A solar panel is a device that converts sunlight into electricity by using multiple solar modules that consist of photovoltaic (PV) cells. PV cells are made of materials that produce excited electrons when exposed to light.

A solar inverter or photovoltaic (PV) inverter is a type of power inverter which converts the variable direct current (DC) output of a photovoltaic solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a…

Renewable energy (also called green energy) is energy made from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, bioenergy/biomass, and hydropower.

The 1979 oil crisis, sometimes referred to as the second oil crisis (in reference to the 1973 oil crisis), refers to the drop in oil production in the aftermath of the Iranian Revolution that led to an energy crisis in 1979. Although the global oil supply only decreased by approximately four percent, the oil markets'…

A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by using the photovoltaic effect. It is a type of photoelectric cell, a device whose electrical characteristics (such as current, voltage, or resistance) vary when it is…

On Monday, 28 April 2025, at 12:33 CEST (11:33 WEST; 10:33 UTC), a major power blackout occurred across the Iberian Peninsula affecting mainland Portugal and peninsular Spain, where electric power was interrupted for about ten hours in most of the Peninsula and longer in some areas. The power cut caused severe…

Many countries and territories have installed significant solar power capacity into their electrical grids to supplement or provide an alternative to conventional energy sources. Solar power plants use one of two technologies: Photovoltaic (PV) systems use solar panels, either on rooftops or in ground-mounted solar…

An electricity meter, electric meter, electrical meter, energy meter, kilowatt-hour meter, or power meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device over a time interval. Electric utilities use electric meters installed at customers'…

During the 2000s, United States housing prices experienced a sharp run up and subsequent collapse affecting over half of the U.S. states. In many regions, a real estate bubble was the impetus for the subprime mortgage crisis.

Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer. Insulation may be categorized by its composition (natural or synthetic materials), form (batts, blankets, loose-fill, spray foam, and panels), structural contribution (insulating…