Solution “Typical” Payback (Months)

Energy Savings (%)

Advantages Considerations

Automatic Monitoring and Targetting (aM&T)

3 to 12 3 - 10% of total utility use

Highly useful for effective energy management

Critical information for employee engagement programmes

Can identify low, medium, high cost opportunities for energy and utility consumption

Can identify exceptional consumptions immediately

High quality performance reporting

Need to consider means for collecting data

Essential to have appropriate reporting and processes

Level of sophistication tailored to energy spend

Resource support considerations

High efficiency motors

3 to 12 2 - 5% Improved intrinsic efficiency

Direct replacements for standard motors

Implement as part of a motor management programme

Efficiency level IE2 is mandatory from June 11

Not necessary for very light duty applications (say less than 1000 hours per year)

May not be suitable for high torque applications - e.g. Crushers in the aggregates industry

Appropriate alignment (laser) should be considered for direct drive applications

Variable Speed drives

3 to 12 20-70% Smoother control of process - reduced maintenance and improved reliability

Controlled starting and stopping

Longer system life

Different level of savings for Variable Torque and Constant Torque applications

Ensure that the motors are suitable for VSD operation - esp. old or cheap motors

May not be able to reduce the speed greatly if high constant head pressure is required

Correct installation and maintenance is important

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LED’s 1 to 12 70% Higher lumens / Watt Consideration must be given to the environment in which lamps are being fitted

Colour rendition qualities need to be considered

(Metal Halide) High Frequency fittings

12 to 36 10-30% Integrate controls

Dimmable

Maximum savings available where daylight savings to be made

(T5 Fluorescent)

12 to 36 10-50% Dimmable

Integrate controls

Higher number of fittings may be required if retrofitting existing Fluorescent lamp installation

High Frequency adapters

12 to 36 20-50% Reduced installation requirements

Energy savings similar to high frequency fittings

Maintenance

May not be possible to retrofit to older fittings

Controls [including constant light control with DALI,KNX etc]

12 to 48 30% Improved control of lighting

Reduced ‘lighting pollution’

Extend lamp life

A number of light fittings will not be compatible with controls

Consideration should be given to integrating lighting control to local environment / process control

Enhanced Automation Systems

12 to 48 2 -10% Operational efficiency improvements

Less labour intensive

Quality of product - consistent

Integrate data collection and energy management functions into existing automation systems

Solution “Typical” Payback (Months)

Energy Savings (%)

Advantages Considerations

Voltage Optimisation 24 to 60 3-8% (Can be higher in special cases)

Reduce energy consumption by providing the optimium voltage (most sites have an ‘over’ voltage condition)

Can improve reliability of equipment - reduce failures and maintenance

Can integrate other power quality measures such as harmonics

Similar benefits may be achieved through ‘tapping down transformers’. Sometimes the benefits are “oversold”

A power survey should be carried out in order to evaluate benefits

Consider full installation costs and impact

Savings depend on the mix of loads in the facility so it needs careful consideration

Combined Heat & Power

36 to 84 80-90% Reduced CO₂ emissions through high overall system efficiency typically 80-90% for reciprocating prime mover

Cooling with tri-generation

Reduce ‘supply’ risk

Unit needs to be sized so that the majority of heat can be used

Consider environmental impact of the CHP systems - noise, pollution, access etc

Use of Absorption chillers. Economics subject to using heat that would otherwise be rejected. Ensure Availability of skills needed for maintenance of tri-generation systems

Consideration needs to be given to the fuel source (renewable?) and type of CHP used taking into account Heat:Power ratio

Anaerobic Digestion 36 to 60 80-90% Reduce chemical oxygen demand (COD) and therefore effluent charges

Pass gases through CHP set

Reduce costs associated with disposing of organic waste

Reduce site CO₂ emissions

Effluent strength, quality and amount of “feedstock” materials need to be sufficient to maintain production of gases

Treatment of gases maybe required prior to use in CHP set

Environmental planning and regulation

Dependent of ROCs / FIT

Power Management Controls

12 to 48 Costs savings mainly derived via tariff power factor correction charge offset

Reduce costs - e.g. tariff management

Improve power quality

Reduce energy demand

Benefits will depend upon the tariff charges from the supplier

Can improve system reliability

Higher power factor and lower harmonics reduce kWh consumption

Building Management System

3 to 48 15-25% Improve plant control (AHUs, Chillers etc)

Improves the comfort and flexibility of the facility

Consider integrating into process control systems

Building Controls 3 to 48 15-25% Improve plant control (local level)

Possibility of intelligent building automation

Enhanced building comfort and flexibility

Consider integrating into building systems

Correct installation and maintenance is important

Use BMS as the energy management system

High efficiency fans 36 to 84 20% Improved intrinsic efficiency Consider as part of larger project (VSD) as the payback will be significantly shorter

HVAC (Filters)

3 to 24 10-25% Reduce pressure drop across filters

Reduce fan power for same volume (VSD)

Greater savings realised when installed in system fitted with VSD

Solution “Typical” Payback (Months)

Energy Savings (%)

Advantages Considerations

HVAC (Free Cooling) 1 to 24 up to 75% of cooling requirement

Free Cooling can displace use of refrigeration plant

Reduce CO₂ emissions

Where displaces use of cooling systems

Compressed Air (VSD)

3 to 24 10-35% Increased efficiency kW/cfm at part loads

Particularly suitable for sites with varying demand

Base load should be managed by fixed speed compressors

Compressed Air (Pressure)

0 to 24 3-12% Reduce the power demand kW/cfm

Reduce the power demand kW/cfm

Pressure should be reduced gradually to ensure that there are no adverse effects on production

Compressed air (leaks)

0 to 12 10-30% Reduce demand

Reduce base load

Best approach is to aim to reduce 80% of leaks

Survey plant monthly

Wind Power

72 to 120 N/A Renewable energy

Claim ROC’s & FiTs

Reduce CO₂ emissions

Planning in built up areas is expensive and can be difficult

Small scale wind may struggle with payback once maintenance is included

Large scale is more economic

Ground Source Heat Pumps (GSHP)

36 to 84 N/A Renewable energy

Reduced CO₂ emissions

Claim RHI

Heat obtained is low grade and therefore usually only suitable for under floor heating. Buildings should be thermally efficient to minimise space heating load

Air Source Heat Pumps (ASHP)

36 to 84 N/A Renewable energy

Reduced CO₂ emissions

Claim RHI

Integrating into existing heating systems may be difficult

Solar Thermal 12 to 36 N/A Renewable energy

Reduced CO₂ emissions

Claim RHI

Provides domestic hot water, although could be integrated into a space heating system

Boilers (Combustion Efficiency)

3 to 12 2-45% Optimise Efficiency, Reduce primary energy

Reduced CO₂ emissions

Ensure correct burner setup

Boilers (Steam raising efficiency)

1 to 12 3-30% Reduce energy

Reduced CO₂ emissions

Reduce water use through optimised water treatment

Consider optimising boiler heat exchange, inc cleaning & use of economisers, boiler load control

Leak and steam trap assessment

Reducing blowdown

Biomass

36 to 84 N/A Renewable energy

Reduced CO₂ emissions

Claim RHI

Fuel type, storage space and delivery are important considerations

Refrigeration (COSP) 3 to 18 10-45% Reduce energy

Increased efficiency - kWh cooling/kWh electrical input

Reduced CO₂ emissions

Reduce pump power using VSD’s

Solution “Typical” Payback (Months)

Energy Savings (%)

Advantages Considerations

Refrigeration (Pressure)

12 to 36 2-6% Reduce energy

Seasonal benefits

Reduced CO₂ emissions

Reduce compressor power

Link to ambient temperature

Refrigeration (Cooling Tower Fans)

12 to 36 20-70% Reduce energy

Control fan power to meet cooling demand (VSD)

Reduced CO₂ emissions

Care when considering other conflicting options for energy conservation

Re-balancing is often required on a more regular basis in cooling towers

Natural Ventilation

1 to 120 Site specific Reduce energy & CO₂ emissions Displaces energy from use of mechanical plant & equipment. Best achieved when integrated into building design

Optimise the ventilation requirements prior to calculating “payback” times

Solar Photovoltaic (PV)

48 to 120 N/A Renewable energy

Claim FiTs

Reduced CO₂ emissions

Improved economics when integrated into building fabric when constructed

Check feasibility of larger systems based on new FiTs

Can also be very helpful in improving building ratings (e.g. BREEAM & LEED)