Energy (sokitt assumes electricity will go up by 5% a year – but this can be changed in Advanced Options) and was Rated at 1.5 stars. How embarrassing!
My bluetooth power meter told me that it is currently using 891kWh per year: that’s 200kWh per year I’m piddling down the drain.
I kinda knew that my fridge should be maintained – but this has shocked me into getting off my ass and doing something about it. So I defrosted my fridge (there was a lot of ice in the freezer) and re-seated the door seals that had come off in places and re-measured my fridges performance with my wireless energy meter. The graph of Watts vs. time over 24 hrs looks like this:
save energy - defrost your fridge!
That’s better – at least now the compressor switches off regularly (although it is still swutched on more than it is off – but hey it’s a crappy 1.5 star fridge whattdya expect?).
(by the way I think the really high spike is the auto-defrost where little heaters suck heaps of juice in an attempt to melt the ice off the coils)
Extrapoloating the kwhs measured over 365 days tells me that my fridge now uses 722kWh per year which is within 5% of it’s new performance and is as good as I can expect from a fridge this old.
So by defrosting my fridge overnight and pushing some door seals into place I’ve saved nearly 200 kWh per year. Not bad, but get this: If I’m typical for an Aussie household – multiply that by 10 million Australian homes and you’ve saved 2 million MWh (a MWh is 1000 x kWh). To put that in perspective that is 20 times the total amount of electricity generated by every solar panel in Australia in 2006. Oh yeah – the power of energy efficiency.
But before I get too smug – my fridge is still pretty crappy on the energy front at 1.5 stars. Hell you can buy 6 star fridges these days.
Before sokitt the place to go for appliance comparisons was www.energyrating.gov.au . This has some amazingly useful data except for one fatal flaw – it doesn’t display the prices of the appliances. It drives me freakin’ mad because you see your dream 6* fridge, then have to spend 10 minutes on Google looking for the price and you find out it costs $4,000 dollars and the freezer is another 2 grand on top!
Anyway, we’ve developed an appliance energy comparison tool that mashes up price and energy data and lets you compare current appliances with your old ones. When I put my fridge model in I find out (in about 5 seconds flat) some interesting things (to a tight-ass efficiency geek like me anyway):
See the comparison with my crappy fridge here
The best payback for a similar size fridge is 10 years (assuming 5% increase per year in elec prices) and that is actually a 3.5 star fridge. (pay back is how long it would take for my savings in my bill to pay for the fridge)
So should I buy a new fridge? You think it would be a no-brainer with a 1.5 star guzzler…
But I can’t answer that question until I have measured every electricity using device in my house and I have worked out the cheapest way to get my electricity down. There may well be much bigger wins to be had in terms of dollars per kWh saved where I should focus my limited funds first. We’ll see what the wireless power meter says over the next few weeks…
