Overview
E-Day's online meters display real-time electricity data that has been collected at four different geographic scales (UK, Isles of Scilly, Five Islands School and a local family).
Measurements have been taken using different equipment and standards, but presented in as consistent and accurate a fashion as the data permits.
National Data
National data have been collected from the National Grid (the company that monitors and controls the UK's high voltage electricity distribution system).
This data is occasionally interrupted, due to circumstances outside E-Day's control, such as server upgrades or maintenance.
In the UK, peak electricity demand can reach about 55 Gigawatts (GW) over the winter but drops to about 30 GW during the summer.
Isles of Scilly Data
Island data have been collected from Western Power Distribution (the company that run the low voltage power lines in the south west of the UK).
This data is collected via the cables that link the Isles of Scilly to the mainland and only available when the mainland is powering the islands.
Measurements are not available when the small power station on the Isles of Scilly is keeping the lights on.
The cable from the mainland delivers about 3.5 Megawatts (MW) of electricity to the islands and this can be substituted with local diesel generation, on the islands, if the link to the mainland is ever broken.
School and Family
School and family data have been collected using specially adapted off-the-shelf household electricity monitors, which are less accurate than the mains meters used to calculate electricity bills.
Each device should be relative consistent in the measurements it takes and therefore useful, in terms of indicating when electricity use goes up and down. However it cannot be claimed that these devices are as accurate as mains electricity meters.
In general, the Five Islands School uses about 3 kilowatts (kw) of electricity during holidays and weekends. During the busiest moments of term time this jumps to nearer 45 kw.
The family we are following uses between 150 watts and 5 kw, depending on what they are doing.
Instantaneous Measurements : Spot Data (e.g. 3:01pm)
Instantaneous readings compare spot measurements that have been taken at the same time of day (e.g. 3:01pm) both yesterday and today.
Cumulative Measurements : Total Data (e.g. midnight - 3:01pm)
Cumulative and demand curve graphics compare the total amount of electricity used between midnight and latest time interval measured (e.g. Midnight - 3:01pm) both yesterday and today.
Timescales and Percentage Change
Meters which compare measurements taken over different timescales at the same geographic scale; such as spot measurements on the Isles of Scilly (e.g. 3:01pm yesterday and today) and cumulative measurements on the Isles of Scilly (e.g. the total amount of electricity used between midnight and 3:01pm) will frequently show different percentages of change. This is normal.
The longer timescale is a better reflection of the day's overall trends, but the spot data has been added out of interest.
Data Samples
Data has been sampled, transmitted and processed at different rates, as there are not universal open standards for electricity data.
Different types of equipment and measurement standards have had to be used at the national, regional and local scales. Where data is only available in 30 minute intervals, forecasts have been used inbetween data points.
Historic data
E-Day has avoided the use of 24 hour predictions, as an unexpected cold snap during last year's E-Day made the National Grid of national electricity demand very inaccurate.
As a result, E-Day has limited itself to comparing today's live (or almost live data) with yesterday's historic data.
Days of the week
Patterns of electricity demand vary at the daily, weekly, seasonal and annual timescales, so the choice of days to compare has been difficult.
Weekends require the least electricity as many offices and factories are closed.
In general, electricity use jumps from weekend levels on both Mondays and Tuesdays, then declines from Wednesday to Friday.
This means that E-Day's effort to buck the upward trend seen on Tuesdays is ambitious.
However, it should mean that a good proportion of any reductions in electricity use seen on E-Day at the islands, school and family levels, when compared to the national trend, will be attributable to E-Day.
National baseline
The percentage change seen at the national level should act as a good (if not perfect) guide to the normal effects of the same day's weather and work habits.
E-Day doesn't know what will end up happening, but it is possible be that only one or two of the island, school and family being monitored will succeed in make a saving on E-Day.
Any reductions will be a success, but the more the merrier. Nobody has to take part if they don't want to.
Matt has simply asked everyone on the Isles of Scilly who wants to take part, to do what they can to save energy on E-Day.
Hopefully a few energy saving habits will stick if we all give it a go at working together, and then feel a little bit easier to live with...
Just for fun!
What E-Day is doing is a world first, experimental, slightly crazy and just for fun.
E-Day's meters are primarily intended for educational use and should only be used to identify basic trends and treated as a first attempt at making visible information, which is normally invisible.
The majority of E-Day's meters will be left running after E-Day.
Please get in touch if you would like to work with us on reducing your energy use and/or developing unique online measurement tools.