www.americansolar.com solar energy technology for commercial facilities john archibald american...

www.americansolar.com

Solar Energy Technologyfor Commercial Facilities

John ArchibaldAmerican Solar, Inc.

Association of Energy EngineersBaltimore Chapter

March 2002


What do solar energy systems offer?

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


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 < 110 deg. F

• Passive Thermal Systems heat without fans or pumps


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


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


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


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

• Don’t 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


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


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


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

www.americansolar.com solar energy technology for commercial facilities john archibald american...

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