3-8 Whitehall Place

What are the big red spikes that appear through weekdays?

These red spikes have created a lot of interest. It isn't obvious what they represent unless you know how the building's systems work. The spikes show the gas demand caused by DECC's boilers firing up to heat the hot water for the sinks and showers, etc.

There is a heavy load first thing in the morning to get the system up to temperature before occupancy starts to ramp up and then during the course of the day the boilers fire up 4 or 5 times under lighter load to keep the temperature of the water at the correct level.

The visualisation tells us a lot about the way the building works, and how the building is managed. We're not sure yet how widespread this spiky pattern will be among buildings, some may be much smoother. Seeing the graphs for different buildings will tell building managers a lot about the different approaches that are in use, and help to drive efficiency improvements.

Why does the building use so much energy at night and on weekends?

There are a number of major uses of night-time and weekend energy at DECC. One of these is the provision of 24-hour cooling for IT servers, which requires air handling units to operate as well as the chillers themselves. The installation of a new dedicated IT chiller has significantly reduced this element.

Other overnight energy use is accounted for by lighting needed for security patrols, lighting for stairwells and some lighting in the basement, though all of this is minimised by the lighting system in the building.

There is also electricity used by docking stations, monitors, printers, photocopiers, desktop PCs which have been left on overnight etc. Security guards do regularly switch these off in the evenings, and the Sustainability & Estates team are looking at other ways to minimise energy use from IT equipment out of hours. Finally, there is energy use from water heating and pumping equipment from 6am to provide domestic hot water when staff arrive in the mornings.

How do you calculate the CO₂ emissions from a unit of electricity and gas used?

The government produces conversion factors that describe the typical carbon impact of different energy sources. These allow us to take the electricity use (in kWh) and gas use (in m³) , and calculate the approximate carbon dioxide emissions, normally measured in kilograms of carbon dioxide equivalents (kgCO₂e). We have used the conversion factors from Defra's 2011 Guidelines. The factors in use at each particular building are noted below in the Assumptions section.

Why is there no scale on the small real time graph?

We made a small, simple real time display graph (we call it a 'teaser') so that organisations can communicate about real-time energy use on their homepages. The intention of the teaser is to present very simple, somewhat intriguing information that attracts browsing users to the profile page (this page!). It has to work in a very small area, and it can't support detailed enquiry.

The building profile page where you are now is where the real information lives. This is where we provide much more detail for those who have the time and inclination to learn more.

What do the colours on the graph mean?

The colours in the graph show approximately how the current level of usage would lead to a given Operational Rating – as set out on a Display Energy Certificate (DEC) – if the performance for a given moment carried on for an entire year. This goes from dark green for ‘A’ to red for ‘G’. We calibrate this using input data used for generating the building’s DEC, together with information relating to 'normal' buildings of its type.

How much does this organisation pay for its energy?

Prices come from the latest energy bills for the Department for Energy and Climate Change, which are noted below in the Assumptions section. These are of course subject to change, and will be updated by the organisations themselves as tariffs are revised.

Can you show data from the transport emissions of this organisation/ building?

Data of CO₂ emissions created by transport used by organisations is very interesting and powerful data to show here. We are working on ways to display and reduce the transport impacts of different organisations, and you will see some of the products of this work on these pages very soon.

How do you get this data from the buildings?

Getting this energy data out of some buildings is harder than others, but in general the buildings contain a small low-power computer which takes very frequent readings from the electricity and gas meters and stores the data. Every few seconds, this computer sends the information it has collected to a server. Your browser will then ask this server for the data it needs in order to draw the real-time detailed graphs and website teasers. The energy impact of this process is very low, and it gets lower with each additional site that uses the system.

Why are you using these units and what do they mean?

We provide three different measures of the energy used: the amount of energy, its monetary cost, and the carbon impact of the energy used.

Energy use is measured in kilowatt hours (kWh), which are the standard ‘units’ of a home energy bill (1kWh is the amount of electricity used by leaving ten 100W light bulbs on for one hour).
For electricity this number represents the amount of energy that flows into a building through the meter. For gas it is the amount of energy that is theoretically available by burning all the gas. For district heating it reflects a flow of temperature over time, after the heat produced by burning the fuel has been transported to the meter. So these numbers mean very different things - this is one reason that we try to use 'units per hour' when combining them. Really it would be better not to combine them at all, because it can lead to confusion

Monetary cost is calculated using the costs per 'unit' for each utility in every building. The figures used are noted below in the Assumptions section.

The carbon impact is measured in kg of CO₂e (the e stands for equivalent) which takes other climate-affecting gasses into account besides carbon dioxide.

Aren't DECC worried about Legionnaire’s disease?

Yes, of course. DECC runs its domestic hot water systems in full accordance with the HSE Approved Code of Practice and Guidance for the control of Legionella bacteria in water systems. This is commonly referred to as L8. They also have a current Legionella Risk Assessment.

As the real time information shows, DECC does not run its hot water all day, every day. Instead, the water is raised to the required temperature well before the building is occupied. The calorifier temperature set point is 65 degrees C which means that they can maintain a calorifier return temperature of 50 degrees C. This is in accordance with L8. They also carry out monthly sampling of the domestic hot water systems for lab analysis and monthly pasteurisation of the calorifiers. Both actions go beyond the requirements of L8. They also have continuous automatic monitoring of the domestic hot water temperatures and alarms are generated if the temperatures fall to low.

DECC has had no results from their sampling to indicate that they have any bacterial contamination within their domestic hot water system or in any of the fixtures and fittings associated with the system. DECC continues to monitor these systems closely.