We Must Ensure Our Electrical Grid is Fit for Purpose by James Fleay

We Must Ensure Our Electrical Grid is Fit for Purpose by James Fleay

 

“Most human beings have an almost infinite capacity for taking things for granted”.

  • Aldous Huxley

“Taken in its entirety, the grid is a machine, the most complex machine ever made. The National Academy of Engineering called it the greatest engineering achievement of the 20th century. It represents the largest industrial investment in history.”

  • Phillip Schewe, The Grid: A Journey Through the Heart of Our Electrified World

Over the course of the 20th century, nations with advanced economies gradually built electrical networks to transmit electrical power long distances, from power stations to large load centres and to then distribute it within those load centres (T&D). Developing nations are now busily building out their own electrical infrastructure.

But why did electricity become the ubiquitous form of energy? After all, gas lighting was common in the early 20th century as were kerosene fridges and wood stoves and water heaters. Industry made extensive use of centralised steam-driven rotating energy. Why has lighting and refrigeration been completely converted to electricity and why is cooking heat, water heating and space heating dominated by electrical appliances? And why does industry rely on electrical motors for over 99% of mechanical drive applications?

Other than a handful of visionaries, it was not obvious to people that electricity was that useful to begin with. Kerosene lanterns served as admirable sources of light and, unlike the new electric light technology, did not require expensive cables be retrofitted to homes and businesses. But then the electric motor was developed. Over time, inventors and engineers realised that the same cable could be used to provide power to run fans, compressors, heating elements and dozens of other devices. Many challenges had to be overcome to make this invisible, silent, and potentially dangerous source of energy safe for widespread adoption. Advances in transformers, insulation technologies, protective relaying and measurement were all necessary. Innumerable power and control devices located throughout the network and working in perfect coordination was a crucial precondition for a reliable grid and this is still true today. A second precondition was prudent investment in power system redundancy.

Much later, and only because electricity was so widely available, computer scientists and engineers realised that microelectronic circuits and later computers could use this source of convenient and reliable energy. The preceding 50 years of development in electrical power engineering enabled the development, then boom in industrial and personal electronics which are now as ubiquitous as the electricity network which spawned them.

And the spread of electrification is not over, in fact it is likely entering another growth phase which will dwarf the demand increases seen in advanced economies over the last 30 years. As governments and citizens around the world grow more concerned about the impact of CO2 emissions on our planet and changing geopolitical realities heighten the importance of energy security or sovereignty, more of our transport sector will transition from using fossil fuels to electric vehicles (EVs) or hydrogen fuel cell vehicles (FCVs). The hydrogen for FCVs does not exist in nature in useable form (unlike fossil fuels) but is released from water using electrical power. Lots and lots of electrical power. Industry is also looking at ways of using electricity or hydrogen to replace coal in traditional blast furnaces used for steel manufacturing & increase the efficacy of recycling to reclaim raw materials.

Regardless of which automotive technology is taken up in greater numbers, our society’s demand for electricity is set to soar.

This sprawling and complex network does not operate autonomously – in fact it is rather fragile and requires constant intervention by network operators. Importantly, the control of the electrical network is centralised because historically, this has proven to be the only viable operating approach. Every second of every day, network operators, demand forecasters and power station operators need to ensure that the supply of electricity exactly matches the demand and that the network of power lines can get the electricity to where it is needed without becoming overloaded. Failure to do so results in power blackouts which, mercifully, are exceedingly rare in Australia. One reason for this is the disciplined and well-trained personnel that operate and maintain our electrical infrastructure and I feel lucky to have observed and worked alongside these men and women in a professional capacity.

So, we understand that operating the traditional electrical grid, with large, centralised power stations and one-way power flows is already complex. We also know that our demand for electricity, and so out reliance on it, is set to increase as EVs and FCVs replace cars, trucks and buses that run on petrol and diesel. And the recent blackouts in Texas have reminded us that modern societies like Australia rely on electricity to a degree that is only apparent when it is taken away from us.

And despite all this, AEMO and various state government policies are going to dangerously compromise network reliability by making electrical grid operations even more complex. It is not yet clear how generation redundancy will be impacted by increasing solar and wind but as it becomes less financially viable to leave coal generators supplying the grid at low capacity factor, privately-owned generators will be forced to retire these units instead of suffering ongoing losses.

Whilst our legacy coal-fired power fleet have become reviled for their outsized CO2 emissions, they continue to provide essential operational flexibility to network operators. Power station operators are learning to ramp their generators up and down with a regularity that were never anticipated when they were designed and built. Combined with open cycle gas turbines (OCGT), this gives grid operators the ability to compensate for rapid swings in power output from wind and solar generation or when another baseload generator trips. They also provide non-energy grid services which can only be provided by thermal generators such as frequency control and spinning reserve that allow network operators to shore-up the robustness of the grid.

Many of these power stations are approaching the end of their operating lives and are being operated in a fashion that is making them less reliable overtime. What will replace them?

There is much talk of battery storage, but this excitement is sadly misplaced. The mathematics of providing grid-scale back-up of intermittent renewables across hours, days or weeks for an advanced industrial society quickly establishes that hope should be abandoned when it comes to grid-scale batteries.

Note: Grid scale batteries such as Hornsdale are very effective for fast response services and will be essential as renewable energy becomes more widespread. This does not mean they are suitable for grid scale storage which spruikers claim can be combined with intermittent renewables to replace baseload thermal generators. These are very different applications which operate on very different scales.

Whilst expensive, pumped storage is more readily scalable than batteries and, providing our dry nation receives consistent annual rainfall, projects like Snowy 2.0 will increase our ability to store modest amounts of renewable energy, round trip losses notwithstanding. Unfortunately, we don’t have the climate or geography of Norway, Sweden or Canada so whilst pumped hydro could be part of the energy-storage mix, it will never be the silver bullet that can replace thermal generation.

What about hydrogen storage? Despite having poorer round-trip efficiency than batteries and despite the need for vast amounts of ultra-pure water and despite the difficulties of constant operating swings of electrolysis units to match the changing output of wind and solar (aka yo-yo operation) and despite the difficulty of economically sourcing enough platinum, ruthenium and iridium to make the cathodes and anodes (some of the rarest and most expensive elements)…hydrogen (actually ammonia) does have some promise. But let’s be realistic. All the worlds industrial capacity to economically scale ammonia storage and propulsion technologies will not be enough to displace fossil fuels in transport applications till the end of the century. And then it might be considered a serious option for grid-scale energy storage…we need to replace our current generation fleet at least once, maybe twice, during that time.

What about demand response? International experience indicates that the uptake is very minimal and doesn’t provide good value for money. Similarly, household solar generation and storage is not only the most expensive way to produce electricity, it also creates the most waste and creates enormous headaches for distribution networks which require substantial upgrades to reverse the direction of power flow twice a day. As the subsidies for home PV systems gradually wind down before disappearing in 2030, only crippling energy prices would prompt anyone to replace these systems at their own cost and it is likely that by mid-century, home PV systems will be a thing of the past.

Note: The winding down of subsidies from the small-scale renewable energy scheme commenced in 2017 and decreases each year until 2030 when the scheme ends.

We are already seeing some evidence of the grid becoming more difficult to manage. AEMO uses two market facilities to give network operators access to certain attributes that can only be provided by power stations with a rotating generator (coal, gas, hydro, nuclear). These are called RERT (reliability and emergency reserve trader) and FCAS (frequency control ancillary services). Previously there was little requirement for these services, or in the case or RERT, none at all. But that has changed in recent years as shown in the chart below.

There is no single reason for the escalating RERT and FCAS costs, however accommodating the increasing penetration of intermittent renewable energy is known to be a major contributor to the increased difficulty of grid operations implicit in the trends above. Ailing reliability of legacy coal-fired power stations is another factor.

Finally, the traditional grid has one advantage over the “grid of the future” – it’s already built and operational. The cost of adding new transmission lines, upgrading existing transmission and distribution capacity and re-configuring the way these systems work so they can accommodate constant, large and fast changes in power flows will cost a bomb. Recent American and European experience points to the difficulty of permitting new transmission lines and this is before one considers the enormous cost – costs that are rarely acknowledged in public discussions when spruikers talk about growing penetration of intermittent wind and solar and “the grid of the future”.

Conclusion

Under the AEMO ISP, our electrical grid will soon be expected to manage patchy grid-scale storage, increasing reverse power flows or “vanishing loads” from behind-the-meter PV systems, dozens of infrequently operated OCGTs, unreliable demand response markets… all whilst trying to integrate more intermittent renewable energy. This will compromise system reliability and place more strain on our electrical grid and the men and women who operate it 24/7/365. I’m afraid that losing our legacy coal-fired power stations will tip them (and us) into widespread blackouts more frequently than what we are accustomed to.

The electrical grid of an advanced industrial nation needs to be as simple and robust as possible. It also needs an “anchor tenant”. Nuclear energy is the only technology that can replace coal-fired power stations and allow us to integrate more renewable energy whilst maintaining the reliability that is essential. Anyone who tells you that we don’t need a dispatchable baseload “anchor tenant” to backstop our electrical grid is expecting our society to take a leap of faith which has a high probability of ending badly.

13 Comments
  • Paul Kristensen
    Posted at 13:16h, 23 March Reply

    Everyone needs to forward this excellent article to their local political representative(s).

    • James Fleay
      Posted at 13:12h, 24 March Reply

      Hi Paul,
      Thanks for your feedback – we can only hope that our representatives start to take note.
      Regards
      James Fleay

    • Rob Parker
      Posted at 13:40h, 24 March Reply

      Thanks Paul, We will take this on board. Please note this post has been sent to a large group of local, state and federal government politicians

  • Geoff Russell
    Posted at 13:56h, 23 March Reply

    Good article and wonderful cartoon? Who did the cartoon? I can’t read the signature block.

    I fear however that the article will resonate most with people who already understand the background, while not
    adequately explaining things to people who don’t. For example the interaction of frequency and “spinning reserve” isn’t explained but is
    crucial for understanding the increasing fragility of the grid. As we speak, the 4 stationary condensers are being installed in SA to (touch
    wood) prevent another 2016 state wide blackout. I think once people understand the concept of inertia and it’s impact on frequency
    in the face of load changes, the rest is obvious. A second stand-alone piece on that concept would fill a hole!

    • James Fleay
      Posted at 13:33h, 24 March Reply

      Hi Geoff,
      Feel free to get my contact details off Rob Parker if you’d like me to put you in contact with Vicki. She is a wonderful artist and a pleasure to work with – she is also a very good sounding board.
      Your comment on the technical aspects of rotating mass (inertia) and how this is irreplaceable when it comes to system strength and voltage and frequency control is very true. There is some good work being done by operators and technology providers of IBRs (inverter based resources in AEMO parlance) and it is encouraging that solar and wind operators are actively trying to find ways of contributing to system strength…however there are limitations and no analysis I’ve read suggests that they can entirely replace the inertia of large rotating generators.
      A good friend of mine is a senior network operations engineer and I’ll discuss with him a future article that goes into more detail.
      For the best power system analogies from a true power system expert, I don’t think you can go past Bruce Millers articles on LinkedIn – https://www.linkedin.com/in/bruce-miller/detail/recent-activity/posts/
      In particular the one he did where he explained power system dynamics using the analogy of a train – https://www.linkedin.com/pulse/power-system-analogies-bruce-miller/
      Regards
      James Fleay

    • Rob Parker
      Posted at 13:38h, 24 March Reply

      Geoff, Pleased you liked the article. The cartoonist is a lady from Perth. Her names Vicki and she really captures the essence of what we’re trying to do

  • Richard McDonagh
    Posted at 16:05h, 23 March Reply

    Thanks James, a timely and well considered analysis. We already have a grid in place and we need to enhance it. An electrical grid that remains reliable, robust, and fit for purpose now and in the future.

    In April 2008, the UAE released its Policy on ‘The Evaluation and Potential Development of Peaceful Nuclear Energy’. This policy is built on the most exacting standards of safety, transparency and security, making the country a role model for nuclear energy development worldwide. Their policy emphasizes six key principles:
    • Complete operational transparency
    • The highest standards of non-proliferation
    • The highest standards of safety and security
    • Working directly with the premier International Agency (IAEA) and conforming to its standards
    • Partnerships with responsible nations and appropriate experts
    • Long-term sustainability

    I suggest all methods of electricity generation and storage, including their entire lifecycle (as is the case with nuclear) should be assessed based on the UAE model above. To use current Government lexicon: to make decisions that are “Technology Neutral”.

    Best regards
    Richard

    • James Fleay
      Posted at 13:44h, 24 March Reply

      Hi Richard,
      Thank you for your feedback. The UAE is really the best recent exemplar for how a non-nuclear nation makes a choice to pursue nuclear energy and then puts that choice into action. “Technology neutral” has become a tongue-in-cheek expression with regards to nuclear energy in Australia – the Government couldn’t be less technology neutral than when it comes to nuclear energy!
      Regards
      James

  • Peter Norton-Baker
    Posted at 16:24h, 23 March Reply

    A good article, however I feel that there needs to be more details on the types and benefits of nuclear power options available and in development.

    • Rob Parker
      Posted at 16:26h, 23 March Reply

      Peter,
      Thank you for your comment and that’s one of the directions we’ll be following in the near future

  • Alex Coram
    Posted at 20:39h, 23 March Reply

    James. Great. A lot of important ideas here. The problem is that most of the analysis does not look at the network as a whole. It looks at accounting figures for partial time limited bits rather than looking at welfare and efficiency across the entire network and across trajectories of development.
    Coincidentally I have started to study the mathematics of large systems. I will send you an email with some details.

  • Mick Caine
    Posted at 20:48h, 23 March Reply

    “AEMO uses two market facilities to give network operators access to certain attributes that can only be provided by power stations with a rotating generator (coal, gas, hydro, nuclear). These are called RERT (reliability and emergency reserve trader) and FCAS (frequency control ancillary services).”

    FYI this is very inaccurate. Both batteries and demand response participate in the FCAS markets (… curiously, the ability of batteries to provide FCAS is actually alluded to earlier in the article). In fact, batteries now have over 25% of the FCAS market share. Similarly, demand response is the largest contributor to RERT.

    To be clear – they are absolutely not only be provided by power stations with a rotating generator

    • James Fleay
      Posted at 13:29h, 24 March Reply

      Hi Mick,

      Thanks for taking the time to respond. On a second reading, I think your comment is fair and the wording in the article should have been clearer. My intention was to convey that rotating generators were the only type of generation that could provide certain types of grid services (batteries and demand response not being generation). I understand the the Hornsdale battery is an effective provider of some grid services (as I mentioned in the article) but would point out that this kind of project is only really necessary in a grid with large amounts of non-synchronous, intermittent generation – AEMO didn’t really have to pay for these things previously as they were provided intrinsically and with sufficient strength by the incumbent synchronous generators.
      I am also aware of some trial work that was completed at the Hornsdale wind farm which recently resulted in them being allowed to offer 6 of the 8 FCAS services and some ongoing trials for solar farms to provide grid strengthening – so this space is changing quickly.

      Thanks again for taking the time to comment.

      James

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