Where to after CHP?

While combined heat and power is considered as the standard measure when it comes to large carbon emissions reduction in commercial (in particular healthcare and industrial) buildings, there are further avenues healthcare professionals can exploit for often very effective results. Here Dalkia’s Derry Carr considers the wider measures available to organisations, if they ask the right questions and seek the best advice. 

Along with the emphasis on CO2 reduction, in all sectors of business and industry, comes a common perception among decision makers that it is expensive to implement those measures that deliver carbon savings. However, it has been proven that even small steps can be taken that can help to make big differences in the amount of energy used and carbon generated by organisations and the buildings they use and operate.

Different building applications have very different energy demands. For example a hospital’s requirement for constant and unquestionably reliable power is different to the demand for heat in the form of steam that a factory production plant needs to operate effectively. With such variation there is no simple model that organisations can follow to guarantee they have access to and use the right level of heat and power, in the most carbon efficient way.

It is true that combined heat and power (CHP) is a popular method of onsite cogeneration. It is used frequently in the healthcare sector and is also a proven solution for other applications that require a consistently high volume of hot water, such as hotels and universities.

Providing a CHP plant is sized according to the demand, it can deliver very tangible cost and carbon savings in the longer term. However, generating energy in an efficient way is one part of the equation – how this is utilised onsite by the various processes such as HVAC, lighting and building controls is ultimately key to the energy efficiency of the building.

Energy performance

Cutting carbon emissions as well as the cost of the energy used in a building, doesn’t have to be expensive or time consuming process though. With the right help and an energy performance contracting partnership, organisations can look to make small changes with the aim of achieving incremental improvements over a longer period.

The beauty of energy performance contracting is the performance-based procurement method it offers. Such a route provides a financial mechanism for building renewal, without the need for large upfront investment. Under such a contract the savings that result from initial energy improvements are ploughed back into the building to pay for the cost of the project. It is underpinned by a guarantee, which forms part of the KPIs, to ensure the savings never fall short of the outlay. The benefit to organisations is reassurance that can help in planning for the longer term.

Prior to implementing any changes, an initial audit will help an energy services company identify where the key areas for maintenance, renewal and refurbishment are to be found. Staff may be used to struggling with inefficient and unreliable services such as ventilation, heating controls and lighting. Even tired and outdated building fabric presents its own challenges, affecting functional considerations like heating demand, as well as the general perception and mind-set of building users. The result of such degradation is generally a gradual hiking of the operational energy costs of the building.

A tactical approach to energy generation makes sense when it is integrated with a strategy for carbon reduction too. With this in mind an energy performance contract is built on the considerable opportunities for a joined up approach to energy procurement and energy management.

Reduction programme

Lighting is often one of the first elements tackled as part of a phase one reduction programme. Without addressing such a large energy consumer within the building, it stands the risk of simply becoming a sink for energy that is otherwise efficiently generated. Re-lamping at the initial stages will harness the energy and ensure it is not wasted through outmoded lighting arrays. Further into a partnership contract there are amends and small tweaks that can be made to lighting systems, to create improved efficiencies. Intelligent controls and proximity sensors are further steps that can help to ensure lighting is only used as it is needed. 

Advice and consideration should also be diverted for renewable technologies, a popular route for gaining additional savings. A site audit can help to ascertain viability for such solutions. For example where there are south facing pitched roofs there may be a case to be made for photovoltaic systems as a secondary method of power generation. Meanwhile the location and geography of other sites can lend themselves to the use of other renewables, such as biomass as an alternative fuel source for a CHP plant, or ground source heat recovery systems.

Building fabric must also be addressed as a point of action. With many older buildings there is a need to look at the glazing and ensure windows and doors are upgraded and operate efficiently to conserve heat and power.

Positive effect

The impact of building management systems should also be brought to bear on the building’s energy performance. In fact, upgrading a BMS can have a positive effect on the way systems such as HVAC and lighting operate within the building, helping to optimise the opportunity for savings.

Building fabric is a key concern. As with many older hospital buildings there is a need to ensure glazing is efficient and windows and doors operate effectively to conserve heat. Equally, building management systems are invariable out of date or not utilised to best effect.

When improvements are made it is important to engage with an energy management specialist to ensure the resulting savings are tracked and measured. Only by making small alterations and carefully recording the impacts these have can a true understanding of the unique route map for individual buildings be drawn.

Collaborative approach

The hearts and minds of those who use the building on a daily basis need to be factored into the success of any new measures. This is because, despite a high level of automation in proximity lighting, mechanical ventilation and even BMS, ultimately the effectiveness of any measures comes down to the way facilities and systems get used by the building occupiers. This is why the most successful programmes are underpinned by a collaborative approach in fostering an environmental culture that collectively seeks to proactively conserve heat and power.

There are administrative benefits too. A single long term contract has the added advantage of reduced paperwork. By integrating both energy procurement and energy management under a robust and simple process with the condition of a long term fixed cost for the provision of energy services, lighting and maintenance options, the result is a combined saving of cost, energy and carbon.

1