Solar energy is the energy received by the earth from the sun in the form of solar radiation. Solar power is the generation of electricity from sunlight directly with photovoltaics (PV) or indirectly with concentrating solar power (CSP).

Solar photovoltaics are arrays of cells containing a material that converts solar radiation into direct current electricity. The production cost of silicon-based solar cell module in 2008 was at some point 4-5 times higher than that of thin film modules. The efficiency in practice is from 6% to 9% and research labs are targeting 20% to 40% (Wikipedia: Solar cell).

Wikipedia: Deployment of solar power to energy grids provides information of solar energy use on each continent.

Trees and shrubs have been used for many years to reduce traffic noise from busy roads. Plants can also help to reduce background noise levels inside buildings by absorbing, diffracting or reflecting noise. Some plant species are more effective than others and the benefits are most pronounced in buildings with hard, reflective surfaces.

Here are a few guidelines for planting a tree fence:

• Place the fence as close to the noise source as possible.
• Plant trees and shrubs as close together as possible.
• Use dense foliage plants.
• Use evergreen species for year round protection.
• Make the fence as tall as possible.
• Make the fence as wide as possible.

Interior plants for reducing background noise level, Good interior plants of noise-reducing include Spathiphyllum wallisii (peace lily), Philodendron scandens (sweetheart plant), Dracaena marginata (Madagascan dragon tree) and Ficus benjamina (weeping fig). Positioning several arrangements around a space works better than concentrating the plants in one location. plants-in-buildings.com has a table of noise-absorption coefficients of plants.

Green energy or renewable energy has a host of social, environmental, and economic benefits. To be truly sustainable, an energy source must meet these criteria:

• minimal or no negative environmental or social impact.
• little or no net carbon or other greenhouse gas emissions.
• protect air, land and water.
• not deplete natural resources.
• not burden future generations with unnecessary risk.
• meet the needs of people today and in the future in an accessible, equitable and efficient manner.

Green energy sources include:

• Solar Energy is the Sun’s radiant light and heat that has been harnessed by using a range of evolving technologies to produce energy. The most common technologies used are photovoltaic (creating electricity) and solar thermal (heating air and water). The energy captured by these technologies can be used to provide electricity to the grid, or to offset energy needs that would have otherwise been produced using other fuel sources.
• Biomass & Biogas are both derived from combustible plant and animal materials that can be used to produce heat and power. Biogas is processed into a gas, while biomass is used as a solid. While these fuels do emit carbon, they are considered renewable. Unlike fossil fuels, the carbon emitted by biofuels can be recaptured in a single life-cycle by re-growing the source fuel, making them carbon neutral.
• Wind Power is created by capturing the force of the wind and converting it into electricity, typically using technologies such as wind turbines. Friction caused by the wind’s forces spins the turbine and is converted to electricity.
• Water Power or hydroelectric power is typically produced by harnessing the force of falling or fl owing water to turn a turbine. Like wind power, it uses the friction created to generate electricity. Water power can also be used for peaking power, by storing water in reserves for later use. Hydroelectric power is the most widely used form of renewable energy.

Green Computing is the study and practice of using computing resources efficiently. The primary objective of such a program is to account for the triple bottom line, an expanded spectrum of values and criteria for measuring organizational (and societal) success. The goals are similar to the goals of green chemistry that reduce the use of hazardous materials, maximize energy efficiency during the product’s lifetime, and promote recyclability or biodegradability of defunct products and factory waste.

Modern IT systems rely upon a complicated mix of people, networks, hardware and software. Green computing includes the implementation of energy-efficient central processing units (CPUs), servers and peripherals as well as reduced resource consumption and proper disposal of electronic waste (e-waste).

Here is a list of what we can do to contribute:

• Turn off the computers and all peripherals during extended periods of inactivity.
• Try to do computer-related tasks during contiguous, intensive blocks of time, leaving hardware off at other times.
• Power-up and power-down energy-intensive peripherals such as laser printers according to need, read manuals for suggestion.
• Use LCD monitors rather than CRT monitors.
• Use laptop computers rather than desktop computers whenever possible.
• Use energy-saving features to turn off monitors, hard disks or hibernate computers after several minutes of inactivity.
• Minimize the use of paper and properly recycle waste paper.
• Dispose of e-waste according to federal, state and local regulations.
• Employ alternative energy sources for computing workstations, servers, networks and data centers.
• Follow industrial standards when design, code software systems to enable reusability of models, source code and services to reduce cost and cycle time.
• Support and use open source software that millions of software developers and IT organizers have been working together to develop.