The Energy Consultant's Guide to a Green Energy Brief

Posted by John Hyde on 17-Mar-2015 11:30:00

A practical overview of how Combined Heat and Power technology can be specified to meet a green brief.


The UK is leading the way on global climate change.

BlogImageThe UK government continues its strategy to reduce carbon, reduce cost and improve security of energy supplies by reinforcing its energy conservation policies and energy legislation - to promote and sustain organic growth.

Targets: “To cut greenhouse gas emissions by at least 35% by 2020 and 80% by 2050”.

Incentives: “Environmental taxes that encourage businesses to operate in a more environmentally friendly way”.

Increasing the amount of energy from renewable and low carbon technologies will:

  • Reinforce the security of the UK’s energy supply.
  • Encourage investment and growth in projects that support new business.
  • Help target the reduction in greenhouse gas emissions.


The green energy brief for new projects

Renewable and low-carbon technologies support energy efficiency and sustainability – key terms used in specifications for new energy projects.

When a green energy brief talks about conserving energy, reducing energy costs, reducing CO2 emissions, and improving the reliability of energy supply, energy consultants should consider Combined Heat and Power (CHP), which can generate:

  • Low carbon energy – using fossil fuels, e.g. natural gas.
  • Renewable (zero-carbon) energy – using non-fossil fuels.


How do the credentials of CHP stand up to a green brief?

CHP is the simultaneous generation of electrical and heat energy.

  • CHP operates at energy efficiencies of up to 85%
  • It offers energy savings of 30% over conventional generation (power station/boilers)
  • Waste energy is reduced
  • Energy is recycled – CHP heat is utilised instead of being ‘rejected’ to atmosphere
  • Carbon emissions are reduced by up to 30%
  • CHP is a proven and reliable technology – providing sustainability


How to specify CHP for optimum efficiency

To achieve optimum energy efficiency, CHP must be sized to match the site’s electrical and heat energy profiles.

  • Energy profiles should include any likely future energy conservation measures.
  • Correctly sized CHP will produce an optimum level of energy and CO2 savings - allowing the scheme to classify as Good Quality CHP.
  • Undersized CHP will mean a shortfall in energy and CO2 savings.
  • Oversized CHP will mean a failure to deliver the energy and CO2 savings that CHP can produce, and the client will not benefit from the business incentives available.
  • Installation design should include good access for long-term operation and maintenance.


Alternative renewable fuel options

Renewable or zero-carbon CHP units are fuelled by:


A gaseous biofuel produced by the biological breakdown of organic matter (biomass), e.g. raw materials such as agricultural plant waste, food waste, manure.


A liquid biofuel produced from natural oils, e.g. rapeseed oil, sunflower seeds, reclaimed vegetable or animal fats.

CHP provides an excellent high-energy solution when installed alongside anaerobic digestion plants producing biogas fuel. The process generates renewable heat and electricity, and may additionally qualify for renewable energy financial incentive schemes:

  • Renewables Obligation Certificates (ROC)
  • Renewable Heat Incentives (RHI)
  • Feed-in Tariff (FiT)



  • CHP can help energy consultants deliver a client’s green energy brief.
  • The green credentials of CHP mean higher efficiencies than conventional energy supplies.
  • The CHP must be correctly sized to achieve its optimum efficiency.


Find out everything you need to know about specifying CHP. Get your free eGuide now: Essential CHP Checklist - What every consultant needs to know

Essential CHP Checklist - What Every Consultant Needs to Know

Topics: CHP / Cogeneration, Consultants

John Hyde

Mechanical & Manufacturing Engineer with over twelve years’ experience in the UK, USA & European Low Carbon Technology industries. Based in London, John works with consultants from early feasibility stages to investigate variables which influence CHP design. Endeavouring to increase awareness of the economic implications and best practice design of CHP through presentations of CPD seminars.