Australian news, and some related international items

No, Mr Turnbull, coal is NOT our future: renewables with energy storage, are here

Map Turnbull climateWhy Coal Is Not Our Future, Skeptical Science  15 December 2016 by Riduna

Coal Problems

Australian Prime Minister, Malcolm Turnbull, has repeatedly asserted that coal will remain in use for electricity generation for ‘many, many decades to come’. He argues that moving to renewable energy would reduce production and use of coal resulting in unacceptable loss of mining and transport jobs, particularly in rural areas. However, the threat of larger job losses did not stop his predecessor from withdrawing subsidies for the car industry, resulting in its closure nationwide – action supported by the present Prime Minister.

Recently, Energy Minister Friedenberg asked Australia’s Chief Scientist, Dr Finkel, to prepare a Discussion Paper on electricity security during the transition to renewable energy. The Paper, presented to the Prime Minister and Premiers on 9 December, 2016 recommended that an energy intensity scheme be applied to the electricity generating sector. This would see the highest emitters leave electricity generation and promote orderly replacement of coal by gas and, increasingly, renewable energy generators.

The Paper reported that existing policies lacked clarity and certainty for investors and would not achieve Australia’s commitment to reduce greenhouse gas emission by 26-28% below 2005 levels by 2030, given under the Paris Agreement. Even before recipients of the paper had time to consider it, the Prime Minister rejected its main conclusions.

In declaring coal Australia’s present and future energy source, Turnbull has chosen to ignore the dangers of coal production and use to public health or, more accurately, public death. Clear evidence shows that coal mining in Australia not only causes respiratory problems through inhalation of airborne particles but that this results in the incurable ‘black lung disease resulting in a slow and painful death. Its combustion in power stations results in emissions which increase the incidence and severity of health problems among populations living up to 100 km away.

As the Prime Minister knows, coal has to compete with renewable clean energy sources, particularly solar and wind. It’s a no brainer of course. Coal has to be purchased at a price which sustains production, while sunlight and wind are free. At present coal can compete because neither solar or wind can do what coal does – reliably produce electricity 24/7. What clean energy sources can do and are increasingly doing, is make inroads into the amount of electricity generated by coal or other fossil fuels, thus reducing the amount of coal burned for this purpose.

The operative words are “at present”. At present, coal relies on the fact that electricity can only be stored to provide for a few hours demand, or at most a day or so. Given the location of wind and solar farms, it is quite possible that neither wind nor sunshine is continuously available to keep them operating 24/7 and when this occurs, coal fired power stations must be available to provide any shortfall. But will this always be the case for the ‘decades to come’ which Malcolm Turnbull assures us is the time span for on-going use of coal? Well, no.

Energy is at present largely stored in one of four ways:

  1. As molten salt heated by concentration of solar energy, depicted above [on original] :
  2. As solar or wind generated electricity, stored in batteries and released to meet demand when the energy source is not available. It is the latter which is of short-term importance to consumers.
  3. As unused capacity of fossil fuelled power stations, particularly those burning gas, to meet shortfall in generation or increase in demand
  4. As water pumped uphill by electricity generated from renewable sources then released to turn a turbine producing hydro-power:

Solar energy is concentrated and focused on an elevated point where it converts water to steam and salt to a molten state. The former is used to drive a turbine, the latter is stored and used to convert water to steam when the sun is not shining, enabling 24/7 electricity generation.

The solar concentrator facility operated by Sundrop Farms at Port Augusta, South Australia generates 39 MW of power and provides a reliable, continuous electricity supply used to operate a desalination plant, pump water, maintain temperature of greenhouses and supply residential and business premises.

The wide distribution of wind-farms makes it unlikely that this source will be becalmed and cease generating electricity nation-wide, however it is likely that lack of energy from this source will fail to meet regional or local demand 24/7, so it is essential that back-up be provided in the form of stored electricity.

Of greater importance is the need for back-up of electricity generated by solar panels since these only operate when the sun is shining. Public policy should require solar farms to be supported by fossil fuelled generators or include appropriate battery storage to ensure that in the absence of sufficient solar energy, continuity of electricity supply is provided.

The National Grid in Australia presently relies on back-up from existing fossil-fuelled power stations, many of which generate electricity at less than full capacity because cheaper electricity generated by renewable sources (wind, solar and hydro) is available. As the number of renewable power sources increase, demand for more expensive fossil fuelled electricity falls, ultimately leading to closure of the least efficient power stations.

This process has already begun with closure of all coal fired power stations in South Australia, though gas-fired generation continues in that State and the planned closure of the Hazelwood (Victoria) power station in 2017. Loss of generating capacity resulting from these closures is more than compensated for by the increasing number of fossil-fuelled power stations already operating below capacity.

Over the next 10-20 years electricity generated by renewable sources will increase both in Australia and globally, resulting in gradual closure of all remaining coal-fired power stations and, as this occurs, the need for backup provided by battery storage will increase. Battery storage is already available in two sizes: domestic and utility.

Domestic Battery Storage….... In Australia, over 16% of households or some 1.5 million dwellings, have solar panel displays – and that number is growing. If less than half of these equip with battery storage over the next 4 years, they represent a significant source of renewable energy, potentially available to the National Grid, at prices competitive with those offered by coal-fired generators.

This could enable the Grid operator to purchase electricity required to meet peak demand of other consumers during the day and sell to households during off-peak periods, usually at night – and do so at commercially attractive rates.

This arrangement provides the grid with an additional tool with which to ensure that energy levels in the grid are maintained at appropriate levels and can wholesale at lower prices. It further reduces demand for coal fired electricity generation and is likely to result in these generators operating at well below full capacity until the least efficient among them can no longer operate profitably, and closes. A result of this is that demand for coal by electricity generators will decline as battery prices fall and their capacity and uptake by dwellings rise.

Utility Scale Storage…… Very large scale storage, virtual power stations, such as that being developed for Adelaide, South Australia has a capacity of 5 MWh. Like solar-photovoltaic power plants, they can be located close to the communities they supply. It is likely that as improvements are made in storage capacity, virtual power stations of much larger capacity will become an increasingly common feature able to ensure both grid balance, continuity of supply and security of distribution in the event of grid damage by increasingly severe climate events……….

December 16, 2016 - Posted by | AUSTRALIA - NATIONAL, energy

1 Comment »

  1. Comments on

    CEDA Speech by AEMO Chairman, Dr Tony Marxsen
    2nd December 2016.

    Dennis Matthews
    December 2016


    ”Designing the grid of the future must take into account three core goals: affordability, reliability/security, and Australia’s commitment to emissions reduction.”

    I would hope that the electricity grid of the future would integrate, rather than balance, the three goals of affordability, reliability/security and greenhouse gas emissions reduction.

    State-wide Blackout in South Australia

    “Some generating units had embedded protection schemes, a previously unknown feature, which were set to ride through only a limited number of disturbances in a two minute interval.”

    Dr Marksen is referring to wind generators but, in fact, every other element of the on-grid electricity generation system has embedded protection schemes. This includes thermal (coal or gas) generators and interconnectors.

    “A sequence of events such as this involving multiple failures or trips occurs very rarely and is classified as ‘non-credible’ in the National Electricity Market Rules.”

    In fact, the second in two months such sequence of events happened one day before Dr Marxsen’s speech. This second failure involved the Portland aluminium smelter and once again the Heywood interconnector, both in Victoria. This failure had nothing to do with wind generators either in SA or Victoria, and resulted in loss of 230 MW of supply to SA through the Heywood interconnector. Even worse, the failure of the interconnector led to an automatic attempt to supply Victoria from SA with about 480 MW for the Portland smelter.

    The SA-wide blackout on 28th September 2016 and the failure of the Heywood interconnector had one feature in common, there were no contingency measures in place, simply because the failures that occurred were classified as non-credible.

    Power System of the Future

    “if we look at South Australia, wind capacity is now more than 30% of total capacity in the state, and if we add PV, renewables make up more than 45% of total capacity.”

    These developments have occurred over the last ten years but AEMO and industry regulations have not kept up with the changing nature of electricity supply in SA.

    From the National Electricity Market (NEM) consumption outlook, “You can clearly see the factors driving down consumption from the grid, such as rooftop PV and uptake of more energy efficient appliances.”

    “customer demand is no longer the primary driving force of network investment, instead investment in the future will be driven by ….. affordability / security and reliability / lower emissions.”

    “the next 20 years will be characterised by unprecedented transformation in the power industry as it transitions to a low carbon future.”

    Over the next 20 years a secure and reliable supply can be maintained “only if the network remains interconnected during and after disturbances.” “A more interconnected NEM can improve system resilience.” These two statements sound like AEMO trying to justify its own existence and expansion.

    If, as Dr Marxsen claims, “A lot of power generation will be dispersed over wide areas, including urban areas”, then less interconnection and more self-sufficiency would seem the logical outcome.

    Buildings will have not only rooftop solar photovoltaic (PV) panels but also electricity storage and the ability to reduce their reliance on fossil-fuelled vehicles by using electric vehicles recharged from in-house solar generator/storage systems.

    Wind farm/storage systems will have the same ability but on a bigger scale (10 MW rather than 10 kW) and hence would be able to service a bigger demand such as farming equipment and towns with the equivalent demand of up to 1000 homes.

    Recent experience in SA suggests that less interconnection would be more reliable than more interconnection. If electricity generation becomes more distributed and if electricity is generated closer to where it is used then this should be seen as an advantage that reduces the distance that electricity is transmitted.

    Given the resilience of the Murraylink, direct current (DC) interconnector compared to the Heywood, alternating current (AC) interconnector, and given that solar PV generators and wind generators both produce DC, then greater use of DC would decrease the need for DC to AC inverters. This in turn would create a demand for DC appliances and new industries and employment opportunities. It would also reduce exposure of the AC electricity transmission system to the problem of the need for rigorous frequency control.

    Comment by Dennis Matthews | December 18, 2016 | Reply

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