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Responding to the spread of coronavirus – Message from our Managing Director

Specify long-term CHP operational efficiency

Maximise the efficiency of your Combined Heat and Power with these steps.

Enjoy expected environmental and financial benefits from CHP by ensuring its lifetime operation is efficient and sustainable. Efficiency is more easily achievable when the objectives of the project are defined early on and then correctly translated into a robust project specification. 

Define objectives for the CHP

Whether the project is for a new or existing building, an upgrade, or a replacement of equipment, the objectives will generally cover one or more of the following:

  • Reduce energy waste and save on energy costs
  • Reduce greenhouse gas emissions and improve carbon footprint
  • Enhance the security and reliability of energy supplies
  • Reduce utility costs with on-site generation.

Outline and agree all project goals with stakeholders during the project specification page. This will help to measure the success of the CHP project later down the line.

Understand the requirements of your CHP specification

The typical (gross) operational efficiency of CHP is approximately 80–85% (or 90% net). To achieve this efficiency, the CHP system will need to be designed and installed in line with the building heating and electrical system. 

Accurately size the CHP 

Accurately match the CHP output to the site’s energy baseloads demands by correctly sizing the system. Correct sizing prevents the CHP from running at part-load, which could negatively impact long-term operational efficiency. 

Analyse the operational energy profiles and make use of energy monitoring to provide accurate data. Use this data to inform CHP specification, ensuring it is selected to provide the actual energy output required to meet demand. 

Think integrated when it comes to system design

The CHP system needs to be well-designed so that it operates and transfers all the heat and electricity generated efficiently. The design should allow the system to integrate easily on-site. To get the most from your system: 

  • Always optimise the operation of the CHP heat recovery system, even under part-load conditions, so that it does not waste heat unnecessarily.
  • Maximise the use of CHP heat output by ensuring the CHP operates as the lead heat source (prioritise the use of CHP heat over heat from boilers).
  • Control the heating system’s return temperatures so that the CHP operates continuously, without stopping.

CHP that is sized correctly to meet actual site electrical demands will operate at maximum electrical output and achieve maximum efficiencies. In circumstances when it’s not possible to match varying heat and electricity demand exactly, CHP can be set to modulate its output and continue operating at all times.

The integrated design of the CHP unit and its associated mechanical and electrical services should pay due consideration to suitable, safe access for regular maintenance and servicing. Equipment that is difficult to access will increase the time taken for maintenance, which will increase CHP downtime and overall maintenance costs.

The ideal scenario is a CHP located near a natural gas line, hot water connections and the electrical distribution board, but that doesn’t necessarily always happen.

Prioritise CHP operation and maintenance

Prioritise maintenance throughout the entirety of your CHP project. It will require periodic inspection and routine servicing, as recommended by the equipment supplier. Remote monitoring of the complete CHP system is also essential to frequently check operational performance. This enables engineers to respond fast, diagnose faults, rectify problems remotely, and provide onsite support, where necessary.   

Recognise all financial benefits to demonstrate ROI

Aim to qualify your system under the CHPQA scheme. Receiving certification for ‘Good Quality CHP’ goes hand-in-hand with high efficiency and environmental performance. The benefits of compliance with the CHPQA scheme include:

  • Exemption from the Climate Change Levy (CCL), an environmental tax on fuel supplies and electricity use.
  • Eligibility for Enhanced Capital Allowances (ECAs), where a business can write off the full capital cost of the investment against taxable profits in the year of investment.
  • Business Rates exemption for CHP power generation plant and machinery, where rates apply.

Key takeaways

  • CHP specifications need to consider long-term operational efficiency and sustainability.
  • CHP needs to be correctly sized and the system well-designed.
  • Servicing, maintenance and monitoring are key to achieving sustainability of CHP during its lifetime.
  • The additional financial benefits associated with CHP energy efficiency and environment performance should not be overlooked.

Discover how we can help to power your CHP specification.