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


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

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

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

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

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

Longer charges

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

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

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

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

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

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

Safer batteries

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

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

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

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

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

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

Storing sunlight as heat

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

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

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

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

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

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

Advanced renewable fuels

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

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

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

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

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

Kerry Rippy, Researcher, National Renewable Energy Laboratory

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

Australia has failed greater gliders: since they were listed as ‘vulnerable’ we’ve destroyed more of their habitat


Josh Bowell , Author provided

Darcy Watchorn, Deakin University and Kita Ashman, Deakin UniversityIn just five years, greater gliders — fluffy-eared, tree-dwelling marsupials — could go from vulnerable to endangered, because Australia’s environmental laws have failed to protect them and other threatened native species.

Our new research found that after the greater glider was listed as vulnerable to extinction under national environment law in 2016, habitat destruction actually increased in some states, driving the species closer to the brink. Now, they meet the criteria to be listed as endangered.

Despite this, the federal government has put forward a bill that would further weaken Australia’s environment laws.

If Australia wants to ditch its shameful reputation as a global extinction leader, our environmental laws must be significantly strengthened, not weakened.

Why is the greater glider losing its home?

At about the size of a cat, greater gliders are the largest gliding marsupial in the world, and can glide up to 100 metres through the forest canopy. They nest in the hollows of big old trees and, just like koalas, they mostly eat eucalypt leaves.

A dark morph greater glider in a patch of old growth forest in Munruben, Logan City, south of Brisbane.
Josh Bowell

Greater gliders were once common throughout the forests of Queensland, New South Wales, and Victoria. However, destructive practices, such as logging and urban development, have cut down the trees they call home. The rapidly warming climate and increasingly frequent and severe bushfires are also a major threat.

Together, these threats are causing the greater glider to rapidly disappear.

For our new study, we calculated the amount of greater glider habitat destroyed in the two years before the species was listed as vulnerable under Australia’s environment law, the Environment Protection and Biodiversity Conservation Act (EPBC) Act. We then compared this to the amount of habitat destroyed in the two years after listing.

In Victoria, we measured the amount of habitat that was logged. In Queensland and NSW, we measured the amount of habitat cleared for all purposes, including logging, agriculture, and development projects.

What we found

The amount of greater glider habitat logged in Victoria remained consistently high, with a total of 4,917 hectares logged before listing compared to 4,759 hectares after listing. And of all forest logged in Victoria after listing, more than 45% was mapped as greater glider habitat by the federal government, according to our research paper.

State-owned forestry company VicForests is responsible for the lion’s share of native forest logging in Victoria. The Conversation contacted VicForests to respond to the arguments in this article. A spokesperson said:

There are 3.7 million hectares of potential Greater Glider habitat in Victoria under the official habitat model. The most valuable areas of this habitat are set aside in conservation reserves that can never be harvested.

The total area harvested by VicForests in any year is around 0.04% of this total potential habitat.

A small bulldozer used for tree ‘thinning’ in Queensland, May 2017.
WWF-Australia

In Queensland, habitat clearing increased by almost 300%, from a total of 3,002 hectares before listing compared to 11,838 hectares after listing. The amount of habitat cleared in NSW increased by about 5%, from a total of 15,204 hectares to 15,890 hectares.

We also quantified how much greater glider habitat was affected by the 2019-2020 Black Summer bushfires, and found approximately 29% of greater glider habitat was burnt. Almost 40% of this burnt at high severity, which means few gliders are likely to persist in, or rapidly return to, these areas.

As a result, earlier this year — just five years after listing — an assessment by the Threatened Species Scientific Committee found the greater glider is potentially eligible for up-listing from vulnerable to endangered.

A greater glider found in burnt bushland, Meroo National Park, NSW, December 2019.
George Lemann, WWF-Australia

Why was habitat allowed to be cleared?

Development projects can take decades to be implemented after they’ve been approved under the EPBC Act. Therefore, a lot of the habitat cleared in NSW and Queensland was likely to have been approved before the greater glider was listed as vulnerable, and before the 2019-2020 bushfires.

Once a project is approved, it is not reassessed, even if a species becomes vulnerable and a wildfire burns much of its habitat.

This means the impact of clearing native vegetation can be far greater than when initially approved. It also means it can take many years after a species is listed until its habitat is finally safe.

This young greater glider was displaced by clearing near Chinchilla on the Darling Downs, Queensland. It was rescued by a fauna spotter/catcher who was present.
Briano, WWF-Australia

In Victoria and parts of NSW, the forestry industry is allowed to log greater glider habitat under “regional forest agreements”. These agreements allow logging to operate under a special set of rules that bypasses federal environmental scrutiny under the EPBC Act.

The logging industry is required to comply only with state regulations for threatened species protection, which are are often inadequate.




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In 2019, the Victorian government updated the protection measures for greater gliders in logged forests. However, these still allow logging of up to 60% of a forested area authorised for harvest, even when greater gliders are present at high densities.

The spokesperson for VicForests said the company prioritises live, hollow-bearing trees wherever there are five or more greater gliders per spotlight kilometre (a 1 kilometre stretch of forest surveyed with torches). But this level of protection is limited and is unlikely to halt greater glider decline, as the species is highly sensitive to disturbance.

Recently logged native forest from the Central Highlands, Victoria.
Darcy Watchorn

In May 2020 the Federal Court found VicForests breached state environmental laws when they failed to implement protection measures and destroyed critically endangered Leadbeater’s possum and greater glider habitat.

Despite this, earlier this year, the Federal Court upheld an appeal by VicForests to retain their exemption from the EPBC Act. This ruling means VicForests will not be held accountable for destroying threatened species habitat, even when it is found in breach of state requirements.




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The spokesperson for VicForests said the company takes sustainable harvesting seriously.

VicForests operations are subject to Victorian laws, and enforced by the Office of the Conservation Regulator (OCR) and Victorian courts when necessary. The recent federal court appeal decision has not changed that fact.

They add that VicForests surveys show greater gliders continue to persist in recently harvested areas, under its current practices.

VicForests has not seen any evidence that even a single Greater Glider has died as a result of our new harvesting approach.

The government isn’t learning its lesson

The EPBC Act is currently undergoing a once in a decade assessment that considers how well it’s operating, with a recent independent review criticising the EPBC Act for no longer being fit for purpose. Our new research reinforces this, by showing the act has failed to protect one of Australia’s most iconic and unique animals.

And yet, the federal government wants to weaken the act further by implementing a streamlined model, which would rely on state governments to approve actions that would impact threatened species.

There’s a raft of reasons why this would be problematic.




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For one, state environmental laws operate independently, and don’t consider what developments have been approved in other states. Cutting down trees may seem insignificant in certain areas, but without considering the broader impacts, many small losses can accumulate into massive declines, like a death by a thousand cuts.

As a case in point, despite the devastation of greater glider habitat from the Black Summer fires in NSW, the Queensland government have recently approved a new coal mine, which will destroy over 5,500 hectares of greater glider and koala habitat.

What needs to change?

The greater glider is edging towards extinction, but there is still no recovery plan for this iconic marsupial. Adding to this, new research suggests there are actually three species of greater glider we could be losing, rather than just one as was previously thought. Significant effort must be invested to create a clear plan for their recovery.

Because Australia has such a rich diversity of wildlife, we have a great responsibility to protect it. Australia must make important changes now to strengthen — not weaken — its environmental laws, before greater gliders, and many other species, are gone forever.The Conversation

Darcy Watchorn, PhD Candidate, Deakin University and Kita Ashman, Threatened Species & Climate Adaptation Ecologist, Deakin University

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

‘Do-gooders’, conservatives and reluctant recyclers: how personal morals can be harnessed for climate action


Jacqueline Lau, James Cook University; Andrew Song, University of Technology Sydney, and Jessica Blythe, Brock UniversityThere’s no shortage of evidence pointing to the need to act urgently on climate change. Most recently, a report by the Intergovernmental Panel on Climate Change confirmed Earth has warmed 1.09℃ since pre-industrial times and many changes, such as sea-level rise and glacier melt, cannot be stopped.

Clearly, emissions reduction efforts to date have fallen abysmally short. But why, when the argument in favour of climate action is so compelling?

Decisions about climate change require judging what’s important, and how the world should be now and in future. Therefore, climate change decisions are inherently moral. The rule applies whether the decision is being made by an individual deciding what food to eat, or national governments setting goals at international climate negotiations.

Our research reviewed the most recent literature across the social and behavioural sciences to better understand the moral dimensions of climate decisions. We found some moral values, such as fairness, motivate action. Others, such as economic liberty, stoke inaction.

graph with arrow leading upwards
Those who prioritise economic liberty may be less willing to take climate action.
Shutterstock

Morals as climate motivators

Our research uncovered a large body of research confirming people’s moral values are connected to their willingness to act on climate change.

Moral values are the yardstick through which we understand things to be right or wrong, good or bad. We develop personal moral values through our families in childhood and our social and cultural context.

But which moral values best motivate personal actions? Our research documents a study in the United States, which found the values of compassion and fairness were a strong predictor of someone’s willingness to act on climate change.

According to moral foundations theory, the value of compassion relates to humans’ evolution as mammals with attachment systems and an ability to feel and dislike the pain of others.

Fairness relates to the evolutionary process of “reciprocal altruism”. This describes a situation whereby an organism acts in a way that temporarily disadvantages itself while benefiting another, based on an expectation that the altruism will be reciprocated at a later time.




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Conversely, a study in Australia found people who put a lower value on fairness, compared to either the maintenance of social order or the right to economic freedom, were more likely to be sceptical about climate change.

People may also use moral “disengagement” to justify, and assuage guilt over, their own climate inaction. In other words, they convince themselves that ethical standards do not apply in a particular context.

For example, a longitudinal study of 1,355 Australians showed over time, people who became more morally disengaged became more sceptical about climate change, were less likely to feel responsible and were less likely to act.

Our research found the moral values driving efforts to reduce emissions (mitigation) were different to those driving climate change adaptation.

Research in the United Kingdom showed people emphasised the values of responsibility and respect for authorities, country and nature, when talking about mitigation. When evaluating adaptation options, they emphasised moral values such as protection from harm and fair distribution of economic costs.

people on crowd hold signs
Moral reasoning helps shape climate beliefs, including climate scepticism.
Joel Carrett/AAP

Framing climate decisions

How government and private climate decisions are framed and communicated affects who they resonate with, and whether they’re seen as legitimate.

Research suggests climate change could be made morally relevant to more people if official climate decisions appealed to moral values associated with right-wing political leanings.

A US study found liberals interpreted climate change in moral terms related to harm and care, while conservatives did not. But when researchers reframed pro-environmental messages in terms of moral values that resonated with conservatives, such as defending the purity of nature, differences in the environmental attitudes of both groups narrowed.

Indeed, research shows moral reframing can change pro-environmental behaviours of different political groups, including recycling habits.

In the US, people were found to recycle more after the practice was reframed in moral terms that resonated with their political ideology. For conservatives, the messages appealed to their sense of civic duty and respect for authority. For liberals, the messages emphasised recycling as an act of fairness, care and reducing harm to others.




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person opens lid of recycling bin
Reframing of messages can help encourage habits such as recycling.
James Ross/AAP

When moralising backfires

Clearly, morals are central to decision-making about the environment. In some cases, this can extend to people adopting – or being seen to adopt – a social identity with moral associations such as “zero-wasters”, “voluntary simplifiers” and cyclists.

People may take on these identities overtly, such as by posting about their actions on social media. In other cases, a practice someone adopts, such as cycling to work, can be construed by others as a moral action.

Being seen to hold a social identity based on a set of morals may actually have unintended effects. Research has found so-called “do-gooders” can be perceived by others as irritating rather than inspiring. They may also trigger feelings of inadequacy in others who, as a self-defense mechanism, might then dismiss the sustainable choices of the “do-gooder”.

For example, sociologists have theorised that some non-vegans avoid eating a more plant-based diet because they don’t want to be associated with the social identity of veganism.

It makes sense, then, that gentle encouragement such as “meat-free Mondays” is likely more effective at reducing meat consumption than encouraging people to “go vegan” and eliminate meat altogether.

Looking ahead

Personal climate decisions come with a host of moral values and quandaries. Understanding and navigating this moral dimension will be critical in the years ahead.

When making climate-related decisions, governments should consider the moral values of citizens. This can be achieved through procedures like deliberative democracy and citizen’s forums, in which everyday people are given the chance to discuss and debate the issues, and communicate to government what matters most to them.




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The Conversation


Jacqueline Lau, Research Fellow, ARC Centre of Excellence for Coral Reef Studies, James Cook University; Andrew Song, Lecturer / ARC Discovery Early Career Research Fellow (DECRA), University of Technology Sydney, and Jessica Blythe, Assistant Professor, Environmental Sustainability Research Centre, Brock University

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