Maximising Energy Savings - Estate-Wide

Industry comment

Published: 14 August

Type: Industry comment

Year: 2017

When tackling energy waste across a diverse estate it makes sense to consider a consistent solution that can be applied to all built assets – large and small. Tony Willis of Sabien Technology explains

When implementing initiatives to reduce energy costs and carbon footprint, many organisations focus initially on the largest buildings on their estate. Very often these are the most ‘energy-hungry’ built assets they have, so this makes perfect sense. Larger buildings are also more likely to have a building management system (BMS) that can be fine-tuned to help improve the energy performance of, for example, heating systems (though more improvements are generally possible, see below).

However, in many estates these larger buildings with BMS may only account for a small percentage of the total buildings on the estate. Across a local authority estate, for example, there could be as many as 80% of buildings where boiler control is based on just basic temperature set-points and timers etc.

This situation presents a challenge when it comes to rolling out energy savings across the entire estate. Indeed, it is these buildings with only rudimentary control that are typically subject to the highest energy waste in percentage terms.

Installing a BMS in, say, a primary school or a high-street bank will usually be cost-prohibitive so lower cost measures that can deliver a fast payback are generally a more viable solution. In doing so, it makes sense to use a retrofit technology that can be applied to all types of buildings, has a proven track record and will work in harmony with whatever type of control is already in place – from simple in-built boiler controls to a full-blown BMS.

When rolling out a retrofit technology across multiple buildings, the ability of the supplier to manage the project is also important to avoid over-stretching in-house resources.

Boiler dry cycling

These principles are clearly illustrated by boiler dry cycling and short cycling. This is a common phenomenon that happens with the majority of boilers, irrespective of size or age where the boiler(s) fire to maintain the set point temperature of the water in the boiler(s) even when there is no demand for heat from the building directly, but the boiler cools down due to the standing losses only.

The potential for energy wastage is significant. Tackling boiler dry cycling/ short cycling with Sabien’s M2G boiler load optimisation technology has been shown to reduce boiler fuel consumption by 10-25%, with paybacks ranging from 6 months to two years (figures based on installation of over 10,000 M2Gs in a range of building types).

Crucially, boiler dry cycling can occur even when other control measures are in place – be they simple boiler controls, weather compensation or the latest BMS strategies. Moreover, M2G works alongside other controls to deliver additional energy savings over and above those already being achieved by the incumbent controls. This makes M2G ideal for roll-out across an estate that already has a diverse range of boiler controls.

Another important point, in terms of life cycle costs, is that M2G units are self-learning and require no maintenance or seasonal calibration and can be easily transferred to new boilers if existing plant is replaced in the future.