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.

Check your mirrors: 3 things rooftop solar can teach us about Australia’s electric car rollout

Bjorn Sturmberg, Australian National University; Kathryn Lucas-Healey, Australian National University; Laura Jones, Australian National University, and Mejbaul Haque, Australian National UniversityGovernments and car manufacturers are investing hundreds of billions of dollars on electric vehicles. But while the electric transport revolution is inevitable, the final destination remains unknown.

The electric vehicle transition is about more than just doing away with vehicles powered by fossil fuels. We must also ensure quality technology and infrastructure, anticipate the future and avoid unwanted outcomes, such as entrenching disadvantage.

In Australia, the electric vehicle rollout has been slow, and federal action limited. But some state governments are working to electrify bus fleets, roll out public charging networks and trial smart vehicle charging in homes.

Australia’s world-leading rollout of rooftop solar power systems offers a guide to help navigate the transition. We’ve identified three key lessons on what’s gone well, and in hindsight, what could have been done differently.

solar panels on roofs — Australia’s rooftop solar boom offers insights into the electric vehicle revolution.
Shutterstock

1. Price isn’t everything

Solar systems and electric vehicles are both substantial financial investments. But research into rooftop solar has shown financial considerations are just one factor that guides purchasing decisions. Novelty, concerns about climate change and a desire for self-sufficiency are also significant – and electric vehicle research is producing similar findings.

When considering the electric vehicle rollout, understanding these deeper motivators may help avoid a race to the bottom on price.

About one in four Australian homes has rooftop solar, with almost three million systems installed. Solar companies have often sought to highlight the low price of rooftop systems over other considerations. This has created consumer demand for low-priced, lower-quality products – and led to potentially hundreds of thousands of substandard installations across Australia.

So what are the lessons here for the electric vehicle rollout? First, when planning public infrastructure where electric vehicles can be charged, construction costs should not be the only consideration. Factors such as night-time safety and disability access should be prioritised. Shortcuts today will reinforce barriers for women and people with disabilities and create complex problems down the track.

Like rooftop solar, the point of sale of electric vehicles offers a unique opportunity to teach customers about the technology. Companies, however, can only afford to invest in customer education if they aren’t too stressed about margins.

“Smart” charging is one measure being explored to ensure the electricity network can handle future growth in electric vehicle uptake. Smart chargers can be remotely monitored and controlled to minimise their impact on the grid.

The point of sale is a pivotal moment to tell new owners of electric vehicles that their charging may at times be managed in this way.

EVs on charge — Electric vehicle charging infrastructure should be safe and accessible.
Shutterstock

2. Plan ahead

The uptake of rooftop solar in Australia has been a raging success. In fact, rooftop solar is now the largest generator in the national power system.

This raises issues, such as how rooftop solar systems will respond to a major disturbance, such as the failure of a transmission line. A large amount of solar power feeding into the grid can also challenge electricity network infrastructure.

In response, electricity networks have implemented changes such as limiting solar exports and therefore, returns to solar system owners, and charging fees for exporting solar.

Such retrospective changes have been unpopular with solar owners. So to maintain reliable electricity supplies, and avoid angering consumers, it’s vital to plan where and when electric vehicles are charged.

If every vehicle in Australia was electric, this would add about a quarter to national power demand. The rise in demand would be greatest near bus and logistics depots and ultra-fast highway chargers.

Timing is key to maximising the use of a network connection without overloading it. For example, if everyone charged their vehicle in the evening after they get home from work, as this would put further pressure on electricity supplies at this peak time.

Governments and electricity providers should encourage electric vehicle charging during the day, when demand is lower. This might mean, for example, providing vehicle charging facilities at workplaces and in public areas.

Until Australia’s power grid transitions to 100% renewables, the use of solar energy should be strongly encouraged. This would ensure the vehicles were charged from a clean, cheap energy source and would help manage the challenges of abundant solar.

The question of road user charges for electric vehicles drivers is another example where it’s best to avoid retrospective changes. Such charges are necessary in the long run and best introduced from the outset.

woman's arm holds EV charger on car — Vehicle charging during the day, when power demand is lowest, should be encouraged.
Shutterstock

3. Coordination is key

Electric vehicle policy spans many government portfolios: transport, infrastructure, energy, planning, environment and climate change. Nationally, and from state to state, different ministers are in charge.

This makes coordination difficult, and creates the risk of policies undermining each other. For example, one policy might encourage the charging of electric vehicles from rooftop solar, to reduce carbon emissions. But because solar energy is so cheap, this might encourage more private vehicle use, which worsens road congestion.

So policies to encourage electric vehicle uptake should not come at the cost of creating more attractive and efficient public transport networks.

And new technologies can entrench societal disadvantage. For example, the rooftop solar rollout often excluded people who could not afford to buy the systems. Without policies to address this, the electric vehicle transition could lead to similar outcomes.

traffic queues in Sydney — Encouraging electric vehicle use could worsen road congestion, if not well managed.
Shutterstock

Lessons in the rear-view mirror

As Australia’s experience with rooftop solar has shown, successful technology transitions must be carefully planned and attentively steered.

In the case of electric vehicles, this will ensure the benefits to owners, society and the environment are fully realised. It will also ensure a smooth-as-possible transition, the gains from which all Australians can share.

Bjorn Sturmberg, Research Leader, Battery Storage & Grid Integration Program, Australian National University; Kathryn Lucas-Healey, Research Fellow, Australian National University; Laura Jones, Senior Analyst – Economics and Business models, Australian National University, and Mejbaul Haque, Research Fellow, Battery Energy Storage and Grid Integration Program, Research School of Engineering, Australian National University

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

Stop removing your solar panels early, please. It’s creating a huge waste problem for Australia

Deepika Mathur, Charles Darwin University and Imran Muhammad, Massey UniversityInstalling solar panels is an easy way to lower your carbon footprint and cut electricity bills. But our recent research found there are many incentives to remove them prematurely, adding to Australia’s massive waste problem.

Researchers predict Australia will accumulate 1 million tonnes of solar panel waste by 2047 — the same weight as 19 Sydney Harbour Bridges.

But this number is likely to be higher, as we found people often choose to remove panels after just 10 to 12 years of use. This is much earlier than their estimated end-of-life age of 30 years (and potentially older).

Unfortunately, recycling is just a small part of the solution. So why is this happening, and what can we do about it?

Australia’s shocking ‘material footprint’

Australians have heeded the call to increase renewable energy. The installed capacity of panels across Australia has increased dramatically from 25.3 megawatts in 2007 to 77,078 megawatts in 2017. Likewise, the rooftop solar market capacity has almost doubled between 2014 and 2018.

Australia has committed to the UN Sustainable Development Goal of using fewer resources. And this requires us to use products (like solar panels) efficiently, with less waste. But Australia’s 2020 progress update shows our per capita material footprint is increasing. In fact, it’s one of the highest in the world, at 70% above the OECD average.

To help lower our growing material footprint and keep e-waste out of landfills, we need to ensure solar panels are sustainable in life, as in death.

It is assumed the primary reason why people remove solar panels is due to technical failures, such as when they’ve reached their expiry after 30 years, or breaking due to extreme weather or during transport. But failing to generate electricity doesn’t explain why many are thrown away prematurely.

So, we interviewed solar panel installers, recycling organisations, advocacy groups and local government waste managers across the Northern Territory. And our resulting qualitative research found social and economic incentives for removing solar panels.

Out with the new, in with the newer

We found a whole system of panels gets removed when only a few panels are damaged, as the new panels must have similar electrical properties to the old.

If the panels are still under warranty, the manufacturer often pays to replace the whole set, even when only a few are faulty. This means working panels are removed alongside the faulty panels, prematurely turning into waste.

Solar panels have also become a commodity item. Many of us dump old phones and cars when newer technology becomes available, and solar panels get the same treatment. After recovering the investment in solar panels through reduced electricity bills, some people are keen to get newer, more efficient models with a new warranty.

Our research also suggests government incentives aimed at rolling out more solar panels have caused consumers to replace their entire solar array. This is because previous rebates didn’t cover the replacement of only one or a few panels.

Finally, the life of solar inverters is usually 10-12 years, much shorter than the 30-year life span of the panels themselves. Some people use this as an opportunity to install a new set of solar panels when they change their inverters.

So why can’t we just recycle them?

There’s currently little research on what we can do with panels when they’re removed for reasons other than technical failure.

Researchers often put forward recycling as the preferred option for removed panels. But sending the growing number of working panels to recycling facilities is a tremendous waste of resources, and increases the burden for panel recycling, which is still in its nascent stages.

Managing waste is the responsibility of states and territories, and they align their waste strategies with the federal government’s National Waste Policy.

But there’s no directive yet at the national level on solar panel disposal, specifically. This means there’s a patchwork of policies across the states and territories for managing this waste.

Victoria, for example, has identified solar panels as the fastest growing waste stream in the state’s overall e-waste flow, and the state government has banned them from landfills.

But such measures wouldn’t work for the Northern Territory, given its lack of processing facilities and the distance to the recycling centres in southern Australia, which are at least 1,500 kilometres away. With ample open land, they’re more likely to end up dumped illegally.

What do we do?

Australia needs clear guidelines at a national level on collecting, transporting, stockpiling and disposing solar panels. A lack of clear policy hampers state, territory and local governments from managing this waste effectively.

By proposing recycling as preferred option to manage this waste, we risk excluding other important options in the waste management hierarchy, such as reducing waste in the first place by making solar panels that last, extending their life.

The federal government has also touted “product stewardship” as a potential solution. This is where those involved in producing, selling, using and disposing products share the responsibility to reduce their environmental impact.

But this model wouldn’t effectively service regional and remote areas, as collecting and transporting goods from remote locations comes at a very high financial and environmental cost.

It’s worth noting some panels do undergo a kind of “second life”. There’s a unique demand for secondhand panels from people who can’t afford new systems, those looking to live off-grid, small organisations keen to reduce energy bills, and mobile home and caravan owners.

But with a number of massive solar farms proposed across northern Australia, it’s more important than ever to explore new strategies to manage removed solar panels, with clear policies and creative solutions.

The authors gratefully acknowledge the contributions of Robin Gregory from Regional Development Australia, Northern Territory to this article.

Deepika Mathur, Research Fellow, Northern Institute, Charles Darwin University and Imran Muhammad, Associate Professor of Urban and Regional Planning, Massey University

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

Labor proposes discounts for electric cars and ‘community batteries’ to store solar power

Michelle Grattan, University of CanberraAnthony Albanese will promise a Labor government would deliver a discount to cut the cost of electric cars and install community batteries, in modest initiatives costing $400 million over several years.

The announcement, to be made Wednesday, comes as Labor debates its platform at a “virtual” national conference involving some 400 participants.

At present only 0.7% of cars sold in Australia are electric – considerably under the global average of 4.2%. There are only about 20,000 electric cars registered in Australia.

Labor’s policy would cut taxes on non-luxury vehicles – the luxury threshold is $77,565 in 2020-21 – exempting them from tariffs and fringe benefits tax.

The Electric Vehicle Council has estimated a $50,000 model would be more than $2000 cheaper if the import tariff was removed. These tariffs are not on all the imported vehicles – there are exclusions where Australia has free trade agreements.

If a $50,000 vehicle was provided through employment, exempting it from the fringe benefits tax would save the employer (or employee, depending on how the FBT was arranged) up to $9000 annually, Labor says.

The opposition at the last election had a policy to promote electric cars, with a target of 50% per cent of new car sales being electric vehicles by 2030.

This came under heavy attack from the government, which cast it as a “war on the weekend”.

The government recently released a discussion paper on electric cars, and flagged it would trial models for the COMCAR fleet which transports politicians.

In a statement on the initiatives, Albanese and energy spokesman Chris Bowen said electric vehicles remain too expensive for most people, although a majority of Australians say they would consider buying one. There are no electric cars available in Australia for less than $40,000.

“By reducing upfront costs, Labor’s electric car discount will encourage uptake, cutting fuel and transport costs for households and reducing emissions at the same time,” Albanese and Bowen said.

The discount would begin on July 1 2022 and cost $200 million over three years.

The community batteries would help households who have solar panels but do not have their own battery storage, which is expensive.

Australia has one in five households with solar, but only one in 60 households has battery storage, which gives the capacity to draw overnight on the solar energy produced during the day.

Labor would spend $200 million over four years to install 400 community batteries across the country. This would assist up to 100,000 households.

Albanese and Bowen said the measure would cut power bills, reduce demands on the grid at peak times and lower emissions.

“Households that can’t install solar (like apartments and renters) can participate by drawing from excess energy stored in community batteries.”

A community battery is about the size of 4WD vehicle and provides about 500kWH of storage that can support up to 250 local households.

Michelle Grattan, Professorial Fellow, University of Canberra

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

Solar panel fire season is all year round and it’s getting more intense in Australia

Timothy O’Leary, University of Melbourne and David Michael Whaley, University of South Australia

2020 was a bumper year for solar power in Australia. More solar PV systems were installed in the first nine months than in all of any previous year.

Almost one in four Australian houses now have rooftop solar panels. But the number of solar panel incidents reported by fire and emergency services has increased too.

Fire and Rescue NSW reportedly put out 30 blazes sparked by panels in just three months late last year.

The exponential growth in solar PV and associated problems has attracted media and political attention.

In 2018, federal Energy Minister Angus Taylor warned his state counterparts lives were at risk from substandard solar panel installations. An audit of the Clean Energy Regulator by the Australian National Audit Office found there were potentially tens of thousands of badly installed and even unsafe rooftop systems. The regulator had inspected just 1.2% of rooftop installations.

It’s a nationwide problem

State and territory regulators are responsible for electrical safety. Only Victoria mandates an inspection of each installed system.

Taylor announced an inquiry into the industry last August.

Last October, Fire and Rescue NSW Superintendent Graham Kingland said:

Over the last five years we have seen solar panel related fires increase five-fold. It is not uncommon to see solar panels cause house and building fires.

On Christmas day, ACT Fire & Rescue attended a fire at a home in Theodore where the solar panels caught alight. Coincidentally, the location was Christmas Street!

Last month, Energy Safe Victoria warned the public to get solar systems serviced.

And Queensland Fire and Emergency Services attended at least 16 incidents caused by solar panels in the first half of 2017 and 33 in 2016.

9 News reports on the fire risks of poorly installed solar panel systems in Queensland.

Components such as DC isolators and inverters, rather than the actual panels, are the cause of most solar-related fires. A DC isolator is a manually operated switch next to a solar panel array that shuts off DC current between the array and the inverter. It was intended as an extra safety mechanism, but the switches have caused more problems than they have solved – particularly when not installed correctly or when poor-quality components are used.

Solar is cheaper in Australia but poorly regulated

A recent report rated Australia as one of the cheapest per kilowatt for solar PV, but it questioned our safety standards. Most solar systems sold in Australia use DC voltages that can pose a serious fire risk.

Unfortunately, Australia has been slow to adopt safer solar regulations. In contrast, the United States has had safety standards preventing the installation of conventional DC solar systems since as early as 2014.

It’s more difficult for lower-voltage, microinverter-based systems (requiring no DC isolator switch) to catch fire, but it’s not impossible.

An amendment to the DC isolator standard (AS/NZS 5033:2014) to improve product datasheets and ensure isolators can withstand the harsh Australian climate took effect on June 28 2019. By then, over 2 million systems had been installed on Australian rooftops.

Added to issues such as flammable cladding, dodgy electrical cable and other “grey imports” (products not sourced from approved manufacturers) in the building industry, we are now playing a game of catch-up.

Poor-quality solar rooftop components have led to an expanding list of product recalls. The latest Australian Competition and Consumer Commission (ACCC) recall list includes installations managed by industry giants such as Origin and AGL.

One notable recall in 2014 reported a risk of “arcing” and “eventual catastrophic failure, resulting in fire”. It listed no fewer than nine traders operating nationally as having used this failed product. The recall noted that the product supplier, Blueline Solar Pty Ltd, was insolvent.

What should consumers do? The ACCC said:

Owners should immediately shut down the PV system following the standard shutdown procedure.

If a consumer suspects they have one of the affected units, they should have an electrician inspect and replace the DC isolators.

Solar systems do not fall under the National Construction Code unless an ancillary structure is being created. Most systems are simply fixed with rails to an existing roof. If the code covered rooftop solar, this would require private certification and a compliance check on any system, as is the case overseas.

Know what is on your roof

Research has shown consumers’ knowledge of solar systems is poor. Many owners have little idea if their system is working properly, or even at all.

And how would a consumer know what kind of DC isolator is on their roof or how to shut down the system in the event of a fire?

Solar panel systems are a growing incident category for firefighters. Yet even among firefighters there is some confusion on procedures to deal with a fire on live solar panels.

Firefighters put out a solar panel fire — Even some firefighters aren’t clear about how to deal with fires on live solar panels.
riopatuca/Shutterstock

Solar panel fires have yet to make it onto a top 10 list of domestic fire causes (statistically, your Christmas tree lights are a greater risk). But the sheer volume of installations and ageing components in uninspected older systems are increasing the risks.

One Aussie inventor has developed a product PVStop — “a spray-on solution to mitigate solar panel risks by reducing DC output to safe levels to offer homeowners and emergency personnel peace of mind”.

The latest update on Clean Energy Regulator inspections completed to June 30 2020 shows a negligible 0.05% decrease in substandard systems. Roughly one in 30 systems (3.1%) have been deemed unsafe and another 17.9% substandard.

Chart showing causes of unsafe and potentially unsafe solar PV installations — The Conversation. Data: Clean Energy Regulator SRES report

Without adequate solar PV industry standards, tools, inspection regimes, procedures or training, dangerous scenarios may increasingly put lives at risk. The high uptake of solar is very good news for reducing household electricity bills and carbon emissions, but safety issues undermine these positives.

The surge in installations, the introduction of batteries, the ageing of panels and components together with more extreme weather events mean solar panel incidents are likely to continue increasing.

Australia prides itself on being a world leader in household solar but until now we have not fully appreciated the safety risks. Fire authorities would do well to update fire safety guides that omit specific information on solar. And system owners should ensure they understand the risks and shut-down procedures.

Timothy O’Leary, Lecturer in Construction and Property, University of Melbourne and David Michael Whaley, Lecturer, University of South Australia

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

Up to 90% of electricity from solar and wind the cheapest option by 2030: CSIRO analysis

Paul Graham, CSIRO

With the cost of energy generated from wind and solar now less than coal, the share of Australia’s electricity coming from renewables has reached 23%. The federal government projects the share will reach 50% by 2030.

It is at this point that integrating renewables into the energy system becomes more costly.

We can add wind and solar farms at little extra cost when their share is low and other sources – such as coal and gas generators now – can compensate for their variability. At a certain point, however, there comes a need to invest in supporting infrastructure to ensure supply from mostly renewable generation can meet demand.

But by 2030, even with these extra costs, adding new variable renewable generation (solar and wind) to as high as a 90% share of the grid will still be cheaper than non-renewable options, according to new estimates from the CSIRO and Australian Energy Market Operator.

Calculating energy costs

International research, including from the International Renewable Energy Agency, suggests solar and wind power are now the cheapest new sources of electricity in most parts of the world.

Our estimates, made for the third annual “GenCost” report (short for generation cost), confirm this is also now the case in Australia.

We compare the cost of new-build coal, gas, solar photovoltaics (both small and large scale), solar-thermal, wind and a number of speculative options (such as nuclear).

What we’ve been able to more accurately estimate in the new report is the cost of integrating more and more renewable energy into the energy system, as coal and gas generators are retired.

The two key extra integration costs are energy storage and more transmission lines.

Storage costs

For any system dominated by renewables, storing energy is essential.

Storage means renewable energy can be saved when it is overproducing relative to demand – for example, in the middle of the day for solar, or during extended windy conditions. Stored energy can then be used when renewables cannot meet demand – such as overcast days or at night for solar.

Among options being considered for large-scale investment in Australia are batteries and pumped hydro energy storage (using excess renewable power to pump water back up to dams to again drive hydroelectric turbines).

Capital costs of storage technologies in $/kWh (total cost basis). Aurecon and Entura are engingeering businesses who publish project cost estimates. AEMO ISP is the Australian Energy Market Operator’s Integrated System Plan, which also includes technology cost estimates.
CSIRO

Pumped hydro sites can provide storage for hours or days. There are three schemes in Australia: Talbingo and Shoalhaven in New South Wales, and Wivenhoe near Brisbane.

Battery costs have been falling steadily and tend to be most competitive for storage electricity for less than eight hours. South Australia’s big battery (officially known as the Hornsdale Power Reserve) is the most obvious example.

Transmission costs

The other key cost to integrate more renewable energy generation into the electricity grid is building more transmission lines. Right now those lines mostly run from coal and gas power stations near coal mines.

But this not where new large-scale renewable generation will be. Solar farms are best placed inland, where there is less cloud cover, and in the mid to northern regions of Australia. Wind farms are generally better located in elevated areas and in the southern regions. We’ll need to build new transmission links to these “renewable energy zones”.

Transmission links between the states in the National Electricity Market (Queensland, New South Wales, Australian Capital Territory, Victoria, Tasmania and South Australia) will need to be improved so they can better support each other if one or more are experiencing low renewable energy output.

Total integration costs

So how much extra will it cost for Australia to have a higher share (up to 90%) of electricity from wind and solar (variable renewable energy)? The following graph summarises our findings based on 2030 cost projections.

Projected renewable generation and integration costs by variable renewable energy share in 2030. — Projected renewable energy generation and integration costs by variable renewable energy share in 2030.
CSIRO

The cost of generating energy from wind and solar (shown in light blue) is about A$40 per megawatt-hour (MWh). This is is slightly below current average market prices.

A higher share of renewable energy adds storage costs (in black) and transmission costs (grey and dark blue). These integration costs increase from A$4/MWh to A$20/MWh as the variable renewable energy share increases from 50% to 90%.

At 90% renewable energy, the total cost is A$63/MWh. But that’s still cheaper than the cost of new coal and gas-fired electricity generation, which is in the range of A$70 to A$90/MWh (under ideal assumptions of low fuel pricing and no climate policy risk).

The 2020-21 GenCost report is now in the formal consultation period with stakeholders including industry, government, regulators and academia. The final report is due to be published in March 2021.

Paul Graham, Chief economist, CSIRO energy, CSIRO

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

It might sound ‘batshit insane’ but Australia could soon export sunshine to Asia via a 3,800km cable

John Mathews, Macquarie University; Elizabeth Thurbon, UNSW; Hao Tan, University of Newcastle, and Sung-Young Kim, Macquarie University

Australia is the world’s third largest fossil fuels exporter – a fact that generates intense debate as climate change intensifies. While the economy is heavily reliant on coal and gas export revenues, these fuels create substantial greenhouse gas emissions when burned overseas.

Australia doesn’t currently export renewable energy. But an ambitious new solar project is poised to change that.

The proposed Sun Cable project envisions a ten gigawatt capacity solar farm (with about 22 gigawatt-hours of battery storage) laid out across 15,000 hectares near Tennant Creek, in the Northern Territory. Power generated will supply Darwin and be exported to Singapore via a 3,800km cable slung across the seafloor.

Sun Cable, and similar projects in the pipeline, would tap into the country’s vast renewable energy resources. They promise to provide an alternative to the export business of coal, iron ore and gas.

As experts of east-Asian energy developments, we welcome Sun Cable. It could pioneer a renewable energy export industry for Australia, creating new manufacturing industries and construction jobs. Importantly, it could set our economy on a post-fossil fuel trajectory.

Long-term cost benefits

Sun Cable was announced last year by a group of Australian developers. The project’s proponents say it would provide one-fifth of Singapore’s power supply by 2030, and replace a large share of fossil fuel-generated electricity used in Darwin.

Submarine cables are laid using deep-sea vessels specifically designed for the job.
Alan Jamieson/Flickr, CC BY

To export renewable energy overseas, a high-voltage (HV) direct current (DC) cable would link the Northern Territory to Singapore. Around the world, some HVDC cables already carry power across long distances. One ultra-high-voltage direct current cable connects central China to eastern seaboard cities such as Shanghai. Shorter HVDC grid interconnectors operate in Europe.

The fact that long distance HVDC cable transmission has already proven feasible is a point working in Sun Cable’s favour.

The cost of generating solar power is also falling dramatically. And the low marginal cost (cost of producing one unit) of generating and transporting renewable power offers further advantage.

The A$20 billion-plus proposal’s biggest financial hurdle was covering initial capital costs. In November last year, billionaire Australian investors Mike Cannon-Brookes and Andrew “Twiggy” Forrest provided initial funding to the tune of up to A$50 million. Cannon-Brookes said while Sun Cable seemed like a “completely batshit insane project”, it appeared achievable from an engineering perspective.

Sun Cable is expected to be completed in 2027.

Bringing in business

The proposal would also bring business to local high-technology companies. Sun Cable has contracted with Sydney firm 5B, to use its “solar array” prefabrication technology to accelerate the building of its solar farm. The firm will pre-assemble solar panels and deliver them to the site in containers, ready for quick assembly.

The Northern Territory government has also shown support, granting Sun Cable “major project” status. This helps clear potential investment and approval barriers.

Across Australia, similar renewable energy export plans are emerging. The Murchison Renewable Hydrogen Project in Western Australia will use energy produced by solar and wind farms to create renewable hydrogen, transported to east Asia as liquid hydrogen.

Similarly, the planned Asian Renewable Energy Hub could have renewable hydrogen generated in Western Australia’s Pilbara region at 15 gigawatts. This would also be exported, and supplied to local industries.

These projects align with the Western Australian government’s ambitious Renewable Hydrogen Strategy. It’s pushing to make clean hydrogen a driver for the state’s export future.

Reliable solutions

Generating and transmitting power from renewable resources avoids the energy security risks plaguing fossil fuel projects. Renewable projects use manufactured devices such as solar cells, wind turbines and batteries. These all generate energy security (a nation’s access to a sufficient, affordable and consistent energy supply).

Australia controls its own manufacturing activities, and while the sun may not shine brightly every day, its incidence is predictable over time. In contrast, oil, coal and gas supply is limited and heavily subject to geopolitical tensions. Just months ago in the Middle East, attacks on two major Saudi Arabian oil facilities impacted 5% of global oil supply.

Renewing international links

Apart from exporting electricity produced on its own solar farm, Sun Cable could profit from letting other projects export electricity to Asia through shared-cost use of its infrastructure.

This would encourage future renewable energy exports, especially to the energy-hungry ASEAN nations (Association of Southeast Asian Nations) – Indonesia, Malaysia, the Philippines, Singapore and Thailand.

This would strengthen Australia’s economic relationships with its ASEAN neighbours – an importantc geo-economic goal. In particular, it could help reduce Australia’s growing export dependence on China.

However, as with any large scale project, Sun Cable does face challenges.

Other than raising the remaining capital, it must meet interconnection standards and safety requirements to implement the required infrastructure. These will need to be managed as the project evolves.

Also, since the power cable is likely to run along the seabed under Indonesian waters, its installation will call for strategic international negotiations. There has also been speculation from mining interests the connection could present national security risks, as it may be able to send and receive “performance and customer data”. But these concerns cannot be validated currently, as we lack the relevant details.

Fortunately, none of these challenges are insurmountable. And within the decade, Sun Cable could make the export of Australian renewable energy a reality.

John Mathews, Professor of Strategic Management, Macquarie Graduate School of Management, Macquarie University; Elizabeth Thurbon, Scientia Fellow and Associate Professor in International Relations / International Political Economy, UNSW; Hao Tan, Associate professor, University of Newcastle, and Sung-Young Kim, Senior Lecturer in the Department of Modern History, Politics & International Relations, Macquarie University

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

How an Aussie invention could soon cut 5% of the world’s greenhouse gas emissions

Australian-designed technology will soon be responsible for 50% of all solar energy produced globally.
Glenn Hunt/AAP

Andrew Blakers, Australian National University

In the 1980s, a global race was underway: to find a more efficient way of converting energy from the sun into electricity.

Some 30 years ago, our research team at the University of New South Wales (UNSW) came up with a breakthrough, called the PERC silicon solar cell. The cells have become the most widely deployed electricity generation technology in terms of capacity added globally each year – comfortably exceeding wind, coal, gas, hydro and others.

PERC stands for Passivated Emitter and Rear Cell. By the end of this year, PERC technology will be mitigating about 1% of global greenhouse gas emissions by displacing coal burning. Assuming that its rapid growth continues, it should be reducing greenhouse gas emissions by 5% by the mid-2020s and possibly much more in later years.

The terrible bushfires in Australia this summer, enhanced by the hottest and driest year on record in 2019, underline the need for urgent reductions in greenhouse gas emissions. By far the most effective way is driving coal out of electricity systems through very rapid deployment of solar and wind.

Soon, our Aussie invention will be generating half the world’s solar power. It is a pertinent reminder of Australia’s capacity for finding transformative technical solutions to address climate change. But we need the right government support.

A solar farm near Canberra.
Lukas Coch/AAP

An Aussie invention

Solar cells convert sunlight directly into electricity without moving parts. More efficient solar cells generally produce cheaper electricity because fewer solar cells, glass covers, transport, land and support structures are needed for a given solar power output.

By the early 1980s, the best laboratory cells around the world had reached 17% efficiency. This means that 17% of the sunlight was converted to electricity, and the rest (83%) of the solar energy was lost (as heat).

During the 1980s, our research team at UNSW led by Martin Green and myself created a series of world-record-efficient silicon solar cells. We reported 18% efficiency in 1984, 19% efficiency also in 1984, and the important milestone of 20% efficiency in 1986.

In 1989 our group reported a new solar cell design called “PERC”, with a record efficiency of 22-23%.

This new, more efficient cell was better than the old ones because we eliminated some defects in the silicon crystal surface, which led to lower electronic losses. The PERC design also enabled us to capture the sunlight more effectively.

In the 1990s, further improvements to laboratory PERC cells were made at UNSW, leading to cells in the 24-25% efficiency range. The global silicon solar cell efficiency record remained at UNSW until recently.

There was a 25-year gap between development of the PERC cell and its rapid commercial adoption, which began in 2013. During this time, many people worked to adapt the PERC design to commercial production.

PERC cells are more efficient than previous commercial cells. Strong incentives for more efficient cells have recently arisen due to the continually falling share of cell costs as a proportion of total solar power system costs (including transport, land and mounting systems).

The big benefits of solar

Currently, solar power constitutes more than 40% of net new electricity generation capacity additions, with fossil, nuclear, wind, hydro and other renewables making up the balance.

Solar is growing faster than the other electricity generation technologies. Over time, as fossil-fuelled power stations are retired, solar (and wind) will dominate electricity production, with consequent large reductions in greenhouse gas emissions.

Solar power has experienced sustained rapid exponential growth over decades, while other generation technologies are currently experiencing static, falling or negligible sales.
https://www.irena.org/publications/2019/Mar/Renewable-Capacity-Statistics-2019

This year, enough PERC solar modules will be sold to generate 60-70 gigawatts of power. According to projections, PERC will reach three quarters of annual solar module sales in the mid-2020s, enough to match the generation capacity additions from all other technologies combined.

About A$50 billion worth of PERC modules have been sold to date. This is expected to reach several hundred billion Australian dollars later this decade.

Just imagine

Australian emissions (excluding those from bushfires) are falling because we are installing solar and wind four times faster per capita than the EU, US, Japan and China.

Our position as a global leader in renewables installation is uncertain because the Renewable Energy Target, which was achieved in 2019, has not been extended.

With supportive policy, such as facilitating more transmission to bring solar and wind power to the cities, Australia could greatly increase the speed at which wind and solar are deployed, yielding rapid and deep cuts at about zero-net cost.

Such policy would entail stronger and sustained government support for renewables deployment, and research and development of new technologies.

Renewables must replace polluting coal-fired power if the world is to tackle climate change.
SASCHA STEINBACH/EPA

Looking ahead

Solar energy is vast, ubiquitous and indefinitely sustainable. Simple calculations show that less than 1% of the world’s land area would be required to provide all of the world’s energy from solar power – much of it on building roofs, in deserts and floating on water bodies.

Solar systems use only very common materials (we could never run out), have minimal need for mining (about 1% of that needed for equivalent fossil or nuclear fuels), have minimal security and military risks (we will never go to war over solar access), cannot have significant accidents (unlike nuclear), and have minimal environmental impact over unlimited time scales.

Australia is making major contributions to mitigating climate change both through rapid deployment of wind and solar and technology development such as our PERC cells. But with better government support, much more can be done – quickly and at low cost.

Andrew Blakers, Professor of Engineering, Australian National University

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

Curious Kids: how do solar panels work?

Installing solar panels on a roof.
Shutterstock/lalanta71

Andrew Blakers, Australian National University

How do solar panels work? – Nathan, age 5, Melbourne, Australia.

The Sun produces a lot of energy called solar energy. Australia gets 20,000 times more energy from the Sun each day than we do from oil, gas and coal. This solar energy will continue for as long as the Sun lives, which is another 5 billion years.

Solar panels are made of solar cells, which is the part that turns the solar energy in sunlight into electricity.

Solar cells make electricity directly from sunlight. It is the most trusted energy technology ever made, which is why it is used on satellites in space and in remote places on Earth where it is hard to fix problems.

How do solar cells work?

Solar cells are made using silicon atoms. An atom is basically a building block – just like a Lego brick but so tiny you’d need a special machine to see them.

Because the silicon atoms are so small you need trillions and trillions of them for a solar cell.

To make the solar cell you need a wafer layer of silicon, about the same size as a dinner plate but much much thinner – only about three times the thickness of a strand of your hair.

This silicon layer is changed in a special way using hot temperatures of up to 1,000℃. Then, a sheet of metal is put onto the back of the layer and a metal mesh with holes in it, like a net, is put on the front. It is this mesh side of the layer that will face the Sun.

When 60 solar cells are made they are fixed together behind a layer of glass to make a solar panel.

On this roof you can see one solar hot water collector (top left) and 42 solar electricity panels, each of which is made of 60 solar cells combined behind a protective glass.
Shutterstock

If your house has a solar power system, it will probably have 10 to 50 solar panels attached to your roof. Millions of solar panels are used to make a large solar farm out in the countryside.

Each silicon atom contains extremely tiny and lightweight things called electrons. These electrons each carry a small electric charge.

Each tiny silicon atom has a nucleus at the centre made up of 14 teeny-tiny protons and 14 teeny-tiny neutrons. And 14 teeny-tiny electrons go around the nucleus. It doesn’t really look exactly like this diagram but you get the idea.
Shutterstock

When sunlight falls on a solar panel it can hit one of the electrons in a silicon atom and knock it free.

These electrons can move around but because of the special way the cell is made they can only go one way, up towards the side that faces the Sun. They can’t go the other way.

So whenever the Sun is shining on the solar cell it causes many electrons to flow upwards but not downwards, and this creates the electric current needed to power things in our homes such as lights, the television and other electrical items.

If the sunlight is bright, then lots of electrons get hit and so lots of electric current can flow. If it is cloudy, then fewer electrons get hit and the current will be cut by three quarters or more.

At night, the solar panel produces no electric power and we need to rely on batteries or other sources of electricity to keep the lights on.

How are solar cells being used?

Solar cells are the cheapest way to make electricity – cheaper than new coal or nuclear power stations. This is why solar cells are being installed around the world about five times faster than coal power stations and 20 times faster than nuclear power stations.

In Australia, nearly all new power stations are either solar power stations or wind farms. Solar and wind electricity can be used to run electric cars in place of polluting petrol cars. Solar and wind electricity can also heat and cool your house and can be used in industry in place of coal and natural gas.

Windmills and solar panels can produce electricity.
Shutterstock

Solar and wind are helping lessen the amount of greenhouse gases which damage our Earth. They are cheap, and they continue to get even cheaper and the more we use it the quicker we can stop using energy that can hurt the Earth (like coal, oil and gas).

What’s more, silicon is the second most common atom in the world (after oxygen). In fact, sand and rocks are made of mostly silicon and oxygen. So, we could never run out of silicon to make more solar cells.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au

Andrew Blakers, Professor of Engineering, Australian National University

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

We can make roof tiles with built-in solar cells – now the challenge is to make them cheaper

This, except printed directly onto your roof tiles.
Cole Eaton Photography/Shutterstock

Md Abdul Alim, Western Sydney University; Ataur Rahman, Western Sydney University, and Zhong Tao, Western Sydney University

Despite being such a sunkissed country, Australia is still lagging behind in the race to embrace solar power. While solar panels adorn hundreds of thousands of rooftops throughout the nation, we have not yet seen the logical next step: buildings with solar photovoltaic cells as an integral part of their structure.

Our lab is hoping to change that. We have developed solar roof tiles with solar cells integrated on their surface using a specially customised adhesive. We are now testing how they perform in Australia’s harsh temperatures.

Our preliminary test results suggest that our solar roof tiles can generate 19% more electricity than conventional solar panels. This is because the tiles can absorb heat energy more effectively than solar panels, meaning that the tiles’ surface heats up more slowly in sustained sunshine, allowing the solar cells more time to work at lower temperatures.

Australia’s greenhouse emissions continue to rise, making it harder to meet its commitments under the Paris agreement.

Globally, commercial and residential buildings account for about 40% of energy consumption. Other countries are therefore looking hard at reducing their greenhouse emissions by making buildings more energy-efficient. The European Union, for example, has pledged to make all large buildings carbon-neutral by 2050. Both Europe and the United States are working on constructing buildings from materials that can harness solar energy.

Here in Australia, buildings account for only about 20% of energy consumption, meaning that the overall emissions reductions on offer from improved efficiency are smaller.

That’s not to say that we shouldn’t go for it anyway, especially considering the amount of sunshine available. Yet compared with other nations, Australia is very much in its adolescence when it comes to solar-smart construction materials.

Taking Australia’s temperature

In a recent review in the journal Solar Energy, we identified and discussed the issues that are obstructing the adoption of solar power-generating constructions – known as “building-integrated photovoltaics”, or BIPV – here in Australia.

According to the research we reviewed, much of the fear about adopting these technologies comes down to a simple lack of understanding. Among the factors we identified were: misconceptions about the upfront cost and payback time; lack of knowledge about the technology; anxiety about future changes to buildings’ microclimates; and even propaganda against climate change and renewable energy.

Worldwide, BIPV systems account for just 2.5% of the solar photovoltaic market (and virtually zero in Australia). But this is forecast to rise to 13% globally by 2022.

Developing new BIPV technologies such as solar roof tiles and solar façades would not only cut greenhouse emissions but also open up huge potential for business and the economy.

According to a national survey (see the entry for Australia here), Australian homeowners are still much more comfortable with rooftop solar panels than other systems such as ground-mounted ones.

In our opinion it therefore stands to reason that if we want to boost BIPV systems in Australia, our solar roof tiles are the perfect place to start. Our tiles have a range of advantages, such as low maintenance, attractive look, easy replaceability, and no extra load on the roof compared with conventional roof-mounted solar arrays.

Challenges ahead

Nevertheless, the major challenges for this technology are the current high cost, poor consumer awareness, and lack of industrial-scale manufacturing process. We made our tiles with the help of a 3D printing facility at Western Sydney University, which can be attached to an existing tile manufacturing machine with minor modifications.

The current installation cost of commercial solar tiles could be as high as A$600 per square metre, including the inverter.

What’s more, we have little information on how the roof tiles will perform in long-term use, and no data on whether solar tiles will have an effect on conditions inside the building. It is possible that the tiles could increase the temperature inside, thus increasing the need for air conditioning.

To answer these questions, we are carrying out a full life-cycle cost analysis of our solar tiles, as well as working on ways to bring down the cost. Our target is to reduce the cost to A$250 per square metre or even less, including the inverter. Prices like that would hopefully give Australian homeowners the power to put solar power into the fabric of their home.

The lead author thanks Professor Bijan Samali for valued supervision of his research.

Md Abdul Alim, Postdoctoral researcher on sustainable development (Energy and Water), Western Sydney University; Ataur Rahman, Associate Professor, Western Sydney University, and Zhong Tao, Professor, Western Sydney University

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

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Long-term cost benefits

Bringing in business

Reliable solutions

Renewing international links

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An Aussie invention

The big benefits of solar

Just imagine

Looking ahead

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How do solar cells work?

How are solar cells being used?

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Taking Australia’s temperature

Challenges ahead

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