The Impact of Tankless Water Heaters

Table of Contents

• Table of Contents
• Energy Insights Opinion
• Executive Summary
• The Main Points
• Introduction
• Water Heating Technology
• Figure: Tankless Water Heater Advertisement
  • Storage water heaters
  • Tankless water heaters
  • Heat pump water heaters
  • Tankless coil and indirect water heaters
  • Solar water heaters
  • Table: Energy Factors of Best-Performing 2003 Models Vs. 2004 Federal Standard
• Water Heater Sales Trends
  • Pros and cons of tankless water heaters
• Tankless Water Heater Applications
  • Whole-house installation
    • Electric whole-house installation
    • Gas whole-house installation
  • Point-of-use installation
    • Electric point-of-use installation
• Residential Hot Water Use
• Figure: U.S. Residential Energy Use, End Use Comparison
• Figure: U.S. Residential Electric Use
• Figure: Residential Electric Unit Energy Consumptions
• Figure: Typical Household Hot Water Consumption by Place of Use
  • Hot water load profiles
    • System-wide profiles
    • Figure: Diversified Average Hot Water Load Shapes, West Central Region
    • Storage water heater profiles
    • Figure: Storage Hot Water Metered Profile, Winter Weekday
    • Figure: Storage Hot Water Metered Profile, Summer Weekday
    • Tankless water heater profiles
    • Figure: Tankless Water Heater Profile, Winter Weekday
    • Figure: Storage Water Heater Profile, Winter Weekday
• The Utility Perspective
  • System peak impacts
  • Figure: Tankless Water Heater Diversified Average Load Shape, Typical Winter Weekdays
  • Distribution system impacts
  • Table: Probability of Simultaneous Tankless Water Heater Operation
  • Figure: Transformer Load Duration Curve
  • Utility anecdotal experience
• Notes
  • Synopsis