Sustainable energy in Australia

We are suffering terrible climate change damage – consider the decline in run-off in the Murray Basin, rising temperatures, increased frequency of storms and hurricanes, increased ferocity of bushfires, increasing acidity of the oceans, the decline in rainfall in the southern half of the country, the damage to the Great Barrier Reef, etc. – we should reduce our CO₂ production levels for our own benefit.

Energy conservation is a big part of the answer, but sustainable energy generation is too, hence this page.

Contents

Matters relating to sustainable energy

Changes needed in the electricity supply system

Major tabels

Reference

News

2009/06/22
Renewable energy rebate for remote homes axed

2009/04/30
Gov'ts approves renewable energy target plan

Extracted from a media release by the Renewable Energy Council.

Comparative costs of power generation

Nuclear power is very difficult to cost because, if the figure is to be meaningful, it must cover mining, building the power station, running costs for the full life of the power station, protecting the nuclear material from possible theft by terrorists, decommissioning costs, and costs of disposing of the radioactive wastes and protecting them from disturbance for many years.

Cost of electricity generated by various methods, including capital costs

Electricity generating costs in Australia

Note that wind-generated electricity is not greatly more expensive than the estimated cost of 'responsible' coal-fired power (Coal with geosequestration). Note also that coal-fired power with geosequestration of carbon dioxide has never been proven at any price.

Solar here, I believe, refers to photo-voltaic.

Balance in sustainable energy rebates

At the time of writing (2009/02/28) there are rebates for installing photovoltaic power on private homes and schools, but no rebates for installing small wind turbines, except in isolated areas not connected to the electricity supply grid. This is very unfair to the manufacturers and suppliers of small wind turbines and it discourages development of this, potentially important, sector of the sustainable energy industry.

Transport

Electric cars do seem to be near practicality, and they can be 'green' if their batteries are recharged using green power (not fossil-fuel or nuclear generated power). Their biggest drawback is their relatively short range; around 100 to 150km.

Electric Car

The idea is that people would buy the cars and then pay by the mile to use them. The range on one charge would be around 100km, the cars would be aimed at the commuting market, and the company would provide numerous recharging stations.

The quote below is from the Better Place page on the subject...

"We selected Australia, the world's sixth largest country, to show that our model works in any country, regardless of size. If Australia can do it, so can others. We will build an electric vehicle network capable of supporting the switch of Australia's 15 million gas cars to zero emission vehicles. We have two strong partners: AGL Energy, with Australia's largest portfolio of privately-owned renewable generation; and Macquarie, well known for making smart infrastructure investments around the globe. AGL will provide all of the renewable energy - from wind and other sources - needed to power the electric vehicles and work with Better Place to optimize the network. Macquarie will provide financial advice to help raise AUD $1 billion for the initial network build. Moving Australia off oil will benefit the economy and the environment."

Of course the suggestion that the cars will have zero emissions is marketing bullshit; emissions do not only come from the vehicle fuel. However, they should be far better than the present petroleum based cars.

I have written at greater length on sustainable transport, in the global context, elsewhere.

Balancing generation and load

Price-responsive-load, in which the electricity market can respond to retail electricity price changes, must be adopted as soon as possible. For this to work several changes must be made to the way electricity is sold, especially at the retail level:

• The retail electricity price must be allowed to rise and fall, depending on supply and demand, just as the wholesale electricity price does;
• Consumers must have access to the price at all times, and have the option of using electricity or not depending on the price;
• Consumers must have the option of selling electricity as well as buying it.

I asked Terry Teoh of Pacific Hydro whether PH was looking into pumped-storage hydro as a means of levelling supply and demand relating to wind energy development. A part of his answer...

"In the short term the intermittency of wind can more easily be dealt with (from both technological and cost perspective) by using gas generators to handle the increased dynamic variability. Gas generators already perform the bulk of the balancing function for SA as our overnight demand is roughly 50% of daytime demand. Adding more wind into the system causes gas generators to be a bit 'busier' and for now this is cheaper than storage. The existing market design should allow this to occur quite readily."

Storing electricity

Storing electricity as a way of balancing the grid is closely linked to the principle of Price-responsive-load.

This graph shows how a number of energy storage techniques are placed in terms of capital cost per unit of power and capital cost per unit energy. (CAES = Compressed air energy storage). Source: Electricity Storage Association

The graph at the right shows some energy storage techniques and their capital costs in terms of energy and power. An important factor that it does not show is the efficiency of each process, that is, how much energy is lost in storing the energy and getting it back. Capacitors and flywheels can be highly efficient, batteries less so, and perhaps compressed air least of all?

The length of time the power must be stored is an important variable. Capacitors and flywheels are well suited for storing power for short periods (capacitors leak and flywheels run down), hydro suits longer periods because the water stays where it is put until it is needed.

Pumped-storage hydropower is a part of the answer; heat storage in solar-thermal plants is another part, techniques like the reversible formation of ammonia from hydrogen and nitrogen (experimental and not shown on the graph) could be another part.

The capital costs of most of these techniques is quite high. An opportunity will arise when and if electric vehicles become common, the batteries will already exist for use in the cars; there will be no additional capital cost. It will be possible for the car batteries - which will be connected to the power grid for recharging - to be used to help balance electrical supply and demand. They will, at the same time, produce some extra income for their owners who will be selling electricity when it is expensive and buying at lower prices.

It is possible to store huge amounts of compressed air in geological formations; this involves much less capital expense than storage in man-made tanks.

All these methods depend on opening the electricity market to free trade, similarly to most other markets.

Storing electricity is also discussed in my page on Sustainable electricity in the international context.

The need for transmission lines:
Efficient power transmission over long distances

High voltage direct current (HVDC) Extract from Wikipedia... "HVDC has the ability to transmit large amounts of power over long distances with lower capital costs and with lower losses than AC. Depending on voltage level and construction details, losses are quoted as about 3% per 1000 km. High-voltage direct current transmission allows efficient use of energy sources remote from load centers." The same Wikipedia article indicated that 5GW was quite feasible for a transmission line with four cables (bipolar, two pairs of cables). Cost of high voltage direct current transmission lines Extract from a World Bank document... A graph indicates that for a 2GW transmission line DC is cheaper than AC over distances greater than about 700km, and for a 1200km line the cost would be around US$550m. (Information from Miles George of Babcock and Brown suggests that the cost could be above Aust$1.2b.) "Assumptions made in the price calculations: For the AC transmission a double circuit is assumed with a price per km of US$250 000 (each), AC substations and series compensation (above 600 km) are estimated to US$80m. For the HVDC transmission a bipolar OH line was assumed with a price per km of US$250 000, converter stations are estimated to US$250m." The same document states that construction times for HVDC systems are lower than for HVAC systems.

A map and table on my Wind Power Potential page give more detail on the areas within Australia where wind power could be harnessed. The potential of these areas could be realised if collector transmission lines were built in the wind farm areas and high voltage direct current (HVDC, see box on right) transmission lines to take the power to the markets in the eastern states where NSW and Queensland in particular have much inferior wind resources to SA, Tasmania and WA.

There needs to be a grand plan; adding a wind farm here, a solar power station there and upgrading a transmission line somewhere else is not the way, and by definition we cannot stay with unsustainable energy.

Epuron has proposed a 1GW wind farm for Silverton near Broken Hill. If it is to be run effectively a high capacity transmission line will have to be built from Broken Hill to connect with a larger power market (Average power consumption for the whole of SA is about 1.5GW; Broken Hill could not use 1GW). Epuron intends to build a 290km transmission line from Silverton to an existing high capacity line (the Murraylink Interconnector) at Redcliffs. An imaginative government committed to sustainable energy might rather build a 5GW transmission line from Mid North SA through Broken Hill to Sydney (1200km), with a branch to Brisbane to cater for expansion in the SA sustainable energy industry.

Importantly such a line could also feed power back into SA when needed. In the record heat-wave of January 2009 that affected Victoria and South Australia a number of large areas had to be blacked-out because of record power consumption and the failure of the Bass-Link line to Tasmania. Heat-waves often affect both Victoria and South Australia at the same time; a link between South Austarlia and NSW would be very valuable at those times.

Australian governments have always been willing to build transmission lines to serve new fossil-fuel power stations, why - if they are as much in favour of sustainable energy as they claim to be - are they unwilling to build them for sustainable energy development?

Should we follow the lead of Texas? From Terry Teoh (Pacific Hydro)...

"Texas is in process of implementing their CREZ (competitive renewable energy zones) policy which is a departure from contemporary electricity sector micro-economic thinking in the industrialized world. Under CREZ, government takes the up front risk of building the backbone transmission system to remote regions which have world class wind resources. The transmission capacity is then auctioned to the private sector. So government takes a 'build and hope' approach."

Western and northern SA have huge potential for geothermal and solar power. They could use the same interstate connectors: once they have been proven to be economically viable, an HVDC line from around Inaminka to Broken Hill (supposing that by that time Broken Hill is connected to both east and west by a high capacity transmission line) should be built.

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