Archive for the ‘wind power’ Category
Canto: So what’s the latest on SA’s statewide blackout of September 28 last year, who’s to blame, who’s blaming who, and what solutions are in the offing, if any?
Jacinta: Well the preliminary report on the NEM, which we’ve been reading and writing about, has a few things to say about this, and they’re based on the findings of the Australian Energy Market Operator (AEMO) in its own preliminary report.
Canto: He said she said.
Jacinta: Well maybe sort of. So the SA blackout is presented as a case study. Here in SA we have a very high proportion of VRE (variable renewable energy) generation – one of the highest in the world. Our peak demand as a region is 3300 MW, and our supply capacity is almost 2900 MW of gas, almost 1600 MW of wind, and 700 MW of installed solar. We’re connected to the rest of the NEM by two interconnectors, an AC connector with a capacity of 600-650 MW, and a DC connector with a capacity of 220 MW. With electricity demand here declining, or at least not growing, synchronous generation and supply have reduced, with a resultant reduction in system inertia.
Canto: I presume by system inertia you mean the tendency for a machine, a vehicle, or a generator, whatever, a system to keep going once the power’s switched off. Like the QE2 has a lot of system inertia.
Jacinta: Right, but it’s a particularly important term in reference to power generation. There are some neat explanations of this online, but I’ll give a summary here. Coal-fired power stations work through the burning of coal which generates steam to turn a turbine, putting energy into the grid, and being massive, it has a lot of spinning inertia. Slow to fire up, slow to wind down. Solar, though, doesn’t work that way. It has no spinning or even moving parts. When the sun’s off, it’s off, but when it’s on it’s on. There’s really no inertia at all in a conventional solar PV system.
Canto: And wind? That’s the principal renewable energy here.
Jacinta: Yes that has inertia, certainly, but it’s variable and not as significant as perhaps it could be. So anyway on the morning of the blackout weather forecasts were grim, but not enough for AEMO to put out alerts for a ‘credible contingency event’. As it turned out there were at least seven tornadoes in the north of the state that day, as well as numerous lightning strikes and high winds which caused structural damage to transmission lines. At blackout time electricity demand in the state was a little over 1800 MW, with nearly half of it being supplied by wind farms, and of the rest about a third came from gas-fired generators, and the other 600 or so megawatts came through the interconnectors from Victoria. The main Heywood connector was approaching its operating limit. Short circuits to the transmission lines, caused by lightning, were the probable proximal cause of the blackout. Thirteen wind farms were in operation at the time, and eleven of them experienced ‘voltage dips’. What happens in these circumstances is that ‘fault ride-though’ responses are invoked. However, nine of the eleven farms had a lower pre-set limit for the ride-through response to proceed, and after a number of dips those nine wind farms cut their connection. The other two had higher pre-set limits and continued operation.
Canto: Ahh, so those preset limits were set too low?
Jacinta: Maybe – that’s one for further investigation. So the lack of generation from the wind farms caused an overload on the Heywood interconnector, and it was disconnected as per protection systems, resulting in frequency failure on the grid, and blackness fell upon all the land.
Canto: Right, so how did things get restarted? What’s the normal procedure?
Jacinta: Well, there’s this contracted service, called the System Restart Ancillary Service, which in SA is contracted to two major electricity generators (unnamed in the report), who can supposedly restart regardless of the grid situation, and provide power to the transmission network, but these servers failed for unexplained reasons, and power was finally restored through the Heywood interconnector together with the Torrens Island power station.
Canto: Okay, so now the fallout. How could things have been done differently?
Jacinta: Some near-term fixes have been implemented already. Firstly, having to do with frequency rates which I won’t go into here, and secondly in relation to wind farms. Five of them have made changes to their fault ride-through settings, and AEMO is looking at this issue for wind farms across the NEM. The Australian Energy Regulator, another bureaucratic body, will have completed a full analysis of the blackout by early next year to determine if there were any breaches of regulations. Obviously it’ll be looking at the conduct of AEMO throughout, as well as that of the transmission operator, ElectaNet. It’ll also look at these fault ride-though settings of wind farms and the failures of the System Restart Ancillary Service. It all sounds as if everything’s being done that can be done, but the major problem is that grid security as it stands can only be provided by large generators. The report again mentions gas-fired generators as the best solution, at least in the short to medium term.
Canto: So, as the grid, and the general provision of electricity, undergo these transformations, we’ll no doubt experience a few more of these hopefully minor setbacks, which we can learn from as we develop security for a more diverse but more integrated system…
Jacinta: Greater integration might require less squabbling about the future of energy. I can’t see that happening in the near future, unfortunately.
Australia’s Chief Scientist, Alan Finkel, who also happens to be a regular columnist for Cosmos, Australia’s premier science magazine, of which I’m a regular reader, has released his panel’s preliminary report on our national electricity market (NEM), and it has naturally received criticism from within the ranks of Australia’s conservative government, which is under pressure from its most conservative elements, led by Tony Abbott amongst others, who are implacably opposed to renewable energy.
The report confirms that the NEM is experiencing declining demand due to a range of factors, such as the development of new technologies, improved energy efficiency and a decline in industrial energy consumption. It makes a fairly reasonable assumption, but one unwelcome to many conservatives, that our electricity market is experiencing an unprecedented and irreversible phase of transition, and that this transition should be managed appropriately.
The NEM has been in operation for over 20 years, and the recent blackout here in South Australia (late September 2016) was its first real crisis. The issue as identified in the report is that variable renewable energy (VRE) sources are entering and complicating the market, which heretofore has been based on the synchronous generation of AC electricity at a standard system frequency. VRE generation is multiform and intermittent, and as such doesn’t sit well with the traditional system.
There are a number of other complicating issues. Improvements in building design and greater public awareness regarding emissions reduction have led to a decrease in overall energy consumption, while high peak demand on occasion remains a problem. Also the cost of electricity for the consumer has risen sharply in recent years, largely due to network investment (poles and wires). It’s expected that prices will continue to climb due to the closure of coal-fired power stations and the rising cost of gas. Interestingly, the report promotes gas as a vital energy source for this transitional period. It expresses concern about our overseas sales of gas, our low exploration rates, and negative attitudes to the fuel from certain states and territories. Rooftop solar systems, numbering more than 1.5 million, have further complicated the market, as the Australian Energy Market Operator (AEMO) understandably finds it difficult to measure their impact. System integration, which takes solar and wind energy system contributions into account, is clearly key to a successful NEM into the future.
The report also stresses Australia’s commitment to emissions reductions of 26-28% by 2030. It points out that business investors are turning away from fossil fuels, or what they call ’emission intensive power stations’, and financial institutions are also reluctant to back such investments. Given these clear signals, the report argues that a nationally integrated approach to a system which encourages and plans for a market for renewables is essential. This is clearly not what a backward-looking conservative government wants to hear.
So the report describes an ‘energy trilemma’: provision of high level energy security and reliability; affordable energy services for all; reduced emissions. More succinctly – security, affordability and the environment.
In its first chapter, the report looks at new technology. The costs of zero-emission wind turbines and solar PVs are falling, and this will maintain their appeal at least in the short term. Other such technologies, e.g. ‘concentrated solar thermal, geothermal, ocean, wave and tidal, and low emission electricity generation technologies such as biomass combustion and coal or gas-fired generation with carbon capture and storage’ (p13), are mentioned as likely technologies of the future, but the report largely focuses on wind and solar PV in terms of VRE generation. The effect of this technology, especially in the case of rooftop solar, is that consumers are engaging with the market in new ways. The penetration of rooftop solar in Australia is already the highest in the world, though most of our PV systems have low capacity. Battery storage systems, a developing technology which is seeing cost decreases, will surely be an attractive proposition for future solar PV purchasers. Electric vehicles haven’t really taken off yet in Australia, but they are making an impact in Europe, and the AEMO has projected that 10% of cars will be electric by 2030, presenting another challenge to an electricity system based largely on the fossil fuels such vehicles are designed to do without.
The management of these new and variable technologies and generators may involve the evolution of micro-grids as local resources become aggregated. Distributed, two-way energy systems are the likely way of the future, and an Electricity Network Transformation Roadmap has been developed by CSIRO and the Energy Networks Association to help anticipate and manage these changes.
In chapter 2 the report focuses on consumers, who are becoming increasingly active in the electricity market, which was formerly very much a one way system – you take your electricity from the national grid, you pay your quarterly bill. With distributed systems on the rise, consumers are becoming traders and investors in new forms of generation. The most obvious change is with rooftop PV. The national investment in these systems has amounted to several million dollars, with the expectation that individual households will be generating electricity more cleanly, more efficiently, and also more cheaply, notwithstanding the traditional electricity grid. Developments in battery storage and other technologies will inevitably lead to consumers moving off-grid, likely creating financial stress for those who remain. The possibilities for developing micro-grids to reduce costs will further complicate this evolving situation. Digital (smart) metering and new energy management software empower consumers to control usage. And while this is currently occurring mostly at the individual level, industrial consumers will also be keen to curb usage, creating added pressure for a more flexible and diverse two-way market. The report emphasises that the focus should shift more towards demand management in terms of grid security. One of the obvious problems from the point of view of consumers is that those on low incomes, or renters, who have little capacity to move off-grid (or desire in the case of passive users), may bear the burden of grid maintenance costs at increasing rates.
Chapter 3 deals with emissions. In reference to the Paris Agreement of 2015, which has been ratified by Australia, the report makes this comment which has been picked up by the media:
While the electricity sector must play an important role in reducing emissions, current policy settings do not provide a clear pathway to the level of reduction required to meet Australia’s Paris commitments.
The current Renewable Energy Target does not go beyond 2020 and national policy vis-à-vis emissions extends only to 2030, causing uncertainty for investors in an already volatile market. Clearly the report is being critical of government here as it has already argued for the primary role of government in developing policy settings to provide clarity for investment. The report also makes suggestions about shifting from coal to gas to reduce emissions at least in the short term. The report discussed three emissions reduction strategies assessed by AEMO and AEMC (Australian Energy Market Commission): an emissions intensity scheme, an extended large-scale renewable energy target, and the regulated closure of fossil-fuelled power stations. The first strategy is basically a carbon credits scheme, which was assessed as being the least costly and impactful, while an extended RET would provide greater policy stability for non-synchronous generation, so adding pressure to the existing grid system. Closure of coal-fired power stations would reduce low-cost supply in the short to medium term. Base load supply would be problematic in that scenario, so management of closures would be the key issue.
Chapter 4 looks at how VRE might be integrated into the system. It gets a bit technical here, but the issues are clear enough – VRE will be an increasing part of the energy mix, considerably so if Australia’s Large-scale renewable energy target is to be met, along with our international commitment vis-a-vis the Paris Agreement. However, VRE cannot provide spinning inertia or frequency control, according to the report. Basically this means that they cannot provide base load power, at a time when coal-fired power stations are closing down (nine have closed since 2012) and eastern states gas is being largely exported. The Hazelwood brown coal power station, Australia’s largest, and one of the most carbon intensive power stations in the world, will cease operation by April next year.
The difficulty with non-synchronous, distributed, intermittent and variable energy generation (e.g. wind and solar PV) is that these terms seem to be euphemisms for ‘not effing reliable’ in terms of base load, a problem currently being encountered in South Australia and likely to spread to other regions. The report identifies frequency control as a high priority challenge.
Frequency is a measure of the instantaneous balance of power supply and demand. To avoid damage to or failure of the power system the frequency may only deviate within a narrow range below or above 50 Hertz, as prescribed in the frequency operating standards for the NEM.
It’s likely that this narrow range of frequency proved a problem for South Australia when it suffered a blackout in September. I’ll look at what the report has to say about that blackout next time.
Jacinta: So the problem is, or was, that the whole state of South Australia was left without power for a long period of time – more than 24 hours in some places, it varied between regions. This affected some 1.7 million people, endangering lives in some instances.
Canto: And how did it come to be a problem? First because of storm conditions, particularly north of Adelaide, described as unprecedented. This might be seen as the proximate cause, with many describing the ultimate cause as anthropogenic global warming, which will see conditions such as these arising more often.
Jacinta: Well another cause, whether proximate or ultimate, might be degraded transmission infrastructure – the big towers. The transmission network, which is operated and managed by ElectraNet, is the long-distance network, carrying power to the distribution network – the poles and wires – which connects homes and businesses. The distribution network is owned and managed by SA Power Networks, which is 51% owned by Cheung Kong Infrastructure/Power Assets (CKI), a Hong Kong Chinese company. But it’s ElecraNet that we need to focus on. It’s apparently owned by a consortium of companies, but the largest share is 46.5%, owned by China’s State Grid Corporation (SGCC), the largest electric utility company in the world. I’ve heard rumours that there were complaints by technicians regarding rusty and poorly-maintained towers, complaints dating back over five years, but I’ve found nothing as yet to confirm those rumours.
Canto: So overseas ownership may feature in answering the question of how this came to be a problem. Another factor might be the interconnectors.
Jacinta: Yes, to be clear, there are two interconnectors between SA and Victoria, with some speculation about a third being built connecting us to NSW, and allowing us to export our renewables-based energy to that state from time to time…
Canto: Can you describe what an interconnector actually is, and how it works? I’ve heard that they actually work as surge protectors, among other things, shutting down the system when it’s overloaded or in crisis.
Jacinta: It connects transmission systems between different states, or different countries, allowing states to import or export power according to differential capabilities at different times, which helps stabilise or standardise the power available to interconnected states or regions. I should point out that SA imports far more power than it exports, so we are reliant on the national electricity grid, as we always have been I think, for regular, stable supply. Apparently, in terms of area, this is the largest electricity grid in the world. In 2013-2014 SA’s import to export ratio was 6 to 1. If you look at the chart on the SA government website, you’ll notice that SA generates less power within its borders than any other state, including Tasmania, which gets most of its power from hydro. But this varies – not long ago, when Tasmanian dams were low, that state was the least productive. The two interconnectors to Victoria are the Heywood interconnector, with a 460MW capacity, and the smaller Murray Link, which was not operational at the time of the storm. An ABC article quotes the SA Premier as saying the interconnector ‘played no role in the blackout’, but the same article quotes Paul Roberts of SA Power Networks: “We believe — and this is only early information — that there may have been some issue with the interconnector but the state’s power system is shut down I think possibly as a protection”. This statement is vague – it tends to contradict the Premier, but it doesn’t say that the interconnector had a direct role in the statewide shut-down.
Canto: Sounds like people are being cagey and defensive right from the start.
Jacinta: Well, of course – avoiding blame here is a big thing, in terms of money as well as reputation. It’s probably being overly naive to assume that nobody really knows whether the shut-down was caused by the interconnector, or whether that shut-down, if caused by the interconnector, was absolutely necessary. But it looks like nobody’s going to admit knowledge.
Canto: So the problem may or may not have been related to the interconnector, but it was definitely caused by a major storm north of Adelaide, which may or may not have been due to anthropogenic global warming, and it caused damage to infrastructure which may or may not have been avoided if that infrastructure was being upgraded effectively by ElectraNet. Sounds like we’re getting nowhere fast.
Jacinta: What about this idea that the state’s relying too much on renewables. What evidence is there about that?
Canto: Well, unsurprisingly, the state’s opposition leaders and their fellow-travellers are lining up to score points out of this event. SA’s conservative party leader Steven Marshall says there should be an investigation into the state’s ‘lack of base-load power generation’, the Prime Minister, Malcolm Turnbull, who now heads a conservative government in spite of having been a long-time advocate of renewables, has ‘rebuked’ state labor governments for having ‘ideological’ renewable energy targets, and the populist MP Nick Xenophon has expressed a rather vague but passionate outrage.
Jacinta: Okay so let’s look first at SA’s lack of base-load power generation. Hasn’t this been a perennial problem for SA? As I’ve already said, we’ve been importing a lot of power from interstate, on a variable basis, really since the year dot. Or since we’ve been able to do so, via the interconnectors.
Canto: Well there’s something of a new mantra among the renewable advocates that the base-load concept is out-dated, but I’d rather not get into that now, I’m really a novice about electricity markets and grids and such. The fact is that SA is running neck-and-neck with Tasmania as the state that produces the least electricity in the nation, though of course SA is a much bigger state. It’s just that now we’re generating more from wind, so we’ve shut off our coal generators. So the argument will be that renewables had nothing to do with the outage, which damaged transmission lines and initiated a shut-down of our only operating interconnector. This would’ve happened regardless of the power source, though there may be questions about the interconnector, and about the maintenance of the transmission lines.
Jacinta: Okay, that’ll do, though I’d like us to discuss the whole topic of renewable energy, in SA and elsewhere, on an ongoing basis in the future. It’s a hot topic, with a lot of people implacably opposed to it, particularly readers of the rather reactionary Australian newspaper, apparently. All very amusing. And perhaps we can educate ourselves a bit more about the National Electricity Market (NEM), the Australian Energy Market Operator (AEMO) and the future of grids and off-grid electricity supply.
For more interesting articles on this issue:
Canto: So we’re tasked with solving the problem or problems in SA’s energy system.
Jacinta: We are? What problem? Or should I say crisis, what crisis?
Canto: That’s a good question Jass, because as you know the first step in finding a solution is to define the problem.
Jacinta: Yes I knew that. So we’re talking about how all the power died for a period of – what, 24 hours or so, statewide here in South Africa.
Canto: South Australia, don’t confuse our international readers. So I’ve heard the crisis framed in a number of different ways. First, in terms of the SA government’s irresponsible, unrealistic go-it-alone pursuit of risky renewable energy. Second, in the more or less opposite terms of other states’ and especially the federal govt’s foot-dragging and negative approach to said energy, leaving SA unsupported. Third, in terms of privatisation – a number of electrical pylons fell down like ninepins in the outback, because, it’s claimed, the private owners are pursuing profits over infrastructure maintenance. And a fourth and most comprehensive framing invokes climate change itself – SA was subjected to an unprecedented weather event likely caused by the emissions our gallant state government is trying to reduce..
Jacinta: And our little Torrens River has been torrenting like the mighty Amazon.
Canto: Yeah right. So with all these and more framings of the problem, it looks like we’ll have to spend a few posts on this issue.
Jacinta: Or a lifetime. But yes let’s try to be thorough. And positive. I thought we might start with the 9-point plan for solutions to complex problems which we found in the enlightening book The origin of feces by Stuart Waltner-Toews, and which was presented in simplified form on the Solutions OK blog.
1. What is the problem situation or issue? How did it come to be a problem?
2. Who are the stakeholders? What do they care about? Where are they coming from (motives, investments)? What are the agreements, discords among them?
3. What are the stories being told by these different stakeholders re their roles and concerns in the problem?
4. What’s our best systematic, scientific understanding of the situation/problem?
5. What’s our best understanding of the social & cultural issues to be addressed?
6. How are 4 & 5 related? How do they constrain or support each other?
7. What are the scenarios and narratives here that people most connect with? On what things can we agree on? What are the power relations between people who agree or disagree? Given these constraints and acknowledgements what do we realistically expect that we can do?
8. What course of action, governance structure and monitoring system will best enable us to implement our plans and move towards our goals?
9. Implement. Monitor. Adjust. Learn. Re-Start.
Canto: Yeah, that’s pretty comprehensive all right, maybe too comprehensive.
Jacinta: No I think it’s a good basis. Take point 1. What’s the problem? That’s easy. The problem is that SA had all its power cut for the best part of a day, and although many are saying this was a one-off, freak event, many others are saying it could happen again and that SA’s the most vulnerable state, it wouldn’t have happened to any other state.
Canto: Though I think our Premier said the exact opposite, it could’ve happened anywhere. Lots of conflicting narratives and opinions. So let’s get started.
Jacinta: Well let me first say that, whatever the cause, we are experiencing extreme weather here for October – rainy and stormy conditions which have certainly never been experienced here in a good long lifetime. And right now we’re got rain and strong wind conditions. There’s been little let-up for some time.
Canto: Interesting – we’re only a few days into October, but the average rainfall for September in Adelaide, since records have been kept, is about 58 millimetres. This year it was over 130 millimetres. October, though, might be the most interesting month for records. Certainly I can’t recall anything like this, and we have flooding in many parts of the state.
Jacinta: So we have extreme weather conditions, and the direct cause of the outage, according to our Premier, was freak weather conditions north of Adelaide, including two tornados which knocked over transmission towers near Melrose. More than 20 transmission lines were damaged. The question being asked, of course, is how could these storms knock out the power for a whole vast state for a long period? What were the back-up arrangements?
Canto: Well the back-up apparently relies on two interconnectors to the east coast. Presumably there must be some arrangement so that when local power isn’t forthcoming, the interconnectors receive a signal to transmit. However, only one was operational at the time of the outage. Now I don’t really understand this interconnector thing and how they work. I’m not clear on why one interconnector was shut down and why the other one didn’t just do the job. Is it just a matter of ‘firing up’ an interconnector and a whole state’s lights come back on? How simple or complex is it?
Jacinta: And what, if anything, has this got to do with renewable energy and the shutting down of the coal power station in Port Augusta?
Canto: We might get to that later. I haven’t been able to find exactly how interconnectors work, and nothing much at all on interconnectors in Australia, but currently in the UK there are four interconnectors, linked to France, the Netherlands, Northern Ireland and the Republic of Ireland, of which the France one is largest, with 2GW capacity. It would be interesting to know the capacity of the two interconnectors linking us to the east, and whether that has any relevance. Anyway, these interconnectors are spruiked as providers of energy security and flexibility, so the more interconnectors the better. Maybe there’s a case for having a third interconnector, so that we’re never, or rarely reduced to having just one to rely on.
Jacinta: So why did we have no power? Why didn’t the interconnector provide it for so long? Or was it the interconnector that provided it, or was it the local system?
Canto: Well there was certainly local work going on from the start, as soon as conditions allowed, to fix local faults, but I can’t find too much info on the role of the interconnector. However, word has just come out that there’ll be a state inquiry into South Australia’s unique situation, so maybe there’s no point in us continuing this conversation.
Jacinta: Wait up, I think it might be fun speculating on and researching the matter, and then comparing our findings with the inquiry.
Canto: Which’ll come out in, what, five years?
Jacinta: An unnecessarily jaded remark. So let’s get stuck into some research, and look for solutions, always keeping in mind that 9-point plan.
There is more global investment in solar power today than there is in fossil fuels. We’re talking about hard-headed investment for profit by business and governments worldwide, not greenies or special interest groups. And another interesting factoid: China today is generating more energy from wind power than the whole of Australia’s energy production. Not to mention the Chinese government’s massive investment in other renewables. That’s info I got from a recent ABC Science Show podcast. Renewable energy really is making inroads, and this is most encouraging for those around the world fighting the damaging environmental effects of mining and fracking in their regions, though it’s clear that such operations are dying hard.
I remember some time ago at a meeting of skeptics (not climate change ‘skeptics’, just regular sciencey anti-quackery, anti-UFO-type skeptics), when I was spruiking the virtues of wind power, so successfully taken up here in South Australia, being told dismissively that it was too expensive to be really viable. However, wind-power only really has establishment costs. Ongoing costs are quite minimal. Furthermore, a research group conducted by the Carnegie Institution for Science’s Global Ecology Department has recently conducted the most wide-ranging expert survey on wind (or any other) energy. Sure, it was a survey of those already heavily invested in wind, but that does make them the experts in the field. Predictions about the cost of wind energy into the future were based on two approachess. First, a projection into the future of falling costs over the past three decades or so – what they call the ‘learning curve’. One would assume those projections would vary from ‘most optimistic’ to ‘most pessimistic’, with consensus somewhere in between. The second approach involved a ‘bottom-up engineering assessment’, looking at the costs of individual turbine components into the future. Science Daily has summarised the findings:
On average, the participants expected wind power costs to continue falling for the next several decades, for three major classes of wind turbines, both onshore and offshore, with prices falling by 24-30% by 2030, and 35-41% by 2050.
Meanwhile governments worldwide are getting on board in a determined effort to drive down the cost of solar. Vox Energy & Environment reports on the US target:
…the US Department of Energy has a program, the SunShot Initiative, devoted entirely to driving down the cost of electricity generated by solar panels — the target is solar power with $1 per watt installed costs by 2020, a 75 percent reduction in costs from 2010.
It’s hard to get the head around the growth of solar energy worldwide since about 2007. It’s been a whirlwind ride, but starting from an extremely low level. And in the US since 2012, large or utility-scale solar has been growing faster than domestic, rooftop solar, and with falling prices and increasing module efficiency, the growth trend in big and small solar should continue well into the future. Yes, there’s government stimulus, but solar is being seen more and more as a sound investment on its own terms. Solar’s steady growth also makes for sound investment against the high volatility of the natural gas market. And this of course is just as relevant for many regions outside the US.
I’ll be taking another look at Australia’s situation, while many of our governments bicker and focus elsewhere, in an upcoming post.