On the Path to Zero Energy Homes Lew W. Pratsch Building America Program U. S. Dept. of Energy Association for Energy Service Professionals Zero Energy Home Brown Bag August 24, 2006
Buildings use 71% of electricity Industry 33% Transportation 28% Why Buildings: Huge Opportunities Buildings 39% Cooking 2% Computers 3% 18% Refrigeration 4% Ventilation 7% Office Equip 7% Water Heat 7% 21% Other 10% Cooling 13% Wash 5% Cooking 5% Electronics 5% Computers 1% Other 4% Refrigeration 9% Lights 28% Heating 16% Cooling 10% Lights 12% Water Heat 13% Heating 32% Residential Commercial Source: 2004 Buildings Energy Databook with SEDS distributed to all end-uses
Moving Toward Zero Energy Homes Today s marketable ZEH cut utility bills at least 50% including EE & renewable energy Tomorrow s ZEH Energy savings of 50-70% plus 30-50% on-site renewable energy Integrate/optimize best components for whole house design by climate zone
Progression to Full ZEH by 2020 NAHB-RC national survey (February 2006) shows 82% consumer acceptance of ZEH when energy savings offset mortgage increase
Building America Approach Experts in building science and system engineering offer home builders cost-shared technical support Design assistance Energy modeling Performance specification writing Training and workshops On-site consulting Monitoring Access to Building America research Develop Building America s Best Practice series
Systems Engineering Research Considers Moisture and Thermal Climate Zones
Zero Energy Home Benefits Zero (Net) Energy Zero Peak Load Zero Emissions Zero Complaints (from homebuyers) Zero Cost (83% in Nat. Survey of 1700 indicated that positive cash-flow with mortgage & utility bills is fine) Ideally suited for Time-of-Use pricing Improved comfort of homebuyers
Zero Energy Homes Coverage No More Electric Bills Well, not quite. But 'zero-energy homes' keep them low. power bills routinely topped $200. The grand total over the 10 months they ve lived in the three-bedroom stucco and stone house: $75. August 15, 2005 2006 ACEEE Summer Study Less is More: En Route to Zero Energy Buildings
ZEH Builders/Suppliers
SheaHomes First major production home builder in Nation to build ZEHs as standard in a subdivision 306 homes sold out one year early Shea Homes appreciated faster More profitable to offer as standard than as option If builder, utility or major manufacturer provides warranty, buyer accepts SheaHome Features Homes about 40% better than Title 24 All have solar water heaters 120 have 1.2 kw or 2.4 kw of PV (about 25 upgraded) SheaHome shifted subdivision under construction from above code to ZEH in four months
SheaHomes, San Angelo, San Diego
SheaHomes & Comparison Surveys 367 surveys delivered 231 (63%) response rate ($10 included in survey) 132 (57%) of respondents signed utility release forms Qualitative analysis at 2002 ACEEE Preliminary survey findings reported at 2004 ACEEE Summer Study
Property Value Appreciation Variable Length of ownership (range) Mean length of ownership before resale Mean $ gain Mean % of $ gain Mean $ gain/mo. owned SheaHomes 9.9 43.9 mos. 22.5 mos. $306,510 55.4% $14,492 Comparison 17 40.2 mos. 28.1 mos. $262,968 44.7% $9,301
Bill Savings vs. Comparison Homes (Actual Gas & Electric Utility Bills) Home Category Comparison homes Shea energy efficiency & solar water heating (SEE) Shea SEE + 1.2 kw PV Shea SEE + 2.4 kw PV Avg. Monthly Bill $174 $149 $123 $ 80 % Savings NA 14% 29% 54%
Respondents Agreeing with Statements Shea Non- PV Shea PV owners Control Builders should build very EE homes if they cost less/month to own/operate 92% 93% 92% CEC should give a rebate for solar PV & solar water heaters 80% 91% 84% Federal Gov. should support ZEH R&D 80% 91% 81%
SunChoice Power Meter
PV Owners Digital Display Feedback Shows PV kwh production & household consumption in real time or cumulatively 58% used the digital display at least once a week (15% once a day) 70% help change energy-consuming behavior 40% help determine if system was functioning Homeowners who selected 2.4 kw PV nearly doubled energy saving vs 1.2 kw PV system
PV Owners Like Utilities PV owners have more positive attitudes toward SDG&E than do non-pv owners Believe electric rates have come down 67% of PV owners brag about utility bills vs. 26% of non-pv owners Appears that cutting utility bills over 50% is a tremendous attention getter for selling new homes and provides bragging rights
Clarum Homes Building only ZEH in the future Over 500 ZEHs completed including townhomes & apartments Selling faster than competition ZEH Senior Community under construction Hundreds of ZEHs planned in 6 subdivisions
Premier Homes ZEH Community
Premier & Morrison Homes Annual Energy Bill Comparison 1200 1000 Annual Energy Bill ($) 800 600 400 200 Other Energy Use Water Heating Space Cooling Space Heating 0 Typical New Home ComfortWise / Energy Star Premier BA & ZEH
Average Monthly Elect. Bills 200 Mo. Bill 150 100 50 0 Sept, 04 Oct, 04 Nov, 04 Dec, 04 Jan, 05 Feb., 05 March, 05 April, 05 May, 05 June, 05 July, 05 August, 05 Premier Non-ZEH
Today News Show Testimonials Our utility bills were $150-200/m with the 4 of us in a smaller house. Here it s a bigger house & the bills are $30-50/m I m pretty upset when he calls & says--my monthly bill was $6. What s yours looking like I m forking out about $265. Today Show, May 26, 2006, See link below: http://video.msn.com/v/us/v.htm?g=fead2a8e-5d44-41bc-85dd- 1528fae31594&f=rssimbot_us_m_3549&fg=email
Centex Homes Second Generation ZEH Power Save Plus saves over 50% of traditional energy, including solar electric Zero electric bill based on time-of-use rates Positive cash flow - annual energy savings exceed incremental increase in mortgage payments Power Save options offered at Design Center 56% take $4,000 energy efficiency upgrade 2006 Building 30 home ZEH subdivision
ZEH Market Research (CA) If you have a product that is both energy efficient AND green, over 2/3 of the market is going to be interested in it. The appeal of a two-pronged attack is much wider. (Source: America LIVES, Inc)
John Wesley Miller NAHB s 2005 Energy Value Housing Award Builder of the Year 99 ZEH Heating/cooling bills guaranteed at about $1/day by Tucson Elect. PV & SWH Average utility bill is $15.73/m including $5 meter fee
ZEH Developments in California Builder Location # ZEH PV Savings SheaHomes San Diego 16 2.4 kw 62% Premier Homes Sacramento 99 2.4 kw 56% Premier Homes Sacramento 50 2.4 kw 57% Clarum Homes Watsonville 257 Varied 47% Centex Homes San Ramon 32 3.5 kw 58% Lennar Homes Hunter s Pt 1600 TBD >50% Clarum Homes Pajaro Vista 70 1.8 kw 64% Grupe Homes Sacramento 149 2.4 62-66%
NAHB-Research Center ZEH Study ZEH has the potential to reverse National upward trends in home energy consumption Evaluated homeowner attitudes & opinions Focus Group National internet survey of 1,700 homeowners Market research findings Over 80% will buy ZEH with positive cash flow between mortgage and utility bills Buyers want credible guarantees from builder, major manufacturer or utilities for new features
How do we achieve full ZEH? Continue to aggressively address EE & Solar R&D Address biggest remaining loads such as water & space heating loads, and plug loads Design for Zero Peak Communities Automate energy management system Plug Load Study Smart Economizer, TOU, Gridwise, etc Create demand (Prior to 2005-- Builders say Homeowners are not asking for energy efficiency)
Zero Peak Communities Zero summer peak load when utility needs it How will utilities value ZEH? Capacity, distribution, transmission benefits Ideal for Time-of-use rates Real time pricing Net-metering California s ZENH (1kw summer peak load) Green product, RPS or competitive contract
SMUD s Analysis of 36 Homes 18 ZEH Premier Homes compared to 18 control homes shaved peak by 55% on 107 degree day And, control homes were designed to shave peak about 35% Sample included 5 Premier Homes with east facing PV system if all PV was on south to west facing the July peak reduction would have been 67% or.86 kw
Utilities Dampen Capacity, & T&D Growth Closing in on zero-peak-demand communities 4 Avg Peak Demand ZEH vs Non-ZEH July 15, 2005 High Temp 107 degrees F Min Temp 71 degees F 3.5 Avg Peak Demand Savings @ 5 pm 1.51 kw 3 2.5 Average of ZEH Net Grid Load (kw) Average of Power Produced by PV (kw) Average of Non-ZEH Net Grid Load (kw) 2 1.5 Avg Peak Demand Savings Noon -7 pm 1.95 kw 1 0.5 0 7/15/05 0:15-0.5 7/15/05 2:15 7/15/05 4:15 7/15/05 6:15 7/15/05 8:15 7/15/05 10:15 7/15/05 12:15 7/15/05 14:15 7/15/05 16:15 7/15/05 18:15 7/15/05 20:15 7/15/05 22:15-1
Peak Load Reduction Potential in High Growth Market: Phoenix, Arizona Technique kw Reduction Total kw 19,500 Zero Peak Homes (30% of new Home starts) 2,000 Zero Peak Condos 100k existing homes w/cpp & automated energy management 6.6 5 2 128,700 10,000 200,000 Total Savings: 340 MW System Load: 6020 MW
3 ZEH Business Models Optional ZEH hardest to sell Sales staff must be trained & motivated Pre-plotted 10-30% as ZEH sells fine Excellent PR ZEH sells as fast as other homes Full ZEH subdivision Excellent PR Builders say, Sell faster than nearby subdivisions Homebuyers do not seek ZEH but like it once they have it, plus they brag about it Given two equal subdivisions the ZEH subdivision sells better than the conventional subdivision
Zero Energy Home Summary Today s ZEH, i.e. cutting utility bills at least 50% sells very well Zero Peak Communities improve grid Dozens of National events Extreme Makeover, CNN, Today Show, NAHB Show Home, CBS Evening News, & Newsweek ZEH has the potential to reverse National upward trends in home energy consumption
For Additional Information Buildingamerica.gov Lew W. Pratsch @ 202 586-1512 lew.pratsch@ee.doe.gov