A device that changes its electrical resistance according to temperature. Used in the control system of a solar thermal system to measure collector and storage tank temperatures.

Fusing used to protect module interconnections as well as the internal components of the module from other sources of power to which the module is connected.

The structural covering, such as plywood, oriented strandboard, prefabricated panels, etc. that is attached to the exterior of a structure.

The current a PV cell or module produces with no resistance or loads in the circuit; this occurs at zero voltage (and thus zero power); also known as Isc.

A handheld level used for measuring head on a hydro site.

A tracker at a fixed tilt angle that follows the movement of the sun east to west across the sky (azimuth angle).

Structural insulated panels (SIPs) are solid wall and roof panels typically made of two faces of oriented strand board with a core of expanded polystyrene foam insulation.

Rings of bronze (or similar material), which in conjunction with brushes allow the electrical output from the yawing wind generator to be transmitted to the fixed wiring down the tower. Double brushes (on the yawing wind generator) for each of the AC phases or the two DC outputs ride on the rings (on the fixed tower).

The horizontal aspect of the sun's position relative to a defined direction. In the Northern Hemisphere, it is measured in degrees east or west of true south.

Cooking food using heat from the sun.

The time when the sun is at its highest altitude angle for the day, and the solar azimuth angle is 0 degrees (true south).

True south--180 degrees on a compass, plus or minus the magnetic declination.

A technology that harnesses the sun's energy as heat; applications include domestic hot water and space heating.

Solar tubes have three components: a round, domed plastic skylight that mounts on the roof; a cylindrical metal tube with a highly reflective interior surface; and a diffuser that mounts on the ceiling. Sunlight enters the skylight dome and reflects downward through the reflective tube to the diffuser, which delivers the light below.

Either of the two times a year when the sun is at its greatest distance from the celestial equator: about June 21, when the sun reaches its northernmost point on the celestial sphere, and about December 22, when it reaches its southernmost point.

A valve and a nozzle in one fitting that gives continuous control over the flow. A motorized spear valve controlled by logic circuits can maintain constant water level in the intake and maximize energy production.

Spray foam insulation is a two-component mixture composed of Isocyanate and resin comes together at the tip of a gun, and forms an expanding foam that is sprayed onto roof tiles, concrete slabs, into wall cavities, or through holes drilled in into a cavity of a finished wall.

A state of no flow through a solar collector. Stagnation temperatures are the highest attainable by the collector.

Systems that include a PV array, charge controller, battery bank, and DC load(s).

Also referred to as an off-grid system; not connected to the utility grid and the only power source for the connected loads.

Methods used to test modules and generate their power specifications.

Roofs constructed of metal sheets where the seam between the sheets is raised and crimped, keeping moisture from penetrating the surface.

The percentage representing the amp-hours remaining in the battery bank. 100% SOC indicates a full battery.

Standard test conditions (STC) are used to test modules and generate their power specifications.

Vegetable oil that is suitable for fuel in diesel engines or heating oil, a term generally used to distinguish between it and biodiesel. Unlike waste vegetable oil, it is not a waste or byproduct of other industries.

A building technique using straw bales for the walls. The straw bales can be used as non-structural infill around the building's structural system or used to create the load/roof-bearing walls.

Calculating the number of modules per source circuit in order to properly match the modules to a specific inverter.

A composite building material consisting of an insulating layer of rigid polymer foam sandwiched between two layers of structural board.

A popular term used for a length of wood or steel used in or for wall framing. The area created by a stud is the stud cavity.

Charts that depict the sun's path (altitude and azimuth angles) across the sky at any time of day and any time of year. Many site-evaluation tools use sun charts to predict shading for a site.

By simply orienting the home to the south, adding insulation, and modestly increasing the windows on the south side of the home, a sun-tempered design can provide modest energy savings. This approach includes no additional thermal mass; heat is absorbed by the “incidental” mass within the structure, for example, floors, wall surfaces, and furnishings.

Uses the utility side of the AC service-disconnecting means, between the existing electrical meter and AC service panel to make the grid interconnection for a PV system.

A voltage-actuated device designed to safeguard equipment from electrical surges and spikes, including those caused by lightning.

The area (in square feet or meters squared) that a wind generator's rotor (blades) sweep. This is the collector area for a wind generator. The larger the collector, the more energy it will capture. Besides the wind itself, this has the largest effect on wind generator production.