Monday, November 27, 2017

What's the Net Cost of Using Renewables to Hit Australia's Climate Target? Nothing
by Andrew Blakers, Australian National University; Bin Lu, Australian National University, and Matthew Stocks, Australian National University, The Conversation:

Australia can meet its 2030 greenhouse emissions target at zero net cost, according to our analysis of a range of options for the National Electricity Market.

Our modelling shows that renewable energy can help hit Australia’s emissions reduction target of 26-28% below 2005 levels by 2030 effectively for free. This is because the cost of electricity from new-build wind and solar will be cheaper than replacing old fossil fuel generators with new ones.

Currently, Australia is installing about 3 gigawatts (GW) per year of wind and solar photovoltaics (PV). This is fast enough to exceed 50% renewables in the electricity grid by 2030. It’s also fast enough to meet Australia’s entire carbon reduction target, as agreed at the 2015 Paris climate summit.

Encouragingly, the rapidly declining cost of wind and solar PV electricity means that the net cost of meeting the Paris target is roughly zero. This is because electricity from new-build wind and PV will be cheaper than from new-build coal generators; cheaper than existing gas generators; and indeed cheaper than the average wholesale price in the entire National Electricity Market, which is currently A$70-100 per megawatt-hour.

Cheapest option

Electricity from new-build wind in Australia currently costs around A$60 per MWh, while PV power costs about A$70 per MWh.

During the 2020s these prices are likely to fall still further – to below A$50 per MWh, judging by the lower-priced contracts being signed around the world, such as in Abu Dhabi, Mexico, India and Chile.

In our research, published today, we modelled the all-in cost of electricity under three different scenarios:
  • Renewables: replacement of enough old coal generators by renewables to meet Australia’s Paris climate target
  • Gas: premature retirement of most existing coal plant and replacement by new gas generators to meet the Paris target. Note that gas is uncompetitive at current prices, and this scenario would require a large increase in gas use, pushing up prices still further.
  • Status quo: replacement of retiring coal generators with supercritical coal. Note that this scenario fails to meet the Paris target by a wide margin, despite having a similar cost to the renewables scenario described above, even though our modelling uses a low coal power station price.
The chart below shows the all-in cost of electricity in the 2020s under each of the three scenarios, and for three different gas prices: lower, higher, or the same as the current A$8 per gigajoule. As you can see, electricity would cost roughly the same under the renewables scenario as it would under the status quo, regardless of what happens to gas prices.

Levelised cost of electricity (A$ per MWh) for three scenarios and a range of gas prices. Blakers et al.

Balancing a renewable energy grid

The cost of renewables includes both the cost of energy and the cost of balancing the grid to maintain reliability. This balancing act involves using energy storage, stronger interstate high-voltage power lines, and the cost of renewable energy “spillage” on windy, sunny days when the energy stores are full.

The current cost of hourly balancing of the National Electricity Market (NEM) is low because the renewable energy fraction is small. It remains low (less than A$7 per MWh) until the renewable energy fraction rises above three-quarters.

The renewable energy fraction in 2020 will be about one-quarter, which leaves plenty of room for growth before balancing costs become significant.

Cost of hourly balancing of the NEM (A$ per MWh) as a function of renewable energy fraction.

The proposed Snowy 2.0 pumped hydro project would have a power generation capacity of 2GW and energy storage of 350GWh. This could provide half of the new storage capacity required to balance the NEM up to a renewable energy fraction of two-thirds.

The new storage needed over and above Snowy 2.0 is 2GW of power with 12GWh of storage (enough to provide six hours of demand). This could come from a mix of pumped hydro, batteries and demand management.

Stability and reliability

Most of Australia’s fossil fuel generators will reach the end of their technical lifetimes within 20 years. In our “renewables” scenario detailed above, five coal-fired power stations would be retired early, by an average of five years. In contrast, meeting the Paris targets by substituting gas for coal requires 10 coal stations to close early, by an average of 11 years.

Under the renewables scenario, the grid will still be highly reliable. That’s because it will have a diverse mix of generators: PV (26GW), wind (24GW), coal (9GW), gas (5GW), pumped hydro storage (5GW) and existing hydro and bioenergy (8GW). Many of these assets can be used in ways that help to deliver other services that are vital for grid stability, such as spinning reserve and voltage management.

Because a renewable electricity system comprises thousands of small generators spread over a million square kilometres, sudden shocks to the electricity system from generator failure, such as occur regularly with ageing large coal generators, are unlikely.

Neither does cloudy or calm weather cause shocks, because weather is predictable and a given weather system can take several days to move over the Australian continent. Strengthened interstate interconnections (part of the cost of balancing) reduce the impact of transmission failure, which was the prime cause of the 2016 South Australian blackout.

The ConversationSince 2015, Australia has tripled the annual deployment rate of new wind and PV generation capacity. Continuing at this rate until 2030 will let us meet our entire Paris carbon target in the electricity sector, all while replacing retiring coal generators, maintaining high grid stability, and stabilising electricity prices.

Andrew Blakers, Professor of Engineering, Australian National University; Bin Lu, PhD Candidate, Australian National University, and Matthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National University

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

Tuesday, November 14, 2017

Over 15,000 Scientists Just Issued a 'Second Notice' to Humanity. Can We Listen Now?

by Andrea Germanos, staff writer, Common Dreams: 

Reassessing warning issued 25 years ago, the "second notice" to humanity warns of "widespread misery and catastrophic biodiversity loss" unless business-as-usual is upended.


Over 15,000 scientists hailing from more than 180 countries just issued a dire warning to humanity:

"Time is running out" to stop business as usual, as threats from rising greenhouse gases to biodiversity loss are pushing the biosphere to the brink.

The new warning was published Monday in the international journal BioScience, and marks an update to the "World Scientists' Warning to Humanity" issued by nearly 1,700 leading scientists 25 years ago.

The 1992 plea, which said Earth was on track to be "irretrievably mutilated" baring "fundamental change," however, was largely unheeded.

"Some people might be tempted to dismiss this evidence and think we are just being alarmist," said William Ripple, distinguished professor in the College of Forestry at Oregon State University, and lead author of the new warning. "Scientists are in the business of analyzing data and looking at the long-term consequences. Those who signed this second warning aren't just raising a false alarm. They are acknowledging the obvious signs that we are heading down an unsustainable path."

The new statement—a "Second Notice" to humanity—does acknowledge that there have been some positive steps forward, such as the drop in ozone depleters and advancements in reducing hunger since the 1992 warning. But, by and large, humanity has done a horrible job of making progress. In fact, key environmental threats that demanded urgent attention a quarter of a century ago are even worse now.
Among the "especially troubling" trends, they write, are rising greenhouse gas emissions, deforestation, agricultural production, and the sixth mass extinction event underway.

Taking a numerical look at how some of the threats have grown since 1992, the scientists note that there's been a 26.1 percent loss in fresh water available per capita; a 75.3 percent increase in the number of "dead zones";  a 62.1 percent increase in CO2 emissions per year; and 35.5 percent rise in the human population.

"By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperiled biosphere," they write.

Among the steps that could be taken to prevent catastrophe are promoting plant-based diets; reducing wealth inequality, stopping conversions of forests and grasslands; government interventions to rein in biodiversity loss via poaching and illicit trade; and "massively adopting renewable energy sources" while phasing out fossil fuel subsidies.
Taking such actions, they conclude, are necessary to avert "widespread misery and catastrophic biodiversity loss."

"Soon it will be too late to shift course away from our failing trajectory, and time is running out. "

The goal of the paper, said Ripple, is to "ignite a wide-spread public debate about the global environment and climate."