Solar Energy Technology

1
Solar Energy Technology for Commercial Facilities
John Archibald American Solar, Inc.
Association of Energy Engineers Baltimore
Chapter March 2002
2
What do solar energy systems offer?

• Energy savings
• Cost savings
• Reduced maintenance
• Improved reliability
• Improved operability
• Improved environment for workforce

3
What types of solar energy systems are available?

• Solar Electric
• Photovoltaics (Electricity from solar cells)
• Solar thermal electric (Focussed heat for steam
  turbine electricity)
• Active Thermal Systems pump air or water
• Air heating up to 190 deg.F
• Mid temperature water heating 110-180deg.F
• Low temperature pool heating lt 110 deg. F
• Passive Thermal Systems heat without fans or pumps

4
Where should solar electricsystems be deployed?

• Photovoltaics
• Remote applications with complex fuel/electricity
  delivery
• Small local applications with high cost power
  line installation
• Security lighting, sensors, and radio/call boxes
• Lighting for critical operations
• Solar Thermal Electric
• High cost electricity with concurrent heating
  needs
• Combined heating, absorption cooling, and power
  applications
• Energy Savings Performance Contracts for solar
  heat

5
Where should water heating systems be deployed?

• Mid temperature water heating
• Displace high cost electric resistance domestic
  water heating
• Large volume water preheating for labs, medical,
  or equipment washdown
• Water tube radiant floor space heating
• Swimming pool heating
• Almost all heated outdoor pools
• Heated indoor pools without heat recovery from
  dehumidification
• Heated indoor pools with high cost electric
  dehumidification

6
Where should solar air heating systems be
deployed?

• Low temperature air - less than 110 deg.F
• Ventilation preheating in cold climates
• High volume low temperature drying applications
• Mid temperature air 110 - 190 deg.F
• Emergency generator standby heating all climates
• Boiler air pre-heating all climates
• Ventilation air heating and preheating
• Heat pump pre-heating
• Hot water heating with air to water heat
  exchanger
• Air radiant floor and under floor ventilation

7
What makes a good solar application?

• Year round load, year round load, year round load
• Make the system repay investment every day the
  sun shines
• Dont try to make solar meet 100 of the peak
  energy needs for large systems
• Use solar to cut annual costs of large energy
  systems
• Displace electric, propane, oil heat with solar
  heat
• Avoid conversion from the original solar energy
  for use or storage
• no AC inverter, no batteries, no thermal storage
  tank, no grid connection

8
What makes a good solar application?

• Low installed cost
• under 25/sq ft
• High solar efficiency
• 10 to 30 units of solar energy gathered for every
  unit of energy used to run fans or pumps
• greater than 20 of available solar energy
  converted to heat or electricity
• Building integrated
• makes building walls or roof do double duty
  (weather envelope and energy production) for no
  extra cost
• Buy the energy not the system, if capital funds
  are not available but operating funds for energy
  bills are

9
Standby heating of emergency generators

• Electric heaters keep engine jacket water at 130
  deg F all year
• 2-8 KW typical load
• Solar heated air floods generator enclosure,
  reduces electric heating
• Warm air keeps engine ready to start
• Payback period well under 10 years
• Free storage building

New Federal Application
10
Solar energy looks better and does more than
ever before!

• New aesthetics with building integrated
  technologies
• New solar roofs
• New solar walls
• New solar applications
• EDGs, boiler air, heat pump preheat, ventilation
  air
• Lower installed costs
• Higher energy delivery
• Attractive economics