Achieving Energy Efficiency in Buildings

transcript

Boston University Slideshow Title Goes Here

Achieving Energy Efficiency in BuildingsMichael Gevelber, Associate Professor

Mechanical EngineeringCo-chair, BU Energy Committee

Member, BU Sustainability Committeegevelber@bu.edu

•Results of BU Energy Audit Course

•Overview of US Building Energy Use

•Achieving Energy Efficiencies in Commercial Buildings

•Residential: Perform your own energy audit

Boston University Slideshow Title Goes HerePlasma Spray: TBC’s & Fuel Cells

Ebeam deposition: optical coatings Electrospinning: nanofiber

H Crystal Growth

Advanced Control Research Application Areas

Boston University Sustainable Neighborhood Living Lab

What’s Global Warming & What Causes it?

Michael Gevelber, Associate Professor Mechanical Engineering, co-chair BU energy working group, member of

BU Sustainability Comm & CEESI

20082008 20092009

Summary of Findings from GE 520/MN 500: “Energy Audit/Conservation Analysis of BU’s Charles River Campus”

20102010

Boston University Slideshow Title Goes HereEnergy Intensity (Per Sq Foot)Total Energy Use

Cleveland, C. (2007, Oct 24). Energy and Emissions Footprint: Boston University Charles River Campus. Presentation to the BU Energy Club.

Results of 2007 Energy Audit

0.0E+00

2.0E+11

4.0E+11

6.0E+11

8.0E+11

1.0E+12

1.2E+12

1.4E+12

1.6E+12

1991199219931994199519961997199819992000200120022003200420052006

Heavy oil

Light oil

Electricity

Natural gas

68% Growth in Energy Use

1991199219931994199519961997199819992000200120022003200420052006

(1000)

18% Increase in Energy Intensity

• What are the reasons for these trends?

• What can be done to reverse these trends?

Building Energy Use by FuelCharles River Campus 2005-2007

Energy Supply106 kBtu

Energy Expenses

Overview of US Building Energy Use

Boston University Slideshow Title Goes HereResidential

Commercial

Industrial

Transportation

Energy Use/Inefficiencies of US End-Use Sectors

12.4 (57%)

11.7 (63%)

12 (39%)

21 (75%)

In Quads

Buildings account for ~40% of energy use!

73% of electricity use

Based on llnl energy flow charts

Major opportunity is focusing on efficiences

Boston University Slideshow Title Goes HereElectricity: 4.7 direct(Electricity GenerationWaste: 10.2)

HeatingGas: 5Oil:1.2Biomass: .5

Total: 21.6

Residential

11.5 Q Direct Use

21.6 Quads Total

22% of U.S. Energy use

Heating ~58% of direct

31% overall

Energy Use/Inefficiencies in Residential and Commercial Sectors

Commercial

8.6 Quads Direct

18.5 Quads Total

19% of U.S. Energy use

Heating ~ 45% overall

9.2 to end-use (43%)

6.7 to end-use (37%)

Electricity: 4.6(Electricity GenerationWaste: 10)

HeatingGas: 3.2Oil: 0.6Coal and Biomass: 0.1

Total: 18.5

Input (Quads)

Direct Waste: 2.3 (20%)

Electricity Waste: 10.2

Total: 12.5 (57%)

Direct Waste: 1.7 (20%)

Electricity Waste: 10

Total: 11.7 (63%)

Waste (Q)

* 1 Quad (Q) = 1015 BTU

Direct waste assumes 80% combustion efficiency.Question: Is that really the total waste?

Where are the opportunities for greater efficiency?

Energy Savings: Solving for the Hidden Costs of HVAC

Our Focus: HVAC is 50-70% of ALL energy used in mid/large size buildings

Achieving Energy Efficiency in Existing Commercial Buildings

Strategy: Reduce high air flow rates which were implemented when energy was cheap.

Our Solution • Develop new tool to re-optimize HVAC control • This is not addressed by current tools• Based on real buildings, experience and data

Funded by MA Clean Energy Center Professor Gevelber & Professor Wroblenski BU Mechanical Engineering

Boston University team Aeolus: MIT Clean Energy Contest -Winners of Energy Efficiency track. 2013

Residential: Perform Your Own Energy Audit

How to Become an Energy Detective: Help save the world and make some money at the same time

Prof. Michael GevelberMichael Cannamela, Ph.D Candidate, Mechanical Engineering

Home Energy AuditINPUTS

Yearly Usage Unit

ELECTRICITY 0 kWh/yr

HEATING gas 0 therms/ yr

oil 0 gal/yr

TRANSPORT

car #10 miles/yr

20 mpg

car #20 miles/yr

20 mpg

car #30 miles/yr

20 mpg

SIZEarea ft2

occupancy 0 persons

LOCATION MA -

ENERGY PRICES

electricity 0.174 $/kwh

gas 1.63 $/therm

oil 2.9 $/gal

gasoline 3 $/gal

RESULTS COMPARISON

yearly

use unit % totaluse value

ENERGY

electricity 0

kBtu/yr

28775 <----MA average

heat 0 86165 <----MA average

transport 0

TOTAL 0

electricity 0

tons/yr

heat 0

transport 0

TOTAL 0 32 <----US average (4 person house)

electricity 0

heat 0

transport 0

TOTAL 0

HOUSEEFFICIENCYPER AREA

electricity

kBtu/yr/ft2

12.87 <----MA average

heat 38.54 <----MA average

TOTAL 51.40 <----MA average

How much energy and carbon your household uses and for what end-uses?

How much money you spend on different forms of energy? Helps to understand what efficiency investments have good payback?

What is the relative efficiency [kbtu/ft2] of your house?

Which areas can more easily be made more efficient?

MA AVG

House size

2236 ft2

Occupancy

2.55 persons

Why focus on energy: what problems does the US face?

• Limited energy supply & global politics– U.S. is only 5% of world population but consumes

20% of world energy

• Pollution and Green House Gas emissions

• $ energy is getting more expensive

How do we know where to focus?

Total Annual Energy Cost

• Being more energy efficient to reduce our carbon footprint also saves $$$$

How’s Goldner’s class doing in terms of GHG emissions?

But how can we do better?

Where should we focus on to reduce energy use?

Energy Use in Your House

• What forms of energy do you use in your house?

• What are you using this energy for?

• How compare relative efficiency? KBTU/sq ft

Household Electricity Use

• What are some ways to increase the efficiency of your electricity use?

• What are the major uses of electricity in your house?

Household Natural Gas Use

• What are the best ways to increase the efficiency of your gas use?

• What are the major uses of Natural Gas?

Distribution of CO2 Sources

• Where should we focus?

Where focus to reduce energy costs?

What’s surprising?

The Importance of Screening Data

• Here is a histogram of the annual gasoline usage of those who participated in the home energy audits.

• Do these values make sense? What would be a good way to go about estimating someone’s average gasoline usage per year?

• In order to estimate someone’s average gasoline usage, you would need to know: how many vehicles they use, how many miles those vehicles can travel with one gallon of gasoline (mpg), and how many miles they travel in a year.

• For example:Someone has 1 car, that gets 20 mpg, and they travel 15000 miles/year. They would use: 15000 (miles/year) / 20 (mpg) = 750 (gallons/year).

• Or:Someone has 1 car, that gets 12 mpg, and they travel 30000 miles/year. They would use: 30000 (miles/year) / 12 (mpg) = 2500 (gallons / year)

• Here is that same histogram with the Environmental Protection Agency’s (EPA) estimates on average annual gasoline usage.

• Here is a histogram of the areas of the different houses that participated in the home energy audits.

• Do all of these values make sense?

• To put things in perspective, Bill Gates’ largest house is a 66,000 ft^2 mansion in Washington (2).

• In order to determine if these values are valid, it might help to look at the Energy Usage Index (EUI). This is a measure of how much energy is used per year, per square foot (kBtu/yr/ft^2).

• As a reference, the Massachusetts average has been added to the plot. How would an increase in area of a house change the EUI? Do you think the energy usage increase as well?

• The house with the largest area corresponds to the house with the lowest EUI. What does this tell you about the data?

Same house

BU Energy Use:

SMG (220)

- Focus on high energy density buildings

Photonics (336)

LSEB (468)

140 BSR (140)

NOTES: (1) BUMC Net Area does not include NEIDL and rental properties (2) Data sources from BU energy audit class (M. Gevelber) & Facilities (P. Zhong & A. Ly)

FY2007 Net Area Energy Cost

CRC 9.3 M ft2 79%

BUMC(1)

1.2 M ft2 21%

Total 10.5 M ft2 100%

Boston University Slideshow Title Goes HereReduce Nighttime Exhaust (8 hrs)

•Find energy used to condition a unit volume of air

•Find volume of air exhausted

•Add energy used to condition air across all units of air exhausted

Estimated Savings

•11% of total oil ($7,400)•7% of total electric. ($10,900)

Estimated Implementation Cost

$17,500—about 1 year payback$17.5k to AndoverThe rest is Rebalance! Was it needed?

Estimate of Potential Setback Savings

Heating oil savings

Cooling electricity savings

Original Estimate Updated

13% ~$20k

$50k <2

21% $12,522

BU Energy Use:

SMG (220)

- Focus on high energy density buildings

Photonics (336)

LSEB (468)

140 BSR (140)

NOTES: (1) BUMC Net Area does not include NEIDL and rental properties (2) Data sources from BU energy audit class (M. Gevelber) & Facilities (P. Zhong & A. Ly)

FY2007 Net Area Energy Cost

CRC 9.3 M ft2 79%

BUMC(1)

1.2 M ft2 21%

Total 10.5 M ft2 100%

Boston University Slideshow Title Goes HereReduce Nighttime Exhaust (8 hrs)

•Find energy used to condition a unit volume of air

•Find volume of air exhausted

•Add energy used to condition air across all units of air exhausted

Estimated Savings

•11% of total oil ($7,400)•7% of total electric. ($10,900)

Estimated Implementation Cost

$17,500—about 1 year payback$17.5k to AndoverThe rest is Rebalance! Was it needed?

Estimate of Potential Setback Savings

Heating oil savings

Cooling electricity savings

Original Estimate Updated

13% ~$20k

$50k <2

21% $12,522

Achieving Energy Efficiency in Buildings

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