'Gridwatch' - Power Monitor console and Download portal The Gridwatch console website presents real-time data for power flows around the UK, updated every 5 minutes. It is hosted jointly by the Elexon Group and Sheffield University. It also allows access to the French equivalent data (top left tab): http://www.gridwatch.templar.co.uk/ G.B. National Grid Status Make T.Fick Browse around and see what it has to offer.The site maintains records dating back to 2311, which may be extracted as Excel spreadsheets by means ofa rather clunky interface. Solar records are more restricted, and date back to November El. As solar generation is difcult to measure explicitly, as there is no centralised metering system, the solar records are estimates based on various strategies, supported by limited data and models. Do not worry about this here, other studies have shown that the gures are reasonably accurate. Shefeld University provides more detail on its Solar website: htt s: www.so]arsheff'ieldachli :Ivlive [The Shefeld portal has been updated recently, and offers a wider range of services, which overlap with those of Gridwatch. They have quite an attractive display, have a look) The Gridwatch data may be analysed, using Excel for example, to reveal some interesting facts and trends on energy supply and usage. This exercise is based on analysis and interpretation of the Gridwatch data. Many of you will obtain jobs where these types of activities [loosely termed 'data mining'] are routinely expected of you. There is an awful lot of data out there... In future the UK grid integrity will rely heavily upon predictions of energy supply and demand, plus storage and smart metering, to ensure our electricity needs are met. is important that you understand the distinction between power (which is the quantity provided by the portal) and energy (crudely, power multiplied by time). To formally calculate energy over a given period, we need to integrate power with respect to time. Power is recorded every 5 minutes by the portal, and as generation and consumption normally varies little on a UK scale over that period, it is easy to integrate this numerically. Say solar power at 1.30 pm today is provided at a rate of 6 GW (gigawatts), over 5 minutes the energy delivered is (6 * (1/12)) = 0.5 GWh (gigawatt-hours, the appropriate energy unit for working on such problems). Note that the spreadsheet download provides power in megawatts (MW). easy way to find out how much energy is delivered or consumed over e.g. a day (using Excel) is to highlight the day of interest in the power column (drag down the relevant column from 00:00 to 23:59), and look at the AVERAGE figure automatically calculated by Excel at the bottom right of the sheet. Because the measurement intervals (5 minutes) are always equal, we can easily obtain the energy per day by multiplying the average power by 24 (hours in a day). If we want to do the same thing for a month, then drag through the data column for the appropriate month, read the average, and multiply it by 30*24 (for a month with 30 days), etc. To average a whole column top to bottom is even easier, just click on it. However, if you wish, you can use the built-in Excel functions, or macros, or VBA. Or read in the data to MATLAB. Up to you.Energy supplies and the UK National Grid The UK National Grid currently relies on a fairly constant supply (approximately 6 GW) of nuclear energy. This amounts to around 21% of annual electricity demand. The renewables (wind, solar, hydro) are by their nature highly variable. They provide around 20%, 5% and 2% of annual demand respectively, but over a windy, sunny weekend, wind + solar combined have reached over 60% of total demand. Despite intermittenty, they provide 25% of our needs 50% of the time. The remainder is provided largely by combined-cycle gas turbine (CCGT) with much smaller contribution from coal-fired generators. Up to 25% of total UK generating capacity is available from coal-fired however, and 50% from CCGT. Coal-fired up-time has been reduced greatly in the last 5 years to meet emissions targets, and its use is restricted mostly to winter, to satisfy increased demand. Only 2% of our annual electricity needs are now met by coal, far less than wind, but the Grid keeps this reserve at hand to guard against harsh winters. CCGT is extremely important all year round, in providing both base-load (45% of annual demand) and flexibility - rapid (1 hour] run-up and run-down. Gas combustion produces CO2 like all fossil fuels, but CCGT is efficient and gas is cheap at present. The UK grid has a small capacity (2 GW) of pumped water storage, that can be brought online very rapidly to meet the 'Coronation Street adverts' surge, when many kettles getswitched on. We import/export several GW of electricity from/to France, Netherlands and Ireland. Both storage and import/export assist in flexibility to meet demand. A POSITIVE number indicates import to UK of power from these sources. * Note however that for Gridwatch, the nett sum of the powers generated at any instant does not always equal UK demand (by several GW), even when factors such as imports/exports etc. are taken into account. There seem to be two main reasons for this. (i] About 30% of onshore wind power is unmetered. It is fed directly into the grid, and this is perceived as an apparent reduction in demand. (ii) There is a column labelled 'Other' in the Excel output, which is not fully explained. Some of it is biomass-fuelled generation. Demand is often apparently greater than supply unless this figure (typically 1-2 GW) is included. It is also unclear to what extent solar generation apparently affecting demand is accounted for. However, we can ignore these discrepancies here. Frequency Supply and demand are fine-tuned by tolerating small variations in the grid frequency - lower frequencies arise when incipient demand exceeds supply. The generators spin more slowly if demand increases, which in turn tends to reduce the demand, and vice-versa. A maximum +1% variation around 50.0 Hz nominal is within the law, though for 95% of the year the frequency lies within +0.2% of 50 Hz. Thus the tuning margin is quite small, and adjustments to maintain 50 Hz rely on bringing generation or pumped storage in or out as required. Increasingly, battery storage is viewed as a solution to maintaining Grid stability. Predictive modelling of demand is also a key requirement. See: https://www.drax.com/energy-policyeed-whole-country-frequency/Illustrations and calculations: . Saturday 16th September 2017: The average solar power is 1181 MW (= 1.18 GW), so the energy produced by solar on that day was 1.18*24 = 28.3 GWh. The total daily demand (obtained similarly) was 27.6*24 = 662 GWh. Thus we may say that solar provided 28.3*100/662 = 4.3% of our (UK) daily electrical energy demand on that day. Though it may be a more honest reflection to say it produced about 9% of our day-time needs, and 0% of our night-time needs. Nuclear, on the other hand, produced 7.38*24 = 177 GWh = 27% of our daily electricity demand, roughly equally day and night. Nuclear is evidently a key base-load supply in UK strategy. ii. Sunday 1st October 2017, 21:20:anda G.B. National Grid Status Sunday 1 October Published # 19:41 UK Warnings Weather Warning hound by the Met Office YELLOW WARNING OF WIND for much of SCOTLAND, NORTHERN ENGLAND and the northeast of NORTHERNTHELAND. Updated Ist October at 10:30 Between 14:05 Man Prod and 23: 55 Mon End we likely to allect sother areas of the LIK on Monday. Bama delays la we likely. Some bus and ban journeys may be afected with sare journeys taking longer Delays for high vehicles on exposed routes and bridges are likely Same shat tom interruptions bo power supplies It's a wild and windy evening across the UK. Electricity demand is 29 GW. Wind power is satisfying 31% of this, more than nuclear at 26%, and CCGT at 29%. Coal is completely off. French and Dutch imports and Biomass are together producing 12%. Coursework Deliverables You are required to carry out the following exercises, using Microsoft Excel, or any other software of your preference, for computations and data displays. You are also asked to comment or draw inferences, supported by your reading.Marks will be awarded for the following: Correct and accurate data collection Correct and accurate analysis of data (be aware that the data can contain glaring errors, e.g. ridiculously large powers, that you should spot by inspection and ignore) . Quality of presentation of graphical data Correctness and relevance of inferences from data Use of literature sources (books, scientific papers, trade journals etc.) . Overall clarity of exposition a. Familiarise yourself with the console, and the data download procedures. Review the above calculations labelled (i) for Saturday 16/09/2017. Note that the file download is best specified only for the time period of interest, and selecting the switches for the data stream (s) you require. If you do not do this, the download will take proportionately longer, as will any calculations or (particularly) graphics. However you may find it easier to work with a few large data sets in the following exercises than lots of smaller ones. The choice is yours b. Solar output varies greatly with the seasons in UK, since the average latitude is around 54 degrees North, and we experience quite a lot of 'weather'. 30th June 2018 was a clear and sunny day across the UK, as noted by the Guardian newspaper:https://www.theguardian.com/environment/2018/jul/02/uk-heatwave-helps-solar- power-to-record-weekly-highs Find a weather forecast or synopsis for that day or period of the month, and include it in your report to confirm (give reference). This, combined with the long day length of late June, provided a large solar energy output. (i) For this day download the demand, and supplies from nuclear, CCGT, coal, wind and solar from Gridwatch. (ii) Confirm the figures in the Guardian report. (iii) Calculate the total daily energy demand, and energy supplies from each of these sources. Express each supply as a percentage of total demand. (iv) Is this day a 'typical' day in terms of demand? c. Create a graph of solar power versus time of day for 30th June 2018, and copy/paste it into your report. Assuming that 50% of UK solar power is generated by solar modules on house roofs, and the average home installation has 3 kW peak capacity, how many solar roofs are there in the UK? Obtain independent figures for the number of homes there are in the UK, and hence estimate what percentage have solar roofs. What is the target or expectation for the future? d. A 4 kWp rooftop solar array in the UK can produce around 3500 kWh of electricity per year. Coincidentally, an average UK family uses around this figure per year, 10 KWh per day. So why aren't we all becoming self-sufficient in electricity? Is this a realistic long-term goal? What 'missing link' is needed to improve the situation? What, if any, are the risks?E. f. Gridwatch now holds approaching four years' worth of solar data, from November 2016 to the present. Process the Gridwatch data to obtain [i] the monthly solar energy totals [in GWh] from January to December 2!] 1'3, [ii] the corresponding UK total monthly demand. Do the same for wind. Plot the percentage of demand met by solar and wind per month, on one Excel column chart. The choice of chart style is up to you. What can you say about the characteristics oleach of these sources of renewable energy over the year? The contribution of coal-fired power stations in the UK has diminished greatly since 2012. From Gridwatch, obtain the average annual electrical power from this source for each full year since 2i]12. btain the equivalent data for wind, nuclear and CEGT since 2i] 12, and plot these annual values on a single Escel column chart, to allow easy comparison. Comment. Lockdown due to Covid-l'El began in the UK on 23rd March 2020, and was not significantly eased until 4 ]uly 2|]2D. Using 2|] 1'3 as a comparator year, estimate the percentage reduction in electrical energy demand between these dates due to the pandemic. it would be prudent to compare dates before and after lockdown to justify the comparison, bearing in mind that demand normally depends on the day of the week. Do you see evidence to a return to 'normal' industrial activity at present, based on this? h. The UK seems torn between two approaches to future electricity supply; build new nuclear power stations (and replace old ones, at end of life), the government's preferred option; or, install more (offshore) wind and develop solar farms and roofs, the 'green' preferred option. What do the figures you have been working on suggest? Does grid infrastructure play a part in these developments? What opportunities/threats do Electric Vehicles present? i. Download the French Gridwatch Excel file (it is not very large). Obtain some data enabling you to make a general comparison between the French and the UK generating strategies, with regard to: base-load provision; uptake of renewables; seasonal variations; import/export. (France is sunnier then UK, but maybe less windy)