Antinuclear

Australian news, and some related international items

South Australian govt and Australian Energy Market Operator should be promoting energy conservation

Dennis Matthews 1 Mar 17, Excessive emphasis on electricity supply overlooks the important role of demand in keeping the lights on.

In years of drought the South Australian public showed that it is capable of rising to the challenge by conserving water. Thanks to information and incentives from the SA Government the public demonstrated great resilience and resourcefulness.

What applies to water also applies to electricity but the Australian Energy Market Operator (AEMO) is sending the wrong signals (The Advertiser, 1/3/17). Instead of encouraging consumers to conserve electricity AEMO is encouraging business as usual.

As amply demonstrated in the last five months, this is putting SA at the mercy of the electricity industry.

Conserving electricity is as simple as conserving water; in summer, turn up the air-conditioner thermostat by a degree or two, in winter do the opposite.

The SA Government can do its bit by providing information and incentives for electricity conservation measures such as double-glazed windows. This will decrease the demand for air-conditioning in summer and heating in winter.

 

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March 1, 2017 - Posted by | General News

3 Comments »

  1. Comments on the

    FINAL REPORT – SOUTH AUSTRALIAN SEPARATION EVENT, 1 DECEMBER 2016
    Australian Energy Market operator (AEMO)
    1 March 2017

    Dennis Matthews

    INTRODUCTION

    The AEMO report is shockingly (!) written.

    It’s full of jargon and acronyms with no easy way of finding what the acronyms mean. We could be forgiven for thinking that AEMO publications are intended to be read only by industry experts rather than concerned consumers.

    Its charts are frequently unreadable, with minute characters used to label the axes, the axes overcrowded with labels, and five figure labels such as 200.00 where 200 would have sufficed.

    The continual use of the words “incident” and “event” are reminiscent of the nuclear industry’s description of its many serious accidents and failures.

    AEMO has uncovered gross inadequate performance by the electricity industry from electricity transmission to fossil fuel electricity generation to systems needed to maintain the integrity of the overall generation-distribution-transmission system. At no stage is there even a hint that severe penalties should be incurred by those responsible. I suspect, even if there were penalties that these would be recovered through increased prices. Competition is almost totally lacking in the industry.

    At no stage was the cause of the “separation event” (failure of the Heywood interconnector from Victoria to SA) the fault of wind or solar electricity generators, quite the opposite. Wind powered electricity generators contributed 6% to power supply and the interconnector failure led to the shutdown of 2 wind farms in Victoria.

    The following discussion uses the same section notation as the AEMO report.

    1. OVERVIEW

    The failure of a high voltage electricity transmission line in Victoria was the result of “equipment failure”, which turns out to be the same cause of the state-wide blackout of SA in September 2016, namely the breaking of transmission lines and subsequent short-circuit. This short circuiting of the high voltage transmission line in Victoria initiated a series of events resulting in a four hour twenty minute power shortage in SA.

    In the case of the September 2016 blackout AEMO has yet to definitively attribute the cause to short-circuiting of the transmission lines in SA (nobody actually saw the transmission lines towers and lines falling down), which has led some commentators to suggest that maybe this wasn’t the cause. Five months after the SA blackout, AEMO has yet to release its final report.

    Two fossil-fuelled power stations in SA, one at Pelican Point and the other on Torrens Island, failed to perform as AEMO expected. The available Pelican Point power station (one was not even available) failed to provide fast-reponse frequency stabilisation of the power supply and the Torrens Island power station had “software problems” which means we will never know the full story. These failures placed the entire SA electricity network in jeopardy but AEMO is quick to point out that the “non-delivery” of fast-reponse frequency stabilisation “did not have a material impact on the incident”. The fact that SA could have experienced its second state-wide blackout in two months is given very little attention. According to AEMO “The power system was not in a secure operating state after this incident for a period of four hours and twenty minutes.”

    Finally, the system used to synchronise the South Australian and Victorian networks also failed due to a “software issue”. Ironically, the non-synchronous, direct-current (DC), Murraylink interconnector remained in operation throughout the failure of the synchronous alternating current (AC) Heywood interconnector.

    With one exception, AEMO is quick to point out that it “took all reasonable steps” and did all that it was required to do to prevent the failure of the system and to get it working again.

    The fact that the Heywood interconnector was made vulnerable by two AEMO-sanctioned maintenance programs (“planned outages”) in Victoria, receives scant attention.

    2. PRE-EVENT CONDITIONS

    Due to AEMO sanctioned maintenance (“planned outage”) only one of the two Heywood Interconnector connections was in service.

    Due to AEMO sanctioned maintenance only one of two connections to the high power demand (473 MegaWatts) Portland aluminium smelter was in service.

    These two “planned outages” left the system vulnerable.

    According to AEMO, “the system was in a secure operating condition” prior to the Heywood Interconnector failure. Only 6.1% of the power was from wind generators the rest was from coal or gas generators.

    AEMO had determined that no frequency stabilisation services would be needed in the event of the loss of the Heywood interconnector because frequency could be maintained by load shedding.

    3. INITIATING FAULT

    The failure of the Heywood Interconnector started with a “single phase to earth fault” (short circuit) in a Victorian high voltage transmission line. Automatic circuit breakers operated to isolate the rest of the system from the faulty transmission line. This is the equivalent of a household mains power switch “tripping” i.e., turning off. Cars and small electrical equipment tend to use replaceable fuses to protect against electrical faults. Once the fault is remedied, the switch may be turned back on or the fuse replaced.

    The “trip” of the Victorian high voltage transmission line severed the interconnection to SA.

    This in turn led to the disconnection of the Portland smelter from SA and the shutting down in Victoria of the McArthur and Portland wind farms.

    Immediately before the failure 217 MW (MegaWatts) was flowing from Victoria to SA. Immediately after the Victorian transmission line tripped the flow reversed with 480 MW flowing from SA to the Portland smelter but this line was quickly (< 0.5 second) disconnected. By this stage SA wind farms were then contributing about 78 MW (5.5%).

    Loss of supply from Victoria to SA resulted in the frequency of the alternating current (AC) falling below acceptable levels and causing automatic load shedding of 190 MW. There was an additional unexplained load shedding of 40 MW (possibly at the Prominent Hill Mine in SA). Because of the low contribution of wind farms (about 78 MW) the cause of the frequency decrease was a problem of excessive demand rather than excessive supply of wind power.

    Three months after the Heywood Connector failure the operator of the failed high voltage transmission line “has not been able to determine the cause of the break”.

    4. FREQUENCY RESPONSE IN SOUTH AUSTRALIA IMMEDIATELY AFTER ISLANDING

    “Frequency” refers to the frequency in cycles per second (or Hertz, Hz) of the alternating current (AC) which is nominally 50 Hz and needs to be kept within certain limits (49.5 to 50.5 Hz). In addition, the rate of change of frequency (RoCoF) must be kept within certain limits (< 1 Hertz per second, Hz/s)

    “Islanding” refers to a region (such as SA) of the national electricity grid being separated from the rest of the grid.

    Certain services are designated to provide a fast response to correcting problems with the AC frequency. Some 51.7 MW of thermal generation in SA was ready (“enabled”) to provide these fast response frequency control auxiliary services (FCAS). The enabled Pelican Point Power Station responded but not for as long as required. Data for the enabled Torrens Island generating units (power stations) was not available due to a “software fault” on the part of the operator and AEMO was unable to determine whether or not they provided the required service.

    No penalty for failure of the enabled fast response FCAS to provide the required services is mentioned by AEMO, rather AEMO reports, that even if the 51.7 MW of fast response FCAS had been delivered by the enabled generators it would not have prevented the frequency falling below 49 Hz, that the frequency didn’t fall below 57 Hz and that it recovered quickly (within about 11 seconds). AEMO estimates that some 460 MW of fast response FCAS would have been required to prevent the frequency falling below 49 Hz.

    I get the impression that adequate frequency control was more good luck than good management and that SA could easily have experienced much more serious “load-shedding”.

    5. RESTORATION

    Restoration was delayed by problems in synchronising the SA and Victorian networks. Firstly, a remotely controlled switch at the Heywood terminal station in Victoria failed to close properly, then 15 minutes later, the synchronising was delayed for a further 6 minutes due to a “software issue”.

    6. OPERATION OF SA WHEN ISLANDED

    “The shortage of contingency FCAS meant that the power system in SA was not in a secure operating state.”

    All available fast response FCAS was enabled. A footnote points out that the reduced availablity at Pelican Point was due to only one of the two gas turbines being in service.

    Any off line generating units that had the capability of providing fast response FCAS would not have been able to be started on time. This suggests that more generating capacity should have been ready (enabled).

    “The power system was not in a secure operating state for the duration of the event, a period of approximately four hours and twenty minutes.” To manage the shortage of FCAS the largest industrial load (the Olympic Dam Mine at Roxby Downs) was reduced.

    7. CONCLUSIONS

    “Pelican Point Power Station did not provide fast rise (R6) FCAS immediately after the separation event as required.”

    “AGL was unable to provide the high speed data to enable AEMO to analyse delivery of fast rise (R6) FCAS from the Torrens Island generating units.”

    “The power system was not in a secure operating state after this incident for a period of four hours and twenty minutes.”

    “There was a delay in synchronising the Victoria and SA networks, due to a software issue associated with AusNet’s control system.”

    After all the negative comments from State and Federal politicians and the media about renewable energy not providing synchronous generation I find it ironic that this “event” was 99% related to synchronous thermal (coal and gas) electricity generators. Ill-informed comment from politicians and journalists exposes the subjective ideological underpinning of these commentators.

    AUTHORS FOOTNOTE

    I have no formal qualifications as an electrician or electrical engineer. My formal qualifications are in the area of physical chemistry, specializing in electrochemistry. I would be very grateful for any assistance in interpreting the material produced by AEMO and for pointing out any technical errors that I have made in this document.

    Comment by Dennis Matthews | March 2, 2017 | Reply

  2. The Editor
    The Advertiser

    Some interesting ideas have been floated about possible solutions to SA’s dysfunctional electricity industry (The Advertiser, 3/3/17), but none of them can come into effect this summer and probably not this coming winter.

    If people really care about SA’s reputation then they need to take immediate (i.e., now) action.

    The easiest, most useful, and instantaneous, action that people and businesses can take is to turn their air-conditioning thermostats up a couple of degrees. The discomfort will be minimal but the electricity saving may mean the difference between a blackout and keeping the refrigerators on.

    Dennis Matthews

    Comment by Dennis Matthews | March 3, 2017 | Reply

  3. The Editor
    The Advertiser

    The proposal to renationalise the electricity industry in SA (The Advertiser, 3/3/17) is probably the only sure way to return SA to a secure reliable electricity supply.

    Certainly, this will cost a lot of money but the state is already bleeding millions to overseas concerns through our privatised electricity industry.

    What we don’t want to see is more political point scoring, such as “We had to go ahead with the international nuclear waste dump because the Liberals sold our electricity industry and there is no other way to get the money to buy it back.”

    Let’s have reliable, secure, affordable clean energy AND a safe state.

    Let’s make sure that what we had a generation ago we pass on in better condition to the next generation of South Australians. I believe that’s called progress.

    Dennis Matthews

    Comment by Dennis Matthews | March 3, 2017 | Reply


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