Appendix to Australian Uranium paper
(updated April 2012)
- Australia is heavily dependent on coal for electricity, more so than any other developed country except Denmark and Greece. Three quarters is derived from coal.
- Australia's electricity is low-cost by world standards.
- Natural gas is increasingly used for electricity, especially in SA and WA.
- After many years of low investment, there is a major challenge to build more generating capacity.
Electricity consumption in Australia has been growing at nearly double the rate of energy use overall. In 2008-09 about 11,000 kWh per capita was used, including that incorporated into exports.
Electricity generation takes 44% of Australia's primary energy, and in terms of final energy consumption, electricity provides 24% of the total. test
Energy in Australia
Much of the energy exported from Australia is used for generating electricity overseas; three times as much black coal is exported as is used in Australia, and all of the uranium production is exported.
Australia also exports a significant amount of energy in mineral products. Exports of aluminium metal* alone embed some 25 TWh of electricity per year, about 9% of the country's total gross production. Some 43 TWh is used in non-ferrous metals (aluminium smelter production uses 29 TWh/yr), almost half of the industry total.
*Production 1.98 Mt in 2008, export of 1.67 Mt, @ av 15 kWh/kg.
Most of the growth in value-adding manufacturing in the past 20 years has come from industries which are energy- and particularly electricity-intensive. The growth has occurred in Australia because of relatively low electricity prices coupled with high reliability of supply and the proximity of natural resources such as bauxite/alumina.
In 2009 Australia's power stations produced 261 billion kilowatt hours (TWh) of electricity*, 68% more than the 1990 level and growing at up to 3% pa.
* 254 TWh public supply + 12 TWh for non-grid autoproducers.
Of this gross amount, about 19 TWh is used by the power stations themselves, leaving 242 TWh actually sent out (net production). Then about 17 TWh is lost or used in transmission and 11 more in energy sector consumption, leaving 214 TWh for final consumption (or 189 TWh apart from aluminium exports).*
* Vencorp suggest that typically net TWh are about 10% less than gross TWh, with transmission and distribution losses often being 10%
In 2008-09 the electricity was produced from 56 gigawatts (GWe) capacity, of which 30.3 GWe (54%) was coal-fired, 14.7 GWe (26%) gas or multi-fuel, 1.35 (2.4%) oil, 7.1 GWe (13%) hydro and 2.5 GWe (4.5%) other renewables.
Most of this is associated with the grid-connected National Electricity Market in the southeast and east of the country, the second grid being the South West Interconnected Supply area in Western Australia. A smaller grid is in the Pilbara.
In 2009, 78% of the power was produced from coal, 14% from natural gas, 4.7% from hydro.
In Victoria the main fuel is brown coal (lignite), in NSW and Queensland it is high quality black coal, and in WA and SA it is much lower quality black coal.
Fuels for Electricity, emissions
About 78% of Australia's electricity is produced from 54% of the capacity, reflecting the predominance of base-load demand and the fact that coal provides the main base-load capacity in Australia. See also chart below. Note that electrically, Western Australia is isolated.
Australian coal is mostly very clean by world standards, so electricity is produced without very much sulfur dioxide being emitted (or requiring expensive equipment to avoid its emission).
However, power generation contributes 35% of the country's net carbon dioxide-equivalent emissions (200 out of 580 Mt in 2008). The 2008-09 figure calculated from thermal plants in an ESAA benchmarking study is 204 Mt, about 37% of total. In this, black coal plants in NSW emit 920,000 tonnes CO2 per TWh, Victorian brown coal plants emit 1.29 million tonnes CO2 per TWh.
From mid 2012, a carbon tax of $23 per tonne of CO2 will apply to many industries.
The Cost of Electricity
Much electricity in Australia is now traded so that distribution companies buy at the best price available from hour to hour from competing generators.
The difficulties matching supply with demand can be judged from the fact that Victorian demand ranges from 3900 MWe to 10,000 MWe, and that in NSW from 5800 to 15,000 MWe.
Australian electricity prices were almost the lowest in the world to about 2007, but have risen significantly since then, and international comparisons are exacerbated by the exchange rate. Hence 2011-12 average Australian household prices are above Japan and EU average and much higher than USA. By state, WA, Vic, NSW and SA 2011 prices rank behind only Denmark and Germany.
The earlier low prices created a major problem in attracting investment in new generating plant to cater for retiring old plant and meeting new demand - a 25% increase by 2020 was projected, and in fact a 40% rise occurred by 2011, with another 30% projected to 2013.
Victoria Load Curve
Load curve of the Victorian electricity system in two peak days in 2006, showing the relative contributions of base, intermediate and peak-load plant duty. The shape of such a curve will vary markedly according to the kind of demand. Here, the peaks reflect domestic demand related to a normal working day, with air conditioner demand evident on the hot summer day.
Note that base-load demand accounts for the majority of electricity supplied. The base-load here is about 5300 MWe, and while total capacity must allow for nearly double this, most of the difference is normally supplied by large intermediate-load gas-fired plant. The peak loads are typically supplied by hydro and gas turbines. Under the wholesale electricity market, power stations bid into the market and compete for their energy to be despatched. Thus the sources of supply at any particular moment are determined by some balance between plant which (once installed) can be run very cheaply, and that which while costing less to build, uses more expensive fuel. Source: Vencorp.
Eastern Australia's National Electricity Market (NEM) operates the world’s largest interconnected power system that runs for more than 5,000 kilometres from North Queensland to central South Australia, and supplies some $10 billion electricity annually to meet the demand of more than 10 million end users. The NEM volume-weighted average price in 2008-09 ranged from $36/MWh in Queensland to $49/MWh in Victoria and $69/MWh in SA. NEM infrastructure comprises both state and privately owned assets, and is managed under the overall direction of the Australian Energy Market Operator (AEMO), which was established by the state and federal governments.
Australia has 27,640 km of transmission lines and cable (220 kV and above - 10,300 km 330 kV and above), mostly state-owned and operated, transporting 209 TWh of electricity per year (2008-09). There is no connection between the east of SA and WA.
Because most of Australia's electricity is produced near the main load centres there is less high voltage (500, 330, 275, 220 kV) transmission needed than in some countries. There is nearly as much at 132 kV as at those four higher levels combined. (At 500 kV, transmission losses over 500-1000 km are halved.)
OECD IEA 2009, Electricity Information (2007-08 data).
ABARE, Australian Energy report 05.9
ESAA, Electricity Gas Australia 2010
AER Aug 2008, Network Report 2006-07
AGO 2004, Stationary Sector GHG Emission Projections
Vicpool Information Bulletin 3, 43.
CME report to Energy Users Association, March 2012, Electricity Prices in Australia: An International Comparison