Energy & Green Tech

The hydrogen factory of the future

Hydrogen is indispensable to successfully transitioning to renewables and meeting climate targets. It is the essential building block of sector coupling. While it provides an ecofriendly option to meet industry demand for ...

Energy & Green Tech

Major new study charts course to net zero industrial emissions

A major new study by an interdisciplinary team of researchers finds that it is possible—and critical—to bring industrial greenhouse gas emissions to net zero by 2070. Published Sunday in Applied Energy, the study assesses ...

Engineering

Next generation of greenhouses may be fully solar powered

Many greenhouses could become energy neutral by using see-through solar panels to harvest energy—primarily from the wavelengths of light that plants don't use for photosynthesis. Those are the findings of a new modeling ...

Energy & Green Tech

Tracking power generation and use in the U.S. on an hourly basis

A team of researchers at Stanford University has found a way to track how much electricity is generated and used in the U.S. on an hourly basis. In their paper published in Proceedings of the National Academy of Sciences, ...

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Greenhouse

A greenhouse (also called a glasshouse) is a building in which plants are grown. These structures range in size from small sheds to very large buildings. A miniature greenhouse is known as a cold frame.

A greenhouse is a structure with different types of covering materials, such as a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants, soil, and other things inside the building. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall. In addition, the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red, to which glass is partly opaque, so some of this energy is also trapped inside the glasshouse. However, this latter process is a minor player compared with the former (convective) process. Thus, the primary heating mechanism of a greenhouse is convection. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature drops considerably. This principle is the basis of the autovent automatic cooling system. Thus, the glass used for a greenhouse works as a barrier to air flow, and its effect is to trap energy within the greenhouse. The air that is warmed near the ground is prevented from rising indefinitely and flowing away.

Although there is some heat loss due to thermal conduction through the glass and other building materials, there is a net increase in energy (and therefore temperature) inside the greenhouse.

Greenhouses can be divided into glass greenhouses and plastic greenhouses. Plastics mostly used are PEfilm and multiwall sheet in PC or PMMA. Commercial glass greenhouses are often high tech production facilities for vegetables or flowers. The glass greenhouses are filled with equipment like screening installations, heating, cooling, lighting and may be automatically controlled by a computer.

This text uses material from Wikipedia, licensed under CC BY-SA