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

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

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

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

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

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

Longer charges

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

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

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

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

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

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

Safer batteries

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

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

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

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

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

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

Storing sunlight as heat

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

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

Checking a molten salt valve for corrosion at Sandia’s Molten Salt Test Loop.
Randy Montoya, Sandia Labs/Flickr, CC BY-NC-ND

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

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

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

Advanced renewable fuels

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

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

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

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

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

Kerry Rippy, Researcher, National Renewable Energy Laboratory

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

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Social plants: in the wild, staghorn ferns grow in colonies to improve water storage for all members

Shutterstock/Florist_Yana

Kevin Burns, Te Herenga Waka — Victoria University of WellingtonSocial colonies are nothing new in the animal kingdom. We know bees, ants and termites live in large colonies, divide labour and co-operate to take care of offspring produced by a single queen.

This behaviour, known as eusociality, has evolved independently in insects, crustaceans (certain species of shrimp) and even some mammals (naked mole rats), but it has never been observed in plants. This suggested plants were somehow less complex than animals.

Our study, published this week, turns our understanding of the evolution of biological complexity on its head. It documents the life history of a remarkable species of fern that grows in the tops of rainforest trees on Lord Howe Island, a small volcanic island in the north Tasman Sea.

Rather than growing as individual ferns in the treetops, the staghorn fern (Platycerium bifurcatum) lives in colonies, in an adaptation to its harsh habitat high above the water and nutrients stored in the soil below.

Individuals differ markedly in size, shape and texture. But they always grow side-by-side within colonies, fitting together like puzzle pieces to form a bucket-like store of water and nutrients available to all colony members.

Many individuals forgo reproduction and instead focus on capturing or storing water to the benefit of other colony members.

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Life in the tree tops

Staghorn ferns belong to a group of tree-dwelling plants known as epiphytes. Tree canopies are a challenging environment for plants to grow. Without access to soil, epiphytes are regularly exposed to severe water and nutrient stress.

Epiphytes have evolved several ways to mediate the lack of access to water and nutrients. Bromeliads grow cup-shaped leaves, while orchids have specialised root tissues. But staghorn ferns have developed a colony lifestyle to overcome the problem.

On Lord Howe Island, staghorn ferns grow in colonies.
Author provided

Staghorn ferns can be bought at many garden stores and will grow like any other pot plant. But in the wild on Lord Howe Island, we discovered individual plants collaborate, specialising in different tasks in the construction of the communal water and nutrient store, often at the cost of their own reproduction — just like social insects.

This radically changes our understanding of biological complexity. It suggests major evolutionary transitions towards eusociality can occur in both plants and animals. Plants and beehives aren’t as different as they might seem.

For decades, scientists interested in eusociality argued for a strict definition — many felt the term should be reserved for only a select group of highly co-operative insects.

This perspective led to widespread scepticism about its occurrence in the natural world. Perhaps this is why it was overlooked for so long in one of horticulture’s most popular pot plants.

Evolution of biological complexity

Four billion years ago, life began as simple, self-replicating molecules. Today’s diversity arose from these simple origins towards increasingly complex organisms.

Evolutionary biologists think that biological complexity developed in abrupt, major evolutionary transitions, rather than slow and continuous changes. Such transitions occur when independent entities begin to collaborate, forming new, more complex life forms — such as, for example, when single-celled organisms evolved into multi-cellular organisms.

Early in the evolution of plants, single-celled algae joined to form more complex structures.
Shutterstock/Lebendkulturen.de

Another example is the transition from unspecialised bacterial (prokaryotic) cells to cells with an enclosed nucleus and specialised organelles that perform particular functions, known as eukaryotic cells.

Co-operation underpins the evolutionary origins of organelles — they likely evolved from free-living ancestors that gave up their independence to live safely within the walls of another cell.

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There are eight commonly recognised major evolutionary transitions — and eusociality is the most recent. Eusocial animals differ from others in three fundamental ways:

• they live in colonies comprised of different generations of adults
• they subdivide labour into reproductive and non-reproductive groups
• they care for offspring co-operatively.

Our observations over the past two years on Lord Howe Island found staghorn ferns meet these criteria.

In highly eusocial species, caste membership is permanent and unchanging. But in primitively eusocial species, individuals can alter their behaviour to suit many roles required by the colony. Staghorn ferns probably fit under the latter category.

Our ongoing research will determine the staghorn’s position along this continuum of eusociality. But, for now, we know plants and animals share a similar evolutionary pathway towards greater biological complexity.

Kevin Burns, Professor, Te Herenga Waka — Victoria University of Wellington

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.

Dishing the dirt: Australia’s move to store carbon in soil is a problem for tackling climate change

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Robert Edwin White, University of Melbourne and Brian Davidson, University of Melbourne

To slow climate change, humanity has two main options: reduce greenhouse gas emissions directly or find ways to remove them from the atmosphere. On the latter, storing carbon in soil – or carbon farming – is often touted as a promising way to offset emissions from other sources such as energy generation, industry and transport.

The Morrison government’s Technology Investment Roadmap, now open for public comment, identifies soil carbon as a potential way to reduce emissions from agriculture and to offset other emissions.

In particular, it points to so-called “biochar” – plant material transformed into carbon-rich charcoal then applied to soil.

But the government’s plan contains misconceptions about both biochar, and the general effectiveness of soil carbon as an emissions reduction strategy.

Soil carbon storage is touted as a way to offset emissions from industry and elsewhere.
Shutterstock

What is biochar?

Through photosynthesis, plants turn carbon dioxide (CO₂) into organic material known as biomass. When that biomass decomposes in soil, CO₂ is produced and mostly ends up in the atmosphere.

This is a natural process. But if we can intervene by using technology to keep carbon in the soil rather than in the atmosphere, in theory that will help mitigate climate change. That’s where biochar comes in.

Making biochar involves heating waste organic materials in a reduced-oxygen environment to create a charcoal-like product – a process called “pyrolysis”. The carbon from the biomass is stored in the charcoal, which is very stable and does not decompose for decades.

Plant materials are the predominant material or “feedstock” used to make biochar, but livestock manure can also be used. The biochar is applied to the soil, purportedly to boost soil fertility and productivity. This has been tested on grassland, cropping soils and in vineyards.

Biochar is produced by burning organic material in a low oxygen environment.
Shutterstock

But there’s a catch

So far, so good. But there are a few downsides to consider.

First, the pyrolysis process produces combustible gases and uses energy – to the extent that when all energy inputs and outputs are considered in a life cycle analysis, the net energy balance can be negative. In other words, the process can create more greenhouse gas emissions than it saves. The balance depends on many factors including the type and condition of the feedstock and the rate and temperature of pyrolysis.

Second, while biochar may improve the soil carbon status at a new site, the sites from which the carbon residues are removed, such as farmers’ fields or harvested forests, will be depleted of soil carbon and associated nutrients. Hence there may be no overall gain in soil fertility.

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Third, the government roadmap claims increasing soil carbon can reduce emissions from livestock farming while increasing productivity. Theoretically, increased soil carbon should lead to better pasture growth. But the most efficient way for farmers to take advantage of the growth, and increase productivity, is to keep more livestock per hectare.

Livestock such as cows and sheep produce methane – a much more potent greenhouse gas than carbon dioxide. Our analysis suggests the methane produced by the extra stock would exceed the offsetting effect of storing more soil carbon. This would lead to a net increase, not decrease, in greenhouse gas

Farmers would have to increase stock numbers to benefit from pasture growth.
Dan Peled/AAP

A policy failure

The government plan refers to the potential to build on the success of the Emissions Reduction Fund. Among other measures, the fund pays landholders to increase the amount of carbon stored in soil through carbon credits issued through the Carbon Farming Initiative.

However since 2014, the Emissions Reduction Fund has not significantly reduced Australia’s greenhouse gas emissions – and agriculture’s contribution has been smaller still.

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So far, the agriculture sector has been contracted to provide about 9.5% of the overall abatement, or about 18.3 million tonnes. To date, it’s supplied only 1.54 million tonnes – 8.4% of the sector’s commitment.

The initiative has largely failed because several factors have made it uneconomic for farmers to take part. They include:

• overly complex regulations
• requirements for expensive soil sampling and analysis
• the low value of carbon credits (averaging $12 per tonne of CO₂-equivalent since the scheme began).

For many farmers, taking part in the Emissions Reduction Fund is uneconomic.
Shutterstock

A misguided strategy

We believe the government is misguided in considering soil carbon as an emissions reduction technology.

Certainly, increasing soil carbon at one location can boost soil fertility and potentially productivity, but these are largely private landholder benefits – paid for by taxpayers in the form of carbon credits.

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If emissions reduction is seen as a public benefit, then the payment to farmers becomes a subsidy. But it’s highly questionable whether the public benefit (in the form of reduced emissions) is worth the cost. The government has not yet done this analysis.

To be effective, future emissions technology in Australia should focus on improving energy efficiency in industry, the residential sector and transport, where big gains are to be made.

Robert Edwin White, Professor Emeritus, University of Melbourne and Brian Davidson, Senior Lecturer, Department of Agriculture and Food Systems, University of Melbourne

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

There’s a simple way to drought-proof a town – build more water storage

Inland towns need far more water storage.
Flickr/Mertie, CC BY-SA

Michael Roderick, Australian National University

The federal parliament has voted to funnel A$200 million to drought-stricken areas. What exactly this money will be spent on is still under consideration, but the majority will go to rural, inland communities.

But once there, what can the money usefully be spent on? Especially if there’s been a permanent decline in rainfall, as seen in Perth. How can we help inland communities?

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Let’s look at the small inland town of Guyra, NSW, which is close to running dry. Unlike our coastal cities, Guyra cannot simply build a billion-dollar desalination plant to supply its water. Towns like Guyra must look elsewhere for its solutions.

Running dry isn’t just about rainfall

“Running dry” means there is no water when the tap is turned on. It seems to make sense to blame the drought for Guyra’s lack of water. But the available water supply is not only determined by rainfall. It also depends on amount of water flowing into water storage (called streamflow), and the capacity and security of that storage.

While Perth has had a distinct downturn in its rainfall since the 1970s and has built desalination plants to respond to this challenge, no such downturn is evident at Guyra. Indeed, to date, the driest consecutive two years on record for Guyra were 100 years ago (1918 and 1919).

Long-term rainfall records for Perth (left) and Guyra (right). Dashed red line shows the trend and the full yellow line shows 600 mm annual rainfall.
Bureau of Meteorology

Despite the differences, there are some similarities between Perth and Guyra. As a rule of thumb, in Australia, significant streamflow into water storages does not occur until annual rainfall reaches around 600mm. This occurs as streamflow is generally supplied from “wet patches” when water can no longer soak into the soil. Thus, if annual rainfall is around 600mm or below, we generally anticipate very little streamflow.

While Guyra has seen some rain in 2019, it is not enough to prompt this crucial flow of water into the local water storage. The same is true for Perth, with annual rainfall in the past few decades now hovering close to the 600mm threshold.

Importantly, rainfall and streamflow do not have a linear relationship. Annual rainfall in Perth has declined by around 20%, but Perth’s streamflow has fallen by more than 90%.

With little streamflow filling its dams, Perth had little choice but to find other ways of increasing its water supply. They built desalination plants to make up the difference.

Let’s return to Guyra in NSW and the current drought. The rainfall records do not indicate there is a long-term downward trend in rainfall. But even without a rainfall trend, there are still dry years when there is little streamflow. Indeed, in Guyra, the rainfall record shows that, on average, the rainfall will be 600mm or less roughly one year out of every ten years.

Build more storage

So how do the residents of Guyra ensure a reliable water supply, given that they cannot build themselves a desalination plant?

Well, in this case, you can simply get water from somewhere else if it is available. A pipeline is currently under construction to supply Guyra from the nearby Malpas Dam, and is expected to be in operation very soon.

But that’s not always an option. A made-in-Guyra water solution means one thing: expanding storage capacity.

Guyra can generally store around 8 months of their normal water demand (although of course demand varies with the seasons, droughts, water restrictions and price per litre).

To give a point of comparison, Sydney can store up to five years of its normal water demand, and has a desalination plant besides. Despite these advantages, Sydney residents are now under stage one water restrictions which happens when its storages are only 50% full. Yet, even when Sydney’s glass is only half-full, that city still has at least another two years of water left to meet the expected water demand even without using desalination.

By comparison, when water storages in Guyra are 50% full, they have less than six months normal water supply.

It is astonishingly difficult to find accurate data on small-town water supplies but in my experience Guyra is not unique among rural towns. There is a big divide between the water security of those living in Australia’s big cities compared to smaller inland towns. Many rural communities simply do not have sufficient water storage to withstand multi-year droughts, and in some cases, cannot even withstand one year of drought.

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Nature, drought and climate change cannot be blamed for all of our water problems. In rural inland towns, inadequate planning and funding for household water can sometimes be the real culprit. Whether Australians live in rural communities or big cities, they should be treated fairly in terms of both the availability and the quality of the water they use.

Michael Roderick, Professor, Research School of Earth Sciences and Chief Investigator in the ARC Centre of Excellence for Climate Extremes, Australian National University

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

How protons can power our future energy needs

The proton battery, connected to a voltmeter.
RMIT, Author provided

John Andrews, RMIT University

As the world embraces inherently variable renewable energy sources to tackle climate change, we will need a truly gargantuan amount of electrical energy storage.

With large electricity grids, microgrids, industrial installations and electric vehicles all running on renewables, we are likely to need a storage capacity of over 10% of annual electricity consumption – that is, more than 2,000 terawatt-hours of storage capacity worldwide as of 2014.

To put that in context, Australia’s planned Snowy 2.0 pumped hydro storage scheme would have a capacity of just 350 gigawatt-hours, or roughly 0.2% of Australia’s current electricity consumption.

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Where will the batteries come from to meet this huge storage demand? Most likely from a range of different technologies, some of which are only at the research and development stage at present.

Our new research suggests that “proton batteries” – rechargeable batteries that store protons from water in a porous carbon material – could make a valuable contribution.

Not only is our new battery environmentally friendly, but it is also technically capable with further development of storing more energy for a given mass and size than currently available lithium-ion batteries – the technology used in South Australia’s giant new battery.

Potential applications for the proton battery include household storage of electricity from solar panels, as is currently done by the Tesla Powerwall.

With some modifications and scaling up, proton battery technology may also be used for medium-scale storage on electricity grids, and to power electric vehicles.

The team behind the new battery. L-R: Shahin Heidari, John Andrews, proton battery, Saeed Seif Mohammadi.
RMIT, Author provided

How it works

Our latest proton battery, details of which are published in the International Journal of Hydrogen Energy, is basically a hybrid between a conventional battery and a hydrogen fuel cell.

During charging, the water molecules in the battery are split, releasing protons (positively charged nuclei of hydrogen atoms). These protons then bond with the carbon in the electrode, with the help of electrons from the power supply.

In electricity supply mode, this process is reversed: the protons are released from the storage and travel back through the reversible fuel cell to generate power by reacting with oxygen from air and electrons from the external circuit, forming water once again.

Essentially, a proton battery is thus a reversible hydrogen fuel cell that stores hydrogen bonded to the carbon in its solid electrode, rather than as compressed hydrogen gas in a separate cylinder, as in a conventional hydrogen fuel cell system.

Unlike fossil fuels, the carbon used for storing hydrogen does not burn or cause emissions in the process. The carbon electrode, in effect, serves as a “rechargeable hydrocarbon” for storing energy.

What’s more, the battery can be charged and discharged at normal temperature and pressure, without any need for compressing and storing hydrogen gas. This makes it safer than other forms of hydrogen fuel.

Powering batteries with protons from water splitting also has the potential to be more economical than using lithium ions, which are made from globally scarce and geographically restricted resources. The carbon-based material in the storage electrode can be made from abundant and cheap primary resources – even forms of coal or biomass.

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Our latest advance is a crucial step towards cheap, sustainable proton batteries that can help meet our future energy needs without further damaging our already fragile environment.

The time scale to take this small-scale experimental device to commercialisation is likely to be in the order of five to ten years, depending on the level of research, development and demonstration effort expended.

Our research will now focus on further improving performance and energy density through use of atomically thin layered carbon-based materials such as graphene.

The target of a proton battery that is truly competitive with lithium-ion batteries is firmly in our sights.

John Andrews, Professor, School of Engineering, RMIT University

This article was originally published on The Conversation. Read the original article.

Yes, SA’s battery is a massive battery, but it can do much more besides

Dylan McConnell, University of Melbourne

Last Friday, the “world’s largest” lithium-ion battery was officially opened in South Australia. Tesla’s much anticipated “mega-battery” made the “100 days or it’s free” deadline, after a week of testing and commissioning.

Unsurprisingly, the project has attracted a lot of attention, both in Australia and abroad. This is largely courtesy of the high profile Tesla chief executive Elon Musk, not to mention the series of Twitter exchanges that sparked off the project in the first place.

Many are now watching on in anticipation to see what impact the battery has on the SA electricity market, and whether it could be a game-changer nationally.

The Hornsdale Power Reserve

The “mega battery” complex is officially called the Hornsdale Power Reserve. It sits alongside the Hornsdale Wind Farm and has been constructed in partnership with the SA government and Neoen, the French renewable energy company that owns the wind farm.

The battery has a total generation capacity of 100 megawatts, and 129 megawatt-hours of energy storage. This has been decribed as “capable of powering 50,000 homes”, providing 1 hour and 18 minutes of storage or, more controversially, 2.5 minutes of storage.

At first blush, some of these numbers might sound reasonable. But they don’t actually reflect a major role the battery will play, nor the physical capability of the battery itself.

What can the battery do?

The battery complex can be thought of as two systems. First there is a component with 70MW of output capacity that has been contracted to the SA government. This is reported to provide grid stability and system security, and designed only to have about 10 minutes of storage.

The second part could be thought of as having 30MW of output capacity, but 3-4 hours of storage. Even though this component has a smaller capacity (MW), it has much more storage (MWh) and can provide energy for much longer. This component will participate in the competitive part of the market, and should firm up the wind power produced by the wind farm.

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In addition, the incredible flexibility of the battery means that it is well suited to participate in the Frequency Control Ancillary Service market. More on that below.

The figure below illustrates just how flexible the battery actually is. In the space of four seconds, the battery is capable of going from zero to 30MW (and vice versa). In fact it is likely much faster than that (at the millisecond scale), but the data available is only at 4-second resolution.

Hornsdale Power Reserve demonstrating its flexibility last week. The output increased from zero to 30MW (full output) in less than 4 seconds.
Author provided (data from AEMO)

Frequency Control and Ancillary Service Market

The Frequency Control and Ancillary Service (FCAS) market is less known and understood than the energy market. In fact it is wrong to talk of a single FCAS market – there are actually eight distinct markets.

The role of these markets is essentially twofold. First, they provide contingency reserves in case of a major disturbance, such as a large coal generation unit tripping off. The services provide a rapid response to a sudden fall (or rise) in grid frequency.

At the moment, these contingency services operate on three different timescales: 6 seconds, 60 seconds, and 5 minutes. Generators that offer these services must be able to raise (or reduce) their output to respond to an incident within these time frames.

The Hornsdale Power Reserve is more than capable of participating in these six markets (raising and lowering services for the three time intervals shown in the illustration above).

The final two markets are known as regulation services (again, as both a raise and lower). For this service, the Australian energy market operator (AEMO) issues dispatch instructions on a fine timescale (4 seconds) to “regulate” the frequency and keep supply and demand in balance.

The future: fast frequency response?

Large synchronous generators (such as coal plants) have traditionally provided frequency control, (through the FCAS markets), and another service, inertia – essentially for free. As these power plants leave the system, there maybe a need for another service to maintain power system security.

One such service is so-called “fast frequency response” (FFR). While not a a direct replacement, it can reduce the need for physical inertia. This is conceptually similar to the contingency services described above, but might occur at the timescale of tens to hundreds of milliseconds, rather than 6 seconds.

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The Australian Energy Market Commission is currently going through the process of potentially introducing a fast frequency response market. In the meantime, obligations on transmission companies are expected to ensure a minimum amount of inertia or similar services (such as fast frequency response).

I suspect that the 70MW portion of the new Tesla battery is designed to provide exactly this fast frequency response.

Size matters but role matters more

The South Australian battery is truly a historic moment for both South Australia, and for Australia’s future energy security.

While the size, of the battery might be decried as being small in the context of the National Energy Market, it is important to remember its capabilities and role. It may well be a game changer, by delivering services not previously provided by wind and solar PV.

Dylan McConnell, Researcher at the Australian German Climate and Energy College, University of Melbourne

This article was originally published on The Conversation. Read the original article.

With battery storage to the rescue, the Kodak moment for renewables has finally arrived

AAP/Lukas Coch

David Holmes, Monash University

Who would have thought that, scarcely five weeks after Treasurer Scott Morrison, paraded a chunk of coal in parliament, planning for Australia’s energy needs would be dominated by renewables, batteries and hydro?

For months now, the Coalition has been talking down renewables, blaming them for power failures, blackouts, and an unreliable energy network.

South Australia was bearing the brunt of this campaign. The state that couldn’t keep its lights on had Coalition politicians and mainstream journalists vexatiously attributing the blame to its high density of renewables.

But this sustained campaign, which would eventually hail “clean coal” as Australia’s salvation, all came unstuck when tech entrepreneur Elon Musk came out with a brilliant stunt: to install a massive battery storage system in South Australia “in 100 days, or it’s free”.

The genius of the stunt was not to win an instant contract to follow up on such a commitment, but to put an end to decades of dithering over energy policy that major political parties are so famous for in Australia and around the world, and which have intensified the climate crisis to dangerous levels.

Musk’s stunt was not without self-interest. It also aimed to position Tesla as a can-do company for future contracts. But where it was lethal was in completely neutering the campaign against renewables.

Anti-renewable politicians around the country, regardless of whether they are captive to the fossil-fuel lobby, could no longer argue for a dubious “clean-coal” powered station that would take between five and seven years to build when Tesla could fix a state’s energy crisis in 100 days – and not emit one gram of carbon at the end of the process.

Both the South Australian and Victorian governments have responded to Musk’s proposal by bidding for 100 megawatts of battery storage in their states. In South Australia’s case, a state-owned 250MW backup gas-fired fast-start aeroderivative power plant is also to be commissioned.

The state-owned gas power plant is, however, only a support to plans for a renewable-fed grid to be the main source of emergency dispatchable power. It is a plant that anticipates the way extreme weather can impact on energy infrastructure in much the same way desalination plants do for water infrastructure.

This is one reason it must be state-owned. But another is that a private operator would insist on full-time generation to maximise investment and profits. Thus, the South Australian gas plant is actually a critique of the privatisation of energy provision in Australia, which is the single greatest cause of why electricity prices have gone up.

As Giles Parkinson from RenewEconomy points out, within a framework in which privatisation dominates, the current market rules actually disadvantage the merits of non-domestic battery storage for consumers – because private power retailers can exploit arbitrage between low and high prices.

They can load up the batteries when excess wind and solar are cheap and sell it at peak demand for inflated prices. So, storage can actually enhance profits for power suppliers and create a bad deal for consumers.

However, the intrinsic value of storage is that the more you add, the less volatility there will be in a market. This creates a stable price for consumers and less profits for the corporations.

An example Parkinson uses is the Wivenhoe pumped storage facility in Queensland. This is:

… rarely used, because it would dampen the profits of its owners, which also own coal and gas generation.

Nevertheless, as a concept, the battery storage solution proposed by Musk, followed by South Australian Premier Jay Weatherill’s decisive action, really had constricted Malcolm Turnbull’s options. For a start, it makes redundant the longstanding fiction of “baseload power”, which was coined by the fossil-fuel industry to justify coal.

By last week, Turnbull would have already had the results of focus groups telling him that “clean” coal doesn’t wash with voters at all.

So, after reeling for most of last week over the humiliation that the Tesla and Weatherill challenge presented, and after scrambling for a counterpunch, Turnbull came up with Snowy Hydro 2.0. Here Musk’s stunt could only be really met with another stunt, but one in which Turnbull is only trying to salvage a very bad hand that he has played against battery-friendly renewables.

It is true that pumped hydro is currently cheaper than battery storage, but cannot be implemented nearly as quickly, and is not infinitely scalable as battery farms are.

Also, whereas the cost of battery storage continues to fall, the cost of the engineering needed for pumped hydro is not. And there are limited locations suitable for its operation.

But more important than all these considerations is that it while Snowy 2.0 will stabilise the national grid no matter whether clean or dirty energy is powering its pumps, it will only assist decarbonisation if the pumps are powered by wind and solar, which has all been glossed over in its PR sell.

With current energy market rules, there is still some incentive for dirty generators to feed the Snowy pumps. This helps energy security but does nothing for the climate crisis.

Yet, with his PR campaign, Turnbull thinks he is on a winner. The Snowy is also an icon of Australian nation-building and fable. And there is probably some political capital to be scored there. But the Snowy is a once-off, and not a part of the future as battery storage is.

But in having to play the part of the Man from Snowy River, Turnbull may have forestalled the inevitable onset of batteries, the price of which was that he was snookered into committing to an alternative substantial renewable-energy-friendly project.

So significant was the original stunt by Musk that set off a train of events cornering Turnbull into offering counter-storage that Giles Parkinson declared:

Turnbull drives stake through heart of fossil fuel industry.

But then, just when you thought coal had been cremated for the last time, it is revived over the weekend with the work of Chris Uhlmann, the ABC’s political editor, who gained notoriety for his anti-renewable stance on South Australia last year.

In his latest piece on the ABC, Uhlmann forewarns that the closure of the Hazlewood power station (5% of the nation’s energy output) will lead to east coast blackouts and crises in the manufacturing sector.

Uhlmann salutes the language of the coal companies in predicting that an energy crisis will result from no new investment in “baseload” power, even though this is precisely what renewables plus storage actually amounts to. He then quotes a Hazelwood unit controller as his source to raise the bogie of intermitancy once again:

Intermittent renewable energy could not be relied on during days of peak demand.

But the most misleading part of his piece was to point to the Australian Energy Market Operator’s prediction that shortfalls in supply next summer can be attributed to the closure of coal power stations, rather than the fact that climate-change-induced hotter temperatures are driving up demand during this period – as they did in the summer just gone, when Hazelwood was operating.

Perhaps Uhlmann’s piece would not look like such an advertorial for the coal industry had it not appeared on the same day as Resources Minister Matt Canavan’s speculation that a new coal-fired plant could be built in Queensland that will be subsidised by the A$5 billion Northern Australia Infrastructure fund.

On the ABC’s Insiders, Canavan lamented that Queensland did not have a:

… baseload power station north of Rockhampton … We’ve got a lot of coal up here, the new clean-coal technologies are at an affordable price, reliable power and lower emission.

It seems that while South Australia is leading the progress on a renewables Kodak moment, Queensland, with plans to build a coal-fired power stations and the Queensland Labor government going to great lengths to support the gigantic Adani coal mine, at least two states are moving in completely opposite directions.

David Holmes, Senior Lecturer, Communications and Media Studies, Monash University

This article was originally published on The Conversation. Read the original article.

Putting carbon back in the land is just a smokescreen for real climate action: Climate Council report

Martin Rice and Will Steffen, Australian National University

Just as people pump greenhouse gases into the atmosphere by burning fossil fuels, the land also absorbs some of those emissions. Plants, as they grow, use carbon dioxide and store it within their bodies.

However, as the Climate Council’s latest report shows, Australia’s fossil fuels (including those burned overseas) are pumping 6.5 times as much carbon into the atmosphere as the land can absorb. This means that, while storing carbon on land is useful for combating climate change, it is no replacement for reducing fossil fuel emissions.

Land carbon is the biggest source of emission reductions in Australia’s climate policy centrepiece – the Emissions Reduction Fund. This is smoke and mirrors: a distraction from the real challenge of cutting fossil fuel emissions.

Land carbon

Land carbon is part of the active carbon cycle at the Earth’s surface. Carbon is continually exchanging between the land, ocean and atmosphere, primarily as carbon dioxide.

In contrast, carbon in fossil fuels has been locked away from the active carbon cycle for millions of years.

Carbon stored on land is vulnerable to being returned to the atmosphere. Natural disturbances such as bushfires, droughts, insect attacks and heatwaves, many of which are being made worse by climate change, can trigger the release of significant amounts of land carbon back to the atmosphere.

Changes in land management, as we’ve seen in Queensland, for example, with the relaxation of land-clearing laws by the previous state government, can also affect the capability of land systems to store carbon.

Burning fossil fuels and releasing CO₂ to the atmosphere thus introduces new and additional carbon into the land-atmosphere-ocean cycle. It does not simply redistribute existing carbon in the cycle.

The ocean and the land absorb some of this extra carbon. In fact, just over half of this additional carbon is removed from the atmosphere, and split roughly equally between the land and the ocean. However, this leaves almost half of the CO₂ emitted from fossil fuel combustion in the atmosphere. It’s this remaining CO₂ that is driving global warming.

Figure 2. Changes in the global carbon cycle from 1850 to 2014. Positive changes (above the horizontal zero line) show carbon added to the atmosphere and negative changes (below the line) show how this carbon is then distributed among the ocean, land and atmosphere.
Adapted from Le Quéré et al. 2015, data from CDIAC/NOAA-ESRL/GCP/Joos et al. 2013/Khatiwala et al. 2013.

Although Australia’s land sector has absorbed more carbon than it has emitted over the past decade or two, this has been overshadowed by our domestic fossil fuel emissions and those from our exported fossil fuels. These are roughly 6.5 times greater than the uptake of carbon by Australian landscapes.

Under international carbon accounting protocols, emissions are assigned to the country that burns the fossil fuels. However, many Australians are becoming increasing concerned about the ethics associated with exploiting our fossil fuels, no matter where they are burned.

In short, we’ve got a big problem that requires a global response, which includes a strong commitment from Australia.

Falling short of our commitment

Last December, Australia joined the rest of the world in pledging to do everything possible to limit global warming to no more than 2°C above pre-industrial levels, and furthermore to pursue efforts to limit the increase to 1.5°C. Yet Australia lacks a robust, credible long-term plan to cut Australia’s CO₂ emissions from fossil fuel combustion.

Current climate change policies and practices in Australia allow for the use of land carbon “offsets” – that is, carbon taken up by land systems can be used to offset or subtract from fossil fuel emissions. For example, the government’s Emissions Reduction Fund (ERF) provides financial incentives for organisations or individuals to adopt new practices or technologies that reduce or sequester greenhouse gas emissions.

Currently, vegetation (land system) projects represent the majority of ERF-accepted projects (185 out of 348). And yet, while storing carbon on land can be useful, it must be additional to, and not instead of, reducing fossil fuel emissions. Moreover, numerous critiques have questioned the effectiveness of the ERF.

Problems of scale

We also have a problem of scale. Reducing emissions through land carbon methods could save up to 38 billion tonnes of carbon globally by 2050 if combined with sustainable land management practices. By comparison, global carbon emissions from fossil fuel combustion are currently around 10 billion tonnes per year.

If this rate is continued, total fossil fuel emissions from 2015 to 2050 will be about 360 billion tonnes – nearly 10 times larger than the maximum estimated biological carbon sequestration of 38 billion tonnes over the same period.

It is now virtually certain that the carbon budget (the amount of carbon that can be produced while keeping warming below a certain level) will be exceeded. To meet the Paris 1.5°C aspirational target (and probably to meet the 2°C target) will require the use of negative emission technologies throughout the second half of the century.

However, no proposed negative emission technology has yet been proven to be feasible technologically at large scale and at reasonable cost, so this approach remains an in-principle option only. For effective climate action, the emphasis must remain on reducing emissions from fossil fuel combustion.

Using land carbon to “offset” our fossil fuel emissions is ultimately a smokescreen for real climate action.

Our thanks to Jacqui Fenwick for co-authoring this article and the report.

Martin Rice, Head of Research, The Climate Council of Australia and Honorary Associate, Department of Environmental Sciences and Will Steffen, Adjunct Professor, Fenner School of Environment and Society, Australian National University

This article was originally published on The Conversation. Read the original article.

Carbon capture and storage is unlikely to save coal in the long run

Gary Ellem, University of Newcastle

As the world moves to combat climate change, it’s increasingly doubtful that coal will continue to be a viable energy source, because of its high greenhouse gas emissions. But coal played a vital role in the Industrial Revolution and continues to fuel some of the world’s largest economies. This series looks at coal’s past, present and uncertain future.

Coal is the greatest contributor to climate change of all our energy sources. This means that if the world acts to limit global warming to well below 2℃, coal will likely be constrained – unless its greenhouse gas emissions can be removed.

One of the great hopes of the industry is carbon capture and storage (CCS), a way to burn coal, remove the carbon dioxide (CO₂) emissions and store it safely away from the atmosphere. While there have been several breakthroughs, the technology remains expensive.

Advances in energy technologies mean that adding CCS doesn’t just need to work; it needs to work at a lower cost than its growing legion of competitors. And while the alternatives are good news for avoiding dangerous climate change, it’s a substantial challenge for the coal industry.

Capturing carbon

The current range of CCS technologies can be grouped into “pre-combustion” and “post-combustion” methods.

Pre-combustion methods typically react the carbon in the fuel with high-pressure steam to make hydrogen CO₂. The CO₂ is then separated (captured) from the hydrogen before the hydrogen is burned in the power station to make energy, with the only emissions being water vapour.

Post-combustion technologies try to capture the carbon after it has been burned and becomes CO₂. If the fuel is burned in air, then the CO₂ needs to be separated from the exhaust gas stream which, like air, is mostly composed of nitrogen gas. This is usually done by passing the gas stream through a liquid that dissolves the CO₂ but not the nitrogen.

Another technique, called “oxyfuelling”, separates oxygen out of the air and then uses it to burn the fuel in an atmosphere of oxygen and recycled CO₂. The exhaust gas stream from this process is close enough to pure CO₂ that it can be sent directly to the storage process.

Several options have been explored for storing the carbon. These include the deep ocean, depleted oil and gas wells, deep saline aquifers, as manufactured mineralised carbonate rock, or as naturally mineralised carbonate by injection into basalt reservoirs.

Regardless of the technique, the outcomes for coal combustion are similar. The amount of emissions is reduced by 80-100%, while the cost of coal-fired electricity generation increases by at least the same amount.

These costs come from building the capture plant, CO₂ transport pipelines and the sequestration plant. More than double the amount of coal must be burned to make up for the energy cost of the CCS process itself.

When CCS was first considered as an emissions solution, competition from renewables, such as solar and wind, was weak. Costs were high and production volumes were negligible.

How cheap?

In the 1990s, many believed that renewables (other than existing hydro, geothermal and biomass for heating) might never be able to replace coal cheaply. The future of energy was going to be a centralised grid, rather than the distributed power models being discussed today, and there were only two widely backed horses in the technology race: CCS and nuclear.

But the early part of this century has seen an energy revolution in both renewables and fossil fuels. Among renewables, solar and wind have both taken enormous strides in reducing production costs and building manufacturing scale.

For fossil fuels, the expansion in gas pipeline infrastructure, the development of liquefied natural gas (LNG) shipping and the growth of both conventional and unconventional gas production have encouraged fuel switching from coal in European and US markets in particular.

Trying to compare the costs of different types of electricity can be tricky. Power stations require capital to build and have heavy financing, operational and decommissioning costs. Nuclear and fossil fuel power stations also have to buy fuel.

Analysts use the term “levelised cost of electricity (LCOE)” to aggregate and describe this combination of factors for different methods of electricity generation.

A significant challenge for coal and CCS is that the LCOE for wind and solar at a comparable scale is already competitive with coal generation in many places. This is because the cost of manufacturing has fallen as production has increased.

While this seems not to bode well for coal and CCS, there’s a caveat: a coal with CCS power station makes power when the sun doesn’t shine and the wind doesn’t blow.

It’s easier for wind and solar to compete when traditional fossil fuel power stations are there to back them up, but not so easy when renewables become dominant generators and the cost of storage needs to be taken into account to ensure a consistent supply.

A game changer?

That was until batteries came along and offered the ability to store renewable energy for when the sun doesn’t shine. There is considerable hype around the entry of the Tesla Powerwall into the home electricity market.

But that is only one of numerous home battery solutions from the likes of Samsung, LG, Bosch, Panasonic, Enphase and others. All are designed to store excess solar power for use at night.

The emerging breakthrough of these products is the price, which is bringing batteries into the realm of competition with centralised electricity generation.

While a battery won’t take your family entirely off-grid at first, such batteries mean most suburban households can become largely energy-independent. They need only top up from the grid now and then when a run of cloudy days comes along during the shorter days of winter.

In the longer term, there’s a clear pathway for most homes to disconnect completely from the grid, should battery prices continue to fall.

Why are batteries a threat?

The reason that batteries can compete with centralised generation is because the cost of transmission and distribution from a coal-fired power station to your home is considerable.

These costs are not normally considered in the LCOE calculations, because it is assumed that all power generators have access to the same, centralised electricity grid.

But a battery in your home means that these costs are largely avoided. That makes home energy generation and storage much more competitive with traditional power generation in the longer term.

For developing nations without a strong centralised grid it also means that energy systems can be built incrementally, without large investments in infrastructure.

This is an ill wind for the competitive future of CCS, which depends on the centralised generation model and a lack of low-cost competitors to stay viable.

That doesn’t mean the coal industry should give up on CCS. Having a range of options for a low-emission future is a good thing. Affordable energy is at the heart of our modern civilisation and standards of living.

CCS may also lay the foundations for Bioenergy with Carbon Capture and Storage (BECCS), one of the few (albeit expensive) technologies with the potential to recoup significant amounts of CO₂ from the atmosphere. But this points to a renewable biomass future, not a coal future.

The odds that CCS will keep coal alive as an industry into the future are getting longer each year.

What we are seeing is the start of the great transition from fossil fuel mining to manufacturing as the basis for our energy systems. It’s not dominant yet, but you would be starting to get very nervous if you were betting against it.

Gary Ellem, Conjoint Academic in Sustainability, University of Newcastle

This article was originally published on The Conversation. Read the original article.