RuffnReadyOzStyle
11-14-2006, 12:59 AM
I've just finished up studying for the year, and the last thing I had to do was an audit of my residential electricity use. In Australia, about 30% of electricity generation is used by households, so it's important to know where it all goes.
The method is very simple -
1. read your electricity meter and record the reading in kWh and time.
2. make a record every time you turn something on or off for a week.
3. read your electricity meter again a week later and record the reading.
4. multiply the time each appliance has been on during the week (in hours) by its power usage (in W), to get the appliance's power consumption for the week (in Wh). Divide by 1000 for kWh, which is the measure on your electricity bill.
You will find that the total of your calculations is lower than the metered total - that is because many appliances (especially TVs, stereos, DVD/video players, anything with a clock) chew up roughly 10% of their switched-on power demand when on standby.
I recently conducted an audit of my own electricity consumption behaviour. I live alone, which generally consumes more energy per person than a group of people living together, so I was very interested to see how much power I consumed.
Over the week of measurement I used 50.2kWh, an average of 7.1kWh/day, whereas the Australian average is about 9kWh/day. However, it is a warm time of year and I used no heating, so my yearly average is probably close to the community average. Living alone, which means I don't get energy savings from shared activities like cooking, heating and entertainment, I was pretty happy with the result.
The reason I mention it here is that it was a very valuable exercise with some surprises! For example, 45% of my energy is used on entertainment (stereo, TV, video and DVD player, laptop), and a staggering 58% of that was my stereo! Little did I know, but it is a 250W machine - for comparison, the laptop uses 120W, the TV consumes 100W, the video 14W and the DVD player 7W. My stereo is 16 years old, so maybe it's time to invest in one that doesn't chew so much power!
Other interesting finds:
*my stereo, TV, video, DVD player, and laptop combined chew through 6.88kWh a week on standby alone - I am now turning them off at the power point when not in use.
*my modem uses 2.04kWh a week just sitting there - I am now turning it off at the power point when not in use.
*my fridge and hot water heater combined to use 43% of my electricity consumption, about as expected.
So, by switching things with a standby mode off at the powerpoint, I will save roughy 464kWh (8.92x52) of electricity a year, which is close to 20% of my consumption. By getting a more energy efficient stereo, I'll add to the savings. Oh, and that means about $200 bucks a year savings, which I can then choose to put into offsetting the extra cost of buying renewable energy (which costs me about an extra $450/yr).
Who would have thought it was so easy to make a significant difference to your energy consumption?
Who would have thought my stereo would chew through 13.68kWh in a week!? I listen to a lot of music, and run my TV sound through the stereo, but I never thought it would consume so much electricity.
This is a really valuable exercise. It forces you to examine your energy consumption patterns closely, rather than just paying a bill every three months, and then you can make better informed choices about your consumption.
I highly recommend that you give it a go yourself. In fact, it should be something every kid is doing in high school. We are far too detached from the real consequences of the decisions we make, and this is one way of bringing the consequences of our automatic behaviours to the forefront of our minds.
The method is very simple -
1. read your electricity meter and record the reading in kWh and time.
2. make a record every time you turn something on or off for a week.
3. read your electricity meter again a week later and record the reading.
4. multiply the time each appliance has been on during the week (in hours) by its power usage (in W), to get the appliance's power consumption for the week (in Wh). Divide by 1000 for kWh, which is the measure on your electricity bill.
You will find that the total of your calculations is lower than the metered total - that is because many appliances (especially TVs, stereos, DVD/video players, anything with a clock) chew up roughly 10% of their switched-on power demand when on standby.
I recently conducted an audit of my own electricity consumption behaviour. I live alone, which generally consumes more energy per person than a group of people living together, so I was very interested to see how much power I consumed.
Over the week of measurement I used 50.2kWh, an average of 7.1kWh/day, whereas the Australian average is about 9kWh/day. However, it is a warm time of year and I used no heating, so my yearly average is probably close to the community average. Living alone, which means I don't get energy savings from shared activities like cooking, heating and entertainment, I was pretty happy with the result.
The reason I mention it here is that it was a very valuable exercise with some surprises! For example, 45% of my energy is used on entertainment (stereo, TV, video and DVD player, laptop), and a staggering 58% of that was my stereo! Little did I know, but it is a 250W machine - for comparison, the laptop uses 120W, the TV consumes 100W, the video 14W and the DVD player 7W. My stereo is 16 years old, so maybe it's time to invest in one that doesn't chew so much power!
Other interesting finds:
*my stereo, TV, video, DVD player, and laptop combined chew through 6.88kWh a week on standby alone - I am now turning them off at the power point when not in use.
*my modem uses 2.04kWh a week just sitting there - I am now turning it off at the power point when not in use.
*my fridge and hot water heater combined to use 43% of my electricity consumption, about as expected.
So, by switching things with a standby mode off at the powerpoint, I will save roughy 464kWh (8.92x52) of electricity a year, which is close to 20% of my consumption. By getting a more energy efficient stereo, I'll add to the savings. Oh, and that means about $200 bucks a year savings, which I can then choose to put into offsetting the extra cost of buying renewable energy (which costs me about an extra $450/yr).
Who would have thought it was so easy to make a significant difference to your energy consumption?
Who would have thought my stereo would chew through 13.68kWh in a week!? I listen to a lot of music, and run my TV sound through the stereo, but I never thought it would consume so much electricity.
This is a really valuable exercise. It forces you to examine your energy consumption patterns closely, rather than just paying a bill every three months, and then you can make better informed choices about your consumption.
I highly recommend that you give it a go yourself. In fact, it should be something every kid is doing in high school. We are far too detached from the real consequences of the decisions we make, and this is one way of bringing the consequences of our automatic behaviours to the forefront of our minds.