Enough ambition (and hydrogen) could get Australia to 200% renewable energy



Hydrogen infrastructure in the right places is key to a cleaner, cheaper energy future.
ARENA

Scott Hamilton, University of Melbourne; Changlong Wang, University of Melbourne; Falko Ueckerdt, Potsdam Institute for Climate Impact Research, and Roger Dargaville, Monash University

The possibilities presented by hydrogen are the subject of excited discussion across the world – and across Australia’s political divide, notoriously at war over energy policy.




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On Friday Australia’s chief scientist Alan Finkel will present a national strategy on hydrogen to state, territory and federal energy ministers. Finkel is expected to outline a plan that prioritises hydrogen exports as a profitable way to reduce emissions.

It is to be hoped the strategy is aggressive, rather than timid. Ambition is key in lowering the cost of energy. Australia would do better aiming for 200% renewable energy or more.

It’s likely the national strategy will feature demonstration projects to test the feasibility of new technology, reduce costs, and find ways to share the risk of infrastructure investment between government and industry.

There are still a number of barriers. Existing gas pipelines could be used to transport hydrogen to end-users but current laws are prohibitive, mechanisms like “certificates of origin” are required, and there are still key technology issues, particularly the cost of electrolysis.

These issues raise questions of what a major hydrogen economy really looks like. It may prompt suspicions this is just the a latest energy pipe dream. But our research at the Australian-German Energy Transition Hub argues that an ambitious approach is better than a cautious one.

Aggressively pursing hydrogen exports will reduce costs of domestic energy supply and provide a basis for new export industries, such as greens steel, in a carbon-constrained world.




Read more:
Making Australia a renewable energy exporting superpower


Optimal systems cost less

We used optimisation modelling to examine how a major hydrogen industry might roll out in Australia. We wanted to identify where major plants for electrolysis could be built, asked whether the existing national electricity market should supply the power, and looked at the effect on the cost of the system and, ultimately, energy affordability.

Australian Hydrogen export locations.

Our results show the locations for future hydrogen infrastructure investment will be mainly determined by their capital costs, the share of wind and solar generation and the capacity of electrolysers to responsively provide energy to the system, and the magnitude of hydrogen production.




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How hydrogen power can help us cut emissions, boost exports, and even drive further between refills


We also identified potential demonstration projects across Australia, such as:

  • large-scale production of liquid hydrogen and export from the Pilbara in Western Australia
  • hydrogen to support steel manufacturing in South Australia
  • injecting hydrogen into the gas networks in Victoria and support industry and electricity generation
  • hydrogen to supply transport fuel for major users such as trucks, buses and ferries in New South Wales, and
  • hydrogen to produce ammonia at an existing plant in Queensland.

An export-oriented economy

If we assume electrolysers remain expensive, around A$1,800 per kilowatt, and need to run at close to full-load capacity all the time, the result is large hydrogen exporting hubs across the country, built near high quality solar and wind power resources. Ideal locations tend to be remote from the national energy grid, such as in Western Australia and Northern Territory, or at relatively small-scale in South Australia or Tasmania.

There is much debate around the current cost of electrolysis, but consensus holds that economies of scale will substantially reduce these costs – by as much as an order of magnitude. This is akin to the cost reductions we have seen in solar power and batteries.

200 per cent renewables scenario

This infrastructure requires some major investment. However, our modelling shows that if Australia produces 200% of our energy needs by 2050, exporting the surplus, we see major drops in system costs and lower costs of energy for all Australia. If Australia can produce 400 Terrawatt-hours of hydrogen energy for export, modelling results show the average energy cost could be reduced by more than 30%.

Hydrogen ambition reduces costs of electricity supply.

The driving factor is our level of ambition. The more we lean into decarbonising our economy with green energy, the further the costs fall. The savings from the integrated and optimised use of electrolysers in a renewable-heavy national electricity market outweigh the cost of building large renewable resources in remote locations.

A large hydrogen export industry could generate both substantial export revenue and substantial benefits to the domestic economy.

Hydrogen export economy versus true RE economy

To sum up, the picture above shows two possible hydrogen futures for Australia.

In the first, Australia lacks climate actions and electrolyser costs remain high with limited economies of scale, and we export from key remote hubs such as the Pilbara.




Read more:
We need a national renewables approach, or some states – like NSW – will miss out


In the other, ambition increases and costs drop, and the hydrogen export industry connects to the national grid, providing both renewable exports and benefits to the grid. This also promotes the use of hydrogen in the domestic market. Australia embraces a true renewable economy and a new chapter of major energy exports begins.

Either way, Australia is primed to become a hydrogen exporting superpower.The Conversation

Scott Hamilton, Strategic Advisory Panel Member, Australian-German Energy Transition Hub, University of Melbourne; Changlong Wang, Researcher, The Energy Transition Hub, University of Melbourne; Falko Ueckerdt, , Potsdam Institute for Climate Impact Research, and Roger Dargaville, Senior lecturer, Monash University

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

Why municipal waste-to-energy incineration is not the answer to NZ’s plastic waste crisis



Since the Chinese plastic recycling market closed, 58% of New Zealand’s plastic waste goes to countries in South-East Asia.
from http://www.shutterstock.com, CC BY-ND

Trisia Farrelly, Massey University

New Zealand is ranked the third-most-wasteful country in the OECD. New Zealanders produce five times the global daily average of waste per person – and they are getting more wasteful, producing 35% more than a decade ago.

These statistics are likely to get worse following China’s 2018 ban on imports of certain recyclable products. China was the world’s top importer of recyclable plastics, but implemented the ban because it could no longer safely manage its domestic and imported waste. Unsurprisingly, in 2015, China was named the top source of marine plastic pollution in the world.

Since the Chinese market closed, 58% of New Zealand’s plastic waste now goes to Malaysia, Indonesia, the Philippines, Thailand and Vietnam — all countries with weak regulations and high rankings as global sources of marine plastic pollution.

Waste-to-energy (WtE) incineration has been raised as a solution. While turning plastic waste into energy may sound good, it creates more pollution and delays a necessary transition to a circular economy.




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Dirty plastics

Shipments of plastic recycling often arrive in developing countries unsorted and contaminated. Materials that cannot be easily recycled are commonly burned, releasing dioxins into air, soil and water. In response, South-East Asian countries have started returning dirty plastics to developed countries.

Several New Zealand councils have stopped collecting certain plastics for recycling offshore. They are sending them to landfill instead. Available data suggest that even before the China ban plastics made up roughly 15% of the waste in municipal landfills – about 250,000 tonnes a year. Much of this is imported plastic packaging.

Many New Zealanders are very or extremely worried about the impact of plastic waste. We cannot continue ignoring our role in the global plastic pollution crisis while dumping plastic in homegrown landfills or in developing countries.




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In the scramble to find alternatives, waste-to-energy (WtE) incineration has become a hot topic, particularly as foreign investors look to establish WtE incinerators on the West Coast and [other centres]in New Zealand. Some local government representatives have endorsed WtE proposals, or raised WtE as an election issue.

Less plastic good for climate

Like landfills, WtE incinerators symbolise the linear “take-make-waste” economy, which destroys valuable resources and perpetuates waste generation.

Globally, countries are moving to circular approaches instead, which follow the “zero waste hierarchy”. This prioritises waste prevention, reduction, reuse, recycling and composting and considers WtE unacceptable.

Some New Zealanders say Nordic countries have proven that incineration is the environmental silver bullet to our waste woes. But a recent study found these countries will not meet EU circular economy goals unless they replace WtE incineration with policies that reduce waste generation. Such policies include packaging taxes, recycling and recovery rate targets, landfill bans on biodegradable waste, deposit return schemes and extended producer responsibility.

Rejecting linear approaches is also good for the climate. Actions at the top of the waste hierarchy stop more greenhouse gases than those at the bottom.

In contrast, WtE incinerators can produce 1.2 tonnes of carbon dioxide per tonne of municipal solid waste burnt. New Zealand’s zero carbon act means we have a responsibility to ensure we do not increase our greenhouse gas emissions by investing in WtE incineration.

Incinerators also cannot magic away toxins in plastic waste. Even the most high-tech WtE incinerators [[release dioxins and other pollutants into the air]. Meanwhile, toxin-laden fly ash and slag are dumped in landfills to eventually leach into the environment and contaminate food systems.

Shifting responsibility for plastic waste

To address plastic pollution, it is easy to see how prevention and reduction work better than “getting rid of” plastic once produced. Many WtE proponents argue that incineration technology can be a temporary solution for the plastic waste we have already created.

But incinerators are not short-term fixes. They are expensive to build and maintain. Large-scale incinerators demand about 100,000 tonnes of municipal solid waste a year, encouraging increasing production of waste. Investors guarantee returns on their investment by locking councils into decades-long contracts.

The only real solution to our plastics problem is through regulation that moves New Zealand towards a circular economy. We can start by making the linear economy expensive by increasing landfill levies above the current $NZ10/tonne and expanding it to all landfills. We must also invest in better waste collection, sorting and recycling systems, including a national network of resource recovery centres.

Instead of burning or burying plastic that cannot be reused, recycled or composted, we can prevent or reduce it through targeted phase-outs. The government is proposing to regulate single-use plastic packaging, beverage packaging, electronic waste and farm plastics through mandatory product stewardship schemes. This would make manufacturers responsible for the waste they produce and provide incentives for less wasteful and toxic product design and delivery systems (e.g. refill stations).

All of these circular solutions will provide far more jobs than WtE incineration.

Without a swift, brave shift to a circular economy, New Zealand will remain one of the world’s most wasteful nations. Circular economies are developing globally and WtE incineration will only set us back by 30 years.


Hannah Blumhardt, the coordinator of the NZ Product Stewardship Council, has contributed to this article.The Conversation

Trisia Farrelly, Senior Lecturer, Massey 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.




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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.




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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.auThe Conversation

Andrew Blakers, Professor of Engineering, Australian National University

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

Some good news for a change: Australia’s greenhouse gas emissions are set to fall



Renewable energy being installed at a community in the Northern Territory. Researchers have predicted Australia’s emissions are set to fall, but warn the renewables deployment rate must continue.
Lucy Hughes-Jones/AAP

Andrew Blakers, Australian National University and Matthew Stocks, Australian National University

For the past few years, Australia’s greenhouse gas emissions have headed in the wrong direction. The upward trajectory has come amid overwhelming evidence that the world must bring carbon dioxide emissions down. But the trend is set to change.

In a policy brief released today, we predict that Australia’s greenhouse gas emissions will peak during 2019-20 at the equivalent of about 540 million tonnes of carbon dioxide.

After a brief plateau, we expect they will decline by 3-4% over 2020-22, and perhaps much more in the following years – if backed by government policy.

The peak will occur because Australia’s world-leading deployment of solar and wind energy is displacing fossil fuel combustion. Emissions from the electricity sector are about to fall much faster than increases in emissions from all other sectors combined.

This is a message of hope for rapid reduction of emissions at low cost. But we cannot rest on our laurels. If renewable energy deployment stops or slows, emissions may rise again.

Figure 1: Historical and projected total Australian emissions in megatonnes of CO2 (equivalent) per year. Black line: Government emissions projections which assume solar and wind deplpoyment almost stops. Green line: Deployment continues at the current rate.
ANU

Australia: a renewables superstar

Deployment of solar and wind energy is the cheapest and quickest way to make deep emissions cuts because of its low and falling cost. Higher deployment rates would yield deeper emissions cuts, but this requires supportive government policy.

Wind and solar constitute about two-thirds of global net new electricity capacity. Gas, hydro and coal comprise most of the balance. Solar and wind comprise virtually all new generation capacity in Australia because they are cheaper than alternatives.




Read more:
Australia is the runaway global leader in building new renewable energy


Australia is a global renewable energy superstar because it is installing new solar and wind capacity four to fives times faster per capita than China, the European Union, Japan or the United States. This allows Australia to stabilise and then reduce its greenhouse emissions and sends a globally important message.

Figure 2 shows the rapid increase in the proportion of solar and wind energy from 2018 in the National Electricity Market, which covers the eastern states and comprises about 85% of national electricity generation. The proportion of renewable energy generation has reached 25%, including hydro.

Figure 2: Monthly solar and wind fraction of electricity generation in the NEM over 2014-19 showing sharp increase in 2018.
ANU

We are confident Australia’s emissions will fall in 2020, 2021 and probably 2022 because 16-17 gigawatts of wind and solar is locked in for deployment in 2018-20. This reduces emissions in the electricity sector by about 10 million tonnes a year.

The federal government projects that emissions outside the electricity system will increase by about 3 million tonnes per year on average over the 2020s. The difference leaves an overall decline of 7 million tonnes of emissions per year.

100% clean electricity is within our grasp

Beyond our projections for the next few years, continued falls in emissions are not assured. The emissions trajectory for 2022 and beyond depends largely on the level of renewables deployed.

Federal government projections assume solar and wind deployment almost stops in the 2020s. This would mean annual emissions increase from current levels to 563 million tonnes in 2030.

Wind turbines adjacent to the Tesla batteries at Jamestown, north of Adelaide, in 2017.
DAVID MARIUZ/AAP

But it doesn’t need to be this way. If the current renewables deployment rate continued, Australia would reach 50% renewable electricity in 2024, and potentially 80% renewables in 2030. This transformation would be technically straightforward and affordable. It requires governments, mostly the federal government, to encourage more transmission power lines to deliver renewable electricity to where it’s needed. Other off-the-shelf methods to support renewables include energy storage such as pumped hydro and batteries, and managing electricity demand.

The benefits of a consistent renewables rollout would be large. Australia’s electricity emissions in 2030 would be 100 million tonnes lower than government projections and the nation would meet its Paris target of a 26-28% emissions reduction between 2005 and 2030. This could be achieved without the controversial proposal to carry over carbon credits earned in the Kyoto Protocol period.

It should be noted that changes in land clearing rates or coal and gas mining or economic activity would also affect future national emissions.

Electricity infrastructure at the Snowy Hydro scheme. Such hydro projects are key to firming up intermittent renewable energy.
Lukas Coch/AAP

The emissions road ahead

Continued rapid deployment of solar and wind requires that governments enable construction of adequate electricity transmission and storage.

State governments should also continue efforts to establish renewable energy zones, with or without cooperation from the federal government. These zones would be located where there is good wind, sun and pumped hydro energy storage, bringing sustainable investment and jobs to regional areas.




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In the longer term, solar and wind can cut national emissions by two-thirds. Beyond the electricity sector, this involves electrifying motor vehicles, residential heating and cooling and industrial heating. National emissions could be cut by another 10% by stopping exports of fossil fuels, which creates fugitive emissions.

It is clear that solar and wind are the most practical route, globally and in Australia, to cheap, rapid and deep emissions cuts – and government policy will be key.The Conversation

Andrew Blakers, Professor of Engineering, Australian National University and Matthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National University

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

Australia is the runaway global leader in building new renewable energy


Matthew Stocks, Australian National University; Andrew Blakers, Australian National University, and Ken Baldwin, Australian National University

In Australia, renewable energy is growing at a per capita rate ten times faster than the world average. Between 2018 and 2020, Australia will install more than 16 gigawatts of wind and solar, an average rate of 220 watts per person per year.

This is nearly three times faster than the next fastest country, Germany. Australia is demonstrating to the world how rapidly an industrialised country with a fossil-fuel-dominated electricity system can transition towards low-carbon, renewable power generation.

Renewable energy capacity installations per capita.
International capacity data for 2018 from the International Renewable Energy Agency. Australian data from the Clean Energy Regulator., Author provided

When the Clean Energy Regulator accredited Tasmania’s 148.5 megawatt (MW) Cattle Hill Wind Farm in August, Australia met its Renewable Energy Target well ahead of schedule.




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We have analysed data from the regulator which tracks large- and small-scale renewable energy generation (including credible future projects), and found the record-high installation rates of 2018 will continue through 2019 and 2020.

Record renewable energy installation rates

While other analyses have pointed out that investment dollars in renewable energy fell in 2019, actual generation capacity has risen. Reductions in building costs may be contributing, as less investment will buy you more capacity.

Last year was a record year for renewable energy installations, with 5.1 gigawatts (GW) accredited in 2018, far exceeding the previous record of 2.2GW in 2017.

The increase was driven by the dramatic rise of large-scale solar farms, which comprised half of the new-build capacity accredited in 2018. There was a tenfold increase in solar farm construction from 2017.

We have projected the remaining builds for 2019 and those for 2020, based on data from the Clean Energy Regulator for public firm announcements for projects.

A project is considered firm if it has a power purchase agreement (PPA, a contract to sell the energy generated), has reached financial close, or is under construction. We assume six months for financial close and start of construction after a long-term supply contract is signed, and 12 or 18 months for solar farm or wind farm construction, respectively.

This year is on track to be another record year, with 6.5GW projected to be complete by the end of 2019.

The increase is largely attributable to a significant increase in the number of wind farms approaching completion. Rooftop solar has also increased, with current installation rates putting Australia on track for 1.9GW in 2019, also a new record.

This is attributed to the continued cost reductions in rooftop solar, with less than A$1,000 per kilowatt now considered routine and payback periods of the order of two to seven years.

Current (solid) and forecast (hashed) installations of renewable electricity capacity in Australia.
Author provided

Looking ahead to 2020, almost 6GW of large-scale projects are expected to be completed, comprising 2.5GW of solar farms and 3.5GW of wind. Around the end of 2020, this additional generation would deliver the old Renewable Energy Target of 41,000 gigawatt hours (GWh) per annum. That target was legislated in 2009 by the Rudd Labor government but reduced to 33,000GWh by the Abbott Coalition government in 2015.

Maintaining the pipeline

There are strong prospects for continued high installation rates of renewables. Currently available renewable energy contracts are routinely offering less than A$50 per MWh. Long-term contracts for future energy supply have an average price of more than A$58 per MWh. This is a very reasonable profit margin, suggesting a strong economic case for continued installations. Wind and solar prices are likely to decline further throughout the 2020s.

State governments programs are also supporting renewable electricity growth. The ACT has completed contracts for 100% renewable electricity. Victoria and Queensland both have renewable energy targets of 50% renewable electricity by 2030. South Australia is expecting to reach 100% by 2025.

The main impediment to continued renewables growth is transmission. Transmission constraints have resulted in bottlenecks in moving electricity from some wind and solar farms to cities.

Tasmania’s strong wind resource requires a new connection to the mainland to unlock more projects. The limitations of current planning frameworks for this transition were recognised in Chief Scientist Alan Finkel’s review of the National Electricity Market, with strong recommendations to overcome these problems and, in particular, to strengthen the role of the Australian Energy Market Operator.




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Now we need state and federal governments to unlock or directly support transmission expansion. For example, the Queensland government has committed to supporting new transmission to unlock solar and wind projects in the far north, including the Genex/Kidston 250MW pumped hydro storage system. The New South Wales government will expedite planning approval for an interconnector between that state and South Australia, defining it as “critical infrastructure”.

These investments are key to Australia maintaining its renewable energy leadership into the next decade.The Conversation

Matthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National University; Andrew Blakers, Professor of Engineering, Australian National University, and Ken Baldwin, Director, Energy Change Institute, 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.

The solar roof tile.

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.




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New solar cells offer you the chance to print out solar panels and stick them on your roof


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.




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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.




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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.The Conversation

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.

Climate explained: why don’t we have electric aircraft?


Dries Verstraete, University of Sydney


CC BY-ND

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

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

Electric cars, trains, trams and boats already exist. That logically leads to the question: why are we not seeing large electric aircraft? And will we see them any time soon?

Why do we have electric cars and trains, but few electric planes? The main reason is that it’s much simpler to radically modify a car or train, even if they look very similar to traditional fossil-fuel vehicles on the outside.

Land vehicles can easily cope with the extra mass from electricity storage or electrical propulsion systems, but aircraft are much more sensitive.




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For instance, increasing the mass of a car by 35% leads to an increase in energy use of 13-20%. But for a plane, energy use is directly proportional to mass: increasing its mass by 35% means it needs 35% more energy (all other things being equal).

But that is only part of the story. Aircraft also travel much further than ground vehicles, which means a flight requires far more energy than an average road trip. Aircraft must store onboard all the energy needed to move its mass for each flight (unlike a train connected to an electrical grid). Using a heavy energy source thus means more energy is needed for a flight, which leads to extra mass, and so on and on.

For an aircraft, mass is crucial, which is why airlines fastidiously weigh luggage. Electric planes need batteries with enough energy per kilogram of battery, or the mass penalty means they simply can’t fly long distances.




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Short-range planes

Despite this, electric aircraft are on the horizon – but you won’t be seeing electric 747s any time soon.

Today’s best available lithium ion battery packs provide around 200 watt-hours (Wh) per kilogram, about 60 times less than current aircraft fuel. This type of battery can power small electric air taxis with up to four passengers over a distance of around 100km. For longer trips, more energy-dense cells are needed.

Short-range electric commuter aircraft that carry up to 30 people for less than 800km, for instance, specifically require between 750 and 2,000Wh/kg, which is some 6-17% of kerosene-based jet fuel’s energy content. Even larger aircraft require increasingly lighter batteries. For example, a plane carrying 140 passengers for 1,500km consumes about 30kg of kerosene per passenger. With current battery technology, almost 1,000kg of batteries is needed per passenger.

To make regional commuter aircraft fully electric requires a four- to tenfold reduction in battery weight. The long-term historical rate of improvement in battery energy has been around 3-4% per year, doubling roughly every two decades. Based on a continuation of this historical trend, the fourfold improvement needed for a fully electric commuter aircraft could potentially be reached around mid-century.

While this may seem an incredibly long wait, this is consistent with the timescale of change in the aviation industry for both the infrastructure and aircraft design lifecycles. A new aircraft takes around 5-10 years to design, and will then remain in service for two to three decades. Some aircraft are still flying 50 years after their first flight.




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Here come the hybrids

Does this mean long-distance flying will always rely on fossil fuels? Not necessarily.

While fully electric large aircraft require a major, yet-to-be-invented shift in energy storage, there are other ways to reduce the environmental impact of flying.

Hybrid-electric aircraft combine fuels with electric propulsion. This class of aircraft includes design without batteries, where the electric propulsion system serves to improve the thrust efficiency, reducing the amount of fuel needed.

Hybrid-electric aircraft with batteries are also in development, where the batteries may provide extra power in specific circumstances. Batteries can then, for instance, provide clean take-off and landing to reduce emissions near airports.

Electric planes are also not the only way to reduce the direct carbon footprint of flying. Alternative fuels, such as biofuels and hydrogen, are also being investigated.

Biofuels, which are fuels derived from plants or algae, were first used on a commercial flight in 2008 and several airlines have performed trials with them. While not widely adopted, significant research is currently investigating sustainable biofuels that do not impact freshwater sources or food production.




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While biofuels do still produce CO₂, they don’t require significant changes to existing aircraft or airport infrastructure. Hydrogen, on the other hand, requires a complete redesign of the fuelling infrastructure of the airport and also has a significant impact on the design of the aircraft itself.

While hydrogen is very light – hydrogen contains three times more energy per kilogram than kerosene – its density is very low, even when stored as a liquid at -250℃. This means that fuel can no longer be stored in the wing but needs to be moved to relatively heavy and bulky tanks inside the fuselage. Despite these drawbacks, hydrogen-fuelled long-distance flights can consume up to 12% less energy than kerosene.


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Dries Verstraete, Senior Lecturer in Aerospace Design and Propulsion, University of Sydney

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