Renewable Energy: Meeting our growing electricity demand while keeping prices low
Electricity consumption continues to grow. According to ABARE, electricity consumption in Australia is projected to grow at 1.8% per year (Source: “Australian energy projections to 2029-30”, ABARE, Mar 2010). This equates to a 50% increase over current consumption levels by 2030, and more than double current consumption levels by 2050.
This additional consumption must be met by either increased fossil fuel generation or an increase in generation from renewable sources such as wind power.
At the same time, in recognition of the environmental limits of our planet’s ecosystem, the Australian government has set a target of 60% reduction in greenhouse gas emissions by 2050.
Something has to give – we can’t double the amount of electricity used, halve the greenhouse gas emissions resulting from this, and continue to use the same power generation sources that we have always used.
It is therefore essential to maximise the use of zero-emission renewable energy.
While the output of wind and solar farms is variable due to local wind speeds and sunshine, it is also predictable, reliable and dependable - in many cases, more so than aging coal fired power stations.
In the same way that the weather can be predicted hours to weeks in advance, the likely solar or wind farm power output at any point in time can also be forecast. For example, the Australian Electricity Market Operator (AEMO) has established a Wind Energy Forecasting System to predict wind farm production from minutes to days in advance. This system enables AEMO to reliably operate the electricity market taking into account the constantly changing load, availability of and loading on transmission lines, plant outages at major power stations, and the changing output of wind farms.
As more wind and solar projects are built, the level of renewable energy output to the grid will be more consistent. While a storm front or clouds may be affecting one project, when that is only one of 20 or 200 similar projects it will not materially affect Australia’s electricity supply system.
Australia’s large geographic diversity spreads the solar and wind projects over a very large area with all sorts of different weather patterns - this provides us with direct benefits in maximising the use of wind and solar power.
None of our energy options come without limitations. Nuclear power comes with its inherent risks; coal and gas options come with inescapable climate impacts; bioenergy options often compete with land needed for food and timber requirements; and in a dry continent like Australia, hydro options are inherently limited.
For that reason, we must maximise the low risk, low cost options like wind power and solar power, and then use complementary options to ensure our power supplies remains dependable.
Our energy supply system is capable of using all of the wind and solar energy options currently planned in Australia.
A typical 3 Megawatt wind turbine produces enough electricity to supply over 1000 households with electricity. This is based on it operating at an average annual output of around 35 to 40% of the maximum wind farm capacity, which is typical for wind farms in Australia. That means a typical small wind farm of 15 turbines will provide power for more than 15,000 homes.
A medium scale solar project of 35 to 40 megawatts can also power around 10,000 homes, and takes up just 70 hectares, the size of a medium scale hobby farm. Its therefore easily within the scope of regional Australian townships to provide all their energy requirements from solar.