An overview of solar lightHD 13931 is a Sun-like star in the northern constellation of Andromeda. It can be viewed with binoculars or a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.60. This object is located at a distance of 155light years from the Sun, as determined from its parallax, and is drifting further away with a radial velocity of 30km/s.
This is an ordinary G-type main-sequence star with a stellar classification of G0V, which indicates it, like the Sun, is generating energy through core hydrogen fusion. It is slightly larger, hotter, brighter, and more massive than our Sun. The metal content is about 8% greater than the Sun, and it has a quiet (magnetically inactive) chromosphere. The star is an estimated 6.8billion years old and it is spinning with a rotation period of about 26days
In 2009, a very long-period giant planet, more massive than Jupiter, was found in orbit around the star by measuring changes in the star's radial velocity. This planet takes 11.55 years to orbit the star at the typical distance of 5.15AU (770Gm). The planet's eccentricity (0.02) is about the same as Earth.
According to a 2018 research, HD 13931 is the most promising Solar System analogue known, since it has a star similar to the Sun and a planet with mass and semimajor axis similar to Jupiter. Those characteristics yield a probability almost 75% for the existence of a dynamically stable habitable zone, where an Earth-like planet may exist and sustain life.
Whats wrong with my solar lights?maybe the solar light has a controller,which can set a worktime of solar light, you can reset the worktime by the controller
solar energy homework help! please? of solar lightHere is some of the information for you. Read and answer your questions... Main articles: Insolation and Solar radiation
About half the incoming solar energy reaches the earth's surface.The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet.
The absorbed solar light heats the land surface, oceans and atmosphere. The warm air containing evaporated water from the oceans rises, driving atmospheric circulation or convection. When this air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as cyclones and anti-cyclones. Wind is a manifestation of the atmospheric circulation driven by solar energy. Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 Â°C. The conversion of solar energy into chemical energy via photosynthesis produces food, wood and the biomass from which fossil fuels are derived.
Yearly Solar fluxes & Human Energy Consumption
Solar 3,850,000 EJ
Wind 2,250 EJ
Biomass 3,000 EJ
Primary energy use (2005) 487 EJ
Electricity (2005) 56.7 EJ
The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined.
From the table of resources it would appear that solar, wind or biomass would be sufficient to supply all of our energy needs, however, the increased use of biomass has had a negative effect on global warming and dramatically increased food prices by diverting forests and crops into biofuel production. As intermittent resources, solar and wind raise other issues.
Applications of solar technology
Average insolation showing land area (small black dots) required to replace the total world energy supply with solar electricity. Insolation for most people is from 150 to 300 W/m^2 or 3.5 to 7.0 kWh/m^2/day.Solar energy refers primarily to the use of solar radiation for practical ends. All other renewable energies other than geothermal derive their energy from the sun.
Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.
Architecture and urban planning
Main articles: Passive solar building design and Urban heat island
Darmstadt University of Technology won the 2007 Solar Decathlon in Washington, D.C. with this passive house designed specifically for the humid and hot subtropical climateSunlight has influenced building design since the beginning of architectural history. Advanced solar architecture and urban planning methods were first employed by the Greeks and Chinese, who oriented their buildings toward the south to provide light and warmth.
The common features of passive solar architecture are orientation relative to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and thermal mass. When these features are tailored to the local climate and environment they can produce well-lit spaces that stay in a comfortable temperature range. Socrates' Megaron House is a classic example of passive solar design. The most recent approaches to solar design use computer modeling tying together solar lighting, heating and ventilation systems in an integrated solar design package. Active solar equipment such as pumps, fans and switchable windows can complement passive design and improve system performance.
Urban heat islands (UHI) are metropolitan areas with higher temperatures t
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