1 / 9

Solar Water Heating

Solar Water Heating. AKA Solar Thermal. Solar Thermal vs Solar Photovoltaic. Solar Photovoltaic(PV for short) Converts sunlight into electricity 20% efficient 15,000 megawatts worldwide Solar Thermal Directly heats fluid by solar radiation 60% efficient

zeheb
Download Presentation

Solar Water Heating

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Solar Water Heating AKA Solar Thermal

  2. Solar Thermal vs Solar Photovoltaic Solar Photovoltaic(PV for short) • Converts sunlight into electricity • 20% efficient • 15,000 megawatts worldwide Solar Thermal • Directly heats fluid by solar radiation • 60% efficient • 450,000 megawatts worldwide

  3. PV Cost and power output • Solar PV • $6-$7 per watt currently • A typical 3 KW system generates 5500 KwH per year and costs around $18,000 • 5500 KwH = roughly $550 dollars worth of electricity • 33 year payback(without subsidies) • Until recently subsidies in Austin($3.75 per watt) and the federal tax credit pushed the payback time to less than 10 years. • Some were getting “Free” systems in Austin

  4. Solar thermal cost and power output • A standard electric water heater uses 400-800 KwH per year. Sometimes more. • A solar water heater can offset 80% or more of that cost. • Costs around $6000 • Payback 6-12 years depending on Home habits(showers, laundry, etc.) • Payback 2-4 years with subsidies in Austin • $2000 Austin Energy rebate • 30% federal tax credit

  5. How it works • There are several different types • Open loop-most common, used in warm climates • Drainback-used in temperate climates • Glycol pressurized-used in temperate climates • Passive ICS Drainback Open Loop

  6. DrainbackSytems • Preferred system in Texas climate • Panel must be located above drainback tank • Uses gravity to drain the panel during freezing spells • No glycol flushing required • Stores water at temperatures of 150+ degrees.

  7. Cross section of the collector

  8. Solar thermal worldwide • Worldwide, Solar thermal produces 30 times as much energy as solar PV at a fraction of the cost. • Over 90% of the homes in Israel and Cyprus use solar water heating due to high energy costs • China has over 27 million rooftop solar water heaters. • Millions installed worldwide. Very common in Germany, Austria, the Middle East, the Bahamas, anywhere energy prices are high. • In the U.S., they are most common in Florida, California, and Hawaii • Solar water heating is now code required in: • Spain • Israel • Australia • Hawaii

  9. Environmental Benefits • A standard water heater uses the equivalent of 11 barrels of oil per year • Equal to the fuel consumption of a small car • A gas water heater uses 250 therms per year. That’s 250,000 cubic feet of natural gas. • In 2005, worldwide, solar water heating offset: • 70 million barrels of oil • 29 million tons of carbon emissions

More Related