|     
|
|
|
|
|
|
|
|
|
|
Prove that you are not a robot. Please answer these questions:

Is the sun hot or cold?

Leave this field blank

Energy Efficiency Blog

Search this blog

Posts Tagged ‘energy efficiency’

Apr 09

Energy Efficiency Without The Spin

energy efficiency 2 Comments »

Today we launch our 7 day course: “7 days to an energy efficient home”.

Follow the advice here, and slash your bills…

Here are the lessons

Day 1: An Introduction to Energy Efficiency

Day 2: We’ll find out where the biggest savings can be made for a typical Aussie house like yours.

Day 3: We’ll discover how to massively tame your biggest energy guzzler: Space heating and cooling.

Day 4: We’ll decide if you should upgrade your water heater.

Day 5: We’ll look at all the appliances in your home that run 24/7, and find out how to cheaply and easily measure which ones suck the most electricity.

Day 6: We’ll look at all your ‘single use’ appliances and figure out which ones need your urgent attention.

Day 7: We’ll set an energy use target for your home, and find out how to cheaply monitor your whole home’s electricity use to try and stay under that target.

Oct 17

Energy Efficiency Just Ain’t Sexy

energy efficiency No Comments »

(with a big-up to Pete Dormand of Newcastle City Council first made this point…)

Efficiency is not sexy. Having a 6 star fridge does not get you any green street-cred compared with having a big shiny solar panel on your roof for the neighbors to ooh and aah at. But efficiency is by far the cheapest way to reduce emissions, which means that before spending thousands on solar panels, households should do everything they can to see if they could spend that money on efficiency improvements that would make a much bigger difference to reducing emissions per dollar.

example: cost of 1kw solar panel installed = $12,000, energy produced in one year = 1500kwh, cost per kwh saved per year = $8

But spend an extra $220 on a more efficient washing machine and save 548kwh per year, cost per kwh saved per year = $0.40

Energy efficiency here is 20 times cheaper!

Justification of the efficiency numbers using sokitt’s clothes washer efficiency comparison tool.

If you are looking to buy a top loading washing machine, you can pay $704 for a cheap 1.5 star one (just sort by energy rating and top-loading style and scroll to the bottom of the page)

But if you pay an extra $220 for the top rated top loader (3.5 stars) you will save $955 in electricity over 10 years. (look at the clothes washer at the top of the sokitt comparison grid when sorting by energy rating)

My opinion: the government (or a forward thinking retailer) should provide an interest free loan to cover the extra $220, so no-one has to buy the cheap, inefficient one.

Oct 13

DIY Energy Audit : My TV

energy efficiency No Comments »

Next to get the power meter shoved up its jacksy is the goggle box.

Last night we had a baby sitter round (we went to a Michael Franti concert :-) ) and she watched TV solidly from 8pm to midnight. So the profile might be a bit atypical, but here goes anyway.

The power meter tells me that over the last 24hrs my 28 inch CRT TV used 0.576kWh of juice.

Here’s the power profile:

My TV\'s power use over 24 hours

My TV's power use over 24 hours

You can see the big chunk of viewing when the babysitter was here. The TV uses about 80 Watts when it is on. You’ll also see that it uses zero watts when we are not watching, because we are in the habit of switching it off at the wall.

There’s not a lot of scope to reduce our energy use except watch less TV (which isn’t a bad idea).

At least we’ve got an efficient TV. A similar sized plasma would use at least double the power.

P.S. The government announced earlier this year that they are gonna put energy rating stickers on new TV’s. Great news.

Aug 28

How much energy to feed my tea habit?

energy efficiency 1 Comment »

Today the energy audit continues to the most important appliance next to the coffee machine. The kettle. As a pommie, I need my tea, so let’s hope this baby isn’t a planet killer…

If you think about it, the traditional kettle sums up our approach to energy for the last 100 years. i.e we waste energy every day because we are too damn lazy to come up with a better way to get a cup full of boiling water. We use resistive heat to boil much more water that we need in a jug with almost zero insulation, and if you are like me you usually end up boiling it twice because between switching the kettle on and it boiling you’ve got distracted so much that the water’s tepid by the time you realize.

That’s the theory what doe s the power meter tell us over 24 hours? Well here’s the plot of Watts vs. time over 24 hours:

The energy consumption of my kettle over 24 hours

The energy consumption of my kettle over 24 hours

Well it looks like my household has 6 cups of tea in a typical 24 hours (click on the image to enlarge and you’ll see six spikes). And 2 of those spikes are thicker because that’s where I boiled it twice as described above.

The accumulator on the power meter tells me that the kettle used 0.52kWh which extrapolates to 190kWh ($30) per year to feed my family’s tea habit.

So what’s the potential for energy efficiency here?

Well the kettle uses no power in stand-by thanks to the switch breaking the circuit when it switches off, so no savings to be made there. But I know that I always boil more water than I need.

My exhaustive research (i.e. 10 minutes on Google) reveals only 2 alternatives:

Tefal Quick Cup - Is a crap cup of tea worth it treehuggers?

Tefal Quick Cup - Is a crap cup of tea worth it fellow treehuggers?

[caption id="attachment_43" align="alignright" width="300" caption="The ecokettle"]The ecokettle[/caption]

The eco-kettle and the Tefal Quick Cup both claim energy savings – 31% and 65% respectively. The ecokettle is a neat design where you have 2 chambers – one to store the water – which dispenses a measured amount into a second chamber. The idea being you only boil the water you need. The quick-cup boils the water on demand, a bit like an electric shower. The feedback on Amazon is that the quick cup makes a crap cuppa because the water only comes out at 93 degC. Plus it costs $15 in filters every six weeks! Hmmm, what’s the embodied energy in those?

So I think I’ll invest in an ecokettle. They aren’t available in Australia – so it’s off to ebay.co.uk where I can pick one up for 20 quid. If it saves me 30% then that’s a further 60kWh per year lopped off the bill for a total cost of $100 (20 pounds plus shipping from the UK is another 20 pounds = 40 pounds = $100). I’ll stick the power meter on there when I get it and see if the numbers stack up with Australian water ;-)

Stop press: more efficient kettles on the way says the hippy shopper

Aug 22

Foxtel IQ Power Consumption: A shocker in standby

energy efficiency 3 Comments »

The next appliance to get the DIY energy audit is my Foxtel IQ. For those of you outside of Australia, it is a pay TV DVR (a rebadged Sky+ box if your are from the UK).

foxtel iq - how much power?

foxtel iq - how much power?

This box is essentially a PC with a 60GB hard drive. The sad thing about it for energy misers like me is that you aren’t meant to switch it off. Ever. Thats because it needs to be on to receive its software updates and to record your favorite telly programmes when you aren’t there.

Bearing in mind that it’s on 24×365, it’s really important that boxes like these have a low standby consumption. Which is a bummer because as you can see this planet killing piece of junk doesn’t have a standby mode!. That’s right – look at the power draw over 24 hours below – it is always between 21.5 and 23 Watts over 24 hours. So I religiously switch the power button to standby every night, and the little light on the front goes from green to red pretending to be ‘in standby’ whilst all along the lazy ass of an engineer that programmed the firmware couldn’t be bothered to implement any power saving features at all. Which begs the question “why does it have a power switch at all?”.

X axis is minutes, Y axis is Watts

X axis is minutes, Y axis is Watts

Here’s a design for a foxtel IQ that can safely power down to < 1 Watt

Most PC’s can go into standby and only consume less than 1W. The foxtel IQ is just a PC in a box. The manufacturers claim that it can’t go to proper standby because it has to update software and record programmes unattended. Well why not use “Wake-over-LAN” technology to wake the box up when it needs to do these things? Wake-over-LAN is a way to switch PC’s on over the network. This means that as long as foxtel’s central server is switched on the foxtel boxes can all go to sleep safe in the knowledge that if they need to do something they will be politely woken up over their network connection. Hey – this company can even sell them the software to make it happen!

There are about 300,000 foxtel iq boxes in Australia, so if they all powered down for just 10 hours per day they would save 20W x 10 x 365 x 300,000 = 22,000,000kWh per year. Enough to power 6000 homes for a year. Just by changing some software.

As for my bill – the foxtel box is consuming 20W x 24h x365 = 175kWh per year and there is nothing I can do about it except get rid of it – which is a big ask because it is the only way I get to see the Sydney Roosters since I moved away from Sydney. I think I’ll have to upgrade to an IQ2 ;-) and hope that it’s a bit better designed when it comes to standby power use.

In the meantime I’m gonna write to Foxtel and ask them why they don’t try harder to keep my power bill down. I’ll post their response when/if I get it.

Jul 23

DIY Energy Audit Part 1 : How bad is my fridge?

energy efficiency No Comments »

Over the next few weeks I’m going to post every day as I go through every appliance in my house with a prototype version of the sokitt toolkit and take action to get my electricity bill down.

The point of all this is to show you a real life example of how a typical family can painlessly and cheaply get their electricity below a target usage of 1000kWh per person per year. If “kWh” means nothing to you think of 1kWh of electricity as 15 cents, so 100kWh of electricity is $150 worth.

Why get your per person use down to under 1000kWh?

Well the average per-person use of electricity in Oz is 3,000 kWh. So the average person should be able to reduce their bill by 2,000 kWh. That’s $300 per year per person. $1200 bucks per year for a 4 person household. And bear in mind that electricity is probably gonna double in price over the next few years…

The other reason is that we could shut down 2 or 3 of Australia’s biggest dirtiest power stations if we all did this. Which would be nice.

Anyway back to my fridge. 24 hours ago I plugged it into my sokitt compatible power meter. This wireless power meter logs the power that the fridge is using every minute and beams it to my computer (using Bluetooth).

Here’s a graph showing how many Watts my fridge sucks every minute for 24 hours:

fridge power

fridge power

The y-axis on this graph is Watts. The high black areas are when the compressor is running, you can see that the compressor is on a lot more than it is off. This is bad news – fridges are designed to have the compressor switched on for less time that they are off. It looks like my fridge has become a bit of an energy guzzler and has to keep the compressor on for ages to keep the temperature down.

sokitt takes this data and can tell me the following:

1) my fridge is using 2.44kWh per day
2) this is 891kWh per year
3) it’s costing me $131 per year to run
4) it is the equivalent of a zero star rated fridge in 2008 terms! (it’s only 5 years old!)

Remember my budget is only 1000kWh per year per person, so my fridge is using 90% of 1 person’s allowance!

Now what I really want to know is: how does my fridges performance compare with what it was when it was brand new? And what are my options for buying a much more efficient fridge? Should I buy a new one or get this one fixed up?

sokitt can answer all those questions too. I’ll show you how in the next post.