1. Green computing
Green computing is the study and practice of using computing resources efficiently. It aims
to 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.
The plan towards green IT should include new electronic products and services with
optimum efficiency.
Approaches to Green Computing:
1)Virtualization:
It is the process of running two or more logical
computer systems on one set of physical hardware. With virtualization, a system
administrator could combine several physical systems into virtual machines on one single,
powerful system, thereby unplugging the original hardware and reducing power and cooling
consumption.It can make the most efficient use of available system resources.
2)Power Management:
Power management can:
-Prolong battery life for portable and embedded systems.
-Reduce noise.
-Reduce cooling requirements.
-Reduce operating costs for energy and cooling.
The Advanced Configuration and Power Interface (ACPI), an open industry
standard, allows an operating system to directly control the power saving
aspects of its underlying hardware.Lower power consumption also means lower heat
dissipation which makes the system more stable. Some programs allow the user to
manually adjust the voltages supplied to the
CPU, which reduces both the amount of heat produced and electricity
consumed.
3)Power Supply:
If a PSU(power supply) meets the green certification, it will use only the power it needs at a
given load: In other words, it won't use more power than it needs.it's the heart of a green
PC, since it manages
the power for all the other components.
4)Storage:
features like the reduced RPM low-power idle mode with fixed rotation speed for
reduced power consumption has been developed. The second option is to use a 2.5" laptop
hard drive. The lowest-power option is to use a solid state hard drive (SSD).
5)Video Card:

2. A fast GPU may be the largest power consumer in a computer.Energy efficient display
options include Using motherboard video output, using a shared terminal, shared thin client,
Reusing an older video card that uses little power etc.
6)Materials Recycling
This can include finding another use for the system (i. e. donated to charity), or having the
system disassembled in a manner that allows for the safe extraction of the constituent
materials for reuse in other products.Recycling can keep harmful materials such as lead,
mercury,
and hexavalent chromium out of landfills. Obsolete computers are a valuable source for
secondary raw materials, if treated properly. Most major computer manufacturers offer
some form of recycling, often as a free
replacement service when purchasing a new PC.