Building Energy Saving Potential

Cooperative Energy Efficiency Design for Sustainability16 July, 2010James Russell

Asia Pacific Energy Research Centre

Outline

• Purpose of the study• Findings from literature review• Methodology• Data requirements• Next steps

Purpose

The estimate of energy saving potential will:1. provide key decision makers and important

stakeholders with information that they can use to prioritize this particular policy.

2. Put building energy codes into the context of other goals, programs and studies.

In addition to the two main purposes, this study will also provide a better understanding of what data is currently available, and what additional information may need to be collected as part of the policy design process.

9/8/2010 3PURPOSE

Literature Overview• Sources consulted: Academic journals,

conference proceedings, and studies by governments and other organizations

• Key Findings:1. Assessment of the energy saving potential is performed in

many economies prior to code adoption2. A common method for assessing the energy saving

potential is to simulate the before and after energy consumption of a somewhat representative sample of buildings

3. Some previous work on this subject has been conducted by the participating economies and this should be referenced by our analysis.

9/8/2010 4LITERATURE REVIEW

Specific Findings from the Literature• Potentials and costs of carbon dioxide mitigation in the world’s buildings (2008, ongoing) – This

study performed a meta-analysis of previous regional/national studies of energy saving potential to estimate that 29% of global, building-related CO2 emissions can be cost-effectively eliminated.

• The economics of energy efficiency in buildings (2009) – Using the WBCSD model, finds that using codes and standards to induce a 10% premium on building-sector investment (which is recouped in energy savings) and a modest carbon price can reduce CO2 emissions ~50% below BAU in 2050.

• Modeling of end-use energy consumption in the residential sector: A review of modeling techniques (2010) – reviews modeling techniques available to a study of this type, defining bottom-up type approaches (like ours) to be flexible and appropriate for estimating technological changes induced by a building code, but sensitive to assumptions about users’ actual behavior.

• Revised Building Energy Code of Thailand: Potential Energy and Power Demand Savings (2010) – using an audit database to establish the baseline, estimates large savings for the new building energy code in the area of lighting, but only small savings from the modest envelope improvements.

• Building energy efficiency labeling program in Singapore (2008) – summarizes surveys of over 100 buildings. The cutoff for the nation’s top 25% performing buildings is a normalized 178 kWh/m2/year.

• Implementing building energy codes in Hong Kong: energy savings, environmental impacts and costs (2005) – estimates a large benefit:cost ratio for making building codes mandatory.

• Indoor thermal environment and energy saving for urban residential buildings in China (2006) – improving the envelope reduces energy use by 40% (Beijing) and 67% (Shanghai).

• Indonesia: Energy Conservation Partnership Program (2010) – Audits of 62 buildings conducted by 2007 show building energy intensities generally higher than ASEAN’s benchmark intensities.

9/8/2010 LITERATURE REVIEW 5

CON

TEXT

MET

HO

DD

ATA

Scope

9/8/2010 6METHODOLOGY

• Considerations– Likelihood of near-term implementation– Clarity of impact– Data availability

Introducing or strengthening a mandatory building energy code for new buildings in urban areas.

Building Efficiency

New Urban Buildings

Overview of Approach

1. Select key building categories2. Model savings potential of building prototypes3. QA check using building energy intensity data4. Extrapolate savings to future building stock

9/8/2010 7METHODOLOGY

New Building Growth Forecast

in Modeling Period

Building Energy Simulation

[RETScreen]

Baseline PerformanceDefine Building

Categories

Energy Saving per Building Area

High Performance

Total Energy Savingin Modeling Period

Economy CharacteristicsClimate, Materials, Usage

For EachBuildingCategory

Define Baseline CharacteristicsExisting Code, Utility Data,

Past Building Audits, Literature

Define High Performance CharacteristicsInternational Energy Conservation Code

Recently adopted codes (e.g. Hong Kong)

Repeat as Needed

Repeat as Needed

QA Check

How to get to this point depends on

the economy

Select Key Building Categories

Resources

Und

erst

andi

ng

9/8/2010 8METHODOLOGY

• Criteria1. Residential and

public/commercial2. Collectively represent a large

portion of building energy use3. Reflect common

design/construction practices

• Preliminary selection:1. Commercial – office2. Commercial – retail3. Residential – large4. Residential – small

Small ResidentialName Small residential building (SRB)Class ResidentialDescription A 3 story apartment building with 2 units per storyRepresents Estimated to represent __% of new urban residencesEnvelope Wood-framed, clay brick or cement block (select one) + clear glass, and clay tile roofHVAC Split-systems air conditioner (or heat pump) installed by occupantLighting Occupant installed mix of incandescent and compact fluorescent lampsZones and Schedules

Bedrooms – 18-7, M-F; 18-9, Sa-Suliving/dining – 13-22, M-F; 9-21, Sa-Sukitchen/bath – na

Building Energy Code M-mandatory V-voluntary

Chile: Residential building code article 4.1.10 (M)China: Regional Energy Efficiency Codes for Residential Buildings (M)Indonesia: naMalaysia: naMexico: naPhilippines: naVietnam: na

9/8/2010 METHODOLOGY 9

Large ResidentialName Large residential building (SRB)Class ResidentialDescription A 20 story apartment building with 16 units per storyRepresents Estimated to represent __% of new urban residencesEnvelope Mass (tile, cement plaster, heavy concrete, gypsum plaster) + clear glass, and built-

up roof (insulation board, concrete)HVAC Split-systems air conditioner (or heat pump) installed by occupantLighting Occupant installed mix of incandescent and compact fluorescent lampsZones and Schedules

Bedrooms – 18-7, M-F; 18-9, Sa-Suliving/dining – 13-22, M-F; 9-21, Sa-Sukitchen/bath – na

Building Energy Code M-mandatory V-voluntary

Chile: Residential building code article 4.1.10 (M)China: Regional Energy Efficiency Codes for Residential Buildings (M)Indonesia: naMalaysia: naMexico: naPhilippines: naVietnam: na

9/8/2010 METHODOLOGY 10

Commercial - RetailName Retail (RET)Class CommercialDescription A 3 story retail complex with 4 shops per storyRepresents Estimated to represent __% of new commercial floor spaceEnvelope Cavity walls (thin stone, air gap, insulation board, steel frame, gypsum board) + clear

glass, and built-up roof (insulation board, concrete)HVAC Multi-split system air conditioner (or heat pump)Lighting Primarily T12 linear fluorescent lamps with magnetic ballastsZones and Schedules

Retail space – 10-22, M-Su

Building Energy Code M-mandatory V-voluntary

Chile: naChina: National Energy Efficient Design Standard for Public Buildings (M) and Standard for Lighting Design in Buildings (M)Indonesia: Commercial building energy code (V)Malaysia: Guidelines for Energy Efficiency in Buildings (V)Mexico: Mexico Thermal Insulation Standard, Building Envelope Standard, and Lighting Systems Standard (M)Philippines: Philippine National Building Code, energy provisions (V)Vietnam: Vietnam Energy Efficiency Commercial Code (M)

9/8/2010 METHODOLOGY 11

Commercial - OfficeName Office (OFF)Class CommercialDescription A 20 story office buildingRepresents Estimated to represent __% of new commercial floor spaceEnvelope Cavity (concrete panel, air gap, insulation board, steel frame, gypsum board) + clear glass,

and built-up roof (insulation board, concrete)HVAC Water-cooled chiller and one air-handler per floor, + hot water boilers if neededLighting Primarily T12 linear fluorescent lamps with magnetic ballastsZones and Schedules

Lobby – 6-22, M-FOffices – 8-19, M-F

Building Energy Code M-mandatory V-voluntary

Chile: naChina: National Energy Efficient Design Standard for Public Buildings (M) and Standard for Lighting Design in Buildings (M)Indonesia: Commercial building energy code (V)Malaysia: Guidelines for Energy Efficiency in Buildings (V)Mexico: Mexico Thermal Insulation Standard, Building Envelope Standard, and Lighting Systems Standard (M)Philippines: Philippine National Building Code, energy provisions (V)Vietnam: Vietnam Energy Efficiency Commercial Code (M)

9/8/2010 METHODOLOGY 12

Modeling Software

distacfuel

UACDDQ

*

**24

Fuel requirement

System efficiencies

Thermal conductance * Area (including leakage)

Cooling degree days

9/8/2010 13METHODOLOGY

Sample Calculation:

Data: Model Inputs

9/8/2010 14DATA REQUIREMENTS

Baseline ProposedClimate Dimensions ?Operation- Hours of use ?- Heating and cooling set points ?Envelope- U-values (walls, windows, roof) ? Code- “Tightness” ? Code- Window area and solar heat gain coefficient ? Code- Shading ? CodeEquipment- Heating/cooling efficiency ? Code- Ventilation: rate & efficiency ? Code- Lighting: levels & efficiency ? Code- Plug loads ? CodeRetail Energy Prices ?

1

Data: QA and ForecastEnergy use intensity of baseline buildings

9/8/2010 DATA REQUIREMENTS 15

Data Hierarchy: Local Study – Surveys, audits, or other studies of local buildings

Local Expert – economy participants and their recommended expert sources

Regional Study – values from a similar economyAssumed – based on researcher judgment and literature

Data Hierarchy: Local Study – Surveys, audits, or other studies of local buildings

Local Expert – economy participants and their recommended expert sources

Regional Study – values from a similar economyAssumed – based on researcher judgment and literature

Building Efficiency

New Urban Buildings ?

New construction forecast (2010 – 2035)

Example: Taipower provided:1. Consumption by sector and city2. Number of customers by sector and city3. Design assumptions for new building services by sector

2

3

Proposed Schedule for Next StepsTASKS COMPLETION DATE

1. Agree on the key building types This workshop

2. Agree on a schedule for next steps This workshop

3. APERC provides default model inputs to delegates (items 1-3)

October 8

4. Delegates provide approved/revised model inputs to APERC (items 1-3)

November 1

5. APERC models building energy saving potential and provides draft results to delegates for review

December 3

6. Delegates review and provide comments to APERC December 17

7. Results presented and discussed at the second workshop

January

9/8/2010 16NEXT STEPS

FEEDBACK?

9/8/2010 METHODOLOGY 17

THANK YOU!