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Mains frequency

Kelly Marie Angel
Just checked the dynamic demand site and the frequency was down to around49.7 cycles almost down to the lower legal limit never seen that before
  • 0
    Keep away from Ramipril, you might get rashes and swellings that would do a student proud!

    My cardiologist took me through a quantum leap recently.  From  my GP swapping me off Ramipril to something else, then something else and again something else; my cardiologist said STOP and see what happens. My BP has gone a bit higher, and he reckons that if I can lose a "few" kg, then I'll be fine without any BP medication.

    Clive 

  • Former Community Member
    0 Former Community Member
    Guess that's me off a few Christmas Card lists.... 


    Welcome to my world Clive! Well done for the time criticising (sorry, evaluating) their report............... 


    I'm corresponding with a place of education offering a 3 year MEng in Engineering in conjunction with industry that is designed to meet the educational requirements of CEng whose prospectus sells it on the basis of no A level Maths or Physics entry requirements, no lectures and no exams............................................ Ramipril here I come!


    Regards


    BOD
  • 0
    With my County Councillor hat on.

    A couple of weeks ago, I sat through a Council meeting where on page 56 of 216...( http://committeemeetings.flintshire.gov.uk/documents/g4472/Public%20reports%20pack%2028th-Jan-2020%2014.00%20Flintshire%20County%20Council.pdf?T=10&LLL=0 ) I was faced with:-

    Solar PV at Flint Landfill and Crumps Yard Connah’s Quay

    The Council has been investing in renewable energy systems for many years. Many schools, offices, leisure centres etc. have building scale renewable energy including solar PV, solar thermal, wind and biomass heating systems. The Council has completed the installation of 2 ground mounted solar PV systems on former landfill sites in Buckley, which have a combined output of 1 MW. In order to achieve the goals set within the Carbon Management Plan and the Renewable Energy Action Plan further investment in large scale renewable energy is needed.


    This business case is for the development of ground mounted solar PV at Crumps Yard, Connah’s Quay and Flint Landfill. This would potentially generate 3.4MW of electricity per annum. A detailed report explaining the full business case for the scheme was approved by Environment Overview and Scrutiny Committee and Cabinet in December 2019. Construction is due to start in the Spring of 2020.


    Direct Costs:

    The scheme cost to build, and it is assumed that borrowing will be required to finance the project, is between £2.8m and £3.1m.

    Direct Benefits:

    Combined net project income over 35 years is estimated to be between £0.750m and £1.25m or between £0.030m and £0.367m in real terms.


    Meeting the priorities and objectives set within the Council Plan under the ‘Green Council’ theme

    Contributing towards the achievement of Welsh Government targets and obligations under the Climate Change Act, Wellbeing of Future Generations Act and Environment Act.

    Future proofing for the requirement to decarbonise by 2030 from Welsh Government

    Generated income can also be used to hedge against energy price increases


    Indirect Benefits:

    Protecting frontline services by providing a long term income stream

    Supporting wider regional priorities such as the regional growth bid.

    Being a community leader and developing a reputation as a Council who is forward looking, innovative, and invests in the future

    Facilitating further innovation around storage technologies, electric vehicle charging etc.

    Supporting economic growth and job creation through the initial construction and then the long term maintenance of systems as well as providing the energy infrastructure to sustain businesses and economic growth.

    Renewable energy systems are also capital assets which can provide capital receipts on sale/transfer

    Developing new ways of working and partnerships e.g. joint ventures, energy service companies.

    Improving the ecology and biodiversity of sites following best practice, e.g. wildflower meadows on solar farms etc.


    After the presentation, I queried the figures and received this email:-
    Dear Councillor Carver
    Further to your question at Council on Tuesday, I can now confirm the following.

    The estimated annual generation (based on the design calculations) is 3,490,111 kWh or 3.490 MWh. This is the total amount of electricity that is expected to be produced over one calendar year. If you divide this by 365 days then you get a daily output of 9562 kWh, not 10 kWh per day.

    I have also include the Cabinet papers from December when the Business Case was approved.  It had previously been endorsed by the Environment Scrutiny Committee earlier in December.


    I replied:-

    Thank you for your email together with the attached Cabinet papers.

    First of all, when I spoke at Council last Tuesday, my comments were based on the figures before me in the Report which on page 56 paragraph 1.37 “This would potentially generate 3.4MW of electricity per annum”.

    Regretfully, that sentence is totally incorrect.  I say that simply because referring to MW (Megawatt) is actually referring to Power which is an instantaneous quantity; as in a 100 watt light bulb, or a 2 kilowatt electric heater. What should have been advised in that Report, is the total Energy produced in a year, which for electricity generation is measured in watt-hours (W/h), kilowatt-hours (kW/h, Megawatt-hours (MW/h) or Gigawatt-hours (GW/h) etc.

    Reading through the Cabinet papers, the Executive Summary on page 419 only refers to MW as does paragraph 1.01 in “EXPLAINING THE GROUND MOUNTED SOLAR PV AT FLINT LANDFILL AND CRUMPS YARD” on page 420.

    Then on page 426 in paragraph 1.12 is the first mention of MWh where it states, “The schemes will produce around 3.5 MWh of renewable electricity every year…..” (MWh and MW/h both being identical.)

    And again on page 448 in 3.6 Non-Financial Benefits “The schemes will produce around 3.5 MWh of renewable electricity every year…..”

    You can probably now see where I am coming from.

    Both the report to Council and to Cabinet have errors of principle, both in the confusion between MW and MWh and also in the numerical figure.

    Using the figure as stated in the above reports, 3.5 MWh every year DOES equal 9.59 kWh per day (ie 3,500 kWh divided by 365 equals 9.589 kWh)  My 10 kWh per day was from a back of an envelope calculation based on the figures before me.

    However having now read the report to Cabinet, I can see where your figure of 3,490,111 kWh comes from, although this annual figure was not included in the report to Council. However a typo did slip in on your email, since 3,490,111 kWh is 3,490.111 MWh, not 3.490 MWh.

    My concern is that most Members and possibly the writer of the reports do not understand the difference between Power and Energy and if the projected income to FCC in the future does not live up to expectations, analyses of Cabinet and Council decisions at that future time would show the confusion in these documents.

    Although the Glossary on page 434 has “MW: Mega Watt or 1000 kW (kilo watt)” The list does not include MWh let alone MWp, which is the Peak Instantaneous output power of the system. ie at maximum sunshine.

    At least on page 443 where it states, “In 2018-2019 the Council consumed circa 18,641 MWh of electricity (equivalent to the power used in around 5600 homes)…”  I can see some sense in those figures, the daily estimated consumption for each of the 5600 homes being 9.12 kWh, which I will not argue with.

    I should add that I have some experience of electricity generation from when I was in the Merchant Navy; for my last 4 years prior to retirement, I was engaged as an electrical and electronics trouble shooter on container ships where electricity generation was often at 6.6 kV obtained from diesel alternators and static inverters, each typically 2.4 MW about 10 MW total.

    Kind regards


    Guess that's me off a few Christmas Card lists.... 

    Clive




  • 0

    davezawadi:

    Surely this article is joking. a 44 MW help when GW are connected is not going to do much at all. I don't know what the total consumption in SA was, but probably not all that much. This is only about 1000 cars worth of battery, and it saved the day? I suggest it was the industrial load shedding of aluminium heating which really did the trick.

     



    Another article says it's 100MW, storing 129MWh, but they are planning on upgrading it.  But that is just one battery bank.  You wouldn't try to run the entire country off one power station, and one battery bank wouldn't serve the whole of the UK either. https://www.smh.com.au/business/companies/huge-tesla-battery-in-south-australia-primed-for-big-upgrade-20191119-p53byo.html

     

  • 0

    mapj1:

    Well round here there are fields of the damn things springing up on every 1000 sq meter scrap of  land that would be too rough to plough and cannot get planning permission for a housing estate.




    Well, that may be the best use of the land. Around here, a parcel of land has been isolated by the creation of a new road, but on the other side of the road there is already a solar farm. More panels may be somewhat unsightly, but they certainly beat the prospect of extra traffic which would negate the benefits of the new road.

  • 0
    Where are you Mike, there is little point in solar past Birmingham? Although it is often sold, the sun angle and latitude is the controlling factor and even southern England is not very good.
  • Former Community Member
    0 Former Community Member
    Coal is however cheap to mine, and they make a big profit exporting huge quantities of it - burning a bit along the way makes good economic if not environmental sense


    However, the hard of thinking believe the recent fires are a warning from the sainted Greta to mend their ways  - who was it said, they have sown the wind and now shall reap the whirlwind - ahh yes, I remember now.


    Regards


    OMS
  • 0
    What really comes out of that article about Australia, is not the battery at all, but rather just how dependent they are on coal - 5 out of 6 GW in New South Wales and Queensland, and 3.7 out of 3,8 in Queensland ! 

    (NEM is not a state, it is a National Electricity Market, i.e the totals..  and 19GW total - is that really all  ?)

    And given the space and climate how little they make use of either wind or solar.
  • 0
    Big batteries are over here too, doing the same thing. For example
    https://stateraenergy.co.uk/Energy%20Storage%20Facility/pelham-storage/


    ...And in the August 2019 grid wobble, National Grid credited EFR/FFR providers which included batteries, with sustaining the frequency enough to avoid further outages.
    https://www.nationalgrideso.com/information-about-great-britains-energy-system-and-electricity-system-operator-eso

    To save you reading (final report, p4)

    All the “backup” power and tools the ESO normally uses and had available to manage the frequency were used (this included 472MW of battery storage) to stop the frequency fall (at 49.1Hz) and being recovering it towards 50Hz.



    As Simon Barker says, these plant are designed around a very short duty cycle, but also very fast response times, primarily to provide this function (normally less dramatically than the above event mind you). National Grid procures this service directly, just as it does other reserve services. It is not the same as long term storage, which would most likely be better suited to other technologies (flow batteries anyone?) that may struggle to react quickly enough to frequency events.


    Lastly, worth looking at the requirements for G99... All mid-size generators (>1MW), including inverters, now have to incorporate a frequency response mode featuring a droop curve (albeit asymmetric, depending on size, but the point is it responds to network loading), plus feed in to / ride through close in faults, limited network voltage control and provide a DNO control interface.
    https://www.energynetworks.org/assets/files/electricity/engineering/engineering%20documents/ENA_EREC_G99_Issue%201_Amendment_5_(2019).pdf
  • Former Community Member
    0 Former Community Member

    mapj1:

    That was not really my main point- the main point was a large fraction, maybe half, of the generation with inertia on the grid has gone since it was first designed.




     

    And perhaps, more importantly - should we be concerned ?


    Regards


    OMS

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