Melbourne, get to know your energy use
Something we all depend on everyday is energy. Whether it be flicking a switch, twisting a knob, or turning a key, energy use is now so convenient and such a pervasive part of our lives that many of us don’t know a lot about where it comes from. But energy use is one of the most important things to know about, because understanding energy use gives us more control over two big things: how our money is spent, and how much greenhouse gas we are responsible for contributing to the atmosphere.
It is a big topic, but I think there are probably three main things to know about energy:
1. Where it came from;
2. How it is used; and
3. How much greenhouse gas it is responsible for emitting.
What are Victoria’s energy sources?
49% of Victoria’s total energy use comes from coal. In terms of electricity in Victoria, over 90% is supplied by brown coal (lignite). Brown coal is most inefficient fossil fuel because it is composed of two-thirds water so some of its energy content is used just driving off this water.
How is energy used?
Most of us have control over the energy used in our state in the categories of residential energy use (which basically means energy used in households) and energy used in transport. According to Sustainability Victoria …
“In 2004-05, 21% of Victoria’s final energy was used in the residential energy sector and 42% in the transport sector.”
As you can see, adding these two categories together (63%) gives a big slice of the pie.
Looking closer at household energy use in Victoria we can see that 59% goes to space heating and cooling while 21% goes to water heating.
What about greenhouse gas emissions?
Victorian electricity (mostly brown coal) produces 1.392 kg CO2e per kilowatt-hour. Victorian gas produces 0.0636 kg CO2e per megajoule. As there are 3.6 MJ in 1 kWh, brown coal produces 0.387 kg CO2e per megajoule, meaning brown-coal electricity produces six times the greenhouse gas emissions of gas for the same amount of energy. This is why it is better to use a gas cook-top or heater than a electric one.
Victorian electricity produces a lot of greenhouse gas emissions because of its reliance on brown coal. In fact, Victoria’s Hazelwood power station has been ranked the dirtiest power station in the world, according to the WWF.
Sources and more information can be found at:
Sustainability Victoria – Energy Use in Victoria
Sustainability Victoria – Energy Generation in Victoria
Sustainability Victoria – Energy Use by Sector
The Climate Group – The Greenhouse Indicator Victoria
Australian Bureau of Agricultural and Resource Economics data
Environment Victoria – What is brown coal?
Sustainability Victoria – Fact Sheets on Saving Energy in the home
Black vs. Green Energy
The Age – The Dirty State We’re In