Energy & Green Tech

France's $35B innovation plan includes nuclear reactor funds

French President Emmanuel Macron on Tuesday unveiled a 5-year, 30 billion-euro ($35 billion) investment plan for developing innovative technology and industrial activity, including building small nuclear reactors, electric ...

Energy & Green Tech

Nuclear option: Earth's climate panacea or poison?

For its supporters, nuclear energy is the world's best—perhaps only—hope to avoid catastrophic climate change. Opponents say it is too expensive, too risky and totally unnecessary.

Energy & Green Tech

The world's slow transition to cleaner energy

The transition towards cleaner energy has made progress but not quick enough to limit global warming to well below 2 degrees Celsius, as agreed in the 2015 Paris climate agreement.

Other

NASA transfers air traffic management tool updates to FAA

As part of an effort aimed at making aviation more sustainable, NASA has transferred findings from an air traffic management project to the Federal Aviation Administration (FAA) for nationwide implementation, the two agencies ...

Energy & Green Tech

Improving carbon capture efficiency to help net zero emissions

As the UK's National Metrology Institute, NPL has a significant role to play in supporting climate change mitigation action and enabling the innovations which will help industry deliver on their goals of reducing greenhouse ...

Engineering

A supra-photothermal catalyst inspired by the greenhouse effect

Over the past few decades, scientists worldwide have developing a variety of techniques and technologies that can convert carbon dioxide (CO2) into fuel using solar energy. This would ultimately be highly valuable, as it ...

Energy & Green Tech

Biofuels offer a cost-effective way to lower shipping emissions

Marine shipping traffic has grown steadily over the past decade—and so have the associated greenhouse gas emissions. Carbon emissions from ships grew almost 10% between 2012 and 2018, and the industry is a large consumer ...

Energy & Green Tech

A carbon-neutral response to rising electricity demand

Many everyday activities rely on electricity. As we look to 2050, this dependence is set to increase, with demand for electricity in Switzerland likely to rise to 50 percent. The increased demand can only be met by transforming ...

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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