Solar energy and water distillation

Introduction
Clean drinking water is the basic necessity for every
human being, but about 1.1 billion people in the world
lacked proper drinking water.
Clean drinking water is the basic necessity for every
human being, but about 1.1 billion people in the world
lacked proper drinking water.
Water purification
There are many different types of water
purification processes such as filtration, reverse
osmosis, ultraviolet radiation, carbon
absorption, but the most reliable processes are
distillation and boiling .
Boiling and distillation
Boiling is used as a method of water purification.
Boiling is commonly advocated as an emergency
water treatment method, or as a method of
portable water purification in rural or wilderness
settings without access to a potable water
infrastructure.
Water purification, such as distillation, is
especially important in regions where water
resources or tap water is not suitable for
ingesting without boiling or chemical treatment.
Solar water purification
In solar distillation water is evaporated; using
the energy of the sun then the vapor condenses
as pure water. This process removes salts and
other impurities.
Solar energy is allowed into the collector to
heat the water. The water evaporates only to
condense on the underside of the glass. When
water evaporates, only the water vapor rises,
leaving contaminants behind. The gentle slope
of the glass directs the condensate to a
collection trough, which in turn delivers the
water to the collection bottle.

Existing products
Although there are many innovative
products available in the market but most
of these products are either too expensive
,inefficient, heavy and cumbersome or too
complicated to use.
Abstract
There are many methods and processes of solar
distillation and many solar distillation devices
are available in the market, but these devices
are very bulky, expensive or not very efficient.
There is a requirement for a device which is
highly efficient, economical, simple to
manufacture and maintain. This can be
achieved through understanding theory,
experimentation and learning from existing
products.

Theory
Energy from the sun per square meter per day = 1000 Watt (1300 Watt accurately)
= 1000 x 3600 joules perhour
= 3600 kilojoules per hour
Heat of vaporization of water = 2257 kilojoules per kg
Specific heat of water = 4.19 kilojoules per kg per Kelvin

Factors effecting evaporation
Concentration of vapor in air
Surface area of water
Pressure of vessel
Temperature of water
Boiling point of water at sea level is 100 degree C.
Boiling point of water may be decreased by decreasing the pressure.
-pressure may be decreased by going "above sea level".
-pressure may be decreased by "applying a low pressure"
Relatively cooler surface for condensation.
High vapor pressure
Low temperature

Project Aim
Maximize the output of a given source of energy.
Minimize the wastage of energy during the
conversion of energy.

Introduction and Background
Currently, most of the world's electricity is generated by burning
fossil fuels, such as coal, oil and gas.
However, these fuels, when burned, produce toxic emissions that
decrease our air quality and may cause global warming as well.
About 70% of the planet is covered in water, yet of all of that, only
around 2% is fresh water, and of that 2%, about 1.6% is locked up
in polar ice caps and glaciers. So of all of the earths water, 98% is
saltwater, 1.6% is polar ice caps and glaciers, and 0.4% is drinkable
water from underground wells or rivers and streams.
And despite the amazing amount of technological progress and
advancement that the current world we live in has undergone,
roughly 1 billion people, or 14.7% of the earths population, still do
not have access to clean, safe drinkable water.
Clearly, having affordable potable water and electricity readily
available to everyone is an important and pressing issue facing the
world today.

Purpose
Fortunately there is a solution to these problems. It is a technology that is
not only capable of removing a very wide variety of contaminants in just
one step, but is simple, cost-effective, and environmentally friendly. That is
use of solar energy.
Keeping these things in mind, we have devised a model which will convert
the dirty/saline water into pure/potable water using the renewable source
of energy (i.e. solar energy) and lead to generation of electricity at the same
time.
The results are obtained by evaporation of the dirty/saline water and
fetching it out as pure/drinkable water.
The purpose of this project is to design a water distillation system that can
purify water from nearly any source, a system that is relatively cheap,
portable, and depends only on renewable solar energy. From the results of
project calculations a truthful estimate was made to prototype the most
effective geometries of the distiller and concentration system, one that will
maximize evaporation/condensation and re capture waste heat to minimize
thermal losses.



Needs and Specifications
Our project centres on converting the roughly 99.6% of water that is, in its
natural form, undrinkable, into clean and usable water.
After researching and investigation, we outlined our needs to be the
following:
Able to purify water from virtually any source, included the ocean
Relatively inexpensive to remain accessible to a wide range of audiences
Easy to use interface
Intuitive setup and operation
Provide clean useful drinking water without the need for an external energy
source
Reasonably compact and portable

Our aim is to accomplish this goal by utilizing and converting the incoming
radioactive power of the sun's rays to heat and distill dirty and undrinkable
water, converting it into clean drinkable water and use the energy captured
in steam to rotate a turbine that helps us generate electricity.

Before we begin with our proposed
model we need to be familiar with a
few scientific terms and principles.
Light is the medium of energy by which we perceive our environment through our eyes. It is one
form of electromagnetic radiation which also includes things like ultraviolet, infrared, and radio
waves.
Like all electromagnetic radiation, light is transmitted by individual packets (or quanta) of energy
known as photons. These photons are the units by which the combined forces of electricity and
magnetism are communicated between other particles, such as the electrons associated with an
atom. Depending on the circumstances under which it is observed, a photon can behave like a
particle or as a wave. This principle is known as wave-particle duality.
LIGHT
Greenhouse Effect
The greenhouse effect is a process by which thermal
radiation from a planetary surface is absorbed by
atmospheric greenhouse gases, and is re-radiated in all
directions. Since part of this re-radiation is back towards the
surface and the lower atmosphere, it results in an elevation of
the average surface temperature above what it would be in
the absence of the gases.

REFLECTION
Refraction is defined as the bending of a light wave when it passes from one medium to another at the
surface separating the two media. It basically occurs due to the speed of light being different in
different media of different densities.

REFRACTION
Reflection is defined as the bouncing back of a ray of light into the same medium, when it strikes a
surface. It occurs on almost all surfaces - some reflect a major fraction of the incident light. Others
reflect only a part of it, while absorb the rest.
Concave Mirror

A concave mirror has a reflecting
surface that bulges inward.
Concave mirrors reflect light
inward to one focal point.
These mirrors are called
"converging" because they tend to
collect light that falls on them,
refocusing parallel incoming rays
toward a focus. This is because the
light is reflected at different
angles, since the normal to the
surface differs with each spot on
the mirror.
In our machine we have used
curved copper sheets with
electroplating of aluminium on the
inner side as a concave mirror.

Convex Lens
A Convex Lens is also known as a
converging lens. A converging lens is a
lens that converges rays of light that
are traveling parallel to its principal
axis. They can be identified by their
shape which is relatively thick across
the middle and thin at the upper and
lower edges.
The edges are curved outward rather
than inward. As light approaches the
lens, the rays are parallel. As each ray
reaches the glass surface, it refracts
according to the effective angle of
incidence at that point of the lens.
Since the surface is curved, different
rays of light will refract to different
degrees; the outermost rays will
refract the most.
This nature of convex lens helps us
concentrate suns light energy at one
point.
Construction