kwhm2

kWhm2, written as kWh/m^2, is a unit of energy per unit area. It expresses how much energy is incident on or delivered to a surface over a specified period, by dividing energy by the surface area. The unit arises from multiplying power (kilowatts) by time (hours) and then dividing by area (square meters): (kW × h) / m^2 equals kWh/m^2. In practice, the quantity is obtained by integrating irradiance, which is radiant power per unit area measured in W/m^2, over the time period of interest.

This measure is widely used in solar energy and building applications. It is commonly reported as daily or annual insolation on a given surface, such as a horizontal plane or a tilted collector. For example, daily values typically range from around 2 to 6 kWh/m^2 in temperate to sunny regions, depending on weather, latitude, and season. The annual total for a location can vary roughly from about 1,000 to over 2,500 kWh/m^2, with higher figures in sunnier climates.

Applications include estimating the potential energy yield of photovoltaic panels and solar thermal collectors, designing solar-responsive buildings, and performing energy modeling. To translate kWh/m^2 into electrical output, one multiplies the energy per area by the efficiency of the converting system and, for PV, by system losses. In all uses, kWh/m^2 represents a cumulative energy measure per unit area, not a rate.