Feed aggregator

Coal’s long term prospects do not look good in the US, or for that matter anywhere else

How can a Trump Presidency be positive? Surely this is a major setback for action on climate change, inequality, human rights and global security?

With high gas prices partly to blame for the electricity blackouts that hit SA this month, and gas-fired generators caught short in NSW two days later, there are calls for Australia’s onshore gas to flow much more freely.

Melted ice from the Antarctic, a vial of tears, a plastic bottle of water from a firetruck and three different types of wee are all exhibits in the Museum of Water - an exploration of our relationship with the world's most indispensable liquid.

ERM and Alinta top list of retailers failing to meet RET obligations in 2016. Their combined shortfall could have supported nine 100MW solar farms in NSW.

TASK MASTERS: They may have tiny brains, but it turns out that bumblebees can not only learn to use tools by observing others, they can improvise and make the task even easier.

The small island’s energy makeover took less than a decade and was spurred on by local commitment, providing a template for how regional Australia could transition to renewables

Anyone doubting the potential of renewable energy need look no further than the Danish island of Samsø. The 4,000-inhabitant island nestled in the Kattegat Sea has been energy-positive for the past decade, producing more energy from wind and biomass than it consumes.

Samsø’s transformation from a carbon-dependent importer of oil and coal-fuelled electricity to a paragon of renewables started in 1998. That year, the island won a competition sponsored by the Danish ministry of environment and energy that was looking for a showcase community – one that could prove the country’s freshly announced Kyoto target to cut greenhouse gas emissions by 21% was, in fact, achievable.

Continue reading...

‘Real progress’ on reef says Josh Frydenberg, despite warnings of an ‘elevated and imminent risk’ of widespread coral bleaching across the Great Barrier Reef again this year.

With declining coral cover, poor water quality and the impacts of climate change, the future of the Great Barrier Reef has been under close scrutiny in recent years by the World Heritage Committee.

There are calls for Australia's onshore gas to flow much more freely. Glen Dillon, CC BY

With high gas prices partly to blame for the electricity blackouts that hit South Australia this month, and gas-fired generators caught short in New South Wales two days later, it is hardly surprising to hear calls for Australia to expand production.

Even the week before the latest crises, Prime Minister Malcolm Turnbull told the National Press Club that increasing gas supply is “vital” for Australia’s energy future.

Following bipartisan passage of the Victorian moratorium on onshore gas developments, federal Energy Minister Josh Frydenberg called on all governments to support unconventional gas. He has talked of an “urgent” need to increase gas supplies to improve energy security.

But how much extra gas do we need? And how do we square this with the equally pressing need to reduce our use of fossil fuels?

How much gas can we burn?

On average, the National Electricity Market (NEM) emits about 800 grams of carbon dioxide per kilowatt hour of electricity produced. This is almost double the OECD average of 411g per kWh.

According to the International Energy Agency (IEA), this average needs to fall drastically to 15g per kWh by 2050 to achieve the goal of limiting the global increase in temperatures to 2℃. Indeed, the IPCC Fifth Assessment Report shows that limiting global warming to less than 2℃ will require the electricity sector’s greenhouse emissions to reach zero by 2050.

By any measure that is a huge task, particularly for a country like Australia. Currently, around 11% of the electricity in the NEM comes from gas. Even if every coal power station were closed and replaced with zero-emissions technology, the NEM’s emissions intensity would still be three times this 15g per kWh limit.

Gas demand in the NEM states. GPG: gas-powered generation; LNG: liquefied natural gas. The amount of gas burned in the electricity sector would have to reduce to meet emissions reduction targets. Melbourne Energy Institute

This means that at current demand levels we need to burn roughly 70% less gas if we are to stay in this emissions intensity range. That’s a particularly small amount when compared with current total gas demand, as shown in the figure above.

Given this constraint, we need to think about how to maximise the amount of electricity we get from this limited amount of gas, and what new technologies can help us do it.

Technological options

There are several technologies for converting gas to electricity. Older power stations, such as Torrens Island in South Australia, are similar to coal-fired power stations. Energy from combustion is used to heat water, which in turn powers a steam turbine.

Today, gas is generally converted to electricity using two different technologies. First, there are open-cycle gas turbines (OCGTs). These work in a similar way to jet engines: the gas is mixed with air and burned, producing a stream of hot, high-pressure exhaust gas that drives a turbine.

OCGTs are very flexible and can ramp up and down very quickly. They are sometimes described as “peakers”, because they can respond rapidly to peaks in electricity demand. But because of this, they are typically not used very much – some OCGTs in the NEM run at full load for just a few hours a year.

Their thermal efficiency – the proportion of energy from combustion that is converted to electricity – is relatively low, at around 30%. This also means their emissions intensity is relatively high, at 580-670g per kWh.

A second type of gas power station is combined-cycle gas turbines (CCGTs). These power stations effectively recover extra energy from the exhaust stream of an OCGT turbine. This makes them more efficient than OCGTs, typically recovering 50% of the energy from the gas. As a result, their emissions intensity is lower, at roughly 400g per kWh.

One downside, however, is that CCGT technology is less flexible. It cannot stop and start as easily as an OCGT. Hence it tends to run for more of the time, operating more as a source of “baseload” power than as a response to peaks in demand.

Gas generators in the National Electricity Market (NEM) plotted by age and emissions intensity. The size of the markers indicates installed capacity, and the colour indicates technology type. Most installed capacity is flexible OCGT, which typically doesn’t use much gas over the course of a year.

As this chart shows, the efficiency of Australia’s gas power stations depends more on their technology than their age. CCGTs are more efficient. OCGTs are less efficient but more flexible, and typically use less gas overall because they are switched on more sparingly. OCGTs are also better suited to load-following and balancing renewable energy production and providing capacity to the market.

Burning questions

This is not necessarily a question of persisting with one type of gas-fired power station over the other. But it is important to think carefully about how we burn our gas as well as how much of it we burn. We also need to think about how that will help us meet our other energy objectives such as reducing greenhouse emissions and integrating more renewables into the grid.

Using more efficient technologies where possible makes sense. Several old and more inefficient plants are currently being used instead of newer, more efficient ones. Torrens Island and the newer Pelican Point in South Australia are a good example.

Pelican Point is a CCGT that is running considerably below its nominal capacity, while Torrens Island is running at high rates. While the decisions on operation of these plants are commercial and made by private companies, the same gas consumed by Torrens Island could be much more efficiently used by Pelican Point. A unit of gas burned at Pelican Point could theoretically deliver around 50% more energy than the same unit of gas burned at Torrens.

Torrens Island power station: less efficient, but more switched on. Adam Trevorrow/Wikimedia Commons

Part of the reason for this situation is that different companies own the plants. Engie has cut capacity at Pelican Point in response to high gas prices, whereas AGL has opted to keep Torrens Island running at full steam.

This highlights the difficulty, in a privatised market, of ensuring that power is drawn preferentially from the most efficient facilities. Solutions such as managed closures or forced divestment are politically unpalatable. The much-discussed “emissions intensity scheme” would theoretically help push the market in the right direction.

What about the competition?

Many of the services and capabilities that gas turbines provide are also available from other technologies. Flexibility, dispatchability and capacity (as well as other services such as inertia and frequency control) can be provided by storage, other renewable technologies and the cheapest – demand-side management.

Some of these technologies include concentrated solar thermal, battery storage and pumped hydro, which Turnbull also mentioned in favourable terms in his Press Club address.

Indeed, some of these technologies may be able to outcompete traditional sources of capacity like OCGTs.

Whatever the case, the role of gas will need to be carefully considered, and its use will necessarily be limited. In the longer term, the need to increase gas supply is far from certain.

Dylan McConnell has received funding from the AEMC's Consumer Advocacy Panel and Energy Consumers Australia.

UK academics say introduction of herpes virus could also cause ‘catastrophic ecosystem crashes’ in Australia

Scientists in Britain have raised concerns about Australia’s $15m plan to release a herpes virus in the nation’s largest river system to eradicate carp, saying it poses a serious risk to global food security, could cause “catastrophic ecosystem crashes” in Australia, and is unlikely to control carp numbers long term.

In a letter published in the Nature Ecology and Evolution journal this week, University of East Anglia researchers Dr Jackie Lighten and Prof Cock van Oosterhout say the “irreversible high-risk proposal” could have “serious ecological, environmental, and economic ramifications.”

Continue reading...

It’s worth asking who exactly would benefit from Andrea Leadsom’s suggestion that farmers should replace workers with robots (Farmers deliver stark warning over access to EU seasonal workers, 22 February; Letters, 23 February). Not the farmers, who would lose the freedom to exploit their workers while any cost savings associated with the robots would be swallowed up by competition and the supermarkets’ hold over the supply chains. Not the workers, who would lose their jobs, with nothing similar to go to. Not consumers, who would remain at the mercy of the supermarkets’ cynical “price wars”. Ah, I’ve got it: it must be the bankers, who have lent the farmers the money to buy the robots. The secretary of state for the environment, food and rural affairs used to work in banking, I believe.
Richard Middleton
Castle Douglas, Dumfries and Galloway

• Join the debate – email guardian.letters@theguardian.com

Continue reading...

Bumblebees can learn how to manoeuvre a ball by watching others carry out the task, researchers from Queen Mary University of London have discovered. Bees have already been shown to be able to learn how to pull on strings, push caps and even rotate a lever to access food. The Queen Mary study shows that bees are better at problem-solving than was previously thought

Continue reading...

National eNews - Time to Declare a Climate Emergency: Petition and Canberra Events this Weekend

Macquarie insists it is committed to renewable energy – but critics say it could invest in fossil fuels if its bid succeeds

The Australian investment bank on the verge of buying the UK’s publicly owned Green Investment Bank has launched a Westminster charm offensive after parliamentarians of all parties told Theresa May to halt the £2bn sale.

Green party co-leader Caroline Lucas, the Lib Dems’ Vince Cable and former Tory minister Lord Barker last month warned a sale to Macquarie would put the bank’s green purpose at risk and its most valuable assets, such as large windfarms, could be sold off.

Continue reading...

A new report says that using wood pellets to generate low-carbon electricity is a highly flawed policy.

The salt flats in Salar de Uyuni, Bolivia, are the largest in the world and contain 50-70% of the world’’s lithium reserves

Continue reading...

Is there a conservative case for climate change? Former Republican Congressman Bob Inglis believes so.

Protesters have been blocking construction of the pipeline for months, and maintain that they will continue to fight despite the eviction.

A world-first study has been conducted that tracks wild dolphins off the coast of New Zealand.