Green Energy Auditingfor a Low Carbon Economy

Contents

• Who we are• Project introduction• Energy Auditing – Sources– Methods

• GENERATION methodology• UK implementation• Conclusions

Who we are

• tEC – the Environment Centre– Independent Charitable Company– Provide help and advice to individuals, communities, business and

public authorities– Working on EU funded projects

• ARK Specialist Services– Carbon Trust Accredited– Independent Building Services and Energy Management – Focus on Modelling of energy demand

GENERATION Project• Purpose

To create a “simplified” energy auditing process for buildings leading to the reduction of energy consumption and emissions.

• Partners–Andalucían Institute of Technology, Spain–University of Malaga, Spain–tEC, UK–AGH technical university, Krakow, Poland–Province of Modena, Italy

• GENERATION is part of a much larger EU funded research and best practice programme called POWER.

GENERATION Project• Overview

– Project began early 2010 with an 24 month timeframe

– Project partners have external advisory boards• Local authorities• Private companies• Potential end users of the tools

– Regional differences in weather, building fabric and occupancy patterns taken into account

Energy Auditing• Why bother?

– Is your building using too much energy?– How do you know?– What do you compare it against?

• What to audit?– Overall bill– Where is the energy going?– Equipment – User behaviour

The purpose of an energy audit is to highlight both GOOD and BAD

Energy Auditing - Methods• Benchmark Based

– Total consumption is corrected • Weather• Occupancy hours• Production output

– Direct comparison with published averages• CIBSE Guide F, CIBSE TM46:2008• Carbon Trust ECG’s

• No breakdown by usage• Some benchmarks are out of date (1990’s or earlier)• Very simple, low effort, no disruption• Use your DEC - DISPLAY ENERGY CERTIFICATE

Energy Auditing - Methods

• Walk-around– Typically Consultant led but can be done from checklists– Carbon Trust funding was available– Between ½ to 2 days with minimal disruption– “Snapshot” view

• Bills analysis is usually included• Breakdown based on assumptions• Output is a report• Recommendations are consultant dependent

Energy Auditing - Methods

• Detailed audit– Consultant or Energy Manager Led– Long term – weeks, months or years of data gathering– Installation of sub-meters required– Full asset register created

• Breakdown based on measurement• Pre- and Post- implementation checks• Part of an energy management strategy

Energy Auditing - Methods

• Model Based– Create a computer simulation of the building– Very accurate for administration and hospital type buildings– Detailed information required about building fabric

• Does not take into account manufacturing loads• Probably exists for new (post 2006) buildings – SBEM• Allows effect of improvements to be modelled• Provides a bespoke benchmark – particularly for heating• Time consuming

GENERATION Methodology

• There are no Pan-European benchmarks– This rules out the simplest form of audit – the EPC– Benchmarks can’t be used to predict the effect of

improvements

• Walk-around surveys were deemed to require too much specialist knowledge

• GENERATION uses a model based approach

GENERATION MethodologyAnalysis of bills (power supply)

Building Description

Demand calculation by the use of “Generation”

software

Operative COP/EER

Estimation of the Energy

Consumption

Breakdown of the Energy

Consumption

Results validation

Use the model to quantify proposals of

improvement

Adjustment of COP/EER and infiltrations

1. Enter 12 months consumption data2. Create a model of the building

• Building fabric• Zones• HVAC plant

3. Software creates a breakdown and estimated consumption

4. User “tunes” the COP/EER and infiltration to match the actual load

5. Impact of changes can be validated

Problems:

User still needs to know a lot about the building! Not so SIMPLE

Model doesn’t tell you if the building is performing optimally

GENERATION Tool

• There is a tool…..

…… but it is text based and not particularly user friendly.

It is also temperamental

SO…….

Using the GENERATION Methodology

• USE the methodology but not the tool

• The GENERATION tool is similar to iSBEM which is also free

• There are commonly used commercial modelling tools which are much easier to use but more accurate– IES-VE– TAS

• Therefore, for an accurate energy audit we recommend using these tools to build the model

Using the GENERATION Methodology

MonthHeating Cooling Aux Lighting Hot

Water Equipment Total

January 2242.3 0 50.0 1071.0 83.4 765.0 4211.7February 1449.4 0 44.5 962.6 75.1 692.7 3224.3

March 1329.8 0 50.0 1034.9 83.4 765.0 3263.1April 587.0 0 41.7 781.7 72.3 670.5 2153.2May 255.9 0 47.3 803.9 77.9 731.6 1916.6June 61.2 0 47.3 759.5 77.9 728.8 1674.7July 2.8 0 50.1 812.3 83.5 762.3 1711

August 0 0 50.1 829.0 83.5 762.3 1724.9September 130.7 0 44.5 856.8 75.1 698.3 1805.4

October 567.5 0 50.1 1090.5 86.2 792.8 2587.1November 1393.8 0 50.1 1062.7 83.5 768.7 3358.8December 1914.0 0 41.7 926.4 72.3 673.2 3627.6

Month Gas ElectricityJanuary 2326.9 1886.2

February 1523.4 1699.8March 1412.2 1850.0April 658.9 1493.9May 336.4 1583.0June 141.8 1535.7July 86.2 1624.7

August 83.4 1641.4September 208.5 1599.7

October 656.1 1933.5November 1476.2 1881.5December 1984.9 1641.4

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec0

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Predicted GasPredicted EleActual GasActual Elec

Conclusions

• The GENERATION project was ambitious in its objectives • Whilst the tool may not be applicable to the UK, the methods employed

are• Energy audits need not be overly complex

– Choose a level that is appropriate– There is more than one definition of an energy audit !!

• Some expert knowledge will be required– To create an accurate model– To identify savings opportunities

• Consider using DECs as a benchmarking tool

Thank you

Any Questions?