Why is the Australian energy regulator suing wind farms – and why now?



Michael Coghlan/Flickr, CC BY-SA

Samantha Hepburn, Deakin University

The Australian Energy Regulator (AER) is suing four of the wind farms involved in the 2016 South Australian blackout – run by AGL Energy, Neoen Australia, Pacific Hydro, and Tilt Renewables – alleging they breached generator performance standards and the national electricity rules.

These proceedings appear to contradict the conclusions of a 2018 report which said while the AER had found some “administrative non-compliance”, it did not intend to take formal action given the “unprecedented circumstances”.




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However the AER has since said this report focused on the lead-up and aftermath of the blackout, not the event itself. The case hinges on whether the wind farms failed to provide crucial information during the blackout which hindered recovery.

In particular, the AER is arguing the software protecting the wind farms should have been able to cope with voltage disturbances and provide continuous energy supply. On the face of it, however, this will be extremely difficult to prove.

Rehashing the 2016 blackout

The 2016 South Australian blackout was triggered by a severe storm that hit the state on September 28. Tornadoes with wind speeds up to 260 km/h raced through SA, and a single-circuit 275-kilovolt transmission line was struck down.




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After this, 170km away, a double-circuit 275kV transmission line was lost. This transmission damage caused the lines to trip and a series of subsequent faults resulted in six voltage dips on the South Australian grid at 4.16pm.

As the faults escalated, eight wind farms in SA had their protection settings activated. This allowed them to withstand the voltage dip by automatically reducing power. Over a period of 7 seconds, 456 megawatts of power was removed. This reduction caused an increase in power to flow through the Heywood interconnector. This in turn triggered a protection mechanism for the interconnecter that tripped it offline.

Once this happened, SA became separated from the rest of the National Energy Market (NEM), leaving far too little power to meet demand and blacking out 850,000 homes and businesses. A 2017 report found once SA was separated from the NEM, the blackout was “inevitable”.




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What went wrong at the wind farms?

The question then becomes, is there any action the wind farms could reasonably have taken to stay online, thus preventing the overloading of the Heywood interconnector?

The regulator is arguing the operators should have let the market operator know they could not handle the disruption caused by the storms, so the operator could make the best decisions to keep the grid functioning.

Wind farms, like all energy generators in Australia, have a legal requirement to meet specific performance standards. If they fall short in a way that can materially harm energy security, they have a further duty to inform the operator immediately, with a plan to remedy the problem.

To determine whether a generator has complied with these risk management standards, a range of factors are considered. These include:

  • the technology of the plant,
  • whether its performance is likely to drift or degrade over a particular time frame,
  • experience with the particular generation technology,
  • the connection point arrangement that is in place. A generator will have an arrangement with a transmission network service provider (TNSP) that operates the networks that carry electricity between generators and distribution networks. TNSP’s advise the NEM of the capacity of their transmission assets so that they can be operated without being overloaded.
  • the risk and costs of different testing methods given the relative size of the plant.

Plenty of blame to go around

The series of events leading up to the 2016 blackout was extremely difficult to anticipate. There were many factors, and arguably all participants were involved in different ways.

  • The Heywood interconnector was running at full capacity at the time, so any overload may have triggered its protective mechanism.

  • The transmission lines were damaged by an unprecedented 263 lightning strikes in five minutes.

  • The market operator itself did not adopt precautionary measures such as reducing the load on the interconnector, or providing a clearer warning to electricity generators.

Bearing this in mind, the federal court will be asked to determine whether the wind farms complied with their generator performance standards and if not, whether this breach had a “material adverse effect” on power security.

This will be difficult to prove, because even if the generator standards require the wind farms to evaluate the point at which their protective triggers activated, it is unlikely the number of faults, the severity of the voltage dip, and the impact of the increased power flow on the Heywood interconnector could have been anticipated.




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The idea AEMO could have prevented the blackout if the wind farms had alerted it to the disruptive potential of their protective triggers is probably a little remote.

None of the participants could have foreseen the series of interconnected events leading to the blackout. Whilst lessons can be learned, laying blame is more complex. And while compliance with standards and rules is important, in this instance, it is unlikely that it would have changed the outcome.The Conversation

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.

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Taller, faster, better, stronger: wind towers are only getting bigger



Wind towers are getting taller.
Shutterstock

Con Doolan, UNSW

Former Australian Greens leader Bob Brown made headlines this week after he objected to a proposed wind farm on Tasmania’s Robbins Island. The development would see 200 towers built, each standing 270 metres from base to the tip of their blades.

Leaving aside the question of the Robbins Island development, these will be extraordinarily tall towers. However, they fit right in with the current trend for wind turbines.




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Wind turbines come in many designs, but the most common is the so-called “horizontal axis” kind, which look like giant fans on poles. This type of turbine is highly efficient at turning the energy in the wind into electrical energy.

Keen observers will have noticed that these turbines have been gaining in size over the years. In the 1990s, wind turbines typically had hub heights and rotor diameters of the order of 30m. Today, hub heights and rotor diameters are pushing well past 100m.



Shutterstock/The Conversation

Bigger is better

When it comes to wind turbines, bigger is definitely better. The bigger the radius of the rotor blades (or diameter of the “rotor disc”), the more wind the blades can use to turn into torque that drives the electrical generators in the hub. More torque means more power. Increasing the diameter means that not only more power can be extracted, but it can be done so more efficiently.

Larger and longer turbine blades mean greater aerodynamic efficiency. Creating more power in one turbine means less energy is lost as it is moved into the transmission system, and from there into the electrical generator. The economies of scale provide an overwhelming push for wind energy companies to develop larger rotor blades.




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Wind turbines are also growing taller because of the way wind travels around the world. Because air is viscous (like very thin honey) and “sticks” to the ground, the wind velocity at higher altitudes can be many times higher than at ground level.

Hence it is advantageous to put the turbine high in the sky where there is more energy to extract. Hilly terrain (like a mountain ridge) may also distort the wind, requiring engineers to design the wind turbines to be even taller to catch the wind. Wind turbines used offshore are generally larger and taller because of the higher levels of wind energy available at sea.

Typically, onshore turbines (most common in Australia) have blades between 40m and 90m long. Tower heights are usually in the range of 150m. Offshore turbines (those situated at sea and common in Europe) are much larger.

Offshore turbines are typically much larger than onshore towers.
Shutterstock

One of the largest wind turbine designs in the world, General Electric’s offshore 12-megawatt Haliade-X, has 107m blades and a total height of 260m. As a comparison, Sydney’s Centrepoint tower is 309m tall.

If the Robbins Island turbines are indeed built to 270m, as reported in the media, they would eclipse General Electric’s behemoths. I cannot speak to the likelihood of this, but I would assume engineers will have to select the best turbine for the prevailing wind conditions and existing infrastructure.

Challenging heights

The quest for bigger and taller turbines comes with its fair share of engineering challenges.

Longer blades are more flexible than shorter ones, which can create vibration. If not controlled, this vibration affects performance and reduces the life of the blades and anything they are attached to, such as the gearbox or generator.

Materials and manufacturing techniques are constantly being refined to create longer, and longer-lasting, turbine blades.

The longer the turbine’s blades, the more pressure is put on internal mechanisms.
Shutterstock

Taller turbines generate more power, which puts greater loads on the gearbox and transmission system, requiring mechanical engineers to develop new ways of converting the ever-increasing torque into electrical power. Taller wind turbines also need stronger support towers and foundations. The list of challenges is long.

As turbines grow, so too does the noise they make. The dominant source of noise occurs at the outer edge of the blades. Here, turbulence caused by the blade itself creates a “hissing” sound as it passes over the trailing edge. More noise is created when the blade chops through atmospheric turbulence in the wind as it blows into the tower.

Noise isn’t just a matter of size. If one turbine is placed in the wake of another, the sound of its blades passing through the highly turbulent air created by the upstream turbine will be very loud.

Keeping noise under control requires inventive solutions, such as borrowing ideas from nature: the silent-flying owl uses serrated feathers to control noise and these are now being used to make noisy turbines quieter.




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Of course, engineering challenges are not the only considerations for creating wind farms. Environmental effects, noise, visual impacts and other community concerns all need to be considered, as with any large infrastructure project. But wind turbines are one of the most cost-effective and technologically sophisticated forms of renewable energy, and as the developed world comes to grips with climate change we will only see more of them.The Conversation

Con Doolan, Professor, School of Mechanical and Manufacturing Engineering, UNSW

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

Five gifs that explain how pumped hydro actually works


Roger Dargaville, Monash University

People have used moving water to create energy for thousands of years. Today, pumped hydro is the most common form of grid-connected energy storage in the world.

This technology is in the spotlight because it pairs so well with solar and wind renewable energy. During the day, when solar panels and wind farms may be generating their highest level of energy, people don’t need really need much electricity. Unless it is stored somewhere the energy is lost.




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Pumped hydro can cheaply and easily store the excess energy, releasing it again at night when demand rises.

Here’s how it all works:

How it works

Put as simply as possible, it involves pumping water to a reservoir at the top of a hill when energy is in plentiful supply, then letting it flow back down through a turbine to generate electricity when demand increases.

Like all storage systems, you get less energy out than you put in – in this case, generally around 80% of the original input – because you lose energy to friction in the pipes and turbine as well as in the generator. For comparison, lithium ion batteries are around 90-95% efficient, while hydrogen energy storage is less than 50% efficient

The benefit is we can store a lot of energy at the top of the hill and keep it there in a reservoir until we need the energy back again. Then it can be released through the pipes (this is called “penstock”) to generate electricity. This means pumped hydro can create a lot of additional electricity when demand is high (for example, during a heatwave).

The disadvantage of pumped hydro is you need to have two reservoirs separated by a significant elevation difference (more than 200m is typically required, more than 300m is ideal). So it doesn’t work where you don’t have hills. However, research has identified 22,000 potential sites in Australia.




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Pumped hydro is traditionally paired with relatively inflexible coal or nuclear power stations, using under-utilised electricity when demand is low (weekends and nighttime), then providing additional generation when demand increases during the day and into the evening.

With the rapid increase in deployment of wind and solar, pumped hydro is again gaining interest. This is because the output of wind and solar plant is subject to the variability in the weather. For example, solar power plants generate the most electricity in the middle of the day, while demand for electricity is often highest in the evening. The wind might die down for hours or even days, then suddenly blow a gale. Pumped hydro can play a key role in smoothing out this variability.

If the electricity being produced by wind and solar plant is greater than demand, then the energy has to be curtailed (and is lost), unless we have a way to store it. Using this excess power to pump water up hill means the solar or wind energy is not wasted and the water can be held in reservoirs until demand rises in the evening.

There are lots of different kinds of energy storage technologies, each with their own advantages and disadvantages. For large-scale grid-connected systems where many hours of storage are required, pumped hydro is the most economically viable option.




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The Conversation


Roger Dargaville, Senior lecturer, Monash University

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

Here’s how a 100% renewable energy future can create jobs and even save the gas industry



File 20190123 122904 1whjg0s.jpg?ixlib=rb 1.1
The gas industry of the future could manufacture and deliver renewable fuels, rather than mining and processing natural gas.
Shutterstock.com

Sven Teske, University of Technology Sydney

The world can limit global warming to 1.5℃ and move to 100% renewable energy while still preserving a role for the gas industry, and without relying on technological fixes such as carbon capture and storage, according to our new analysis.

The One Earth Climate Model – a collaboration between researchers at the University of Technology Sydney, the German Aerospace Center and the University of Melbourne, and financed by the Leonardo DiCaprio Foundation – sets out how the global energy supply can move to 100% renewable energy by 2050, while creating jobs along the way.

It also envisions how the gas industry can fulfil its role as a “transition fuel” in the energy transition without its infrastructure becoming obsolete once natural gas is phased out.




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Our scenario, which will be published in detail as an open access book in February 2019, sets out how the world’s energy can go fully renewable by:

  • increasing electrification in the heating and transport sector

  • significant increase in “energy productivity” – the amount of economic output per unit of energy use

  • the phase-out of all fossil fuels, and the conversion of the gas industry to synthetic fuels and hydrogen over the coming decades.

Our model also explains how to deliver the “negative emissions” necessary to stay within the world’s carbon budget, without relying on unproven technology such as carbon capture and storage.

If the renewable energy transition is accompanied by a worldwide moratorium on deforestation and a major land restoration effort, we can remove the equiavalent of 159 billion tonnes of carbon dioxide from the atmosphere (2015-2100).

Combining models

We compiled our scenario by combining various computer models. We used three climate models to calculate the impacts of specific greenhouse gas emission pathways. We then used another model to analyse the potential contributions of solar and wind energy – including factoring in the space constraints for their installation.

We also used a long-term energy model to calculate future energy demand, broken down by sector (power, heat, industry, transport) for 10 world regions in five-year steps. We then further divided these 10 world regions into 72 subregions, and simulated their electricity systems on an hourly basis. This allowed us to determine the precise requirements in terms of grid infrastructure and energy demand.

Interactions between the models used for the One Earth Model.
One Earth Model, Author provided

‘Recycling’ the gas industry

Unlike many other 1.5℃ and/or 100% renewable energy scenarios, our analysis deliberately integrates the existing infrastructure of the global gas industry, rather than requiring that these expensive investments be phased out in a relatively short time.

Natural gas will be increasingly replaced by hydrogen and/or renewable methane produced by solar power and wind turbines. While most scenarios rely on batteries and pumped hydro as main storage technologies, these renewable forms of gas can also play a significant role in the energy mix.

In our scenario, the conversion of gas infrastructure from natural gas to hydrogen and synthetic fuels will start slowly between 2020 and 2030, with the conversion of power plants with annual capacities of around 2 gigawatts. However, after 2030, this transition will accelerate significantly, with the conversion of a total of 197GW gas power plants and gas co-generation facilities each year.

Along the way the gas industry will have to redefine its business model from a supply-driven mining industry, to a synthetic gas or hydrogen fuel production industry that provides renewable fuels for the electricity, industry and transport sectors. In the electricity sector, these fuels can be used to help smooth out supply and demand in networks with significant amounts of variable renewable generation.

A just transition for the fossil fuel industry

The implementation of the 1.5℃ scenario will have a significant impact on the global fossil fuel industry. While this may seem to be stating the obvious, there has so far been little rational and open debate about how to make an orderly withdrawal from the coal, oil, and gas extraction industries. Instead, the political debate has been focused on prices and security of supply. Yet limiting climate change is only possible when fossil fuels are phased out.

Under our scenario, gas production will only decrease by 0.2% per year until 2025, and thereafter by an average of 4% a year until 2040. This represents a rather slow phase-out, and will allow the gas industry to transfer gradually to hydrogen.

Our scenario will generate more energy-sector jobs in the world as a whole. By 2050 there would be 46.3 million jobs in the global energy sector – 16.4 million more than under existing forecasts.




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Our analysis also investigated the specific occupations that will be required for a renewables-based energy industry. The global number of jobs would increase across all of these occupations between 2015 and 2025, with the exception of metal trades which would decline by 2%, as shown below.

Division of occupations between fossil fuel and renewable energy industries in 2015 and 2025.
One Earth Model, Author provided

However, these results are not uniform across regions. China and India, for example, will both experience a reduction in the number of jobs for managers and clerical and administrative workers between 2015 and 2025.

Our analysis shows how the various technical and economic barriers to implementing the Paris Agreement can be overcome. The remaining hurdles are purely political.The Conversation

Sven Teske, Research Director, Institute for Sustainable Futures, University of Technology Sydney

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

35 degree days make blackouts more likely, but new power stations won’t help



File 20190115 180516 1u3i8ls.jpg?ixlib=rb 1.1
Whether your energy comes from coal or renewable sources isn’t likely to make a difference to your risk of a blackout this summer.
yellowbkpk/Flickr, CC BY-SA

Guy Dundas, Grattan Institute and Lucy Percival, Grattan Institute

Summer is here with a vengeance. On hot days it’s very likely something in the power system will break and cause someone to lose power. And the weather bureau expects this summer to be hotter and drier than average – so your chances of losing power will be higher than normal.

We’ve analysed outage data from the electricity distribution networks over the past nine years and linked it to Bureau of Meteorology maximum daily temperature data for each distribution network. The findings are stark: customers are without power for 3.5 times longer on days over 35 degrees than on days below 35.




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Grattan Institute

What causes outages on hot days?

Hot weather puts more stress on all parts of the power system. Wires sag and short, fuses blow, transformers overheat, and fires and storms damage power lines. And demand spikes when people get home from work and turn on the air-conditioner.

When the air-conditioner doesn’t work during a heat wave, people get upset and politicians rush to assign blame. They often point the finger at a lack of electricity generation capacity – just ask the current federal energy minister, who responded to a report forecasting supply shortages in Victoria this summer by saying:

This is a direct result of Victorian government policies forcing out reliable 24/7 power, and a failure to prioritise firming of heavily subsidised intermittent wind and solar generation.

Media reports highlight this risk, too. But the truth is, if you do lose power it’s much more likely to be because of problems in your local network.




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There have been generation shortfalls in Australia on only three days in the past fourteen years, whereas there are network failures every summer all around the country, every year.

The last time a lack of generation affected large numbers of customers was in Victoria and South Australia in January 2009. But even on very hot days that summer, Victorians and South Australians lost 14 times more power because of network failures and weather damage than generation shortfalls.

Outages caused by generation shortfalls are also easier to manage than network problems. Power can be restored at a flick of a switch, as soon as demand falls or supply increases. And the blacked-out areas can be rotated, to reduce the impact on any individual customer. By contrast, if your power goes out because of a network failure or storm damage, you’re stuck with the problem until a crew can come out and fix it.

Our analysis of outages shows almost all customers affected by generation shortfalls in 2009 were back on line in less than an hour. By contrast, if your power goes out for other reasons, you will normally be waiting more than an hour to get back on line. In the worst cases, you can be left waiting for more than five hours.


Grattan Institute

What should we do (or not) about summer blackouts?

The main thing governments should to address summer blackouts is… nothing, just sweat it out. If governments over-react to newspaper headlines about blackouts, customers will pay more in the long run. Power failures on a hot day are unpleasant, but the bill to avoid them entirely would almost certainly be worse.

Blackouts in 2004 prompted the New South Wales and Queensland state governments to tighten network reliability standards. This caused over $18 billion of network over-spending and delivered only modest improvements in reliability. Network costs were the largest cause of increasing residential electricity prices in those states over the past decade, which increased more than 50% above inflation in New South Wales, and more than 70% in south-east Queensland.

Customers are unlikely to be willing to pay for more network “gold-plating”. Research by Energy Consumers Australia shows more customers are satisfied with the reliability of their power supply than with the price they pay.




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Customers can also play an important role. If your power does go out, don’t buy into the political blame game. Contrary to the impression the politicians and media might give, it’s very unlikely the outage will have been caused by a lack of power supply – whether coal, gas or renewable.

So be sceptical when a hot-headed politician tells you the solution is their preferred energy generation technology. Neither a new coal-fired power station nor a giant solar-fed battery will keep the power on if your local network fails.The Conversation

Guy Dundas, Energy Fellow, Grattan Institute and Lucy Percival, Senior Associate, Grattan Institute

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

What would a fair energy transition look like?


Franziska Mey, University of Technology Sydney and Chris Briggs

Opposition Leader Bill Shorten announced last week that a federal Labor government would create a Just Transition Authority to overseee Australia’s transition from fossil fuels to renewable energy. This echoes community calls for a “fast and fair” energy transition to avoid the worst impacts of climate change.




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But disruptive change is already here for Australia’s energy sector. 2018 has been a record year for large-scale solar and wind developments and rooftop solar. Renewable energy is now cheaper than new-build coal power generation – and some are saying renewables are now or soon will be cheaper than existing coal-fired power.

Based purely on the technical lifetime of existing power stations, the Australian market operator predicts that 70% of coal-fired generation capacity will be retired in New South Wales, South Australia and Victoria by 2040. If renewables continue to fall in price, it could be much sooner.

We must now urgently decide what a “just” and “fair” transition looks like. There are many Australians currently working in the energy sector – particularly in coal mining – who risk being left behind by the clean energy revolution.

Coal communities face real challenges

The history of coal and industrial transitions shows that abrupt change brings a heavy price for workers and communities. Typically, responses only occur after major retrenchments, when it is already too late for regional economies and labour markets to cope.

Coal communities often have little economic diversity and the flow-on effects to local economies and businesses are substantial. It is easy to find past cases where as many as one third of workers do not find alternative employment.




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We often hear about power stations, but there are almost 10 times as many workers in coal mining, where there is a much higher concentration of low and semi-skilled workers. The 2016 Census found almost half of coal workers are machinery operators and drivers.

The demographics of coal mining workers in Australia suggest natural attrition through early retirements will not be sufficient: 60% are younger than 45.

Mining jobs are well paid and jobs in other sectors are very unlikely to provide a similar income, so even under the best scenarios many will take a large pay cut.

Another factor is the long tradition of coal mining that shapes the local culture and identity for these communities. Communities are particularly opposed to change when they experience it as a loss of history and character without a vision for the future.

Lastly, the local environmental impacts of coal mining can’t be neglected. The pollution of land, water and air due to mining operations and mining waste have created brownfields and degraded land that needs remediation.

What is a ‘just’ transition?

A just transition to a clean energy economy has many facets. Unions first used the term in the 1980s to describe a program to support workers who lost their jobs. Just transition was recognised in the Paris Agreement as “a just transition of the workforce and the creation of decent work and quality jobs”.

However, using the concept of energy justice, there are three main aspects which have to be considered for workers, communities and disadvantaged groups:

  • distributing benefits and costs equally,

  • a participatory process that engages all stakeholders in the decision making, and

  • recognising multiple perspectives rooted in social, cultural, ethical and gender differences.

A framework developed at the Institute for Sustainable Futures maps these dimensions.


Institute for Sustainable Futures

A just transition requires a holistic approach that encompasses economic diversification, support for workers to transition to new jobs, environmental remediation and inclusive processes that also address equity impacts for marginalised groups.

The politics of mining regions

If there is not significant investment in transition plans ahead of coal closures, there will be wider ramifications for energy transition and Australian politics.

In Australia, electricity prices have been at the centre of the “climate wars” over the past decade. Even with the steep price rises in recent years, the average household still only pays around A$35 a week. But with the closure of coal power plants at Hazelwood and Liddell, Australia is really only just getting to the sharp end of the energy transition where workers lose jobs.

There are some grounds for optimism. In the La Trobe Valley, an industry wide worker redeployment scheme, investment in community projects and economic incentives appears to be paying dividends with a new electric vehicle facility setting up.

AGL is taking a proactive approach to the closure of Liddelland networks are forming to diversify the local economy. But a wider transition plan and investment coordinated by different levels of government will be needed.




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We know what is coming: just transition investment is a precondition for the rapid energy transition we need to make, and to minimise the economic and social impacts on these communities.The Conversation

Franziska Mey, Senior Research Consultant, Institute for Sustainable Futures, University of Technology Sydney and Chris Briggs, Research Principal, Institute for Sustainable Futures

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