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Transcript of Solar Energy
Solar Energy
Physics 13033/26/03
Three forms of solar energy.
Passive SolarActive SolarPhotovoltaic
Passive Solar Energy
Sensible architectural design Use sun in the winter Avoid in the summer. Cold climates- large glazing
which may be insulated at night and opened during the day.
Hot climates - blocking the sun and providing good ventilation.
Passive Design
Arizona Cliff Dwelling is an example of traditional low-tech solution to space heating and cooling needs.
Passive Design
This is a modern New Mexico version.
There is movable isolation to put in place at night.
Passive Design
Another interesting design.
The wall is down and the passive collector is collecting solar energy
Passive Design
In this mode, the wall is up and the building is storing solar energy or blocking summer heat gain.
An innovative passive design
Roof Pond House in Atascadero, California
Active Solar Energy
Use pumps and solar collectors to provide energy.
Two types of solar collectors:– flat plate– concentrating
Flat Plate Collector
Made of a black absorbing plate with water running through it or air blowing past it.
Usually a flat plate collector has a glazing to stop heat from escaping.
Efficiency 50% or better.
Flat Plate Collector – Hot Water Heater
Low cost heater in the roof of this modest Miami house
Flat Plate Collector – Hot Water Heater
Low cost heater in the roof of this modest San Antonio house
Flat Plate Collector – Hot Water Heater
Low cost heater in the roof of this modest Miami house
Flat Plate Collector – Hot Water Heater
Solar water heater system has four components:
CollectorTankPumpController
Flat Plate Collector
Flat plate collectors being tested.
Flat Plate Collector
Flat Plate Collector components:
Plate with tubing InsulationGlazing
Concentrating Collector
A concentrating collector includes some kind of lens or mirror.
Tracks the sun. High temperature. Efficiency near 50%.
Concentrating Collector
Components:OpticsGlazingAbsorber InsulationTracking
Concentrating Collector
This one uses a mirror and has no glazing
Concentrating Collector
Used to be on the roof of the Bell center.
Concentrating Collector
This is the solar concentrating collector on the CPS Headquarters building on San Pedro.
It runs the air-conditioning system
Flat Plat Collector Problem
Stop and work the problem.
Photovoltaics
Photovoltaic systems convert solar energy directly into electricity. They have efficiencies near 10%.
Photovoltaics
PV-powered airplane.
Is this really a good idea?
Photovoltaics
PV arrays are widely used for low power loads.
Photovoltacis
A PV array is made up of several panels and a panel is made up of several cells.
Photovoltaics
A complete system has an array, a battery, an inverter and a load.
The system can supply either DC or AC loads.
Photovoltaics
The inverter converts the DC voltage from the PV array into an AC signal to power AC loads or to connect to the grid.
Photovoltaics
Laurel Kaesler and Frank Ehman designed and built the PV Project in the Physics Department
Photovoltaics
The PV project has 4 components:
ArrayControllerBatteryLoad
Photovoltaic
Controller
Photovoltaics
The load is a pair of fluorescent lights in my Physics office.
These lamps supply the only light that I use in this office.
Photovoltaic
This is the solar array on the CPS Headquarters building on San Pedro.
Photovoltaic
The output of the array is inverted into an AC voltage and fed back to the grid.
Photovoltaics
A high-tech solution is to use PV to capture sunlight as electricity and use the electricity to produce microwaves that are beamed back to earth.
PV Problem
Stop and work the problem.
Solar Energy
Do you think solar energy will able to replace a significant fraction of the energy needs of our society?