Communications: NREL PowerPoint Presentation Template with White Background Reducing Cooling Demand in High Performance
Homes Through Integration of Efficiency and
Renewable Energy Systems
Ren Anderson, Craig Christensen, Scott Horowitz
National Renewable Energy Laboratory
THE 2006 SUMMIT ON EMERGING TECHNOLOGIES IN ENERGY EFFICIENCY
October 26-27, 2006
Long Beach, California Development of cost neutral Zero Energy
Homes (ZEH) is a critical part of ongoing
DOE efforts to increase the efficiency of US
energy use.
Why Are We Interested in Low Energy
Homes?
Buildings
consume 39% of
total U.S. energy
71% of electricity
53% of natural gas
(primary consumption) Long Term Goal: Homes that Produce as Much
Energy as they Use on an Annual Basis.
Homes with Zero Demand from Cooling are one Step
Towards this Long Term Goal Base Demand
Additional
Cooling
Demand
Long Beach, July 31 Peak Cooling Day
6 AM
12 Noon
6 PM
1 kW
2 kW
3 kW Level 1- Meets Minimum Residential Performance Requirements:
Technology meets minimum availability, reliability, O&M and durability
requirements and provides high potential value to builders, contractors, and
homeowners.
Market Transformation Challenges Level 1- Meets Minimum Residential Performance Requirements
:
Technology meets minimum availability, reliability, O&M and durability
requirements and provides high potential value to builders, contractors, and
homeowners.
Level 2- Can Be Integrated with the Residential Construction
Process
:
Best practice design details and construction sequencing are known and accepted
by builders, contractors, and local code officials. Costs and benefits have been
validated based on construction of one or more pilot homes.
Market Transformation Challenges Level 1- Meets Minimum Residential Performance Requirements
:
Technology meets minimum availability, reliability, O&M and durability
requirements and provides high potential value to builders, contractors, and
homeowners.
Level 2- Can Be Integrated with the Residential Construction
Process
:
Best practice design details and construction sequencing are known and accepted
by builders, contractors, and local code officials. Costs and benefits have been
validated based on construction of one or more pilot homes.
Level 3- Can Be Built on a Production Basis
:
Quality assurance requirements, quality control requirements, and training
requirements are understood and individual responsibilities are accepted by
suppliers, builders and subcontractors.
Market Transformation Challenges Market Accelerators for Above Code Homes
Builders Tend to Embrace Changes
That:
Reduce risks,
Reduce costs,
Reduce complaints,
Reduce training requirements
Increase the reliability of suppliers,
materials and equipment, and
Reduce planning steps or approvals Example of System Integration Risks:
SIP Panel Failures in Cold Climates What combinations of energy saving
features provide customers with the most
bang for the buck?
What are the estimated costs to achieve
different levels of energy savings?
What approachs lead to future
performance goals?
Key System Integration Questions
to be Answered to Define Builder
Packages That Maximize Value: Researchers at NREL have implemented an
optimized discrete optimization technique
(BEOpt) using hourly energy simulations to
facilitate the residential innovation process.
Discrete Optimization Techniques Offer
An Approach to Answer These
Questions : Uses a Consistent Framework for Evaluation
of Incremental Costs and Benefits for Energy
Efficient Homes that Use Renewable Energy
Considers Specific Residential Energy Saving
Options
Defines the Least Cost Curve
Retains Information on Near Optimal Solutions
BEOpt Analysis Approach Uses a Consistent Framework for Evaluation
of Incremental Costs and Benefits for Energy
Efficient Homes that Use Renewable Energy
Considers Specific Residential Energy
Saving Options
Defines the Least Cost Curve
Retains Information on Near Optimal Solutions
BEOpt Analysis Approach Uses a Consistent Framework for Evaluation
of Incremental Costs and Benefits for Energy
Efficient Homes that Use Renewable Energy
Considers Specific Residential Energy Saving
Options
Defines the Least Cost Curve
Retains Information on Near Optimal Solutions
BEOpt Analysis Approach Uses a Consistent Framework for Evaluation
of Incremental Costs and Benefits for Energy
Efficient Homes that Use Renewable Energy
Considers Specific Residential Energy Saving
Options
Defines the Least Cost Curve
Retains Information on Near Optimal
Solutions
BEOpt Analysis Approach Discrete Energy Savings Options Options and Costs Report
Determining Incremental Costs and
Benefits for Energy Efficient Homes Determining Incremental Costs and
Benefits for Energy Efficient Homes
Changes in energy
are tracked for all
energy uses Determining Incremental Costs and
Benefits for Energy Efficient Homes
Cost savings due to reductions
in equipment size are included
in determination of net cost
increases. Overview of Key BEopt Results
0
500
1,000
1,500
2,000
2,500
0%
100%
Energy Savings (%)
Tot
al Annual Cost
s ($/
y
ear)
mortgage
utility bills
cash flow
1
2
3
4
0
500
1,000
1,500
2,000
2,500
0%
100%
Energy Savings (%)
Tot
al Annual Cost
s ($/
y
ear)
mortgage
utility bills
cash flow
1
2
3
4
0
500
1,000
1,500
2,000
2,500
0%
100%
Energy Savings (%)
Tot
al Annual Cost
s ($/
y
ear)
mortgage
utility bills
cash flow
1
2
3
4
Neutral Cost Point
Incremental, Energy
Related Mortgage
Costs
Minimum
Cost Point
Least Cost
Curve
High Risk/High Return Example Results: Costs and Energy Savings of
All Possible Combinations of Options Base Efficiency
Savings Using
Todays
Technology if
Risks are
Resolved
Monthl
y
Cash Fl
ow
($)/nominal
area
Example Results: Interactions Between Energy
Efficiency and Renewable Energy Base Efficiency
Savings Using
Todays
Technology
Future Low Cost PV
(Capacity is Roof Area
Limited)
Monthl
y
Cash Fl
ow
($)/nominal
area
Example Results: Interactions Between Energy
Efficiency and Renewable Energy Base Efficiency
Savings Using
Todays
Technology
Future Low Cost PV
(Capacity is Roof Area
Limited)
Advanced Efficiency
Savings Using Future
Technology
Monthl
y
Cash Fl
ow
($)/nominal
area
Example Results: Interactions Between Energy
Efficiency and Renewable Energy Solar America
2015 PV
System Cost
Target
Monthl
y
Cash Fl
ow
($)/nominal
area
Current
PV Cost
Example Results: Interactions Between Energy
Efficiency and Renewable Energy
Decreasing
PV Cost
2500 ft2 house in cold climate Emerging Efficiency
(10-15 years)
Base Efficiency
(3-5
years
)
Low Cost PV
(5-10 years)
Advanced Efficiency
(5-10 years)
Estimated Timeframe to Market Entry for Different
Residential Strategies Near Term Solution: Zero Demand
From Cooling in 2592 ft
2
House in
Sacramento Average Hourly Miscellaneous Electric Demand, Not Including
Major Appliances, Cooling or Lighting, 2592 ft2 Home in
Sacramento
0
0.5
1
1.5
2
2.5
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
kW
Miscellaneous Electric Demand Average Hourly Electric Demand,
Not Including Cooling,
2592 ft2 Home in Sacramento
0
0.5
1
1.5
2
2.5
1
3
5
7
9
11
13
15
17
19
21
23
Hour
kW
Lighting
Dish Washer
Clothes Washer
Fridge
MELs
Base Electric Demand plus Major
Appliances and Lighting
Based on home with gas hot water, gas range, and gas clothes dryer Cooling and Non-Cooling Electric Demand
on August 20
0
0.5
1
1.5
2
2.5
0
2
4
6
8
10
12
14
16