Measure to manage

Energy efficiency is paramount in the minds of most organisations.However, according to Loïc Moreau of LEM, many have little idea of whether or not they are efficient, or what the opportunities are for improvement

Energy use often represents a large proportion of an organisation's costs, so any improvement in efficiency will benefit both the bottom line and the environment. Despite this fact, many organisations spend a large amount of time minimising equipment purchase costs, but pay little or no attention to the running costs. For equipment that consumes power this is a big mistake! For example, 95% of the costs of a motor may be the energy it consumes, with maintenance accounting for 3% and the motor's price accounting for only 2% of its total lifetime costs.

Organisations need to understand where and how energy is being used if they are to identify opportunities for reducing energy use. As Lord Kelvin implied more than 100 years ago: "If you can measure it, you can manage it." Energy monitoring is a key factor for compliance with a range of regulations being enacted throughout the EU.

Through legislation, governments hope to achieve CO2 emission targets and to make businesses more competitive. In the UK the carbon reduction commitment requires large organisations to monitor energy use and report on their equivalent carbon dioxide emissions and building regulations require new commercial buildings to record, by function, at least 90% of their energy usage.

Because most organisations don't have a good picture of how and where they consume energy, they need to start measuring without delay. The benefits are clear, so why is it not being used to its full potential? A key reason is the association of monitoring with conventional sub-meters, associated with difficult, disruptive, and expensive installation.

Wireless solutions Modern wireless energy meters offer a simple, low-cost and flexible approach that allows organisations to acquire detailed measurement data, providing facilities managers with the information they need to track and allocate energy costs to particular activities, allowing them to identify where energy is being wasted.

Measuring energy consumption can be particularly useful in industrial applications where it can be used, for example, to benchmark one production cell against another.

Any major discrepancy indicates a need for investigation, which may reveal problems such as motors using too much energy due to worn bearings, or equipment that is operating inefficiently because it is in need of lubrication or other maintenance.

Identifying such issues not only eliminates energy wastage, it helps to prolong the life of machines by highlighting potential problems so they can be remedied before developing into full scale failures.

Wireless communication is suitable for installations in existing buildings, allowing deployment with little or no disruption to those using the premises. It also enables measurement of energy use to be implemented in, for example, historic properties where installation of additional cabling is not permitted and where monitoring usage would previously have been difficult or impossible.

The process of minimising energy consumption is an iterative one, typically following a cycle of plan-do-check-act (also known as a Deming or Shewhart cycle). This approach often means systems measuring energy use need to be modified to allow for more detailed investigation of potential wastage, or to accommodate changes to the internal layout of a building.Wireless transducers can be moved around as needed, with minimal disruption and very little cost.

New technologies mean that no reconfiguration of equipment is required as the transducers automatically recognise and communicate with the nearest repeaters and gateways. This also ensures exceptionally reliable operation, as the system can reconfigure the network to bypass equipment that has failed. The latest devices also offer an RF output power of 10mW, providing a long range within the building, even when transmitting through walls.

Unlike conventional sub-meters, modern energy monitoring systems can provide detailed information on parameters such as active and reactive power, current, and voltage in real time. Understanding shortterm changes gives greater insight into the way energy is used and helps organisations reduce peaks in consumption, which are often linked to higher tariffs.

Modern energy management solutions give organisations the opportunity to integrate their measurement of energy use by monitoring other utilities such as gas and water as well as environmental information such as temperature and humidity. This approach provides much richer measurement data that can often make it easier to identify problems. For example if a heating system is operating on a warm summer day, there is clearly a problem that needs immediate investigation.

Modern wireless solutions, such as Wi- LEM, offer straightforward, non-disruptive, and inexpensive installation and operation as well as the opportunity to monitor other utilities and environmental conditions.With so many benefits and none of the old drawbacks, there is no excuse - organisations should start measuring energy usage now.