Mining data for energy-saving golden nuggets

By Mike Pepler, Ashden UK Awards Manager
At Ashden, we’re always interested in data, whether it’s the number of UK cavity wall insulations completed in the past year, how many people are using improved cookstoves in East Africa or how much energy a school has saved through a behaviour change campaign. It’s only by capturing and analysing data that you know whether your work is delivering the desired results or not, and it’s something we always look for in applicants for the Ashden Awards.

So you won’t be surprised to hear that our attention was grabbed by Demand Logic, who have turned the usual approach to energy saving and data upside down! Any organisation looking to cut its energy bills through efficiency measures probably has a rough idea where to start, and there are estimates of what savings could be delivered for any measure it might choose to install. If an organisation is diligent enough, it may then gather data on energy use after making changes, to see what savings were actually delivered, and use the results to inform future decisions or share publically. However, this kind of data gathering and analysis is often seen as not worth devoting much resource to, and if metering equipment has to be installed it can be expensive too.

The answer to this problem lies in an essential machine that is found in most public and commercial buildings, but is rarely seen by most building users – the Building Management System, or BMS. The BMS controls the heating, cooling and ventilation in a building, and sometimes the lighting as well. As a result it processes a huge amount of information every day, as it reads temperature, humidity and motion sensors, and controls fans, boilers, chillers and lights. However, this data is not usually stored, or even analysed beyond what is required for the BMS to control the building systems – this isn’t a failing in the BMS, as it’s designed to be ultra-reliable at its core task, so hasn’t got time for data storage or analysis.

This is where Demand Logic comes in. It has developed a system that can read data from a BMS and upload it to a server via a secure internet link, then analyse it to present the results in an intuitive graphical form for the building manager. The hardware required to capture data 24/7 from the BMS fits in a slim box, not much bigger than a CD case, which Demand Logic can install and commission in just a few hours. The real work happens once the data is uploaded to Demand Logic’s servers, where complex mathematical routines are used to analyse the vast quantities of data and produce views like those shown below, indicating when equipment is running. Colour coding makes it immediately obvious when heating or cooling systems are operating outside of normal hours. More detailed views can also show when incorrect settings are resulting in a room being heated and cooled at the same time.

Demand Logic’s service is not just useful for those looking to save energy – it can also be used to identify faults, such as malfunctioning temperature or motion sensors, so that more effective maintenance can be carried out. This means it brings advantages for both tenant and landlord – the former saves money on energy use, while the latter saves money on maintenance by not sending engineers to check equipment that is working fine.

The potential energy savings from Demand Logic’s technology are enormous. An American study indicated that “ill-functioning building systems and equipment waste a significant quantity of energy, in some cases equal to up to 30% of the energy consumed by commercial buildings". In the UK services sector, which includes education and government, 59% of energy is used for heating, cooling, ventilation, and lighting, all of which can be controlled by a BMS. So by using Demand Logic, savings of up to 18% of total energy use in the sector could be achieved. That’s equivalent to 3% of all primary energy used in the UK (including transport), simply by plugging in lots of Demand Logic’s clever little boxes, and acting on the data they produce.

Demand Logic is a finalist for the 2014 UK Ashden Awards. The winners will be announced at a ceremony at the Royal Geographical Society on 22 May.