Monthly Archives for November 2017
What’s the net cost of using renewables to hit Australia’s climate target? Nothing
Andrew Blakers, Australian National University; Bin Lu, Australian National University, and Matthew Stocks, Australian National University
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.
Read more: Want energy storage? Here are 22,000 sites for pumped hydro across Australia
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.
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.
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.
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.
Read more: Will the National Energy Guarantee hit pause on renewables?
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.
Since 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.
Mexico: New Ocean Reserve
The link below is to an article reporting on the creation of a new vast ocean reserve by Mexico in the Pacific Ocean.
For more visit:
USA: Colorado – Rocky Mountain National Park
New research suggests common herbicides are linked to antibiotic resistance
Antibiotics are losing their ability to kill bacteria.
One of the main reasons for the rise in antibiotic resistance is the improper use of antibiotics, but our latest research shows that the ingredients in commonly-used weed killers like Round-up and Kamba can also cause bacteria to become less susceptible to antibiotics.
Herbicides induce gene activity
Already, about 700,000 deaths are attributable each year to infections by drug-resistant bacteria. A recent report projected that by 2050, 10 million people a year will die from previously treatable bacterial infections, with a cumulative cost to the world economy of $US100 trillion.
The bacteria we study are potential human pathogens. Seventy years ago pathogens were uniformly susceptible to antibiotics used in medicine and agriculture. That has changed. Now some are resistant to all but one or two remaining antibiotics. Some strains are resistant to all.
Read more: Drug resistance: how we keep track of whether antibiotics are being used responsibly
When bacteria were exposed to commercial herbicide formulations based
on 2,4-D, dicamba or glyphosate, the lethal concentration of various antibiotics
changed. Often it took more antibiotic to kill them, but sometimes it took less.
We showed that one effect of the herbicides was to induce certain genes that they all carry, but don’t always use.
These genes are part of the so-called “adaptive response”. The main elements of this response are proteins that “pump” toxins out of the cell, keeping intracellular concentrations sublethal. We knew this because the addition of a chemical inhibitor of the pumps eliminated the protective effect of the herbicide.
In our latest work, we tested this by using gene “knockout” bacteria, which had been engineered to lose just one pump gene. We found that most of the effect of the herbicide was explained by these pumps.
Reduced antibiotic use may not fix the problem
For decades we have put our faith in inventing new antibiotics above the wisdom
of preserving the effectiveness of existing ones. We have applied the same invention incentives to the commercialisation of antibiotics as those used with mobile phones. Those incentives maximise the rate of product sales. They have saturated the market with phones, and they saturate the earth with antibiotic resistant bacteria.
Improper use of antibiotics is a powerful driver of the widespread resistance.
Knowing this naturally leads to the hypothesis that proper and lower use will make the world right again. Unfortunately, the science is not fully on the side of that hypothesis.
Studies following rates of resistance do generally find a decrease in resistance to specific drugs when their use is banned or decreased. However, the effect is not a restoration of a pre-antibiotic susceptibility, characterised by multi-year effectiveness of the antibiotic. Instead, resistance returns rapidly when the drug is used again.
This tells us that once resistance has stablised in populations of bacteria, suspended use may change the ratio of resistant to susceptible but it does not eliminate resistant types. Very small numbers of resistant bacteria can undermine the antibiotic when it is used again.
Herbicides and other pollutants mimic antibiotics
What keeps these resistant minorities around? Recall that bacteria are very
small, but there are lots of them; you carry 100 trillion of them. They are also found deep underground to high up in the atmosphere.
Because antibiotics are so powerful, they eliminate bacteria that are susceptible and leave the few resistant ones to repopulate. Having done so, we now have lots of bacteria, and lots of resistance genes, to get rid of, and that takes a lot of time.
As our work suggests, the story is even more complicated. We are inclined to think of antibiotics as medicine and agrichemicals, hand soaps, bug sprays and preservatives as different. Bacteria don’t do this. To them, they are all toxic.
Some are really toxic (antibiotics) and some not so much (herbicides). Bacteria are among the longest lived organisms on earth. Nearly four billion years of survival has taught them how to deal with toxins.
Pesticides as antibiotic vaccines
Our hypothesis is that herbicides immunise the bacteria from more toxic
toxins like antibiotics. Since all bacteria have these protections, the use of widely used products to which they are exposed is particularly problematic. So these products, among others, might keep bacteria ready for antibiotics whether or not we are using them.
We found that both the purified active ingredients and potential inert ingredients in weed killers caused a change in antibiotic response. Those inert ingredients are also found in processed foods and common household products. Resistance was caused below legally allowed food concentrations.
What does this all mean? Well for starters we may have to think more carefully about how to regulate chemical commerce. With approximately eight million manufactured chemicals in commerce, 140,000 new since 1950, and limited knowledge of their combination effects and breakdown products, this won’t be easy.
But neither is it easy to watch someone die from an infection we lost the power to cure.
Jack Heinemann, Professor of Molecular Biology and Genetics
This article was originally published on The Conversation. Read the original article.
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