
It is believed that the planet core is comprised of rock and nickel-iron alloy.

The lower layer is made up of the liquid hydrogen which may become metallic just above the core. Below its clouds the gaseous atmosphere gets hotter and thickens to a fluid state. The atmosphere of Neptune consists of mainly hydrogen, helium, and methane, similar to Uranus. The planet's core is believed to be rock and nickel-iron alloy encompassed by an outer layer of extremely hot fluid comprised of water, ammonia, and methane. The planet's atmosphere has small amounts of methane. Uranus is gaseous in composition, mainly comprised of hydrogen and helium as in the case of Jupiter and Saturn. The planet's core is believed to be composed of rock and nickel-iron alloy. It is believed that the liquid hydrogen layer of Saturn is thicker than that of Jupiter, while the liquid metallic hydrogen layer may be thinner. Further down, as in the case of Jupiter, there is a layer of liquid metallic hydrogen. Beneath the clouds, Saturn's hydrogen atmosphere thickens to become a fluid, with no distinct surface separating gaseous hydrogen from liquid hydrogen. Suspended in Saturn's hydrogen-helium atmosphere, in descending order of altitude, a layer of ammonia clouds, a layer of ammonium hydrogen sulfide clouds, and a layer of water clouds. Saturn's mean density is only about two-thirds that of water. The planet core is believed to be comprised of iron-nickel alloy and materials with the composition of rock, etc., at a temperature estimated to exceed 20,000 degrees CelsiusĪs with Jupiter, Saturn is mainly composed of hydrogen and helium and is observed to be of surprisingly low density. The zone of liquid hydrogen extends to a depth where the pressure is so high that it is believed there is a layer of liquid metallic hydrogen at a pressure of 3 million bars. Beneath the cloud layers, the clear atmosphere is denser and warmer and slowly transforms from a gas to a liquid without a sharp boundary to mark the change. We see the cloud tops (beneath a transparent, mostly hydrogen upper atmosphere). In contrast to planetary bodies covered with a hard surface crust (the Earth, for example), there is no jovian surface. Jupiter's composition is mainly hydrogen and helium. Graphic showing o ur best understanding of giant planet interiors in 2003. Oxford, UK: Oxford University Press, 2004. Renewable Energy: Power for a Sustainable Future, 2nd ed. In this case, instead of producing heat, the Sun's energy is converted directly into electricity with high efficiency photovoltaic cells designed specifically to harness concentrated solar energy.įor further information please see the related pages below: Point focus collectors and similar apparatuses can also be utilized to concentrate solar energy for use with Concentrated photovoltaics. These dishes can work alone or be combined into an array to gather even more energy from the Sun. Although very effective at collecting sunlight, they must actively track the Sun across the sky to be of any value. The heat from these collectors is generally used for driving Stirling engines. These collectors are large parabolic dishes composed of some reflective material that focus the Sun's energy onto a single point. Absorber plates can be used if a high temperature increase isn't necessary, but generally devices that use reflective materials to focus sunlight result in a greater temperature increase.įigure 5.

This is a very simple design, but collectors can get very complex. The black material absorbs the solar radiation very well, and as the material heats up the water it surrounds.

The simplest of these devices uses a black material surrounding pipes that water flows through. In general, there is some material that is used to collect and focus energy from the Sun and use it to heat water. There are many different types of solar collectors, but all of them are constructed with the same basic premise in mind. As well as in domestic settings, a large number of these collectors can be combined in an array and used to generate electricity in solar thermal power plants. The use of these solar collectors provides an alternative for traditional domestic water heating using a water heater, potentially reducing energy costs over time. These collectors are generally mounted on the roof and must be very sturdy as they are exposed to a variety of different weather conditions. These devices are primarily used for active solar heating and allow for the heating of water for personal use. A solar collector is a device that collects and/or concentrates solar radiation from the Sun.
