Tag Archives: sustainable

Earth Day, Sustainable Energy

A ‘100% renewables’ target might not mean what you think it means. An energy expert explains

In the global effort to transition from fossil fuels to clean energy, achieving a “100% renewables” electricity system is considered ideal.

Some Australian states have committed to 100% renewable energy targets, or even 200% renewable energy targets. But this doesn’t mean their electricity is, or will be, emissions free.

Electricity is responsible for a third of Australia’s emissions, and making it cleaner is a key way to reduce emissions in other sectors that rely on it, such as transport.

So it’s important we have clarity about where our electricity comes from, and how emissions-intensive it is. Let’s look at what 100% renewables actually implies in detail.

Is 100% renewables realistic?

Achieving 100% renewables is one way of eliminating emissions from the electricity sector.

It’s commonly interpreted to mean all electricity must be generated from renewable sources. These sources usually include solar, wind, hydro, and geothermal, and exclude nuclear energy and fossil fuels with carbon capture and storage.

But this is a very difficult feat for individual states and territories to try to achieve.

The term “net 100% renewables” more accurately describes what some jurisdictions — such as South Australia and the ACT — are targeting, whether or not they’ve explicitly said so.

These targets don’t require that all electricity people use within the jurisdiction come from renewable sources. Some might come from coal or gas-fired generation, but the government offsets this amount by making or buying an equivalent amount of renewable electricity.

A net 100% renewables target allows a state to spruik its green credentials without needing to worry about the reliability implications of being totally self-reliant on renewable power.

So how does ‘net’ 100% renewables work?

All east coast states are connected to the National Electricity Market (NEM) — a system that allows electricity to be generated, used and shared across borders. This means individual states can achieve “net 100% renewables” without the renewable generation needing to occur when or where the electricity is required.

Take the ACT, for example, which has used net 100% renewable electricity since October 2019.

The ACT government buys renewable energy from generators outside the territory, which is then mostly used in other states, such as Victoria and South Australia. Meanwhile, people living in ACT rely on power from NSW that’s not emissions-free, because it largely comes from coal-fired power stations.

This way, the ACT government can claim net 100% renewables because it’s offsetting the non-renewable energy its residents use with the clean energy it’s paid for elsewhere.

SA’s target is to reach net 100% renewables by the 2030s. Unlike the ACT, it plans to generate renewable electricity locally, equal to 100% of its annual demand.

At times, such as especially sunny days, some of that electricity will be exported to other states. At other times, such as when the wind drops off, SA may need to rely on electricity imports from other states, which probably won’t come from all-renewable sources.

So what happens if all states commit to net 100% renewable energy targets? Then, the National Electricity Market will have a de-facto 100% renewable energy target — no “net”.

That’s because the market is one entire system, so its only options are “100% renewables” (implying zero emissions), or “less than 100% renewables”. The “net” factor doesn’t come into it, because there’s no other part of the grid for it to buy from or sell to.

How do you get to “200% renewables”, or more?

It’s mathematically impossible for more than 100% of the electricity used in the NEM to come from renewable sources: 100% is the limit.

Any target of more than 100% renewables is a different calculation. The target is no longer a measure of renewable generation versus all generation, but renewable generation versus today’s demand.

Australia could generate several times more renewable energy than there is demand today, but still use a small and declining amount of fossil fuels during rare weather events. Shutterstock

Tasmania, for example, has legislated a target of 200% renewable energy by 2040. This means it wants to produce twice as much renewable electricity as it consumes today.

But this doesn’t necessarily imply all electricity consumed in Tasmania will be renewable. For example, it may continue to import some non-renewable power from Victoria at times, such as during droughts when Tasmania’s hydro dams are constrained. It may even need to burn a small amount of gas as a backup.

This means the 200% renewable energy target is really a “net 200% renewables” target.

Meanwhile, the Greens are campaigning for 700% renewables. This, too, is based on today’s electricity demand.

In the future, demand could be much higher due to electrifying our transport, switching appliances from gas to electricity, and potentially exporting energy-intensive, renewable commodities such as green hydrogen or ammonia.

Targeting net-zero emissions

These “more than 100% renewables” targets set by individual jurisdictions don’t necessarily imply all electricity Australians use will be emissions free.

It’s possible — and potentially more economical — that we would meet almost all of this additional future demand with renewable energy, but keep some gas or diesel capacity as a low-cost backstop.

This would ensure continued electricity supply during rare, sustained periods of low wind, low sun, and high demand, such as during a cloudy, windless week in winter.

The energy transition is harder near the end — each percentage point between 90% and 100% renewables is more expensive to achieve than the previous.

That’s why, in a recent report from the Grattan Institute, we recommended governments pursue net-zero emissions in the electricity sector first, rather than setting 100% renewables targets today.

For example, buying carbon credits to offset the small amount of emissions produced in a 90% renewable NEM is likely to be cheaper in the medium term than building enough energy storage — such as batteries or pumped hydro dams — to backup wind and solar at all times.

The bottom line is governments and companies must say what they mean and mean what they say when announcing targets. It’s the responsibility of media and pundits to take care when interpreting them.

This article is by James Ha, Associate, Grattan Institute and republished from The Conversation under a Creative Commons license. Read the original article.

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Climate Solutions, News, Observation

Offshore wind farms could help capture carbon from air and store it long-term – using energy that would otherwise go to waste

Video

Off the Massachusetts and New York coasts, developers are preparing to build the United States’ first federally approved utility-scale offshore wind farms – 74 turbines in all that could power 470,000 homes. More than a dozen other offshore wind projects are awaiting approval along the Eastern Seaboard.

By 2030, the Biden administration’s goal is to have 30 gigawatts of offshore wind energy flowing, enough to power more than 10 million homes.

Replacing fossil fuel-based energy with clean energy like wind power is essential to holding off the worsening effects of climate change. But that transition isn’t happening fast enough to stop global warming. Human activities have pumped so much carbon dioxide into the atmosphere that we will also have to remove carbon dioxide from the air and lock it away permanently.

Offshore wind farms are uniquely positioned to do both – and save money.

Most renewable energy lease areas off the Atlantic Coast are near the Mid-Atlantic states and Massachusetts. About 480,000 acres of the New York Bight is scheduled to be auctioned for wind farms in February 2022. BOEM

As a marine geophysicist, I have been exploring the potential for pairing wind turbines with technology that captures carbon dioxide directly from the air and stores it in natural reservoirs under the ocean. Built together, these technologies could reduce the energy costs of carbon capture and minimize the need for onshore pipelines, reducing impacts on the environment.

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Capturing CO2 from the air

Several research groups and tech startups are testing direct air capture devices that can pull carbon dioxide directly from the atmosphere. The technology works, but the early projects so far are expensive and energy intensive.

The systems use filters or liquid solutions that capture CO2 from air blown across them. Once the filters are full, electricity and heat are needed to release the carbon dioxide and restart the capture cycle.

For the process to achieve net negative emissions, the energy source must be carbon-free.

The world’s largest active direct air capture plant operating today does this by using waste heat and renewable energy. The plant, in Iceland, then pumps its captured carbon dioxide into the underlying basalt rock, where the CO2 reacts with the basalt and calcifies, turning to solid mineral.

A similar process could be created with offshore wind turbines.

If direct air capture systems were built alongside offshore wind turbines, they would have an immediate source of clean energy from excess wind power and could pipe captured carbon dioxide directly to storage beneath the sea floor below, reducing the need for extensive pipeline systems.

Researchers are currently studying how these systems function under marine conditions. Direct air capture is only beginning to be deployed on land, and the technology likely would have to be modified for the harsh ocean environment. But planning should start now so wind power projects are positioned to take advantage of carbon storage sites and designed so the platforms, sub-sea infrastructure and cabled networks can be shared.

Using excess wind power when it isn’t needed

By nature, wind energy is intermittent. Demand for energy also varies. When the wind can produce more power than is needed, production is curtailed and electricity that could be used is lost.

That unused power could instead be used to remove carbon from the air and lock it away.

For example, New York State’s goal is to have 9 gigawatts of offshore wind power by 2035. Those 9 gigawatts would be expected to deliver 27.5 terawatt-hours of electricity per year.

Based on historical wind curtailment rates in the U.S., a surplus of 825 megawatt-hours of electrical energy per year may be expected as offshore wind farms expand to meet this goal. Assuming direct air capture’s efficiency continues to improve and reaches commercial targets, this surplus energy could be used to capture and store upwards of 0.5 million tons of CO2 per year.

That’s if the system only used surplus energy that would have gone to waste. If it used more wind power, its carbon capture and storage potential would increase.

Several Mid-Atlantic areas being leased for offshore wind farms also have potential for carbon storage beneath the seafloor. The capacity is measured in millions of metric tons of CO2 per square kilometer. The U.S. produces about 4.5 billion metric tons of CO2 from energy per year. U.S. Department of Energy and Battelle

The Intergovernmental Panel on Climate Change has projected that 100 to 1,000 gigatons of carbon dioxide will have to be removed from the atmosphere over the century to keep global warming under 1.5 degrees Celsius (2.7 Fahrenheit) compared to pre-industrial levels.

Researchers have estimated that sub-seafloor geological formations adjacent to the offshore wind developments planned on the U.S. East Coast have the capacity to store more than 500 gigatons of CO2. Basalt rocks are likely to exist in a string of buried basins across this area too, adding even more storage capacity and enabling CO2 to react with the basalt and solidify over time, though geotechnical surveys have not yet tested these deposits.

Planning both at once saves time and cost

New wind farms built with direct air capture could deliver renewable power to the grid and provide surplus power for carbon capture and storage, optimizing this massive investment for a direct climate benefit.

But it will require planning that starts well in advance of construction. Launching the marine geophysical surveys, environmental monitoring requirements and approval processes for both wind power and storage together can save time, avoid conflicts and improve environmental stewardship.

Originally published on The Conversation by David Goldberg, Lamont Research Professor, Columbia University and republished under a Creative Commons license. Read the original article.

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Climate Solutions, D.I.Y., Lifestyle, Observation

How to Implement small yet Meaningful Changes towards Zero Waste

Above: Image by RikaC from Pixabay 

Cause and Effect of Convenience

We have all experienced how, in the hustle and bustle of everyday life, it can be very challenging to break away from convenience. When it comes to products and services, many large companies utilize fast, cheap, and easily disposable single-use containers made from plastic.

Sodas bottles are plastic, baristas serve coffee in plastic cups with plastic caps and straws, fast food restaurants prepare orders in single use wrappers with plastic containers for condiments, and the list can go on and on. These products are used and then discarded.

Single use plastic items, as the name indicates, are used only once, yet plastic breaks down extremely slow, with some forms taking hundreds of years to degrade as shown in the tweet below from the World Wildlife Fund (WWF):

Read More: Sustainable Energy is Now Essential to Rescue Economy and Planet: Earth Day 2020

Zero Waste Defined

Zero Waste as explained by Waste Management, is a philosophy that aims for resources to be reused, recycled or composted, in order to allow for very little to “zero” trash to be sent to landfills or spill into the ocean.

Clearly this issue is important, and getting more so, therefore should be considered a high priority – the reality is that huge amounts of plastic garbage does end up in the ocean and dumped in landfills. This dire state of affairs continues to jeopardize ocean and wildlife as well as our own health.

The organization Eco-Cycle Solutions urges the need for a complete change to our current system. With dwindling natural resources, a compromised ecosystem, and major changes in climate already evident today and with likely more on the way, there is no way the Earth can sustain for much longer and survive for future generations. 

The obvious need for large-scale changes at the corporate level, regarding plastic usage, is clear, but we also need to ask ourselves: what can be done on an individual scale?

Read More: “The Uninhabitable Earth”: an Apocalyptic Climate Study that Just might Shock you into Action

Small steps can lead to Big Change

Here are a few products that can be swapped-out and used instead of single and disposable use options:

  • Bamboo Toothbrush – both brush and bristles can be composted when time to replace
  • Lunchbox – making meals at home instead of eating out eliminates containers and can also be an opportunity to eat healthier
  • Water and Coffee Bottles (aluminum, glass or BPA free bottle) – can be refilled endlessly
  • Metal or Glass Straws – sturdier than the plastic counterpart and can be used over and over
  • Shopping Bags (canvas or other fabric) – can be used to carry groceries or any purchases
  • Cloth Napkins – for drying hands or wiping up around the house

“Using more sustainable products offers many benefits: saving money, eating healthier, all while creating a smaller ecological footprint in the world. While all are positive steps, most importantly, these small individual acts can ultimately help in the fight for the survival of future generations.”

While it may be impossible to free us of all waste, with effort and change, not necessarily perfection (decades of waste cannot be eliminated by a short term solution), small steps can lead to a better tomorrow.

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