The pitt&sherry Carbon Emissions Index (CEDEX) indicates reduced electricity generation in the National Electricity Market (NEM).
According to this issue of the CEDEX Electricity Update, electricity generation is down 2% while emissions are down by 12.2 million tonnes CO2-e, which is equivalent to just below 7% for the first full year of carbon pricing. The NEM accounts for about 90% of Australian electricity supply.
According to Dr Saddler, Principal Consultant, Energy Strategies, pitt&sherry, the complex relationship between generation and emissions reflects the continually changing interaction between the Large Scale Renewable Energy Target (LRET), the factors driving reduced demand and the carbon price.
He explains that all these factors are important contributors to the good news story of steadily falling Australian electricity generation emissions.
Annualised electricity supplied by black coal generators continued to fall in June, bringing the total fall for the year to 4.7 TWh. Annualised generation from brown coal power stations recorded a very small increase in June, but recorded a fall of 5.5 TWh for the whole year. Black coal generation during the preceding five years had already fallen to over 15%, whereas brown coal had actually increased slightly.
Output from gas and wind generation fell slightly during 2012-13, while hydro generation continued to increase consistently since the beginning of calendar year 2012.
For the 2012-13 year, coal fired generators supplied 72.5% of NEM generation, while gas supplied 12.2% and hydro and other renewables supplied 15.3%.
The CEDEX Electricity Update includes WA demand data for the first time. The Independent Market Operator (IMOWA) reports on electricity sent out from power stations, excluding the substantial quantities of electricity consumed at the power stations themselves, termed auxiliary load. Coal fired power stations have much higher auxiliary loads than gas fired power stations, with brown coal on average, higher than black. Auxiliary load at hydro and wind power stations is effectively zero.
Demand in WA, as defined in the NEM includes auxiliary loads; it also includes electricity generated by coal fired power stations during off-peak periods to pump water to upper storages at the pumped storage facilities in NSW and Queensland.
Adjusting for these factors effectively converts quantities of electricity generated at power stations to quantities of electricity sent out from power stations. These adjustments for pumped storage and auxiliary loads have been applied to total state demand in the NEM, as reported by the Australian Energy Market Operator (AEMO), to convert demand as generated to demand as sent out out—making the WA and NEM figures directly comparable.
Dr Saddler notes that these adjustments have removed about one fifth of the total fall in NEM demand over the year as reported by AEMO, because lower coal fired generation has reduced auxiliary load.
Notwithstanding the very strong economic and population growth experienced in WA over the last few years, demand for electricity in the South West Interconnected System (SWIS), which covers most of the WA population, though not the areas where new LNG plants and iron ore mines are being constructed, has not grown since 2011.
However, the whole of month data published by Independent Market Operator Western Australia (IMOWA) is delayed by several months; it is therefore not possible to ascertain whether the decline in demand, which is apparent in the data to the end of February 2013, is still continuing, as it is in all the NEM states except Tasmania.