From an ethical point of view the main consideration should be how damaging
or benign a particular technology is to our environment; in the real world
cost will often be given higher priority.
Also in the real world, the most desirable mix of energy technologies will
depend on a combination of costs, political pressures and idiologies, and
Coal- and gas-fired generation can be made less environmentally damaging if we are willing to pay substantially higher prices for our electricity.
What variables are involved?The options are discussed below; follow the links.
I have discussed a number of these questions in relation to the world in general in another page on this site: The pros and cons of various methods of generating electricity. On this page I will try to compare their desirability for Australia.
Note that the graph shows that solar PV costs fell substantially between 2012 and 2013; since the compilation of this graph they have continued to fall. Wind power costs in Australia have fallen substantially since 2013.
In regard to the graph, the cost of coal- and gas-fired power is very dependent on the local cost of coal and gas, which may differ substantially from one country to another.
A solar thermal power station to be built in South Australia by 2020 that is contracted to sell power to the state government at a maximum of $78/MWh seems to cast doubt onto the graphed cost of solar thermal energy generation (STEG).
In the end the wholesale electricity price is dictated by supply and demandIn the National Electricity Market (NEM), that serves the eastern states, the wholesale price of electricity is set at frequent intervals depending on bids from the power generators. If there is a lack of competition in a segment of the market at a particular time, prices can go much higher than the cost of generation.
Ms Molyneaux wrote that even this would not reduce emissions sufficiently to meet Australia's target; that would require the addition of carbon capture and storage, putting the price of electricity up to $155/MWh (US$117).
A few days later (2017/02/03), Bloomberg New Energy Finance, as reported in RenewEconomy, announced the following research:
"The research puts the Levelised Cost of Energy (LCOE) of a new ultra-supercritical coal-fired power station in Australia at $A134-203/MWh; significantly higher than the LCOE of new-build wind at $A61-118/MWh), solar $A78-140/MWh or combined-cycle gas at $A74-90/MWh."See the graph on the right.
A coal-fired power station has a typical life of up to 50 years. No coal-fired power station built today will be allowed to continue to burn coal for 50 years, because of climate change. Wind and solar PV are already very economically competitive to coal, their costs are continually declining; a new coal-fired power station will quite probably be economically unviable in ten years. For these reasons, independent financiers are not interested in financing coal-fired power stations.
Then there are peaker plants (usually open cycle gas turbines, OCGT); quoting Wikipedia:
"A peaker plant may operate many hours a day, or it may operate only a few hours per year, depending on the condition of the region's electrical grid. Because of the cost of building an efficient power plant, if a peaker plant is only going to be run for a short or highly variable time it does not make economic sense to make it as efficient as a base load power plant."According to Wikipedia, new peaking gas generators are typically 30 to 42% efficient. OCGTs have low capital costs but high fuel costs. Operators generally have to charge more for the electricity from OCGTs than from CCGTs because of the shorter times that the former are run and their higher fuel costs.
An important factor in the cost of gas-fired power in Australia has been the increase to gas prices that occurred when compressed natural gas (CNG) started to be exported. Before export, Australia's natural gas was cheaper than the global price; following the establishment of the export industry, Australia's price rose to equal the global price.
In Australia, gas-fired electric power is typically more expensive than coal-fired electric power. South Australia's electricity prices are generally higher than other states because SA has a high percentage of electricity generation by gas.
Lynette Molyneaux' research, discussed under cost of coal power, above, in regard to emissions also applies to gas; to minimise emissions from gas-fired generators carbon capture and storage would have to be used, and that would greatly increase the cost.
The very small probability, but colossal costs, of disasters such as with Fukushima should be taken into account with costing; as should the possibility of a nuclear power station becoming a target for terrorists or of enemies in war-time.graph above, the cost of solar PV power is decreasing steaply. In early 2017 I believe that it was comparable to the cost of power from conventional new-built coal-fired power stations and wind power.
I inquired regarding the feed-in tariffs for the Australian Capital
Territory's (ACT's) large-scale solar auction conducted in 2012 and 2013.
On 2017/02/09 I received the following in an email from Dr Greg Buckman,
Senior Policy Officer, Energy Markets and Renewables; Environment, Planning
and Sustainable Development Directorate, ACT Government.
Coal mining damages huge areas of land; greater than any other single form of mining. The rehabilitation of abandoned coal mines is problematic, enormously expensive, and rarely restores anything like the original land condition. Similarly, the ash dumps at coal-fired power stations are difficult and expensive to rehabilitate. (For example, Port Augusta power stations.)
The very substantial health and safety impacts of coal are dealt with elsewhere on this page.
The fracking that is often used in extraction of natural gas could easily lead to leakage, as well as contamination of aquifers.
How recyclable solar panels are at the end of their useful life is questionable.increase the 'surface roughness' of the land in relation to the wind passing over it.
A 'base-load' generator is one that is best suited, for either economic of practical reasons, to run at near full capacity all or most of the time.
A 'peaking' generator is one that is able to come on-line at short notice to cover periods of high electricity demand; at 'peak' times. Hydro-power can supply peak demand, within the limits of the availability of stored water. Some types of gas-fired generators are very well suited for peak-power; more on them below.
Wind and solar PV, the dominant new renewables at the time of writing, only generate power when the wind blows or the sun shines.
Coal and nuclear are generally classed as 'base-load' forms of electricity generation.
Gas-fired power stations come in several varieties. The cheaper and less efficient ones are valuable in being able to vary in their amount of generation to suit the varying demand of the electricity grid; this is called 'peaking power'. Those that are the most energy efficient need to be run a large proportion of the time to justify their high capital cost; they are more 'base-load'.
Wind farms, of course, are available only when the wind blows.
Solar PV installations generate only during daylight hours, and are most productive on clear, sunny days.
Solar thermal with storage can supply power well after the Sun has moved too low into the sky to produce much power from solar PV panels, or has sunk below the horizon. It has the potential to supply the big late afternoon and early evening peak power demands of Australia's hot summers.
Wind and solar power, because they are not available on demand; as well as coal and nuclear, because they are inflexible, need to share the power grid with flexible power generation systems, such as gas, hydro or energy storage, that can quickly respond to changes in demand.
The CSIRO published a study 8th July 2015 into energy storage for the Australian Energy Market Commission. The study dealt mostly with various battery technologies. It mentioned that pumped hydro storage was used mostly for bulk storage of large amounts of electricity for periods of hours to days, while batteries were for storage periods of seconds to hours. The CSIRO document listed the main energy storage installations in Australia; it is interesting to note that the largest battery storage installations were around 3 MW (but this is changing quickly), while the pumped hydro systems were far bigger:
Australia will need to develop sizeable energy storage if renewable energy is to be exploited fully.
Substantial amounts of battery storage are starting to be incorporated into proposed wind and solar power projects in Australia, for example, Crystal Brook Energy Park includes 160 MWh of battery storage.demand-side-management in the power grid, the increasing installation of household batteries and the replacing of fossil-fuelled vehicles with electric vehicles (EVs) will have a strong impact on the need for, and availability of, energy storage.
In the near future there will be wind farms with batteries, homes with batteries, EVs with batteries, solar PV farms with batteries, solar thermal power stations with energy storage, and pumped hydro. There is every reason to believe that all of these should be able to interact – in both directions – with the grid. For example, if electricity has a variable price according to its abundance at any particular time the owner of a home battery or EV battery should be able to buy electricity at a time of high-availability and low price and sell it back to the grid if limited generation produces a high price.
Power to hydrogenIt is possible to use excess electricity to convert water into hydrogen and oxygen. The hydrogen can be stored and later used as an energy source. This is discussed on another page on this site.
Coal and gas fired power generation consumes fossil fuels that are
finite natural resources.
Coal and gas are not sustainable.
Nuclear power stations use a form of uranium (U235) that makes up only 0.7% of all natural uranium. Some nuclear reactors that are not yet proven to be commercially viable also use the bulk of the remaining uranium (U238). Uranium is not a renewable resource; nuclear power is therefore not sustainable.
Wind, solar PV, solar thermal, wave power and biofuels all use fuels and materials that are either unlimited (sunshine, wind, waves) or renewable (agricultural or silvicutural crops). Most of the materials used in construction can be recycled. These technologies are substantially sustainable.
There is a note on the sustainability of batteries elsewhere on this page.
Well informed Australians know that if we are to effectively act on climate change and ocean acidification we should not be opening more coal mines or building new coal-fired power stations.
Recent Australian history shows that people will strongly resist the establishment of new coal mines.
However, a project to search for, or extract gas, especially if fracking is involved, is a very different matter. Anyone proposing this would expect determined local opposition.
The people in any area where a nuclear power station is proposed can be expected to know, or to quickly be informed, that Australia does not need nuclear power stations; we have ample untapped renewable energy resources.Williamsdale instead. these and a few similar points are quite reasonable.
There was little, if any, opposition to wind farm construction in Australia until about 2008. Since then a small number of vocal people have spread largely unjustified concerns about health, noise, land values, fire-fighting implications and other things. These unjustified and often dishonest fear campaigns, from organisations such as the Heartland Farmers on South Australia's Yorke Peninsula, have, not surprisingly, been effective in increasing fear, concerns and opposition among local people.
Proposals to build wind farms have been blamed for causing social conflict, but the fact is that there was no social conflict until the vocal and dishonest opposition became active.
Recently it has been recognised that black lung disease, coalworker's pneumoconiosis, has been harming workers in the coal mining industry for many years. (Medical Journal of Australia, coalworker's pneumoconiosis.) "Coal miners die and suffer more lost time from injuries than all other miners"; Clinical Focus, September 2011.
There are general dust problems with health implications in coal mining, transportation and burning; and following the closure of the Northern Power Station at Port Augusta, South Australia, there have been major problems with dust blowing from the ash-fields, which were kept wet while the power station was operating, but have dried out since (late 2016, early 2017).reported that the Fukushima clean-up would cost Japan Aus$250 billion. The Japanese people were going to face increasingly large electricity bills to cover the costs, and it was expected to be a significant burden on the Japanese economy for many years. And then there are the costs to the people and environment that you can't put in dollars.
A nuclear power station would be a tempting target at time of war or by terrorists. A nuclear bomb contains radioactive material measured in kilograms; a nuclear power station contains radioactive material measured in tonnes.rare-earth minerals that are used in the magnets in at least some wind turbines and many other places has been carried out with little care for health in China.
There is no evidence that wind farms harm the health of people who live in the vicinity or of workers in the industry.
Health and safety: Wave, BiofuelWorkers on wave power projects are working on a developing technology in exposed sea water; there are obvious risks.
Biofuels have the potential to cause air pollution from the combustion products if these are not carefully handled.
Planning and development of a nuclear power station is a notoriously lengthy process; a minimum of 15 years is typical. And there can be expected to be determined objections from the local people, especially in Australia, where there are at present no nuclear power stations; this will slow the process even more.
A solar PV installation will most likely be on a single rural property; little time is needed for negotiating with land owners. It is unlikely to cause substantial local objection or concern from the local council. The parts required are pretty standard and commonly available. Development time will be less than for most power station types.
A wind farm typically takes around three years from a determined proposal to construction so long as finance is available. Many wind farms have been proposed with little reason to expect that financial support will be forthcoming. A legal challange may delay construction.
The very pro-fossil-fuel Abbott and Turnbull federal governments in Australia, which have been in power since September 2013, have done nothing to facilitate the introduction of electric vehicles. Australia is lagging behind the rest of the world in the change over from internal combustion engine (ICE) powered cars to EVs.
The graph on the right shows a growth rate in sales of EVs of 42% in 2016. It is simple to calculate that if this growth rate was to continue all vehicles would be electric by about 2030. If the growth rate was to fall to 30% a third of all vehicles would be electric by 2030.
The amount of electricity required to fully charge an EV depends on the model but is around 20 kWh. A typical daily top-up charge might be around 7 kWh. According to the Australian Bureau of Statistics average daily household elecricity consumption (2013) was around 18 kWh. Plainly, if this increases by another 7 kWh, to 25 kWh (about a 40% increase) in even a half of households, there will be a big impact on total power consumption.
There is very good reason to believe that a large part of the commercial vehicle fleet will also change from ICE to electric. Already in China, the world's biggest market for electric vehicles, a third of the total electric vehicles sold in 2016 were commercial (mainly busses).DSM would use price signals to better match times of high power consumption to times of high power availability. DSM will reduce peak power demand and that will reduce the need for expensive upgrading of the power transmission system and so decrease the cost of electricity.
Daniel Silkstone wrote for ARENA Wire about demand side management on 2017/09/08.
Wind power in particular will fit into a grid including EVs and DSM; they tend to produce more power overnight – fitting in well with charging EVs – than during the day.
There has been speculation that as solar power becomes more common all power
will be generated where it is needed and there will be no need of the
I find this argument highly unconvincing:
Action to reduce greenhouse gas emissions is urgent if damage from
climate change and ocean acidification is to be kept within reasonable limits.
Coal-fired power stations are acceptable only if all the carbon dioxide emissions are sequestered, in which case the technology becomes economically unviable. Coal mines and coal-fired power stations have serious health impacts and are very likely to encounter strong public resistance to their construction.
If Gas-fired power stations are to be used in the long-term they, like coal-fired power stations, must have their carbon dioxide emissions sequestered and this will make their electricity very expensive. However, they are valuable in the short-term for peaking power supply and for filling-in when renewable energy is not available.
Nuclear power is more expensive than wind and solar PV, especially when proper consideration is given to decommissioning the power station at the end of its useful life. Construction of a nuclear power station would be very unlikely to gain acceptance from a community that would have to host it. Nuclear power has risks that renewables do not have and is not sustainable.
Solar PV and wind power are intermittent; they are therefore not sufficient for any power grid without substantial energy storage.
Solar thermal with storage helps overcome the intermittency problem, but it is expensive at the present; the cost will decline as the technology becomes more mature.
Electric vehicles will largely replace fossil-fuel vehicles and this will lead to a power grid that operates in a way more compatible with intermittently available renewable energy.
SummaryRenewables, especially solar PV and wind, but also biofuels, solar thermal and wave power, can and should be used to substantially replace polluting coal. In the short-term gas can be used to 'fill in the gaps' in generation, in the longer term energy storage, especially pumped-hydro could largely fill this need.
It would be easy to achieve 50% renewable energy in Australia (South Australia's very successful adoption of around 50% renewable energy in only 14 years had shown that by the time of writing, 2017), getting to 80% would not be particularly difficult, 100% will be very challenging.
On this siteBase load electricity
Elec. gen. methods compared
South Australia's success with renewable power
Mid-North South Australia, leading the nation in renewable energy
Northern SA's renewables
Wind power in Australia
Impressive renewable energy developments in Australia
Pumped hydro energy storage
Glossary of technical terms relating to wind power
Climate change disasters and the Australian government's actions
Greatest crime in history
Major threatened disasters compared
The end of coal
Coal seam gas: an environmental disaster
The Turnbull Australian Government
On the InternetA glossary of the energy debate; The Conversation.
The big three Australian power generators see no future in coalAGL's statement on the Liddell closure.
Energy Australia boss says there are much better options than keeping the old Liddell coal-fired power station running for a few more years.
Origin Energy boss regects coal
Acceptability to the community|
Acceptability of coal
Acceptability of gas
Acceptability of nuclear power
Acceptability of solar power
Acceptability of wind farms
Base-load, peaking and renewables
Battery storage; a technology to watch
Costs of the available options
Cost of coal power
Cost of gas power
Cost of nuclear power
Cost of solar PV power
Cost of solar thermal power
Cost of wind power
Electric vehicles and the power grid
Environmental impact: Coal
Environmental impact: Gas
Environmental impact: Solar
Environmental impact: Wind
Health and safety
Health and safety: Coal
Health and safety: Nuclear
Health and safety: Solar
Health and safety: Wind power
A power grid will continue to be needed