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.

Yes, it is entirely possible for Australia to phase out thermal coal within a decade

John Quiggin, The University of QueenslandAustralia has received seemingly contradictory messages about coal this week.

In a UK study published today in Nature, scientists found Australia must keep 95% of coal in the ground if we have any hope of stopping the planet warming beyond the crucial limit of 1.5℃.

These findings echo the message of senior United Nations official Selwin Hart, who earlier this week urged Australia to end the use of coal by 2030. He warned if the world doesn’t boost climate action urgently, Australia can expect more frequent and severe climate disasters such as droughts, heatwaves, fires and floods.

Meanwhile, markets for coal seem to be sending the opposite message.

The price of Newcastle thermal coal recently reached a record high of US$180 per tonne due to rising electricity demand in India, China and other Asian countries. That seems to suggest whatever the consequences, Australia and the world are not going to give up on coal or other carbon-based fuels.

But it’s a mistake to place too much weight on fluctuations in coal markets. Earlier this year, the price was about US$50 per tonne and seemed likely to fall further. The current price tells us nothing about the choices we face in reducing emissions by 2030.

It’s entirely feasible for Australia to phase out thermal coal by 2030 — we just need political will.

World economies must decarbonise

The authors of the new modelling study in Nature examined the world’s reserves of oil, gas and coal, and determined how much would have to be left untouched for at least a 50% chance of limiting global warming to 1.5℃.

Overall, it found nearly 60% of the world’s oil and fossil methane gas, and 90% of coal must remain unextracted by 2050. But the estimate for exporters like Australia is even higher.

This means production in most regions must peak now, or in the next decade, and that stronger policies are needed to restrict production and reduce demand.

The study reinforces how urgent it is to decarbonise economies. As Selwin Hart, the Special Advisor to the UN Secretary-General on Climate Action, noted in his speech to the Crawford Leadership Forum:

Decarbonisation of the global economy is quickly gathering pace. And there are huge opportunities to create more jobs, better health, and a stronger and fairer economy for those countries and companies that move first and fastest.

Is an end to coal feasible?

But would it really be possible for Australia to phase out coal by 2030, as Hart insists?

To consider this, it’s important to first distinguish between thermal coal and metallurgical coal. Thermal coal is used to generate electricity, while metallurgical coal is used in steelmaking.

Blast furnaces using metallurgical coal will ultimately be replaced by alternative technologies, such as using “green” hydrogen produced using clean electricity.

That process has begun, but it will take a long time, and can’t start until electricity generation is decarbonised. So, it makes sense to focus on phasing out thermal coal first.

But if decarbonisation of the global economy requires a rapid end to the use of thermal coal, why has its price suddenly surged?

A number of factors determine the thermal coal market, and fluctuations don’t tell us much about what the coal market will look like in 2030.

The recent increase in prices was caused by a combination of the rapid recovery from the pandemic recession, rising gas prices, weather-related disruptions to coal supply from Indonesia, and drought in China. It’s worth noting that despite high prices, the volume of seaborne thermal coal has actually declined.

95% of Australia’s coal must stay in the ground to cap the planet’s warming at 1.5℃
(AP Photo/Matthew Brown, File

Ending thermal coal in Australia would be easy

Given a modest amount of political will, or just the end of obstructionism from the federal government, Australia could easily replace coal-fired electricity generation with a combination of solar and wind, backed by storage.

Most of Australia’s coal-fired power plants were commissioned in the 20th century with obsolete sub-critical technology, and would be approaching the end of their operational lives even in the absence of climate change concerns.

Bringing those dates forward to 2030 or earlier could be almost costless. We could easily double our current rate of installation of utility-scale solar and wind generation, if the federal government got out of the way and let the states tackle the job.

Only five coal plants have been commissioned this century. The Bluewater plant in Western Australia has already been written off as worthless because of competition from solar and wind power.

The remaining four, all in Queensland, have a total capacity of less than 3 gigawatts. Allowing for the fact solar photovoltaic (PV) only operates in daylight hours, this is about the same as one million 10-kilowatt rooftop solar installations (about average for new installations). Queensland already has more than 750,000 solar rooftops, and capacity for another million.

More notably, the cost of decarbonising electricity supply is a fraction of the amount we have collectively spent to respond to the problem of the COVID-19 pandemic. Not only is COVID a smaller threat in the long run than climate change but a comprehensive response to pandemics requires us to stabilise the climate and stop the destruction of natural environments.

Managing the transition for the coal workforce would be more challenging, but still entirely feasible, as countries such as Spain and Germany have shown.

In a report I prepared for the Australia Institute last year, I found Australia could successfully transition the workforce with a mixture of measures including early retirement, retraining, and investments in renewable energy targeted at coal-dependent regions.

The cost of this would be around A$50 million a year, over ten years. That’s less than the estimated cost of a week of COVID lockdown in Sydney.

But would this condemn developing countries to energy poverty?

The reality is it makes economic and environmental sense for all countries to shift away from coal.

The central government in China has committed to reach net zero carbon emissions by 2060. But many provincial governments still see investment in coal plants and other polluting industries as an engine of growth, not to mention a lucrative source of kickbacks and donations.

The picture in India is similarly complex. Coal remains the main source of electricity, but most electricity generation businesses have abandoned new investments in coal-fired power and many have stopped bidding for access to domestic coal supplies.

We can’t do much to influence energy policy in China and India. But a commitment to reduce and ultimately eliminate exports of thermal coal would not, as some have suggested, condemn these and other developing countries to poverty.

Rather, it would strengthen the hand of advocates of clean energy against the established interest groups that defend coal.

John Quiggin, Professor, School of Economics, The University of Queensland

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

Spain and Quitting Coal

These 3 energy storage technologies can help solve the challenge of moving to 100% renewable electricity

Energy storage can make facilities like this solar farm in Oxford, Maine, more profitable by letting them store power for cloudy days.
AP Photo/Robert F. Bukaty

Kerry Rippy, National Renewable Energy LaboratoryIn recent decades the cost of wind and solar power generation has dropped dramatically. This is one reason that the U.S. Department of Energy projects that renewable energy will be the fastest-growing U.S. energy source through 2050.

However, it’s still relatively expensive to store energy. And since renewable energy generation isn’t available all the time – it happens when the wind blows or the sun shines – storage is essential.

As a researcher at the National Renewable Energy Laboratory, I work with the federal government and private industry to develop renewable energy storage technologies. In a recent report, researchers at NREL estimated that the potential exists to increase U.S. renewable energy storage capacity by as much as 3,000% percent by 2050.

Here are three emerging technologies that could help make this happen.

Longer charges

From alkaline batteries for small electronics to lithium-ion batteries for cars and laptops, most people already use batteries in many aspects of their daily lives. But there is still lots of room for growth.

For example, high-capacity batteries with long discharge times – up to 10 hours – could be valuable for storing solar power at night or increasing the range of electric vehicles. Right now there are very few such batteries in use. However, according to recent projections, upwards of 100 gigawatts’ worth of these batteries will likely be installed by 2050. For comparison, that’s 50 times the generating capacity of Hoover Dam. This could have a major impact on the viability of renewable energy.

Batteries work by creating a chemical reaction that produces a flow of electrical current.

One of the biggest obstacles is limited supplies of lithium and cobalt, which currently are essential for making lightweight, powerful batteries. According to some estimates, around 10% of the world’s lithium and nearly all of the world’s cobalt reserves will be depleted by 2050.

Furthermore, nearly 70% of the world’s cobalt is mined in the Congo, under conditions that have long been documented as inhumane.

Scientists are working to develop techniques for recycling lithium and cobalt batteries, and to design batteries based on other materials. Tesla plans to produce cobalt-free batteries within the next few years. Others aim to replace lithium with sodium, which has properties very similar to lithium’s but is much more abundant.

Safer batteries

Another priority is to make batteries safer. One area for improvement is electrolytes – the medium, often liquid, that allows an electric charge to flow from the battery’s anode, or negative terminal, to the cathode, or positive terminal.

When a battery is in use, charged particles in the electrolyte move around to balance out the charge of the electricity flowing out of the battery. Electrolytes often contain flammable materials. If they leak, the battery can overheat and catch fire or melt.

Scientists are developing solid electrolytes, which would make batteries more robust. It is much harder for particles to move around through solids than through liquids, but encouraging lab-scale results suggest that these batteries could be ready for use in electric vehicles in the coming years, with target dates for commercialization as early as 2026.

While solid-state batteries would be well suited for consumer electronics and electric vehicles, for large-scale energy storage, scientists are pursuing all-liquid designs called flow batteries.

Flow battery diagram. — A typical flow battery consists of two tanks of liquids that are pumped past a membrane held between two electrodes.
Qi and Koenig, 2017, CC BY

In these devices both the electrolyte and the electrodes are liquids. This allows for super-fast charging and makes it easy to make really big batteries. Currently these systems are very expensive, but research continues to bring down the price.

Storing sunlight as heat

Other renewable energy storage solutions cost less than batteries in some cases. For example, concentrated solar power plants use mirrors to concentrate sunlight, which heats up hundreds or thousands of tons of salt until it melts. This molten salt then is used to drive an electric generator, much as coal or nuclear power is used to heat steam and drive a generator in traditional plants.

These heated materials can also be stored to produce electricity when it is cloudy, or even at night. This approach allows concentrated solar power to work around the clock.

Man examines valve at end of large piping network. — Checking a molten salt valve for corrosion at Sandia’s Molten Salt Test Loop.
Randy Montoya, Sandia Labs/Flickr, CC BY-NC-ND

This idea could be adapted for use with nonsolar power generation technologies. For example, electricity made with wind power could be used to heat salt for use later when it isn’t windy.

Concentrating solar power is still relatively expensive. To compete with other forms of energy generation and storage, it needs to become more efficient. One way to achieve this is to increase the temperature the salt is heated to, enabling more efficient electricity production. Unfortunately, the salts currently in use aren’t stable at high temperatures. Researchers are working to develop new salts or other materials that can withstand temperatures as high as 1,300 degrees Fahrenheit (705 C).

One leading idea for how to reach higher temperature involves heating up sand instead of salt, which can withstand the higher temperature. The sand would then be moved with conveyor belts from the heating point to storage. The Department of Energy recently announced funding for a pilot concentrated solar power plant based on this concept.

Advanced renewable fuels

Batteries are useful for short-term energy storage, and concentrated solar power plants could help stabilize the electric grid. However, utilities also need to store a lot of energy for indefinite amounts of time. This is a role for renewable fuels like hydrogen and ammonia. Utilities would store energy in these fuels by producing them with surplus power, when wind turbines and solar panels are generating more electricity than the utilities’ customers need.

Hydrogen and ammonia contain more energy per pound than batteries, so they work where batteries don’t. For example, they could be used for shipping heavy loads and running heavy equipment, and for rocket fuel.

Today these fuels are mostly made from natural gas or other nonrenewable fossil fuels via extremely inefficient reactions. While we think of it as a green fuel, most hydrogen gas today is made from natural gas.

Scientists are looking for ways to produce hydrogen and other fuels using renewable electricity. For example, it is possible to make hydrogen fuel by splitting water molecules using electricity. The key challenge is optimizing the process to make it efficient and economical. The potential payoff is enormous: inexhaustible, completely renewable energy.

[Understand new developments in science, health and technology, each week. Subscribe to The Conversation’s science newsletter.]

Kerry Rippy, Researcher, National Renewable Energy Laboratory

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

As the world battles to slash carbon emissions, Australia considers paying dirty coal stations to stay open longer

Tim Nelson, Griffith University and Joel Gilmore, Griffith UniversityA long-anticipated plan to reform Australia’s electricity system was released on Thursday. One of the most controversial proposals by the Energy Security Board (ESB) concerns subsidies which critics say will encourage dirty coal plants to stay open longer.

The subsidies, under a so-called “capacity mechanism”, would aim to ensure reliable energy supplies as old coal plants retire.

Major coal generators say the proposal will achieve this aim. But renewables operators and others oppose the plan, saying it will pay coal plants for simply existing and delay the clean energy transition.

So where does the truth lie? Unless carefully designed, the proposal may enable coal generators to keep polluting when they might otherwise have closed. This is clearly at odds with the need to rapidly cut greenhouse gas emissions and stabilise Earth’s climate.

firefighter and bushfire engulfing house — Extending the life of coal plants is at odds with climate action efforts.
Dan Himbrechts/AAP

Paying coal stations to exist

The ESB provides advice to the nation’s energy ministers and comprises the heads of Australia’s major energy governing bodies.

Advice to the ministers on the electricity market redesign, released on Thursday, includes a recommendation for a mechanism formally known as the Physical Retailer Reliability Obligation (PRRO).

It would mean electricity generators are paid not only for the actual electricity they produce, which is the case now, but also for having the capacity to scale up electricity generation when needed.

Electricity prices on the wholesale market – where electricity is bought and sold – vary depending on the time of day. Prices are typically much higher when consumer demand peaks, such as in the evenings when we turn on heaters or air-conditioners. This provides a strong financial incentive for generators to provide reliable electricity at these times.

As a result of these incentives, Australia’s electricity system has been very reliable to date.

But the ESB says as more renewables projects come online, this reliability is not assured – due to investor uncertainty around when coal plants will close and how governments will intervene in the market.

Under the proposed change, electricity retailers – the companies everyday consumers buy energy from – must enter into contracts with individual electricity generators to make capacity available to the market.

Energy authorities would decide what proportion of a generator’s capacity could be relied upon at critical times. Retailers would then pay generators regardless of whether or not they produce electricity when needed.

Submissions to the ESB show widespread opposition to the proposed change: from clean energy investors, battery manufacturers, major energy users and consumer groups. The ESB acknowledges the proposal has few supporters.

In fact, coal generators are virtually the only groups backing the proposed change. They say it would keep the electricity system reliable, because the rapid expansion of rooftop solar has lowered wholesale prices to the point coal plants struggle to stay profitable.

The ESB says the subsidy would also go to other producers of dispatchable energy such as batteries and pumped hydro. It says such businesses require guaranteed revenue streams if they’re to invest in new infrastructure.

Man gives thumbs up in front of hydro project — Prime Minister Scott Morrison at the Snowy Hydro project. Such generators would also be eligible for the proposed subsidy.
Lukas Coch/AAP

A questionable plan

In our view, the arguments from coal generators and the ESB require greater scrutiny.

Firstly, the ESB’s suggestion that the existing market is not driving investment in new dispatchable generation is not supported by recent data. As the Australian Energy Market Operator recently noted, about 3.7 gigawatts of new gas, battery and hydro projects are set to enter the market in coming years. This is on top of 3.2 gigawatts of new wind and solar under construction. Together, this totals more than four times the operating capacity of AGL’s Liddell coal plant in New South Wales.

It’s also difficult to argue the system is made more reliable by paying dispatchable coal stations to stay around longer.

One in four Australian homes have rooftop solar panels, and installation continues to grow. This reduces demand for coal-fired power when the sun is shining.

The electricity market needs generators that can turn on and off quickly in response to this variable demand. Hydro, batteries and some gas plants can do this. Coal-fired power stations cannot – they are too slow and inflexible.

Coal stations are also becoming less reliable and prone to breakdowns as they age. Paying them to stay open can block investment in more flexible and reliable resources.

Critics of the proposed change argue coal generators can’t compete in a world of expanding rooftop solar, and when large corporate buyers are increasingly demanding zero-emissions electricity.

There is merit in these arguments. The recommended change may simply create a new revenue stream for coal plants enabling them to stay open when they might otherwise have exited the market.

Governments should also consider that up to A$5.5 billion in taxpayer assistance was allocated to coal-fired generators in 2012 to help them transition under the Gillard government’s (since repealed) climate policies. Asking consumers to again pay for coal stations to stay open doesn’t seem equitable.

Steam billows from coal plant — Coal plants have already received billions in subsidies.
Shutterstock

The ultimate test

The nation’s energy ministers have not yet decided on the reforms. As usual, the devil will be in the detail.

For any new scheme to improve electricity reliability, it should solely reward new flexible generation such as hydro, batteries, and 100% clean hydrogen or biofuel-ready gas turbines.

For example, reliability could be improved by establishing a physical “reserve market” of new, flexible generators which would operate alongside the existing market. This generation could be seamlessly introduced as existing generation fails and exits.

The ESB has recommended such a measure, and pivoting the capacity mechanism policy to reward only new generators could be beneficial.

The Grattan Institute
has also proposed a scheme to give businesses more certainty about when coal plant will close. Together, these options would address the ESB’s concerns.

This month’s troubling report by the Intergovernmental Panel on Climate Change was yet another reminder of the need to dramatically slash emissions from burning fossil fuels.

Energy regulators, politicians and the energy industry owe it to our children and future generations to embrace a zero-emissions energy system. The reform of Australia’s electricity market will ultimately be assessed against this overriding obligation.

Tim Nelson, Associate Professor of Economics, Griffith University and Joel Gilmore, Associate Professor, Griffith University

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

Complicated, costly and downright frustrating: Aussies keen to cut emissions with clean energy at home get little support

Hugo Temby, Australian National University and Hedda Ransan-Cooper, Australian National UniversityEven after A$4,000 in repairs, Heather’s $18,000 rooftop solar and battery system is still not working.

Heather worked as a nurse until a workplace accident caused her to leave the workforce. She put most of her compensation towards making a switch to clean energy, hoping to bring down her energy costs and increase her comfort.

But a solar company sold her a system that wasn’t suited to her needs. They also didn’t clearly explain how the system worked or how to maintain it.

Heather’s battery failed after roughly two years. Her system’s complexity, and the limited handover provided by the company, meant she didn’t notice its failure during the short warranty period. Reflecting on the technical written information provided to her, Heather told us it was “way over my head”.

As a result, she is fully responsible for the cost of repairs, which she cannot afford. And she has since been told the battery is irreparable.

Heather’s story is one of many featured in our new report published today. It shows household clean energy technologies — such as rooftop solar, household batteries and electric vehicles — can be unnecessarily complicated, time consuming and costly.

Switching to clean energy at home

The aim of our report was to better understand stories like Heather’s to inform a Victorian Energy and Water Ombudsman review of the various new energy technology regulatory frameworks in Australia. These frameworks have not kept up with the pace of technological change.

We held in-depth interviews in 2020 and 2021 with 68 householders, businesses and industry experts based mainly in Victoria and South Australia. We asked why people were purchasing new energy technology, if it was meeting their expectations, and the issues people were encountering.

Old radiator against a wall — Switching to clean energy technologies from old, emissions-intensive ones shouldn’t be this hard.
Shutterstock

Nearly all householders we spoke with were motivated to some degree by environmental concerns, particularly the desire to reduce their emissions, and many expected some financial returns. Community mindedness, enthusiasm for technology and comfort were other common motivators.

And many wanted greater independence from untrusted energy companies. Distrust of the sector has multiple facets, but it often boils down to a sense the sector doesn’t have the long-term interests of the public in mind.

Going it alone

New energy technologies can be highly complex. It’s not always clear what differentiates one solar panel product from another. Some services, such as virtual power plants or battery aggregation, require a basic understanding of how the broader energy system works, which even energy insiders can struggle to understand.

Some householders told us they found it difficult to source reliable information about different electric vehicle products, which they felt weren’t being sufficiently well covered in mainstream car magazines.

Meanwhile, many householders felt alone and unsupported in dealing with their new technology. Heather, for example, has gone through four different electricians.

Most told us they were investing significant time, effort and funds into researching, choosing, configuring and operating their technologies, with different technologies often interacting and various energy tariffs on offer.

Increasingly, people are being seen as idealised “prosumers” in a “two-sided market”. In other words, rather than asking people how they might like to engage with the energy system, householders are given narrow options revolving around solely financial mechanisms.

Electric cars charging — Australians need support to cut transport emissions with electric vehicles.
Shutterstock

Most Australians don’t have the time and resources to do this work. Without a whole-of-sector strategy to ensure all Australians benefit from new energy technologies, we risk leaving people behind. This includes renters, apartment dwellers, people who can’t afford high up-front costs, or people who simply don’t have the time to do all the extra “digital housework” to maintain these technologies.

Alternative models, such as social enterprises or community energy, could make technology more accessible to renters and low income households. One example of this is solar gardens, where people can buy a share in a solar array located nearby, which in turn provides them with a discount on their bill.

But arguably, such options wouldn’t be required if our emerging energy system had resolved the energy trilemma in the first place.

Why this is so concerning

We know householders are a key part of the solution for climate mitigation, together with businesses and government.

There are many ways householders can decarbonise their electricity and transport. While not all involve buying new energy products, we consistently heard frustration about the lack of a coherent framework for different ways they could contribute.

According to the federal government, it will be “technology, not taxes” that will get us to our Paris emissions reduction commitments.

But this assumes new technology uptake will be straightforward and downplays potential risks. It also implies new technology is always preferable to alternatives like reducing consumption.

A narrow focus on technology also ignores the rebound effect. Research has shown that without deeper engagement with Australians about the energy system, it’s possible lower electricity costs from new energy technologies could actually increase energy use and emissions.

Person installing rooftop solar — The federal government’s ‘technology not taxes’ approach to energy policy assumes new tech uptake will be straightforward.
Shutterstock

Where do we go from here?

Our new research shows we need better support for the nearly 2.8 million (and growing) Australian households and businesses that have already purchased new, clean energy technologies.

To make this happen, we need coordinated, climate wise policy across all levels of government with an engaged, evidence-based and equitable energy policy. This would help rebuild trust in Australia’s energy system.

If our national climate policy is to rely on new energy technology, it will be critical to ensure the technology – and its implementation – is better aligned with people’s needs and aspirations.

Hugo Temby, Doctoral Researcher, Battery Storage and Grid Integration Program, Australian National University and Hedda Ransan-Cooper, Research Fellow, College of Engineering and Computer Science, Australian National University

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

The sunlight that powers solar panels also damages them. ‘Gallium doping’ is providing a solution

Matthew Wright, UNSW; Brett Hallam, UNSW, and Bruno Vicari Stefani, UNSWSolar power is already the cheapest form of electricity generation, and its cost will continue to fall as more improvements emerge in the technology and its global production. Now, new research is exploring what could be another major turning point in solar cell manufacturing.

In Australia, more than two million rooftops have solar panels (the most per capita in the world). The main material used in panels is silicon. Silicon makes up most of an individual solar cell’s components required to convert sunlight into power. But some other elements are also required.

Research from our group at the University of New South Wales’s School of Photovoltaics and Renewable Energy Engineering shows that adding gallium to the cell’s silicon can lead to very stable solar panels which are much less susceptible to degrading over their lifetime.

This is the long-term goal for the next generation of solar panels: for them to produce more power over their lifespan, which means the electricity produced by the system will be cheaper in the long run.

As gallium is used more and more to achieve this, our findings provide robust data that could allow manufacturers to make decisions that will ultimately have a global impact.

The process of ‘doping’ solar cells

A solar cell converts sunlight into electricity by using the energy from sunlight to “break away” negative charges, or electrons, in the silicon. The electrons are then collected as electricity.

However, shining light on a plain piece of silicon doesn’t generate electricity, as the electrons that are released from the light do not all flow in the same direction. To make the electricity flow in one direction, we need to create an electric field.

In silicon solar cells — the kind currently producing power for millions of Australian homes — this is done by adding different impurity atoms to the silicon, to create a region that has more negative charges than normal silicon (n-type silicon) and a region that has fewer negative charges (p-type silicon).

When we put the two parts of silicon together, we form what is called a “p-n junction”. This allows the solar cell to operate. And the adding of impurity atoms into silicon is called “doping”.

An unfortunate side effect of sunlight

The most commonly used atom to form the p-type part of the silicon, with less negative charge than plain silicon, is boron.

Boron is a great atom to use as it has the exact number of electrons needed for the task. It can also be distributed very uniformly through the silicon during the production of the high-purity crystals required for solar cells.

But in a cruel twist, shining light on boron-filled silicon can make the quality of the silicon degrade. This is often referred to as “light-induced degradation” and has been a hot topic in solar research over the past decade.

The reason for this degradation is relatively well understood: when we make the pure silicon material, we have to purposefully add some impurities such as boron to generate the electric field that drives the electricity. However, other unwanted atoms are also incorporated into the silicon as a result.

One of these atoms is oxygen, which is incorporated into the silicon from the crucible — the big hot pot in which the silicon is refined.

When light shines on silicon that contains both boron and oxygen, they bond together, causing a defect that can trap electricity and reduce the amount of power generated by the solar panel.

Unfortunately, this means the sunlight that powers solar panels also damages them over their lifetime. An element called gallium looks like it could be the solution to this problem.

A smarter approach

Boron isn’t the only element we can use to make p-type silicon. A quick perusal of the periodic table shows a whole column of elements that have one less negative charge than silicon.

Adding one of these atoms to silicon upsets the balance between the negative and positive charge, which is needed to make our electric field. Of these atoms, the most suitable is gallium.

Gallium is a very suitable element to make p-type silicon. In fact, multiple studies have shown it doesn’t bond together with oxygen to cause degradation. So, you may be wondering, why we haven’t been using gallium all along?

Well, the reason we have been stuck using boron instead of gallium over the past 20 years is that the process of doping silicon with gallium was locked under a patent. This prevented manufacturers using this approach.

Gallium-doped silicon heterojunction solar cell.
Robert Underwood/UNSW

But these patents finally expired in May 2020. Since then, the industry has rapidly shifted from boron to gallium to make p-type silicon.

In fact, at the start of 2021, leading photovoltaic manufacturer Hanwha Q Cells estimated about 80% of all solar panels manufactured in 2021 used gallium doping rather than boron — a massive transition in such a short time!

Does gallium really boost solar panel stability?

We investigated whether solar cells made with gallium-doped silicon really are more stable than solar cells made with boron-doped silicon.

To find out, we made solar cells using a “silicon heterojunction” design, which is the approach that has led to the highest efficiency silicon solar cells to date. This work was done in collaboration with Hevel Solar in Russia.

We measured the voltage of both boron-doped and gallium-doped solar cells during a light-soaking test for 300,000 seconds. The boron-doped solar cell underwent significant degradation due to the boron bonding with oxygen.

Meanwhile, the gallium-doped solar cell had a much higher voltage. Our result also demonstrated that p-type silicon made using gallium is very stable and could help unlock savings for this type of solar cell.

To think it might be possible for manufacturers to work at scale with gallium, producing solar cells that are both more stable and potentially cheaper, is a hugely exciting prospect.

The best part is our findings could have a direct impact on industry. And cheaper solar electricity for our homes means a brighter future for our planet, too.

Matthew Wright, Postdoctoral Researcher in Photovoltaic Engineering, UNSW; Brett Hallam, Scientia and DECRA Fellow, UNSW, and Bruno Vicari Stefani, PhD Candidate, UNSW

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.
Shutterstock

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.

India’s wicked problem: how to loosen its grip on coal while not abandoning the millions who depend on it

Vigya Sharma, The University of QueenslandIndia is the world’s third largest emitter of greenhouse gases, and its transition to a low-carbon economy is crucial to meeting the goals of the Paris Agreement. But unfortunately, the nation is still clinging firmly to coal.

Our new research considered this problem, drawing on a case study in the Angul district, India’s largest coal reserve in the eastern state of Odisha.

We found three main factors slowing the energy transition: strong political and community support for coal, a lack of alternative economic activities, and deep ties between coal and other industries such as rail.

India must step away from coal, while maintaining economic growth and not leaving millions of people in coal-mining regions worse off. Our research probes this wicked problem in detail and suggests ways forward.

people carry baskets filled with coal — India’s energy transition must ensure those living in poverty are not left behind.
Shutterstock

Why India matters

India’s population will soon reach 1.4 billion and this decade it is expected to overtake China as the world’s most populous nation. This, combined with a young population, growing economy and rapid urbanisation, means energy consumption in India has doubled since 2000.

The International Energy Agency (IEA) estimates India will have the largest increase in energy demand of any country between now and 2040.

An affordable, reliable supply of energy is central to raising the nation’s living standards. A recent World Bank analysis found up to 150 million people in India are poor.

Alongside its massive reliance on coal, India has one of the world’s most ambitious renewable energy plans, including an aim to quadruple renewable electricity capacity by 2030.

The IEA says coal accounts for about 70% of India’s electricity generation. And as the nation rebounds from the coronavirus pandemic this year, the rise in coal-fired electricity production is expected to be three times that from cleaner sources.

Coal-powered generation is anticipated to grow annually by 4.6% to 2024, and coal is expected to remain a major emitter of greenhouse gases to 2040.

While India’s energy trajectory remains aligned with its commitments under the Paris Agreement, the speed and readiness of its transition remains a complex, divisive issue. The World Economic Forum’s 2021 Energy Transition Index ranks India 87th out of 115 countries analysed.

students hold lights — India’s young, growing population is fuelling the nation’s energy demand.
EPA

Bottlenecks in the transition

Our research involved visits to the Angul district in Odisha in 2018 and 2019, where we conducted focus groups and interviews. Angul is home to 11 coal mines.

We found three crucial bottlenecks to the energy transition, which arguably exist in India’s other coal belts and could derail the nation’s decarbonisation efforts.

First, the Odisha government has historically been very pro-business. Politicians across the spectrum support coal mining and seek to position it as the region’s primary economic lifeline.

The official pro-coal position receives little pushback from Angul residents, who are largely unaware of Odisha’s contribution to national greenhouse gas emissions. Any local opposition to coal usually stems from concern about environmental degradation such as air, water and land pollution.

Most of Angul’s residents felt a deep connection to coal because their livelihood depends on it. One participant told us:

even if all the water is polluted and five inches of dust settles on our well, we would prefer mining to continue as my family’s survival depends on (the contract with the mining company).

Most participants considered their farming land as an asset to be sold to the mining companies for a significant sum. The money would, in turn, allow them to start a business, buy a car or arrange a marriage in the family.

people sit in dark room — Coal is important to the livelihoods of millions of Indian people.
AP

Second, the heavy reliance on coal means efforts to diversify the region’s economy have been grossly neglected.

In Angul, mining zones and coal-dedicated railway lines passing through paddy fields mean agricultural productivity has declined over time. Rural development agendas have been short-lived, often set within six months of an election deadline then changed or abandoned.

Skill-development programs in non-coal vocations have also been limited. This lack of viable alternatives implicitly generates local support for coal.

And third, a suite of industries in Odisha – such as steel, cement, fertiliser and bauxite – depend on cheap coal for power. This is reflected across India, where coal has deep ties with other industries in ways not seen elsewhere.

For example, in 2016 Indian Railways earned 44% of its freight revenue from transporting coal. Indian Railways is India’s largest employer and coal revenue helps keep passenger fares low. So in this way, a potential coal phaseout in India would have far-reaching effects.

people look out train window — Coal revenue helps subsidise train fares in India.
EPA

The way forward

We offer these pathways to ensure a steady, just energy transition in India:

India must help its coal regions diversify their economic activities
bipartisan support for a coal-free India is needed. Transition champions such as Germany can show India’s leaders the way
a national taskforce for energy transition should be established. It should include representatives from across industry and academia, as well as climate policymakers and grassroots organisations
India’s coal regions are endowed with metals needed in the energy transition, including iron ore, bauxite and manganese. With improved regulatory standards, these offer economic alternatives to coal
concerns about the coal phase-out from communities in coal regions should be addressed fairly and in a timely way.

The world’s emerging economies are responsible for two-thirds of global greenhouse gas emissions. The energy transition in India, if done well, could show the way for other developing nations.

But as new industrial sectors emerge and clean energy jobs grow, India must ensure those in coal-dependent regions are not left behind.

Vigya Sharma, Senior Research Fellow, Sustainable Minerals Institute, The University of Queensland

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

Kenya: The Price of Clean Energy

Burning buried sunshine

The renewables transition

Other factors to consider

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World economies must decarbonise

Is an end to coal feasible?

Ending thermal coal in Australia would be easy

But would this condemn developing countries to energy poverty?

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Longer charges

Safer batteries

Storing sunlight as heat

Advanced renewable fuels

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Paying coal stations to exist

A questionable plan

The ultimate test

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Switching to clean energy at home

Going it alone

Why this is so concerning

Where do we go from here?

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The process of ‘doping’ solar cells

An unfortunate side effect of sunlight

A smarter approach

Does gallium really boost solar panel stability?

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The time is now

Our findings

Winds of change

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Why India matters

Bottlenecks in the transition

The way forward

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