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On the Path toward Zero Carbon Homes: The Comparative San Diego Case Study

On the Path toward Zero Carbon Homes: The Comparative San Diego Case Study. Barbara C. Farhar, Ph.D. National Renewable Energy Laboratory (Ret.) Senior Research Fellow, IBS Presentation for Center for Science and Technology Policy Research University of Colorado at Boulder

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On the Path toward Zero Carbon Homes: The Comparative San Diego Case Study

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  1. On the Path towardZero Carbon Homes: TheComparative San Diego Case Study Barbara C. Farhar, Ph.D. National Renewable Energy Laboratory (Ret.) Senior Research Fellow, IBS Presentation for Center for Science and Technology Policy Research University of Colorado at Boulder October 20, 2008

  2. Outline of Presentation on Study Highlights • Study background and methods • Home sales prices/builder incentives • Uptake of optional PV systems • Who are the homebuyers? • Resale value • Purchase decision and satisfaction • Utility data analysis • Toward zero-carbon buildings

  3. Photo of Shea Homes Development SheaHomes at Scripps Highlands

  4. SheaHomes Home SheaHomes Home

  5. The Anatomy of High Performance by SheaHomes The Anatomy of High Performance by SheaHomes

  6. SunChoice™ Power Meter

  7. Comparison Home Comparison Home

  8. San Angelo Neighborhood

  9. Tiempo Neighborhood

  10. Preliminary Work • Project advisory group • Numerous interviews of SheaHomes executives/staff, organizations partnering with the builder, and other interested parties • Qualitative face-to-face interviews with 43 respondents in 25 SheaHomes households on reasons for purchase and perception of their energy features Period of study: 2001 - 2006

  11. Other Qualitative Data • Background information/observation home sales processes • Focused interviews with lookers for new homes • Other artifacts, such as TV coverage, print news clips, press releases • Interviews with utility staff on grid-tied PV, net metering, dates of meter reading of study households, and other points

  12. SheaHomes and Comparison Homeowners Surveys • Based on earlier qualitative analysis • Universe of study: 306 SheaHomes, 103 comparison homes (63% response rate) • Four overlapping mail questionnaires

  13. Other Quantitative Data • Home sales and characteristics (SheaHomes data) • Public records on sales • Utility data for 132 SheaHomes and comparison homes (who gave permission) collected on • Therm and kWh usage and costs • Monthly combined utility costs

  14. Home Sales Prices • High-performance homes are competitive on the market • Based on actual sales data, per square foot, they sold for 9.2% less than comparison homes, on average

  15. Sales Prices Controlling for Square Footage

  16. Sales Prices Controlling for Presence of PV System(Mean Price/sq.ft.) • PV - $198.45 • Non-PV - $194.36 • Comparison - $215.89 • p=.000

  17. Optional PV System Prices • 1.2 kW system: $6,000 (later, $7,000) • 1.2 kW upgrade: $4,000 • 2.4 kW system: $10,000 (later, $11,000)

  18. Builder Incentives and Net Costs • Incentives to builder: $750 solar water heating rebate from CEC (SB 1345) (~44%) • 50% subsidy PV system cost from CEC (first time to California builder) • 15% state tax credit on system cost • Net cost of providing each 1.2 kW PV system standard was $3,380 • Estimated net cost of offering the swh and PV was $512,910, or $1,751 per house (n=293 in total; 120 of them PV homes) • SheaHomes: “We didn’t lose money.”

  19. Other Benefits to SheaHomes • Homes sold out a year faster than expected • Partnerships with new organizations • Extensive media coverage worth $1 mn in advertising in less than a year • Enhanced reputation and community goodwill • Favorable relationship with the City

  20. Other Costs to SheaHomes • Learning curve • Selling and scheduling optional PV systems • Obtaining the rebates • Interconnectivity issues • Other issues

  21. Uptake of Optional PV Systems • All SheaHomes highly efficient, came with solar water heating standard • 120 of 306 SheaHomes had PV • Most PV systems came standard • Only 260 homes were PV-eligible • Only 12% of all PV-eligible homes were sold with PV optionally • However, 56% of those who could have purchased optional PV systems were not told about the option • Of those actually offered PV systems, the uptake rate was 44%

  22. SheaHomes Buyer Quotes • “It’s best to integrate the solar electric system into the entire home purchase rather than having it offered as an option in a piecemeal way. It should all be rolled into the overall price.” • “We wanted to get the house because the system was already there. We didn’t have to decide about it. We’re glad it’s here. We’re lucky to have the PV.” • “We feel the builders know what they are doing, so if they offer the solar as part of the package, there must be a reason.”

  23. Who Were These Homebuyers? • Buyers of high performance homes and buyers of new conventional homes shared the same demographic characteristics, environmental attitudes, and early adopter chacteristics • As expected, buyers mostly represented upper-middle class married couples with children, or mature couples • They were relatively affluent with well paying occupations

  24. Respondent Household Demographics No demographic differences between SheaHomes and comparison homes, except income Gender: Male -- 56%; female -- 44% Age: 44% up to 39; 30% between 40 to 49; 26% were 50 years of age or older Marital status: 95% married Households: 68% -- two adults with children; 32%-- two adults

  25. Respondent Household Demographics (cont’d.) Mean household size: 3.53 occupants (range: 1-11) Highly educated: 80% at least Bachelor’s degrees; 20% Master’s degrees, 16% with doctorates Reported occupations: business owners, financial managers, scientists and engineers, doctors and lawyers

  26. Respondent Household Demographics (concluded) 76%of comparison owners report annual household incomes of $200K or more compared with 59% of SheaHomes; 19% of SheaHomes report $200K annual incomes compared with 4% of comparison (p=.048) One-third plan to stay permanently; 44% didn’t know how long they’d stay 86% moved from the San Diego area

  27. Aesthetics • Concern about aesthetics could not be discerned in this study • Resale prices quite high • Homeowner quotes on aesthetics of solar panels • “Huh?” • “Satellite dishes are more offensive”

  28. Original and Resale Prices(as of 2/7/05) Range: Mean: Range: Mean: $482,900– $701,184 $556,344 $680,000– $1,100,000 $862,853 Range: Mean: $538,522– $711,887 $598,028 Range: Mean: $760,000– $995,900 $862,590

  29. Increases in Property Values

  30. Home Purchase Decision Process • 75% of each category of buyers visited the other development • Neither category knew much about energy features when they were shopping • The 2001 San Diego electricity crisis did not drive home purchase decisions • Most of the comparison buyers were unaware of SheaHomes’ energy-efficiency and solar energy features

  31. Important Factors in Purchase Decision

  32. Important Factors in Purchase Decision, (cont’d.)

  33. Important Factors in Purchase Decision (concluded) 3.09

  34. Top Three Most Important Reasons for Home Purchase

  35. Homebuyer Satisfaction “We would buy our same house again if we had it to do over.” (Chi-square test; p=.048)

  36. Respondents Agreeing with Policy Statements

  37. Homeowners Differ…. • On variables affected by their experiences in living in their new homes • Especially, the experience of PV ownership changes attitudes, perceptions, and behavior

  38. PV Owners • Report the lowest monthly utility bills • Tend to think electricity rates fell • Had a more positive attitude toward SDG&E • Used their digital displays for feedback and watched their meters run backwards for “kicks” • Changed to some degree their energy behavior because of feedback • Report they know more about ee/re • Seem more sensitive to savings from solar water heating systems

  39. SheaHomes vs. Comparison Homes (Electricity and Gas Consumption Data)

  40. Home Category Avg. Monthly Bill % Savings Comparison homes $130 NA SheaHomes energy efficiency/ solar water pre-heating (HPH homes) $114 13% Shea HPH + 1.2 kW PV $92 30% Shea HPH + 2.4 kW PV $49 62% SheaHomes vs. Comparison Homes (Electricity Billing Data)

  41. SheaHomes vs. Comparison Homes (Gas Billing Data)

  42. SheaHomes vs. Comparison Homes(Actual Combined Utility Bills)

  43. Combined Annual Utility Bills(Actual Utility Bills)

  44. Monthly Electricity Consumption in 10 Individual Comparison Homes

  45. Monthly Electricity Consumption in 10 Individual PV Homes

  46. Monthly Gas Consumption in 10 Individual Comparison Homes

  47. Monthly Gas Consumption in 10 Individual PV Homes

  48. Market Paradigms for Zero-Energy Homes

  49. Market Paradigms for Zero-Energy Homes

  50. Market Paradigms for Zero-Energy Homes

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