What is high-quality energy?
Hi
The quality of energy is a perception, and it is necessary to
grade the tasks for which the energy is used to understand it
better.
One perception is that You require High quality energy to do
high quality task. Low quality energy cant be used to do a high
quality task, where as high quality energy can be used to perform
any task ,low or high quality.
Another perception is that, High quality energy can be
transformed into several forms of energy with great efficiency
(without much loss of energy when changing form)
Take the example of electricity, which is a high quality form of
energy. It can be converted to mechanical energy (in running
electric motors), Thermal energy (in heating water),
Electromagnetic radiation (in Radio broadcast) with little loss of
energy while changing form.
Here Water heating is a low quality task, which can be met by a
low quality energy such as heat (from burning fuel). Only Electric
energy which is a high quality energy can be used in high quality
tasks such as running a motor.
So Electricity is high quality energy and heat is a low quality
energy. Even among heat, the heat from solar radiation as received
at earth is supposed to be of lowest quality, because of lower
temperature and being diffuse (not concentrated). Blue flame heat
(from burning Natural Gas) is a better quality energy because of
its higher temperature, than say heat from burning wood or paper
which is of lower temperature reddish flame. The higher temperature
heat source ensures better heat transfer coefficients and thereby
faster heat transfer to bodies at lower temperature.
The environmentalists say "use high quality energy for only high
quality tasks and don't use it for low quality tasks". The logic
behind this is high quality energy is produced at great energy cost
and environmental cost. Avoid use of electrical energy for room
heating and cooling, instead use fuel energy or solar energy for
heating and use thermal design such as passive cooling for the
buildings, which lowers the room temperature by 5 to 7 degrees
centigrade.