solar thermal: water heating and...
TRANSCRIPT
Solar Thermal:
Water Heating and Beyond
Domestic
Hot
Water
Pool
Heating
Space
Cooling Space
Heating
Energy
Efficient
Buildings
Jane DavidsonUniversity of Minnesota
Tim Merrigan, Jay BurchNational Renewable Energy Laboratory
Residential Energy Use
Space Htg
Space Clg
Water Htg
Lighting
Refrigeration
Electronics
Other
The Big 3-Thermal loads: 55% of total, 2.34 TWh
Qtot,avg ~ 200 GJprimary
H2O
Cool
Heat
• )
Solar Heating: More installed capacity than ALL other renewables; production ~1/3 all renewable energy
World Market for Solar Thermal Heat
China65 %
Europe17 %
Japan3 %
ROW7 %
Israel8 %
Germany, Greece and Austria are the three largest markets in Europe, with a combined installed solar thermal area of 9.6 million m2.
Austria (8 million people) has an installed solar thermal capacity of 1.5 GWth, equal to that of the installed solar thermal capacity in the US (300 million people).
US Solar Hot Water Market
Energy saved using a glycol solar system with a selective surface collectorSource: Danny Parker, FSEC
(kWh)
Potential Energy Savings
Current Economics of SDHW
The cost required to attain cost-neutrality with electricity
SWH in the U.S.
• Current technology is not cost effective• Except sunny places against electricity
• Small Industry• Continued low volume (~20,000 systems/year)
• No established installers in many areas
• Sustained R&D with vision for short and long-term advances required
U.S. R&D 1999-2009
Low-Cost Solar Hot Water
– Paradigm shift from metal/glass components to integrated systems manufactured with polymeric materials
– Successful project outcomes are a major step toward lower cost
Building integrated systems
FAFCO polymer collector
Example: FAFCO Revolution and Hot2O
Introduced at National Association of Homebuilders (NAHB) International Builders Show, 2007
SRCC OG-300
Everything is in one box
Polymer collectors (48 ft2) Digital controller with animated display 80 Feet of UV resistant polymer tubing and quick
connect fittings Polymer drain back tank Circulation module containing two pumps and a heat
exchanger Roof jacks and mounting hardware Easy to install tank adapter and all plumbing hardware
www.fafco.com www.hot2o.com
-1000
1000
3000
5000
7000
9000
11000
13000
15000
MJ
Solar
H2O
Heat
Cool
Solar Thermal
Space Conditioning26%
13%
One technical challenges is long term, compact thermal storage.
Desired Material Characteristics
Energy density [kWh/m3,
MJ/m3] incls. tank, HX
Operating temperatures –
charge/discharge
Thermal power [W] –
charge/discharge
Storage period
Material stability
Environmentally safe
Non-toxic
Non corrosive
Available and inexpensive
Desired Material Characteristics
Energy density [kWh/m3,
MJ/m3] incls. tank, HX
Operating temperatures –
charge/discharge
Thermal power [W] –
charge/discharge
Storage period
Material stability
Environmentally safe
Non-toxic
Non corrosive
Available and inexpensive
From IEA Task 32 www.iea-shc.org, Hadorn, 2008
• Heating of school in Munich, Germany built by ZAE Bayern
• Diurnal storage of heat from district heating at 130 ºC
• Storage in 700 kg Zeolite (volume 10 m3)
• 450KJ/m3 - 3X capacity of water
• A/C of adjacent Jazz club in summer
Desiccant
and water
thermal
storage
Absorption air-
conditioner Space Cooling
Weak Desiccant
Strong Desiccant
Solar collectors
HeatHeat
Absorption heat
pump
Heat
Combined Solar Heating, Cooling, and Water Heating System
Under development at NREL/University of Minnesota
Solar Thermal Opportunities
• Near term potential to reach a $1000 solar water heater
• Mid-term Opportunity: Open up space conditioning
• Europeans and other countries are seeking these opportunities to address future market needs ---U.S. should do the same or better!
Contact Info:
Jane Davidson
Department of Mechanical Engineering
University of Minnesota
Tim Merrigan Jay Burch
National Renewable Energy Laboratory
Golden, CO 80401