EST Field Trial – Results

and next phase

GSHP Seminar

2nd November 2010

Jaryn Bradford

Development Manager

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Energy Saving Trust

• We are the UK’s leading impartial organisation helping

people save energy and reduce carbon emissions.

• We’ve saved £1.5 billion on people’s fuel bills and

140 million tonnes (lifetime savings) of CO2 since 1994.

Providing quality

assurance for goods,

services and installers

Helping local authorities

and communities

to save energy

Expert insight and

knowledge about

energy saving

Supporting

consumers

to take action

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Technology monitoring is critical

for policy development….

• Micro-wind field trials

• Heat pumps

• Solar water heating

• Condensing boilers

• Heating controls

• Future…• Smart Home Energy Management

• Thermal Stores

• Micro CHP inc.

• Domestic Fuel Cells

• Introduction: project background and update

• Results from field trial

• Presentation of results from field measurements

• Findings from peer review

• Objectives of field trial year 2

Agenda

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Heat pump field trial – objectives

Heat pumps are a proven technology in Europe but

relatively new to the UK residential sector

• Technical focus:

• Factors that influence performance of the technology

• Potential energy and carbon savings

• Implications for policy and standards

• Consumer focus:

• Evaluate how householders use the technology

• Which measures are most appropriate?

• Should heat pumps be adopted by the mass market?

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Project overview

• 83 installations – residential only

• 14 different manufacturers

• Air, ground, & water source

• Many & varied configurations (44 in total)

• All monitoring “outside the box”

• Private & public housing

• Objective – determine the efficiency of the ‘system’

• Not a side-by-side comparison of COPs

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Site selection

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Heat pump locations

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A total of 83 heat pumps

distributed across the

UK were monitored in

the field trial

Generic monitoring arrangement

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System boundaries

• Developed in discussion with UK and EU experts

• Review of CERT, SAP Q, SEPEMO, EN14511,

EN15316, industry comments

• 4 variables

measured:• Heat pump COP

• Heat pump SPF

• System COP

• System SPF

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System efficiency – ASHP/GSHP

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Heat Pump COPs – ASHP/GSHP

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Space and water heating• 74% of users agreed that the system meets their household’s space

heating requirements

• 86% agreed that the system meets hot water requirements

• Private householders reported greater satisfaction (79%) with space

heating than the social housing residents (67%)

• Only small differences between ground and air source systems in user

satisfaction with heating and comfort

Operation and controls• 30% of users had difficulties operating the system

Overall• Maintenance and running costs were one of the main factors affecting user

satisfaction

User feedback

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• Large variance in COP / SEFFs - 1.2 min to 3.6 max

• Little rational statistical correlation of many observed

variables – more study will be undertaken

• Some GSHP generally not performing as expected –

need to find out why.

• Good potential for CO2 savings, especially replacing oil

and direct electric. Savings compared with gas are poor.

• Significant differences of user satisfaction with warmth,

comfort, fuel bills & control

Key findings (i)

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Key findings (ii)

• Careful design of auxiliary systems is required • Pumps/controls/standby

• Performance sensitive to installer skills/knowledge• Different to boilers

• Hot water production• Further investigation is required

• Internal temperatures• Evidence of high internal temperatures

• Comparison being undertaken with other

field trials

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Comparison with EU field trials

• Fraunhofer (Germany)• New-build & retrofits

• GSHP & ASHP

• Swiss Federal Office of Energy• GSHP & ASHP

• 5+ years of data from 200+ sites

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German field trial - GSHP

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German field trial - ASHP

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Swiss field trial – GSHP

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Swiss field trial – ASHP

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Year 2 (i)

The field trial has been extended for a second year to:

• Collect data for an additional year

• Attempt to improve underperforming sites

• Identify and understand good performing sites

• Undertake additional analysis of existing data

• More engagement with manufacturers & installers

• Add new sites

Supported by DECC, ETI, & EST’s members –

but more funding and support is needed!!!

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Year 2 (ii)

Examples of additional work:

• Review sizing strategies

• Investigate control regimes

• Investigate ground loops. etc

• Impact of DHW production of COPs / SEFF

• Undertake on-site interventions

• Replace components

• Upgrade radiators

• Additional monitoring and data collection

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What really has caused the results?

• Load factors?• Are the sinks and sources large/small enough?

• System sizing? • Were the installations under or oversized?

• Use of controls? • Can the occupants use the controls?

• Customer behaviour? • Do certain lifestyle patterns or tenure type affect the results?

• Insulation and air tightness?• Do heat pumps in well-insulated houses perform better?

• Better now with MCS?• Has MCS improved the quality of installations ?

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The Future is SMART