By Kenny Cameron, director of Strategic Development at Energy Assets
I recently had a discussion with the manager of a distribution centre responsible for the supply of goods to over 100 stores. What became clear was that while the data collected through automatic meter reading was key in identifying potential areas for energy efficiency gains, delivering the improvements was hampered by a somewhat cumbersome and load-specific approach to control.
For example, the air-conditioning system required intervention by the manufacturer, the battery chargers for vehicles were ‘always-on’, lighting was based on ‘first man in, all lights on’, water heating was drawing power throughout the day, and adjacent street lighting, also under the control of the centre, operated to a simple ‘on-off’ pattern.
There are, of course, many systems available that could most likely have addressed each of these issues in a piecemeal way, but what is not generally prescribed in even the most sophisticated Building Energy Management System (BEMS) is an ability to communicate holistically, dynamically and remotely as a means of managing electrical loads by event.
Such an approach requires a different mindset to think more creatively about energy efficiency…and a technology platform capable of making it happen. For heavy users of energy – particularly in manufacturing – the ability to control electrical loads remotely and on-demand could be a significant contributor to cutting the estimated £2.2bn over-spend on energy that results from the use of inefficient technology, equipment and controls. Such control could make a significant contribution to maintaining the gap between UK electricity supply and demand – and go straight to the bottom line of Industrial and Commercial users.
The good news is that the energy we use is much more closely monitored and reported on than ever before, thanks in no short measure to Automated Meter Reading systems made possible by the installation of advanced meters and data loggers. The ability to collect and send detailed consumption data remotely to users and to crunch this into meaningful reports via online platforms is putting better information in the hands of I&C energy managers.
With this ability to collected half-hourly consumption data over each 24 hour period, businesses can ‘slice and dice’ in almost an infinite number of ways – comparing like-for-like premises, looking at actual vs target consumption or highlighting event exceptions that quickly indicate a fault in equipment or mistake in human behaviour before the situation escalates.
The model for industry – and indeed for our public services – should be ‘metering with control’. A good example of this is the decision by the City of London Corporation, which is responsible for the famous Square Mile, to invest in LED lighting, along with an intelligent, and dynamic, control system. LEDs enable corporation highway engineers to dim street lighting in order to reduce energy consumption – they do this via the Z-LYNK control system that uses power line communication to send command signals to receivers built into the luminaires, enabling units to be controlled remotely and on demand.
Each lamp can be switched on and off, dimmed to specified levels, or grouped by street or other configuration to meet the needs of specific conditions or events. Control is managed remotely in a browser environment and moves away from the old model of inflexible, period-based control to something that can be pre-programmed but that can also be instantaneous and dynamic.
All this is achievable with Z-LYNK, which works by broadcasting short messages over the 11KV or415V power distribution network, or at a very local level via the mobile phone network on GPRS or through an Ethernet connection.
For 11KV sites, a high power transmitter sends command data over existing power lines to an unlimited number of receivers located within devices to be controlled. On a 415V network, a low power transmitters (LPT) installed on the incoming supply enables I&C users to control every downstream appliance, right down to each 13A socket, via hard-wired receivers. The key feature of the LPT is that on a medium to large site it delivers automated site switching using existing cabling – wherever the power goes, so can the command signal.
On smaller sites, the same effect can be achieved by sending control signals via either the mobile phone network on GPRS or through an Ethernet connection, using a LYNKswitch device to control up to four local loads. This enables energy managers to exercise control, for example, over common area heaters, kitchens, internal lighting etc remotely, either at set times, by associating them with sensors or instantaneously ‘on-demand’. This eliminates situations where appliances or lighting systems are consuming power unnecessarily.
What commercial organisations need – whether manufacturers, distribution sites, retailers or stadia owners – in order to make sense of detailed consumption data available via AMR is an ability to respond dynamically to their energy management requirements and to think more about implementing energy reduction strategies.
For the I&C sector, it’s now possible to control any electrical device remotely and either automatically to a pre-set schedule or on demand using power line and/or GPRS and ethernet communication. This opens up the potential for a much more flexible approach to energy management, carbon reduction and cost control. It also means the manager of the distribution centre can take a more holistic and dynamic view of energy efficiency, controlling everything from one browser-based system that sends command signals that will optimise battery charger power usage, automate internal lighting, link water heating to working time, and switch or dim adjacent street light. In other words, using consumption data to inform energy strategies based on better control.
