See a French translation of this page
We've used the Sun for drying clothes
and food for thousands of years, but only recently have we been
able to use it for generating power.
The Sun is 150 million kilometres away, and
See a French translation of this page
We've used the Sun for drying clothes
and food for thousands of years, but only recently have we been
able to use it for generating power.
The Sun is 150 million kilometres away, and amazingly
Just the tiny fraction of the Sun's energy that
hits the Earth (around a hundredth of a millionth of a percent)
is enough to meet all our power needs many times over.
In fact, every minute, enough energy arrives at
the Earth to meet our demands for a whole year - if only we could
harness it properly.
Currently in the UK there are grants available to
help you install solar power in your home.
to see examples of solar products.
How it works:
There are three main ways
that we use the Sun's energy:-
(really called "photovoltaic", "PV" or "photoelectric"
cells) that convert light directly into electricity.
There's an infographic here to explain how they work
In a sunny climate, you can get enough power
to run a 100W light bulb from just one square metre of solar panel.
This was originally developed in order to provide
electricity for satellites, but these days many of us own calculators
powered by solar cells.
People are increasingly installing PV panels on
their roofs. This costs thousands of pounds, but if you have a
south-facing roof it can help with your electricity bills quite
a bit, and the government pays you for any extra
energy you produce and feed back into the National Grid (called
the "feed-in tariff").
water heating, where heat from the Sun is used to heat
water in glass panels on your roof.
This means you don't need to use so much gas or
electricity to heat your water at home.
Water is pumped through pipes in the panel. The
pipes are painted black, so they get hotter when the Sun shines
on them. The water is pumped in at the bottom so that convection
helps the flow of hot water out of the top.
This helps out your central heating system, and cuts your fuel
bills. However, with the basic type of panel shown in the diagram
you must drain the water out to stop the panels freezing in the
winter. Some manufacturers have systems that do this automatically.
Solar water heating is easily worthwhile in places
like California and Australia, where you get lots of sunshine.
Mind you, as technology improves it's becoming worthwhile in the
Here's a more
advanced type of solar water heating panel.
The suppliers claim that in the UK it can supply 90% of a typical
home's hot water needs from April to November.
This "Thermomax" panel is made of a set
of glass tubes. Each contains a metal plate with a blue-ish coating
to help it absorb solar energy from IR to UV, so that even in
diffuse sunlight you get a decent output. The air has been removed
from the glass tubes to reduce heat loss, rather like a thermos
Up the back of the metal plate is a "heat pipe",
which looks like a copper rod but contains a liquid that transfers
heat very quickly to the top of the glass tube. A water pipe runs
across the top of the whole thing and picks up the heat from the
Find out more at www.solarsense-uk.com/thermomax.php
The main way that a conventional gas "combination boiler"
continually wastes energy is by replenishing stored water as
soon as the volume or temperature decreases.
With solar powered boilers, this is instead
fuelled by the solar power collected through panels on the roof
of your home.
The power collected through the solar tiles is used to fuel
and therefore heat a separate water cylinder, thus saving energy
throughout the course of every day.
Another smaller tank, still powered by gas, is provided with
most solar boiler installations as a backup.
Furnaces use a huge array of mirrors to concentrate
the Sun's energy into a small space and produce very high temperatures.
There's one at Odeillo, in France, used for scientific
It can achieve temperatures up to 3,000 degrees Celsius.
out more from wikipedia...
Solar furnaces are basically huge "solar cookers".
A solar cooker can be used in hot countries to cook food. This
one is in the UK, making tea and coffee, although it does take
a long time!
Solar cells provide the energy to run satellites
that orbit the Earth. These give us satellite TV, telephones, navigation,
weather forecasting, the internet and all manner of other facilities.
The graphic shows a GPS satellite. A satellite navigation receiv