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  2. Solar irradiance - Wikipedia

    en.wikipedia.org/wiki/Solar_irradiance

    The SI unit of irradiance is watts per square metre (W/m 2 = Wm −2). The unit of insolation often used in the solar power industry is kilowatt hours per square metre (kWh/m 2). [12] The Langley is an alternative unit of insolation. One Langley is one thermochemical calorie per square centimetre or 41,840 J/m 2. [13]

  3. Kibble balance - Wikipedia

    en.wikipedia.org/wiki/Kibble_balance

    The Kibble balance is a development of the Ampere balance. The Kibble balance is a more accurate version of the ampere balance, an early current measuring instrument in which the force between two current-carrying coils of wire is measured and then used to calculate the magnitude of the current. The Kibble balance operates in the opposite sense ...

  4. Kilowatt-hour - Wikipedia

    en.wikipedia.org/wiki/Kilowatt-hour

    A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a common billing unit for electrical energy supplied by electric utilities. Metric prefixes are used for multiples and ...

  5. Lead-acid battery - Wikipedia

    en.wikipedia.org/wiki/Lead-acid_battery

    The auto industry uses over 1,000,000 metric tons (980,000 long tons; 1,100,000 short tons) of lead every year, with 90% going to conventional lead-acid vehicle batteries. While lead recycling is a well-established industry, more than 40,000 metric tons (39,000 long tons; 44,000 short tons) ends up in landfills every year.

  6. Earth's energy budget - Wikipedia

    en.wikipedia.org/wiki/Earth's_energy_budget

    Earth's energy imbalance (EEI) Earth's energy budget (in W/m 2) determines the climate. It is the balance of incoming and outgoing radiation and can be measured by satellites. The Earth's energy imbalance is the "net absorbed" energy amount and grew from +0.6 W/m 2 (2009 est. [ 8 ]) to above +1.0 W/m 2 in 2019.

  7. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    In this formula dn–3 is used, because in modern times Earth's perihelion, the closest approach to the Sun and, therefore, the maximum E ext occurs around January 3 each year. The value of 0.033412 is determined knowing that the ratio between the perihelion (0.98328989 AU) squared and the aphelion (1.01671033 AU) squared should be ...

  8. Basal metabolic rate - Wikipedia

    en.wikipedia.org/wiki/Basal_metabolic_rate

    Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. [1] It is reported in energy units per unit time ranging from watt (joule/second) to ml O 2 /min or joule per hour per kg body mass J/ (h·kg). Proper measurement requires a strict set of criteria to be met.

  9. Nominal power (photovoltaic) - Wikipedia

    en.wikipedia.org/wiki/Nominal_power_(photovoltaic)

    The nominal power of PV devices is measured under standard test conditions (STC), specified in standards such as IEC 61215, IEC 61646 and UL 1703. Specifically, the light intensity is 1000 W/m 2, with a spectrum similar to sunlight hitting the Earth's surface at latitude 35°N in the summer (airmass 1.5), the temperature of the cells being 25 °C.