Climate explained: how much of the world’s energy comes from fossil fuels and could we replace it all with renewables?

Climate explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

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How are fossil fuels formed, why do they release carbon dioxide and how much of the world’s energy do they provide? And what are the renewable energy sources that could replace fossil fuels?

Fossil fuels were formed over millions of years from the remains of plants and animals trapped in sediments and then transformed by heat and pressure.

Most coal was formed in the Carboniferous Period (360–300 million years ago), an age of amphibians and vast swampy forests. Fossilisation of trees moved enormous amounts of carbon from the air to underground, leading to a decline in atmospheric carbon dioxide (CO₂) levels — enough to bring the Earth close to a completely frozen state.

This change in the climate, combined with the evolution of fungi that could digest dead wood and release its carbon back into the air, brought the coal-forming period to an end.

Oil and natural gas (methane, CH₄) were formed similarly, not from trees but from ocean plankton, and over a longer period. New Zealand’s Maui oil field is relatively young, dating from the Eocene, some 50 million years ago.

Burning buried sunshine

When fossil fuels are burnt, their carbon reacts with oxygen to form carbon dioxide. The energy originally provided by the Sun, stored in chemical bonds for millions of years, is released and the carbon returns to the air. A simple example is the burning of natural gas: one molecule of methane and two of oxygen combine to produce carbon dioxide and water.

CH₄ + 2 O₂ → CO₂ + 2 H₂O

Burning a kilogram of natural gas releases 15kWh of energy in the form of infrared radiation (radiant heat). This is a sizeable amount.

To stop continuously worsening climate change, we need to stop burning fossil fuels for energy. That’s a tall order, because fossil fuels provide 84% of all the energy used by human civilisation. (New Zealand is less reliant on fossil fuels, at 65%.)

Wind turbines on farm land in New Zealand — Wind energy is one of the renewable sources with the capacity to scale up.
Shutterstock/YIUCHEUNG

There are many possible sources of renewable or low-carbon energy: nuclear, hydropower, wind, solar, geothermal, biomass (burning plants for energy) and biofuel (making liquid or gaseous fuels out of plants). A handful of tidal power stations are in operation, and experiments are under way with wave and ocean current generation.

But, among these, the only two with the capacity to scale up to the staggering amount of energy we use are wind and solar. Despite impressive growth (doubling in less than five years), wind provides only 2.2% of all energy, and solar 1.1%.

The renewables transition

One saving grace, which suggests a complete transformation to renewable energy may be possible, is that a lot of the energy from fossil fuels is wasted.

First, extraction, refining and transport of fossil fuels accounts for 12% of all energy use. Second, fossil fuels are often burnt in very inefficient ways, for example in internal combustion engines in cars. A world based on renewable energy would need half as much energy in the first place.

The potential solar and wind resource is enormous, and costs have fallen rapidly. Some have argued we could transition to fully renewable energy, including transmission lines and energy storage as well as fully synthetic liquid fuels, by 2050.

One scenario sees New Zealand building 20GW of solar and 9GW of wind power. That’s not unreasonable — Australia has built that much in five years. We should hurry. Renewable power plants take time to build and industries take time to scale up.

Other factors to consider

Switching to renewable energy solves the problems of fuel and climate change, but not those of escalating resource use. Building a whole new energy system takes a lot of material, some of it rare and difficult to extract. Unlike burnt fuel, metal can be recycled, but that won’t help while building a new system for the first time.

Research concluded that although some metals are scarce (particularly cobalt, cadmium, nickel, gold and silver), “a fully renewable energy system is unlikely to deplete metal reserves and resources up to 2050”. There are also opportunities to substitute more common materials, at some loss of efficiency.

Engineers working on a wind turbine — Building a new system will require energy and resources.
Shutterstock/Jacques Tarnero

But many metals are highly localised. Half the world’s cobalt reserves are in the Democratic Republic of Congo, half the lithium is in Chile, and 70% of rare earths, used in wind turbines and electric motors, are in China.

Wasteful consumption is another issue. New technologies (robots, drones, internet) and economic growth lead to increased use of energy and resources. Rich people use a disproportionate amount of energy and model excessive consumption and waste others aspire to, including the emerging rich in developing countries.

Research analysing household-level emissions across European countries found the top 1% of the population with the highest carbon footprints produced 55 tonnes of CO₂-equivalent emissions each, compared to a European median of 10 tonnes.

Scientists have warned about consumption by the affluent and there is vigorous debate about how to reduce it while preserving a stable society.

One way of turning these questions around is to start from the bottom and ask: what is the minimum energy required for basic human needs?

One study considered “decent living” to include comfortable housing, enough food and water, 10,000km of travel a year, education, healthcare and telecommunications for everyone on Earth — clearly not something we have managed to achieve so far. It found this would need about 4,000kWh of energy per person per year, less than a tenth of what New Zealanders currently use, and an amount easily supplied by renewable energy.

All that carbon under the ground was energy ripe for the picking. We picked it. But now it is time to stop.

Robert McLachlan, Professor in Applied Mathematics, Massey University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Wind turbines off the coast could help Australia become an energy superpower, research finds

Sven Teske, University of Technology Sydney; Chris Briggs, University of Technology Sydney; Mark Hemer, CSIRO; Philip Marsh, University of Tasmania, and Rusty Langdon, University of Technology SydneyOffshore wind farms are an increasingly common sight overseas. But Australia has neglected the technology, despite the ample wind gusts buffeting much of our coastline.

New research released today confirms Australia’s offshore wind resources offer vast potential both for electricity generation and new jobs. In fact, wind conditions off southern Australia rival those in the North Sea, between Britain and Europe, where the offshore wind industry is well established.

More than ten offshore wind farms are currently proposed for Australia. If built, their combined capacity would be greater than all coal-fired power plants in the nation.

Offshore wind projects can provide a win-win-win for Australia: creating jobs for displaced fossil fuel workers, replacing energy supplies lost when coal plants close, and helping Australia become a renewable energy superpower.

offshore wind turbine from above — Australia’s potential for offshore wind rivals the North Sea’s.
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The time is now

Globally, offshore wind is booming. The United Kingdom plans to quadruple offshore wind capacity to 40 gigawatts (GW) by 2030 – enough to power every home in the nation. Other jurisdictions also have ambitious 2030 offshore wind targets including the European Union (60GW), the United States (30GW), South Korea (12GW) and Japan (10GW).

Australia’s coastal waters are relatively deep, which limits the scope to fix offshore wind turbines to the bottom of the ocean. This, combined with Australia’s ample onshore wind and solar energy resources, means offshore wind has been overlooked in Australia’s energy system planning.

But recent changes are producing new opportunities for Australia. The development of larger turbines has created economies of scale which reduce technology costs. And floating turbine foundations, which can operate in very deep waters, open access to more windy offshore locations.

More than ten offshore wind projects are proposed in Australia. Star of the South, to be built off Gippsland in Victoria, is the most advanced. Others include those off Western Australia, Tasmania and Victoria.

floating wind turbine — Floating wind turbines can operate in deep waters.
SAITEC

Our findings

Our study sought to examine the potential of offshore wind energy for Australia.

First, we examined locations considered feasible for offshore wind projects, namely those that were:

less than 100km from shore
within 100km of substations and transmission lines (excluding environmentally restricted areas)
in water depths less than 1,000 metres.

Wind resources at those locations totalled 2,233GW of capacity and would generate far more than current and projected electricity demand across Australia.

Second, we looked at so-called “capacity factor” – the ratio between the energy an offshore wind turbine would generate with the winds available at a location, relative to the turbine’s potential maximum output.

The best sites were south of Tasmania, with a capacity factor of 80%. The next-best sites were in Bass Strait and off Western Australia and North Queensland (55%), followed by South Australia and New South Wales (45%). By comparison, the capacity factor of onshore wind turbines is generally 35–45%.

Average annual wind speeds in Bass Strait, around Tasmania and along the mainland’s southwest coast equal those in the North Sea, where offshore wind is an established industry. Wind conditions in southern Australia are also more favourable than in the East China and Yellow seas, which are growth regions for commercial wind farms.

Map showing average wind speed — Average wind speed (metres per second) from 2010-2019 in the study area at 100 metres.
Authors provided

Next, we compared offshore wind resources on an hourly basis against the output of onshore solar and wind farms at 12 locations around Australia.

At most sites, offshore wind continued to operate at high capacity during periods when onshore wind and solar generation output was low. For example, meteorological data shows offshore wind at the Star of the South location is particularly strong on hot days when energy demand is high.

Australia’s fleet of coal-fired power plants is ageing, and the exact date each facility will retire is uncertain. This creates risks of disruption to energy supplies, however offshore wind power could help mitigate this. A single offshore wind project can be up to five times the size of an onshore wind project.

Some of the best sites for offshore winds are located near the Latrobe Valley in Victoria and the Hunter Valley in NSW. Those regions boast strong electricity grid infrastructure built around coal plants, and offshore wind projects could plug into this via undersea cables.

And building wind energy offshore can also avoid the planning conflicts and community opposition which sometimes affect onshore renewables developments.

Global average wind speed (metres per second at 100m level.
Authors provided

Winds of change

Our research found offshore wind could help Australia become a renewable energy “superpower”. As Australia seeks to reduce its greenhouse has emissions, sectors such as transport will need increased supplies of renewable energy. Clean energy will also be needed to produce hydrogen for export and to manufacture “green” steel and aluminium.

Offshore wind can also support a “just transition” – in other words, ensure fossil fuel workers and their communities are not left behind in the shift to a low-carbon economy.

Our research found offshore wind could produce around 8,000 jobs under the scenario used in our study – almost as many as those employed in Australia’s offshore oil and gas sector.

Many skills used in the oil and gas industry, such as those in construction, safety and mechanics, overlap with those needed in offshore wind energy. Coal workers could also be re-employed in offshore wind manufacturing, port assembly and engineering.

Realising these opportunities from offshore wind will take time and proactive policy and planning. Our report includes ten recommendations, including:

establishing a regulatory regime in Commonwealth waters
integrating offshore wind into energy planning and innovation funding
further research on the cost-benefits of the sector to ensure Australia meets its commitments to a well managed sustainable ocean economy.

If we get this right, offshore wind can play a crucial role in Australia’s energy transition.

Sven Teske, Research Director, Institute for Sustainable Futures, University of Technology Sydney; Chris Briggs, Research Principal, Institute for Sustainable Futures, University of Technology Sydney; Mark Hemer, Principal Research Scientist, Oceans and Atmosphere, CSIRO; Philip Marsh, Post doctoral researcher, University of Tasmania, and Rusty Langdon, Research Consultant, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The idea of ‘green growth’ is flawed. We must find ways of using and wasting less energy

Michael (Mike) Joy, Te Herenga Waka — Victoria University of WellingtonAs countries explore ways of decarbonising their economies, the mantra of “green growth” risks trapping us in a spiral of failures. Green growth is an oxymoron.

Growth requires more material extraction, which in turn requires more energy. The fundamental problem we face in trying to replace fossil energy with renewable energy is that all our renewable technologies are significantly less energy dense than fossil fuels.

This means much larger areas are required to produce the same amount of energy.

Earlier this year, data from the European Union showed renewable electricity generation has overtaken coal and gas in 2020. But previous research argued that to replace the total energy (not just electricity) use of the UK with the best available mix of wind, solar and hydroelectricity would require the entire landmass of the country. To do it for Singapore would require the area of 60 Singapores.

I am not in any way denying or diminishing the need to stop emitting fossil carbon. But if we don’t focus on reducing consumption and energy waste, and instead fixate on replacing fossil fuels with renewable energy, we are simply swapping one race to destruction with another.

The carbon causing our climate problem today came from fossilised biology formed through ancient carbon cycles, mostly over the 200 million years of the Mesozoic era (ending 66 million years ago).

We must stop burning fossil fuels, but we must also understand that every technology to replace them, while attempting to maintain our current consumption, let alone allowing for consumption growth, requires huge amounts of fossil energy.

Environmental impact of renewables

Carbon reduction without consumption reduction is only possible through methods that have their own massive environmental impacts and resource limitations.

To make renewable energy, fossil energy is needed to mine the raw materials, to transport, to manufacture, to connect the energy capture systems and finally to produce the machines to use the energy.

The new renewable infrastructure requires rare earth minerals, which is a problem in itself. But most of the raw materials required to produce and apply new energy technology are also getting harder to find. The returns on mining them are reducing, and the dilemma of declining returns applies to the very fossil fuels needed to mine the declining metal ore.

Globally, despite building lots of renewable electricity infrastructure, we have not yet increased the proportion of renewable energy in our total energy consumption.

Electricity is only 20% of our total energy use. Renewable electricity has not displaced fossil energy in most countries because our consumption increases faster than we can add renewable generation.

The problems with wanting to maintain industrial civilisation are many, but the starkest is that it is the actual cause of our climate crisis and other environmental crises.

If we carry on with life as usual — the underlying dream of the “green growth” concept — we will end up destroying the life-supporting capacity of our planet.

What happened to environmentalism?

The green growth concept is part of a broader and long-running trend to co-opt the words green and environmentalist.

Environmentalism emerged from the 1960s as a movement to save the natural world. Now it seems to have been appropriated to describe the fight to save industrial civilisation — life as we know it.

This shift has serious implications because the two concepts — green growth and environmentalism — are inherently incompatible.

Traditionally, environmentalists included people like Rachel Carson, whose 1962 book Silent Spring alerted Americans to the industrial poisons killing birds and insects and fouling drinking water, or environmental organisations like Greenpeace saving whales and baby seals.

In New Zealand, being green had its roots in movements like the Save Manapouri campaign, which fought to save ancient native forests from inundation when a hydropower dam was built. Environmentalism had a clear focus on saving the living world.

Now environmentalism has been realigned to reducing carbon emissions, as if climate change was our only impending crisis. Parliamentary Greens seem set to want to reach net zero carbon by 2050 at any cost.

The word “net” allows champions of industry-friendly environmentalism to avoid considering the critical need to reduce our energy consumption.

We must somehow drag ourselves away from our growth paradigm to tackle the multiple crises coming at us. Our only future is one where we consume less, do less, waste less and stop our obsession with accumulating.

If we keep trying to maintain our current growth trajectory, built on a one-off fossil bonanza, we will destroy the already stressed life-supporting systems that sustain us. Protecting these and their essential biotic components is true environmentalism — not attempting to maintain our industrial way of life, just without carbon.

Michael (Mike) Joy, Senior Researcher; Institute for Governance and Policy Studies, Te Herenga Waka — Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Wondering if your energy company takes climate change seriously? A new report reveals the answer

Anna Malos, ClimateWorks Australia and Coral Bravo, ClimateWorks AustraliaA landmark report released last week put coal and gas on notice. For the first time, the International Energy Agency (IEA) declared reaching net-zero emissions by 2050 means no new investments in fossil fuel supply projects.

For Australia – a continent blessed with a bounty of wind and sun – the phasing out of coal and gas investment should be considered a boon. Australia is already deploying wind and solar energy ten times faster than the global average, and still has plenty of unmet renewables potential.

But of course, Australia’s path to a clean energy economy has not been perfectly smooth. A lack of federal leadership on climate policy and a historical dependence on fossil fuels means the IEA’s roadmap presents a big challenge for Australia.

Our latest report released today underscores how big a challenge this is. We assessed Australia’s highest-emitting energy firms and found none were fully or even closely aligned with global climate goals. Just one went even partway, and five appeared to be taking no action at all.

smoke billows from stacks at coal plant — The International Energy Agency says it’s the end of the road for new coal investments.
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A poor showing

Our energy sector report forms part of the Net Zero Momentum Tracker, a project by research organisation ClimateWorks, which works within the Monash Sustainable Development Institute.

We assessed the commitments of Australia’s 20 highest-emitting energy companies against the Paris Agreement goals, which include limiting global temperature rise to well below 2℃, aiming for 1.5℃. The IEA’s latest work shows to reach those goals, the global energy sector must reach net-zero emissions by 2050.

The companies we analysed comprise electricity generators and electricity and gas retailers. Together, they account for almost one-third of Australia’s total annual emissions.

Each company’s commitments were assessed against scenarios we modelled, which map the least-cost trajectories for reducing Australia’s emissions in line with the Paris goals.

We found no large energy company was fully aligned with these trajectories, and most fell well short. Six had set emissions reduction targets and nine others had taken some action to cut emissions.

However, not a single company had commitments that are in line with Australia achieving net-zero emissions by 2050.

boy turns off lamp — No electricity company was taking action fully aligned with the Paris goals.
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How your energy company fares

The 20 companies we assessed account for almost 90% of Australia’s electricity emissions. Together, they generate more than 70% of Australia’s electricity supplies.

French-owned energy generator and retailer ENGIE was the only company with activities on a trajectory supporting Australia’s Paris-aligned transition, because of a target that aims to reduce some of its emissions by 2030. But the target does not cover the majority of ENGIE’s emissions, so the company has much more work to do.

Fourteen companies had a mix of targets or actions we assessed as not aligned with the Paris goals. They are:

AGL
APT Pipelines
ATCO
CS Energy
CK William
Delta
EnergyAustralia
Origin
Pioneer Sail
Snowy Hydro
Stanwell
Synergy
Territory Generation
TransAlta.

And these five companies had no disclosed emissions reduction activities:

Arrow Energy
Bluewaters Power 1&2
NewGen Kwinana
NRG Gladstone Operating Services
OzGen.

French multinational Engie was the only firm assessed to have emissions reduction goals even partially aligned to the Paris Agreement.
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The big four emitters

AGL, EnergyAustralia, Stanwell and Origin are the biggest emitters in Australia’s electricity sector. Collectively, they’re responsible for more than half the sector’s emissions, and so have a particular responsibility to act.

When energy companies talk about reducing their greenhouse gas emissions, they do so in terms of scope 1, 2 and 3 emissions.

Scope 1 covers emissions released to the atmosphere as a direct result of company activity, such as burning coal or gas to produce electricity. Scope 2 covers the emissions created to produce the electricity a company purchases.

Scope 3 emissions are those outside the companies’ direct control. They include upstream processes such as the extraction, production and transport of fuel used to power their operations, and downstream activities such as the distribution and use of gas sold to consumers.

Origin aspires to achieve net-zero emissions by 2050 and has set interim targets to reduce its scope 1, 2 and 3 emissions.

AGL and EnergyAustralia have committed to achieve net-zero operational (scope 1 and 2) emissions by 2050, but have no interim emissions reduction targets.

Stanwell, which operates two of Queensland’s largest coal-fired generators, has no emissions reduction targets.

magnifying glass on Origin website — Origin aspires to achieve net-zero emissions by 2050.
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A rapid renewables shift

Our earlier research shows that under scenarios compatible with the Paris Agreement, renewables make up 70% of electricity generation by 2030. Coal and gas is phased out of Australia’s electricity mix as soon as 2035.

The energy sector is crucial if Australia is to meet the Paris climate goals. Thanks to renewable energy, the sector enjoys some of the easiest and cheapest emissions reduction opportunities. And a zero-emissions energy sector would also help other sectors such as transport, buildings and industry to decarbonise.

Australia’s energy sector has made progress on emissions in recent years. Three-quarters of the energy companies we assessed have implemented wind and solar energy projects. And overall, renewable energy was responsible for almost 28% of Australia’s total electricity generation in 2020.

However our report shows change is not happening fast enough to put Australia on a timely path to net-zero emissions.

At a federal level, the Renewable Energy Target, which ended last year, drove the clean energy shift. New federal policies are now needed to bolster ambitious state and territory policies. This would enable energy market operators and investors to plan a transition aligned with the Paris goals.

Anna Malos, Australia – Country Lead, ClimateWorks Australia and Coral Bravo, Senior Analyst, ClimateWorks Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This $1 billion energy deal promises to cut emissions and secure jobs. So why on earth is gas included?

Samantha Hepburn, Deakin UniversityIn case you missed it, a major A$1 billion energy deal between the Morrison and the South Australian government was revealed recently.

The bilateral deal represents a key driver for the national economic recovery from COVID. It promises to provide jobs in the energy sector and contribute to South Australia achieving net 100% renewables by 2030.

But there’s a big caveat: the agreement involves a joint commitment to accelerate new gas supplies into the east coast market.

With so much money on the table and other nations recently doubling down on climate commitments, let’s look at the good and bad bits of this landmark deal in more detail.

A gas-led economic recovery

The agreement was announced ahead of US President Joe Biden’s climate summit last week, which saw Australia spruik technology growth to cut emissions instead of committing to new climate targets.

In total, the federal government will contribute A$660 million and the South Australian government A$422 million towards the new deal.

Both governments have also agreed to a gas target of an additional 50 petajoules of energy per year by the end of 2023, and 80 petajoules by 2030. Their rationale is the need to improve energy security and reliability.

This focus on gas in the agreement stems from the federal government’s much-criticised, gas-led economic recovery plan, which argues new gas supplies are vital for future energy security.

In February, the Australian Competition and Consumer Commission outlined a potential shortfall of 30 petajoules of gas for the east-coast market leading up to 2024. This shortfall could impact energy supply, and the federal government has used this to help justify opening new gas reserves.

However, nothing is certain — COVID has reduced global demand for gas so any shortfall will likely be deferred. Meanwhile, renewable technology and hydrogen production and use are rapidly advancing.

Bad: investing in gas

With the seismic shift in the economics of renewables over the past decade, investing in new gas supply is unnecessary and retrograde. In fact, it’s now more expensive to transition from coal to gas than from coal to renewables.

For example, the cost of lithium ion batteries used for battery storage has fallen over the past decade by nearly 90%. But the cost of gas — both economically and environmentally — has steadily risen. This inevitably means means its role in the energy market will diminish.

Eventually, gas generators will be retired without replacement. Victoria’s March quarter data, for example, shows black coal generation volumes dropped by 9.5% and gas generation dropped by 43%. Meanwhile, rooftop solar went up 25%, utility solar up by 40% and wind power by 24%.

Solar farm in the desert at sunset — Up to $110 million will be spent on solar thermal and other storage projects in South Australia.
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And at the end of the day, gas is still a fossil fuel. There are approximately 22 major gas production and export projects proposed for Australia. A report from The Australia Institute in September 2020 suggested that, if produced, these projects could lead to about half a billion tonnes of emissions.

If all potential gas resources in Australia were tapped, the report indicates it could result in emissions equivalent to three times the current annual global emissions.

Good: investing in critical infrastructure

The energy deal sets aside $50 million towards the new $1.5 billion electricity interconnector between South Australia and NSW. This is critical infrastructure that will allow South Australia, Victoria and NSW to share energy reserves.

Indeed, the Australian Energy Market Operator has reported in excess of 5,000 megawatts of renewable energy projects near the proposed interconnector. This means South Australian wind and solar could contribute more significantly to electricity generation in both Victoria and NSW.

In turn, this will have a positive effect on pricing. Forecasts suggest the proposed new interconnector could reduce power bills by up to $66 a year in South Australia and $30 in NSW.

The energy deal also reserves funding for “investment priority areas”, which include carbon capture storage, electric vehicles and hydrogen. For example, $110 million is allocated for energy storage projects. This level of funding will help develop a world-class hydrogen export industry in South Australia.

The verdict

The energy deal is a funding win for renewable energy and technology, with energy technology advancing much faster than anticipated. However, its focus on gas is environmentally and economically regressive.

It’s completely inconsistent with the powerful climate plan announced by the Joe Biden administration at the Climate Summit last week, which includes a pause and review of oil and gas drilling on US federal land and doubling energy production from offshore windfarms by 2030.

In March, the European Union’s parliament voted in favour of a Carbon Border Adjustment Mechanism. This will impose a tariff on products being sold into the EU according to the amount of carbon involved in making them. The Biden administration in the US has announced a similar plan.

What’s more, the European Union and the US, as outlined at the recent Climate Summit, are planning to impose fees or quotas on goods from countries failing to meet their climate and environmental obligations. This may mean Australian manufacturers will end up paying for the governments failure to take rapid action to drive down emissions.

Bilateral agreements provide critical planning and funding for Australia’s energy progression. However, they should not prolong the use of fossil fuels under the guise of energy security. To do so undermines global climate change imperatives and hinders Australia’s progress in a new energy era.

Samantha Hepburn, Director of the Centre for Energy and Natural Resources Law, Deakin Law School, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Can we safely burn waste to make fuel like they do in Denmark? Well, it’s complicated

The Amager Bakke power plant in Copenhagen, Denmark.
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Thomas Cole-Hunter, Queensland University of Technology; Ana Porta Cubas, University of Sydney; Christina Magill, GNS Science, and Christine Cowie, UNSW

When it comes to handling the waste crisis in Australia, options are limited: we either export our waste or bury it. But to achieve current national targets, policy-makers are increasingly asking if we can instead safely burn waste as fuel.

Proposals for waste incinerators are being considered in the Greater Sydney region, but these have been lambasted by the Greens and independent members of the NSW parliament, who cite public health concerns.

Meanwhile, the ACT government has recently put a blanket ban on these facilities.

But are their concerns based on evidence? In our systematic review of the scientific literature, we could identify only 19 papers among 269 relevant studies — less than 10% — that could help address our question on whether waste-to-energy incinerators could harm our health.

This means the answer remains unclear, and we therefore call for a cautious approach to waste-to-energy technology.

One person, one year, 500 kilograms of waste

Australia’s waste crisis began in 2018 when China greatly reduced how much waste it imported. China’s waste market was handling about half of the world’s recyclable materials, including Australia’s.

On average, Australia produces roughly 500 kilograms of municipal (residential and commercial) waste each year. This aligns with the OECD average.

New Zealand in comparison, despite its strong environmental stance, is among the worst offenders for producing waste in any OECD country. It produces almost 800 kilograms per person per year.

Now, most recyclable or reusable waste in Australia goes to landfill. This poses a potential risk to both climate and health with the emission of potent greenhouse gases such as methane and the leaching of heavy metals such as lead into the groundwater. As a result, local governments may want to seek alternative options.

Burning waste in Denmark

“Waste-to-energy” incineration is when solid waste is sorted and burned as “refuse-derived” fuel to generate electricity. This can replace fossil fuel such as coal.

The technology is on the rise among OECD countries. Denmark and Japan, for example, rely on waste-to-energy incineration to reduce their dependency on landfills and reach carbon neutrality.

In fact, Denmark’s waste-to-energy incinerator, Amager Bakke, is so well known it has become a tourist attraction, and is celebrated as one of the world’s cleanest waste-to-energy incinerators.

Amager Bakke provides electricity to around 680,000 people.

Every day, around 300 trucks filled with non-recyclable municipal solid waste are sent to Amager Bakke.

This fuels a furnace that runs at 1,000℃, turning water into steam. And this steam provides electricity and heat to around 100,000 households. Generally, people in Denmark warmly welcome it.

So what’s the problem?

In Australia and the US, community reception towards the building of new incinerators has been cold.

The big concern is burning waste may release chemicals that can harm our health, such as nitrogen oxide and dioxin. Exposure to high levels of dioxin can lead to skin lesions, an impaired immune system and reproductive issues.

However, control measures, such as the technologically advanced filters used in Amager Bakke, can bring the amount of dioxin released to near zero.

Another concern is that implementing waste-to-energy incineration may go against recycling schemes, due to the potential for an increased demand for non-recyclable plastics as fuel.

A truck dumping waste to get incinerated — Burning waste may release substances that can harm our health, such as nitrogen oxide and dioxin.
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Supply of this plastic could come from the waning fossil fuel industry. This would work against the goal of establishing a “circular economy” that reuses and recycles goods where possible.

An analysis from 2019 found that to meet European Union circular economy goals, Nordic countries would need to increase their recycling, and significantly shift away from incineration.

This concern is understandable given incinerators operate cleanest when fuelled at full capacity. This is because a higher temperature means a more complete combustion — a bit like less ash and smoke coming off of a well-built campfire.

A lack of evidence

As with many policy solutions, determining the safety of burning waste is complicated.

Our review found a lack of evidence to fully reject well-designed and operated facilities. However, based on the limited number of health studies we found, we support a precautionary planning approach to waste-to-energy proposals.

This means we need appropriate health risk assessment and life cycle analyses built into the approval process for each and every incinerator proposed in the near-future.

The studies we found were all performed in the last 20 years. None were from the Nordic countries, however, where waste-to-energy incineration has been in use for many decades.

The reasons for the Nordic embrace of this technology are speculative. One reason may be that their level of economic development allows large capital investment for safe, state-of-the-art design and operation.

Mechanical claw grabbing a huge pile of mixed waste. — Waste incineration goes against the goals of a circular economy.
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Where to from here?

If councils are determined to pursue waste-to-energy incineration, we suggest they prioritise specific applications.

For example, we found the process with the most favourable life-cycle assessment (the most beneficial to health compared to traditional fossil fuel use) was the “co-incineration” of refuse-derived fuel for industrial cement.

Currently, cement kilns are mostly fuelled by burning coal, and it’s difficult to reach the high temperatures required with traditional renewables. This means substituting coal for refuse-derived fuel could reduce the industry’s dependency on coal, when renewables aren’t an option.

Another solution is to focus instead on the waste hierarchy. This means first minimising waste production, maximising energy efficiency and maximising recycling and reuse of waste materials.

So, while we wait for more knowledge on how waste-to-energy incineration may affect our health, let’s focus on improving our waste hierarchy, rather than exporting our waste to feed a global crisis.

Thomas Cole-Hunter, Research fellow, Queensland University of Technology; Ana Porta Cubas, Knowledge and Translation Broker- Centre for Air pollution, energy and health Research (CAR), University of Sydney; Christina Magill, Senior Natural Hazards Risk Scientist, GNS Science, and Christine Cowie, Senior Research Fellow, Centre for Air Quality & Health Research and Evaluation, Woolcock Institute of Medical Research, University of Sydney; Senior Research Fellow, South West Sydney Clinical School, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia has failed miserably on energy efficiency – and government figures hide the truth

Hugh Saddler, Australian National University

Amid the urgent need to slow climate change by cutting greenhouse gas emissions, energy efficiency makes sense. But as Australia’s chief scientist Alan Finkel last week warned, we’re not “anywhere close to having that nailed”.

Energy efficiency means using less energy to achieve the same outcomes. It’s the cheapest way to cut greenhouse gas emissions and achieve our climate goals. Improving energy efficiency is also vital to achieving so-called “energy productivity” – getting more economic output, using the same or less energy.

But Australia’s national energy productivity plan, agreed by the nation’s energy ministers in 2015, has gone nowhere.

It set a goal of a 40% improvement in energy productivity by 2030. But my analysis, based on the most recent official data, shows that in the three years to 2017-18, energy productivity increased by a mere 1.1%.

Clearly, there is much work to do. So let’s take a look at the problem and the potential solutions.

Energy efficiency reduces power bills for consumers.
Julian Smith/AAP

Energy efficiency: a low-hanging fruit

Better energy efficiency lowers electricity bills, makes businesses more competitive and helps manage energy demand. Of course, it also means less greenhouse gas emissions, because fewer fossil fuels are burnt for energy.

Business, unions and green groups recognise the benefits. Last month they joined forces to call for a sustainable COVID-19 economic recovery, with energy efficiency at the core, saying:

In Australia, a major drive to improve the energy efficiency of buildings and industry could deliver over 120,000 job-years of employment […] Useful upgrades could be made across Australia’s private and public housing; commercial, community and government buildings; and industrial facilities.

The group said improvements could include:

more efficient and controllable appliances and equipment, especially for heating and cooling
improved shading and thermal envelopes (improving the way a building’s walls, ceiling and floors prevent heat transfer)
smart meters to measure energy use
distributed energy generation and storage, such as wind and solar backed by batteries
fuel switching (replacing inefficient fuels with cleaner and economical alternatives)
equipment, training and advice for better energy management.

The International Energy Agency (IEA) has suggested other measures for industry and manufacturing, such as:

installing more efficient electric motors
switching from gas to electric heat pumps
more waste and material recycling.

And in transport, the IEA suggests incentives to get older, less efficient cars off the roads and encourage the uptake of electric vehicles.

Residential buildings offer big opportunities for energy efficiency improvements.
Brendan Esposito/AAP

Governments’ sleight of hand

In 2018 the IEA observed:

the power sector will be at the heart of Australia’s energy system
transformation […] International best practice suggests that both energy efficiency and renewable energy are key drivers of the energy transition.

Since then, renewable energy’s share of the electricity mix has increased. But energy productivity has stalled.

To understand how, we must define a few key terms.

Primary energy refers to energy extracted from the environment, such as coal, crude oil, and electrical energy collected by a wind turbine or solar panel.

Final energy is the energy supplied to a consumer, such as electricity delivered to homes or fuel pumped at a petrol station.

A lot of energy is lost in the process of turning extracted primary fuels into ready-to-use fuels for consumers. For example at coal-fired power stations, on average, one-third of the energy supplied by burning coal is converted to electricity. The remainder is lost as waste heat.

Until 2015, Australia and most other countries used final energy as a measure of how rapidly energy efficiency was improving. But the national productivity plan instead set goals around primary energy productivity – aiming to increase it by 40% between 2015 and 2030.

This has made it possible for governments to hide how badly Australia is travelling on improving energy efficiency. I analysed national accounts figures and energy statistics, to produce the below table. It reveals the governments’ sleight of hand.

Over the three years from 2014-15 to 2017-18, final energy productivity increased by only 1.1%, whereas primary energy productivity increased by 3.5%.

The reduced primary energy consumption is mostly due to a large increase in wind and solar generation. The efficiency of energy used by final consumers has scarcely changed.

A sustainable future

The lack of progress on energy productivity is not surprising, given governments have shown very little interest in the issue.

As Finkel noted in his address, Australia’s energy productivity plan is absent from the list of national climate and energy policies. The plan’s 2019 annual report has not been released. And those released since 2015 have not monitored progress in energy productivity.

What’s more, the plan makes no mention of previous similar agreements, in 2004 and 2009, to accelerate energy efficiency with regulation and financial incentives. Since 2013, almost all Commonwealth programs supporting those agreements have been de-funded or abolished, and many state programs have also been cut back.

The IEA’s sustainable recovery plan, released last week, outlined what a sustainable global economic recovery might look like. In particular, it said better energy efficiency and switching to more efficient electric technologies will deliver triple benefits: increased employment, a more productive economy and lower greenhouse gas emissions.

In this carbon-constrained world, relatively easy and cheap opportunities such as energy efficiency must be seized. And as Australia spends to get its post-pandemic economy back on track, now is the time to act.

Hugh Saddler, Honorary Associate Professor, Centre for Climate Economics and Policy, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Really Australia, it’s not that hard: 10 reasons why renewable energy is the future

Andrew Blakers, Australian National University

Australia’s latest greenhouse gas figures released today show national emissions fell slightly last year. This was by no means an economy-wide effort – solar and wind energy did most of the heavy lifting.

Emissions fell 0.9% last year compared to 2018. The rapid deployment of solar and wind is slashing emissions in the electricity sector, offsetting increases from all other sectors combined.

Renewables (solar, wind and hydro) now comprise 26% of the mix in the National Electricity Market. In 2023, renewables will likely pass black coal to become the largest electricity source.

In an ideal world, all sectors of the economy – transport, agriculture, manufacturing and others – would pull in the same direction to cut emissions. But hearteningly, these figures show the huge potential for renewables.

Here are 10 reasons why renewable energy makes perfect sense for Australia.

Australia leads the world in rooftop solar installations.
David Mariuz/AAP

1. It can readily eliminate fossil fuels

About 15 gigawatts of solar and wind farms will probably start operating over 2018-2021. That’s on top of more than 2 gigawatts of rooftop solar to be added each year.

It averages out at about 6 gigawatts of additional solar and wind power annually. Research from the Australian National University, which is under review, shows the rate only has to double to about 12 gigawatts to eliminate fossil fuels by 2050, including from electricity, transport, heating and industry.

Fossil fuel mining and use causes 85% of total national emissions – and doubling the renewables deployment rate would eliminate this.

The task becomes more than achievable when you consider the continual fall in renewables prices, which helped treble solar and wind deployment between 2017 and 2020.

2. Solar is already king

Solar is the top global energy technology in terms of new generation capacity added each year, with wind energy in second spot. Solar and wind energy are already huge industries globally, and employ 27,000 people in Australia – a doubling in just three years.

3. Solar and wind are getting cheaper

Solar and wind electricity in Australia already costs less than it would from new coal and gas plants.

The price is headed for A$30 per megawatt hour in 2030. This undercuts most existing gas and coal stations and competes with gas for industrial heating.

Renewable electricity is becoming cheaper than coal-fired power.
Petr Josek/Reuters

4. Stable renewable electricity is not hard

Balancing renewables is a straightforward exercise using existing technology. The current high voltage transmission network must be strengthened so projects in regional areas can deliver renewable electricity into cities. And if wind and sun is not plentiful in one region, a stronger transmission network can deliver electricity from elsewhere. Electricity storage such as pumped hydro and batteries can also smooth out supplies.

5. There’s enough land

To eliminate all fossil fuel use, Australia would need about 60 square metres of solar panel per person, and one wind turbine per 2,000 people. Panels on rooftops take up no land, and wind turbines use very little. If global energy consumption per person increased drastically to reach Australian levels, solar farms on just 0.1% of Earth’s surface could meet this demand.

6. Raw materials won’t run out

A solar panel needs silicon, a glass cover, plastic, an aluminium panel frame, copper and aluminium electrical conductors and small amounts of other common materials. These materials are what our world is made of. Recycling panel materials at the end of their life adds only slightly to larger existing recycling streams.

Solar panel materials are relatively easy to obtain.
Tim Winbourne/Reuters

7. Nearly every country has good sun or wind

Three-quarters of the global population lives in the planet’s sunbelt (lower than 35 degrees of latitude). This includes most developing countries, where most of the growth in energy consumption and greenhouse emissions is occurring.

8. We will never go to war over sunshine

Solar and wind power make energy systems much more robust in the face of a pandemic, disasters or war. They are difficult to misuse in any significant way for military, terrorist or criminal activities. And it is hard to destroy billions of solar panels spread over millions of square kilometres.

9. Solar accidents and pollution are small

Solar panel accidents pale in comparison to spilled radioactive material (like Fukushima or Chernobyl), an oil disaster (like BP’s Deepwater Horizon), or a coal mine fire (like Hazelwood in Victoria). Wind and solar electricity eliminates oil imports, oil-related warfare, fracking for gas, strip mining for coal, smokestacks, car exhausts and smog.

10. Payback time is short

For a sunny country like Australia, the time required to recover the energy invested in panel manufacture is less than two years, compared with a panel lifetime of 30 years. And when the world is solar powered, the energy required to produce more panels is non-polluting.

Renewable energy can do they heavy lifting on emissions reduction.
Vincent West/Reuters

The future is bright

While COVID-19 triggered a significant fall in global emissions so far this year, they may bounce back. But if solar and wind deployment stay at current levels, Australia is tracking towards meeting its Paris target.

The Reserve Bank of Australia says investment in renewables may moderate in the near term, but “over the longer term, the transition towards renewable energy generation is expected to continue”.

But there are hurdles. In the short term, more transmission infrastructure is needed. Electrifying transport (with electric vehicles) and urban heating (with electric heat pumps) is straightforward. More difficult is eliminating fossil fuels from industries such as steel and fertilisers. This is a task for the 2030s.

But it’s clear that to get to net-zero carbon emissions by mid century, solar and wind are far and away Australia’s best option.

Andrew Blakers, Professor of Engineering, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate explained: seven reasons to be wary of waste-to-energy proposals

Many developed countries already have significant waste-to-energy operations and therefore less material going to landfill.

Jeff Seadon, Auckland University of Technology

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

I was in Switzerland recently and discovered that they haven’t had any landfill since the early 2000s, because all of their waste is either recycled or incinerated to produce electricity. How “green” is it to incinerate waste in order to produce electricity? Is it something New Zealand should consider, so that 1) we have no more landfill, and 2) we can replace our fossil-fuel power stations with power stations that incinerate waste?

Burning rubbish to generate electricity or heat sounds great: you get rid of all your waste and also get seemingly “sustainable” energy. What could be better?

Many developed countries already have significant “waste-to-energy” incineration plants and therefore less material going to landfill (although the ash has to be landfilled). These plants often have recycling industries attached to them, so that only non-recyclables end up in the furnace. If it is this good, why the opposition?

Here are seven reasons why caution is needed when considering waste-to-energy incineration plants.

Stifling innovation and waste reduction

Waste-to-energy plants require a high-volume, guaranteed waste stream for about 25 years to make them economically viable. If waste-to-energy companies divert large amounts of waste away from landfills, they need to somehow get more waste to maintain their expensive plants. For example, Sweden imports its waste from the UK to feed its “beasts”.
The waste materials that are easiest to source and have buyers for recycling – like paper and plastic – also produce most energy when burned.
Waste-to-energy destroys innovation in the waste sector. As a result of China not accepting our mixed plastics, people are now combining plastics with asphalt to make roads last longer and are making fence posts that could be replacing treated pine posts (which emit copper, chrome and arsenic into the ground). If a convenient waste-to-energy plant had been available, none of this would have happened.
Waste-to-energy reduces jobs. Every job created in the incineration industry removes six jobs in landfill, 36 jobs in recycling and 296 jobs in the reuse industry.
Waste-to-energy works against a circular economy, which tries to keep goods in circulation. Instead, it perpetuates our current make-use-dispose mentality.
Waste-to-energy only makes marginal sense in economies that produce coal-fired electricity – and then only as a stop-gap measure until cleaner energy is available. New Zealand has a green electricity generation system, with about 86% already coming from renewable sources and a target of 100% renewable by 2035, so waste-to-energy would make it a less renewable energy economy.
Lastly, burning waste and contaminated plastics creates a greater environmental impact than burning the equivalent oil they are made from. These impacts include the release of harmful substances like dioxins and vinyl chloride as well as mixtures of many other harmful substances used in making plastics, which are not present in oil.

Landfills as mines of the future

European countries were driven to waste-to-energy as a result of a 2007 directive that imposed heavy penalties for countries that did not divert waste from landfills. The easiest way for those countries to comply was to install waste-to-energy plants, which meant their landfill waste dropped dramatically.

New Zealand does not have these sorts of directives and is in a better position to work towards reducing, reusing and recycling end-of-life materials, rather than sending them to an incinerator to recover some of the energy used to make them.

Is New Zealand significantly worse than Europe in managing waste? About a decade ago, a delegation from Switzerland visited New Zealand Ministry for the Environment officials to compare progress in each of the waste streams. Both parties were surprised to learn that they had managed to divert roughly the same amount of waste from landfill through different routes.

This shows that it is important New Zealand doesn’t blindly follow the route other countries have used and hope for the same results. Such is the case for waste-to-energy.

There is also an argument to be made for current landfills. Modern, sanitary landfills seal hazardous materials and waste stored over the last 50 years presents future possibilities of landfill mining.

Many landfills have higher concentrations of precious metals, particularly gold, than mines and some are being mined for those metals. As resources become scarcer and prices increase, our landfills may become the mines of the future.

Jeff Seadon, Senior Lecturer, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s energy exports increase global greenhouse emissions, not decrease them

Frank Jotzo, Crawford School of Public Policy, Australian National University and Salim Mazouz, Australian National University

When unveiling government data revealing Australia’s rising greenhouse emissions, federal energy minister Angus Taylor sought to temper the news by pointing out that much of the increase is due to liquefied natural gas (LNG) exports, and claiming that these exports help cut emissions elsewhere.

LNG exports, Taylor argued, help to reduce global emissions by replacing the burning of coal overseas, which has a higher emissions factor than gas. In reality, Australian gas displaces a mix of energy sources, including gas from other exporters. Whether and to what extent Australian gas exports reduce emissions therefore remains unclear. Meanwhile, Australia’s coal exports clearly do increase global emissions.

The way Australia can help clean up world energy systems in the future is through large-scale production and export of renewable energy.

In a statement accompanying the latest quarterly emissions figures, the Department of Environment and Energy stated:

Australia’s total LNG exports are estimated to have the potential to lower emissions in importing countries by around 148Mt CO₂-e [million tonnes of carbon dioxide equivalent] in 2018, if they displace coal consumption in those countries.

In truth, the assumption that every unit of Australia’s exported gas displaces coal is silly. The claim of a 148Mt saving is wrong and unfounded. The real number would be much smaller, and there could even be an increase in emissions as a result of LNG exports.

For the most part, exported gas probably displaces natural gas that would otherwise be produced elsewhere, leaving overall emissions roughly the same. Some smaller share may displace coal. But it could just as easily displace renewable or nuclear energy, in which case Australian gas exports would increase global emissions, not reduce them.

How much might gas exports really cut emissions?

Serious analysis would be needed to establish the true amount of emissions displaced by Australian gas. It depends on the specific requirements that importers have, their alternatives for domestic energy production and other imports, changes in relative prices, resulting changes in energy balances in third-country markets, trajectories for investments in energy demand and supply infrastructure, and so forth. No such analysis seems available.

But for illustration, let’s make an optimistic assumption that gas displaces twice as much coal as it does renewable or nuclear energy. Specifically, let’s assume – purely for illustration – that each energy unit of Australian exported LNG replaces 0.7 units of gas from elsewhere, 0.2 units of coal, and 0.1 units of renewables or nuclear.

Australia exported 70 million tonnes of LNG in 2018. A Department of Environment and Energy source told Guardian Australia that this amount of gas would emit 197 million tonnes of CO₂ when burned. We calculate a similar number, on the basis of official emissions factors and export statistics.

Under the optimistic and illustrative set of assumptions outlined above, we calculate that Australia’s LNG exports would have reduced emissions in importing countries by about 10 million tonnes of CO₂ per year. (See the end of the article for a summary of our calculations.)

They might equally have reduced emissions by less, or they might in fact have increased these countries’ emissions, if more renewables or nuclear was displaced than coal. But whatever the the actual number, it’s certainly a long way short of the 148 million tonnes of emissions reduction claimed by the government.

We also should consider the emissions within Australia of producing LNG. The national emissions accounting shows that the increase in national emissions of 3.5 million tonnes of CO₂-e compared with the year before is mostly because of a 22% increase in LNG exports. This means that LNG production in Australia overall may be responsible for 16 million tonnes of CO₂ emissions per year.

A full analysis of global effects would also need to factor in the emissions that would be incurred from the production of alternative energy sources displaced by Australia’s LNG.

Coal exports unambiguously raise emissions

The picture is more clear-cut for coal. If there was no Australian thermal coal (the type used in power stations) in world markets, much of this would be replaced by more coal mined elsewhere. The remainder would be replaced by gas, renewables or nuclear. As for the case of gas, the precise substitution effects are a matter of complex interactions.

The crucial point is that all alternative fuels are less emissions-intensive than coal. In the substitution of Australian-mined coal for coal from other sources, there could be some substitution towards coal with higher emissions factors, but this is highly unlikely to outweigh the emissions savings from the substitution to nuclear, renewables and gas.

So, removing Australian coal from the world market would reduce global emissions. Conversely, adding Australian coal to the world market would increase global emissions.

Australia exported 208 million tonnes of thermal coal in 2018, which according to the official emissions factors would release 506 million tonnes of CO₂ when burned. On top of this, Australia also exported 178 million tonnes of coking coal for steel production.

If a similar “replacement mix” assumed above for gas is also applied to coal – that is, every unit of coal is replaced by 0.7 units of coal from elsewhere, 0.2 units of gas, and 0.1 units of renewables or nuclear – then adding that thermal coal to the international market would increase emissions by about 19% of the embodied emissions in that coal. As in the case of LNG, this is purely an illustrative assumption.

So, in this illustrative case, Australia’s thermal coal exports would increase net greenhouse emissions in importing countries by about 96 million tonnes per year.

This figure does not consider the coking coal exports, nor the emissions from mining the coal in Australia and transporting it.

The real opportunity is in export of renewable energy

Thankfully, there actually is a way for Australia to help the world cut emissions, and in a big way. That is by producing large amounts of renewable energy for export, in the form of hydrogen, ammonia, and other fuels produced using wind and solar power and shipped to other countries that are less blessed with abundant renewable energy resources.

Even emissions-free production of energy-intensive goods like aluminium and steel could become cost-competitive in Australia, given the ever-falling costs of renewable energy and the almost unlimited potential to produce renewable energy in the outback. Australia really could be a renewable energy superpower.

Such exports will then unambiguously reduce global emissions, because they will in part displace the use of coal, gas and oil.

Once we have a large-scale renewable energy industry in operation, the relevant minister in office then will be right to point out Australia’s contribution to solving the global challenge through our energy exports. In the meantime, our energy exports are clearly a net addition to global emissions.

Summary of data and calculations

LNG emissions and displacement – illustrative scenario

Emissions inherent in Australia’s LNG exports of 69.5 million tonnes (in calendar year 2018) are 197 million tonnes (Mt) of carbon dioxide, based on emissions factors published by the Australian government.

If the same amount of energy was served using coal, emissions would be:

197Mt CO₂ + 148Mt CO₂ = 345Mt CO₂

Emissions under the mix assumed for illustration here would be:

0.7 x 197 (LNG) + 0.2 x 345 (coal) + 0.1 x 0 (renewables/nuclear) = 207Mt CO₂

That is 10Mt higher than without Australian LNG.

Coal emissions and displacement – illustrative scenario

Australia’s thermal coal exports were 208Mt in calendar year 2018. Emissions when burning this coal were 506Mt CO₂, based on government emissions factors.

Assuming typical emissions factors for fuel use in electricity generation of 0.9 tonnes of CO₂ per megawatt-hour (MWh) from black coal and 0.5 tonnes of CO₂ per MWh from gas, the emissions intensity of electricity generation under the mix assumed for illustration here would be:

0.7 x 0.9 (coal) + 0.2 x 0.5 (gas) + 0.1 x 0 (renewables/nuclear) = 0.73 tonnes CO₂ per MWh

This is 19% lower than the emissions intensity of purely coal-fired electricity, of 0.9 tonnes CO₂ per MWh.

19% of 506Mt CO₂ is 96Mt CO₂.

Frank Jotzo, Director, Centre for Climate Economics and Policy, Crawford School of Public Policy, Australian National University and Salim Mazouz, Research Manager, Crawford School of Public Policy; and Director at EcoPerspectives, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Burning buried sunshine

The renewables transition

Other factors to consider

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The time is now

Our findings

Winds of change

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Environmental impact of renewables

What happened to environmentalism?

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A poor showing

How your energy company fares

The big four emitters

A rapid renewables shift

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A gas-led economic recovery

Bad: investing in gas

Good: investing in critical infrastructure

The verdict

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One person, one year, 500 kilograms of waste

Burning waste in Denmark

So what’s the problem?

A lack of evidence

Where to from here?

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Energy efficiency: a low-hanging fruit

Governments’ sleight of hand

A sustainable future

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1. It can readily eliminate fossil fuels

2. Solar is already king

3. Solar and wind are getting cheaper

4. Stable renewable electricity is not hard

5. There’s enough land

6. Raw materials won’t run out

7. Nearly every country has good sun or wind

8. We will never go to war over sunshine

9. Solar accidents and pollution are small

10. Payback time is short

The future is bright

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Stifling innovation and waste reduction

Landfills as mines of the future

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How much might gas exports really cut emissions?

Coal exports unambiguously raise emissions

The real opportunity is in export of renewable energy

Summary of data and calculations

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