Glossary
Categories
Solar Energy Definitions
Absorber
The blackened surface in a collector that absorbs the solar radiation and converts it into heat energy.
Active Solar System
A solar heating or cooling system that requires external mechanical power to move the collected heat.
Ambient Temperature
Temperature of the surrounding air.
Auxiliary Heat
The extra heat provided by a conventional heating system for periods of cloudiness or when a solar heating system cannot provide enough.
BTU
British Thermal Unit. The quantity of heat needed to raise the temperature of one pound of water one degree Fahrenheit. An example of a BTU is burning one wooden match.
Closed System
This is a system that is closed off from the environment and its heating fluid is not changed except for maintenance.
Collector
A device that collects solar radiation and converts it to heat.
Cover Plate
A sheet of glass or transparent plastic placed above the absorber in a flat plate collector.
Delta-T
In solar systems a Delta-T is relating the temperature difference between the collector and the storage tank.
Direct System
A system that the potable hot water is used for space heating and domestic hot water. There is no separation between the two.
Drain Back System
The solar heat transfer fluid drains into a tank by way of gravity. A heat exchanger is necessary because the city inlet pressure would prevent draining.
Evacuated Tubing
A collector where solar heat is captured by a collector fluid flowing through an metal tube enclosed inside an evacuated glass tube.
Flat Plate Collector
A solar collection device in which sunlight is converted into heat on a plane surface without the aid of reflecting surfaces to concentrate the rays.
Headers
The flow channel that runs across the edge of an array gathering or distributing the transfer fluid to or from the risers to the collectors.
Heat Dump
Used to prevent overheating. Depending on the type of system, a heat dump could be a finned radiator, radiant heat loop or an extra storage tank.
Heat Exchanger
A device that exchanges heat from one fluid to another without a mixing of the fluids.
Heat Pump
In the summer a Heat Pump is basically an air conditioner with a valve that allows for operation in reverse, removing heat from your home. In the winter the Heat Pump removes heat from outside and delivers it to your home.
Heat Storage
A medium or device that absorbs collected solar heat and stores it for use during periods of cold weather.
Hybrid Solar
Hybrid Solar is a system which uses both passive and active solar methods.
Open System
An Open System is one that is open to the atmosphere. A domestic hot water heater is an open system because the heated fluid is constantly changed.
Passive Solar House
A house that uses a room or another part of the building as a solar collector. Passive also refers to the conversion of light into electricity.
Passive System
A solar heating or cooling system that uses no external mechanical power to move the collected solar heat.
Photovoltaic Cells
Semi-conductor devices that convert solar energy into electricity.
Photovoltaic System
A complete set of components for converting sunlight into electricity by the Photovoltaic process.
Potable Water
Water that is acceptable for drinking.
Renewable Fuels
Fuels that can be easily made or renewed. Types of renewable fuels include solar, wind and hydropower energy.
Riser
The flow channels that distribute the heat transfer liquid across the face of an absorber.
Thermosyphoning
This is the process which makes water circulate between a warm collector and a cooler storage tank above it automatically.