Environmental legislation has certainly given a boost to energy-saving technologies but these still have to be delivered within a commercially viable framework. HVR spoke to Alan O'Brien, founder and CEO of Sabien Technology, to see how the company has addressed these requirements.
Since it was formed in 2004 and floated on the AIM stock market in 2006, Watford-based Sabien Technology has achieved steady growth on the back of its patented M2G intelligent boiler load optimiser.

M2G is a technology that removes boiler dry cycling and, says the company, can deliver proven and validated energy and CO₂ savings for boiler plant, even when a building management system (BMS) is in place.

'There have been many attempts to tackle dry cycling in the past but these have tended to rely on delaying the firing of the boilers for a fixed or predetermined period of time, or reducing the boiler thermostat set point and therefore compromising the comfort levels.' notes O'Brien.

'Consequently, one of our key objectives has been to distance M2G from typical 'time delay' systems and to position our technology firmly as being both trusted and proven. This has been demonstrated during the last five years with more than 90 independent M2G projects which have delivered typical energy savings of between 10 per cent and 25 per cent depending on the building type and application. Across large estates average savings of 12 per cent to 15 per cent are achieved.

'As well as being listed on the Carbon Trust's Energy Technology List the M2G has also achieved TRITECH ETV (Environmental Technologies Verification) certification, providing independent validation of the energy savings achieved,' he adds.

Offer fatigue

O'Brien also suggests the plethora of energy-saving technologies now being offered on the market is creating scepticism and 'offer' fatigue among buyers.


'Organisations are inundated with headline savings rates that, unsurprisingly, make buyers very nonplussed about the claims being made. They want to know the technology is proven and the company can offer the client the opportunity to validate their claims.

'We've tackled this by being very meticulous in the way we measure and demonstrate the savings M2G delivers.

'To that end we've developed a validation methodology for pilot programmes whereby the M2G operates in a save mode one day and then switches to bypass mode the next. This is repeated during a period of several weeks, and the results are then adjusted using degree day data to compensate for day-to-day changes in ambient temperatures.

'This methodology was independently assessed by AEA Technology when we were piloting M2G for BT before their initial rollout.

'On top of that, many of the organisations we work with are already measuring their energy use and independently validating our results either with their AMR and sub metering or using CUSUM (cumulative sum) analysis, which is approved by the Carbon Trust.

'CUSUM is becoming more widely used to illustrate the trends of energy consumption over time following the implementation of energy efficiency technology. Therefore the savings we quote are accurate, transparent and, above all, proven in the field.'

So how important is the payback period when it comes to introducing energy saving technologies and reducing environmental impact?

'There's no doubt that reducing CO₂ is becoming an increasingly important factor for our clients but it still has to stack up commercially,' says O'Brien.

'Some suppliers of energy saving products base their pricing on the predicted energy savings - the higher the potential savings the higher the price. Our clients have told us they don't like this approach; we charge the same for our products irrespective of the savings potential, allowing us to consistently deliver paybacks of two years and under. M2G is very much one of the 'low hanging fruits' that so many people are talking about,' he suggests.

Clearly payback is an important consideration but, as O'Brien observes, this isn't the only barrier that stands in the way of introducing energy saving technologies.

'Return on investment is a major consideration, even in the public sector, but very often there is also a resource issue on the client side. By allocating a Sabien project manager for the day-to-day running of the account, and using reputable nationwide facility companies for the installation, the client doesn't have to micro-manage the rollout programme and enables estate wide rollouts.'

What is dry cycling?

Given the impressive sounding figures quoted by O'Brien we asked him to tell us a bit more about dry cycling.

'When a boiler is in standby, or off at set point, it acts as a large radiator and loses heat to its surroundings - and this is something that happens even with modern well-insulated boilers. Plus there are additional losses from the flue and, in some cases, from purging the combustion chamber before re-firing,' he explains.

'These standing losses are detected by the boiler's temperature sensors and the boiler fires to compensate even when there is no requirement for space heating or hot water. Consequently, this problem is at its worst during spring and autumn when boilers tend to switch on and off or modulate, particularly when boilers are oversized, which accounts for around 80% of the UK's boiler plant.

'Contrary to the beliefs of some, dry cycling also occurs with modulating boilers,' he adds.

O'Brien explaines that the M2G deals with this by constantly monitoring the boiler's thermal response to changing loads, calculating the temperature gradient over time and determining when the boiler should fire and when firing should be inhibited.

'The important thing here is that the M2G is fully adaptive to changing boiler load and heating demand - and the set point and comfort levels aren't compromised. Thus it overcomes the problems that were inherent in earlier attempts to control dry cycling,' he enthuses.

But surely, the BMS should be controlling this phenomenon!

Common misconception

'That is a common misconception but you have to remember a BMS is typically designed to optimise a building rather than optimising individual items of plant. So, in relation to heating plant, the BMS will monitor and respond to common flow and return blended temperature from all boilers; it won't be monitoring the performance of each individual boiler temperature profile under variable load conditions.

'In contrast, the M2G monitors each boiler individually to provide precise control of the boiler plant at individual boiler level.

'Secondly, a BMS is made up of a number of different strategies to control various aspects of a building's performance. Because dry cycling is so rarely recognised, the majority of BMS systems do not include dry cycling control as standard,' O'Brien notes.

So does that mean that a BMS can never deal with dry cycling, or are there situations where this could be achieved? And does the M2G interfere with the BMS when both are being used?

'It is theoretically possible to re-configure an existing BMS but you'd have to know how to do it. A number of clients thought exactly the same thing and approached their BMS providers to explore this option. However, it isn't as simple as it seems; estimates of re-development time vary from 18-24 months. Also, further extra sensors and inputs/outputs are required and the boiler room outstation will probably need to be upgraded as well.'

'Nor is it a matter of either/or. In the majority of the projects we've carried out, we have integrated the M2Gs with an existing BMS so that the two work in harmony and maximise the energy savings achieved. The two technologies are completely compatible, with M2G delivering additional control and fine-tuning with no ongoing maintenance or servicing costs required' he notes.

So what does the future hold for Sabien Technology, we wondered?

'We're at a stage where we are building on the successes we have had with BT, Marriott Hotels, Lloyds Banking Group, O2, Virgin Media, Environment Agency, AVIVA and many others.

There are also a number of service providers: such as British Gas, Jones Lang LaSalle, Serco and Balfour Beatty Workplace - which are now offering M2G to their customers.

'We are also in talks with the majority of the UK's leading service and energy providers about offering M2G to their clients. Our reputation as a tried and trusted player will enable us to become a supplier of choice for UK organisations as they face the challenge of reducing CO₂ emissions, increasing legislation and volatile energy prices', O'Brien concludes.

Further information can be found at www.sabien-tech.co.uk