Andrea Jarchow, age 16, is a pupil at Northcliff High School in
Johanesburg, South Africa. Children of Fire believes that her project could
help provide a different solution to candles in shanty towns, but the work
needs to be taken further. We invite school pupils internationally to email her
via firstname.lastname@example.org to
discuss their ideas.
Is it possible to provide African squatter camps and rural areas with
a low cost electricity source without connecting them to the national grid?
By making use of wind generators and solar panels that convert the
suns energy into electricity. This electricity is used to charge a
12/24/48V DC battery, which is then converted to 220V AC using a step-up
transformer (which is the equivalent voltage rating of a standard household
Q) What makes this system different from other systems available
A) My system is only temporary until South Africa's national grid
(parastatal Eskom makes electricity available to the targeted area) or
permanent if no connection is planned. Provision of Eskom electricity usually
involves wiring houses from scratch. By ensuring that my proposed system is
installed by qualified electrician according to South African Bureau of
Standards (SABS), additional costs could be avoided since the system would
simply tap into the national grid.
Q) What are the advantages of this system?
A) The system can be used independently of the national
The system can tap into the national electrical grid ( if necessary
), due to its SABS rating.
Environmentally friendly; Low maintenance; Easy to
Q) What are the disadvantages of this
A) Initial construction and installation costs are high.
Qualified electricians are required to install the system to ensure
that SABS ratings are guaranteed.
Producing electricity from solar power is not the same as producing heat
using solar power. A solar panel is made of silicon which becomes charged
electrically when exposed to sunlight. When sunlight is absorbed by these
materials, the solar energy knocks electrons loose from their atoms, allowing
the electrons to flow through the material to produce electricity. Solar panels
are directed at solar south in the northern hemisphere and solar north in the
southern hemisphere (which is slightly different to the magnetic north-south
compass directions). The angle at which the panel is installed is determined by
the geographic location and latitude. The panel must be tilted North ( in South
Africa ), and if your geographical position is located at 30 degrees
latitudinal then the panel must be tilted at 30 degrees. It cannot be placed in
an area where there are a lot of shadows. The system will only be cost
effective if the panels were placed close to the house.
Many power plants use fossil fuels as a heat source to boil water. The
steam from the boiling water rotates a large turbine, which activates a
generator that produces electricity. However, a new generation of power plants,
with concentrating solar power systems, uses the sun as a power source. The
energy is then stored in batteries. The battery most often used is called a
deep cycle battery. That means electricity can be used on cloudy days and
several hours after sunset.
Solar power works well for most items except large electric appliances
that use for example an electric heat element such as a water heater, clothes
dryer and electric stove. This is why my proposed system only provides power
for low power appliances or fluorescent light bulbs. This is done so that we
can provide as many houses with electricity as possible, instead of having one
system per house which would not be cost effective. It is not cost effective to
use solar power for high power appliances.
What are the advantages of solar power?
The sun is an abundant energy source.
This system does not make any pollution while converting sun
radiation into electricity that we can use.
The sun is an eco-friendly power source (clean and green energy
The panels are reliable and need minimal maintenance, the sun is
also reliable because it provides the panels with a constant energy supply
which does not change direction, unlike the wind turbines.
Solar panels have a long life ( provided one purchases a good
Reduces greenhouse gasses.
No noise pollution.
Fixed cost of electricity (cents per kilowatt-hour) for the life
of the system.
Solar panels after installation are very easy to operate and
The electrical energy stored in the batteries can be used on cloudy days
or after sunset.
Q) How much does a solar panel cost?
A) The cost of solar panels range from between R300 to R9000. Even
though the R300 one is cheaper, it ends up being more expensive because it has
a life span of about two to four months before it is sun baked and useless. The
R9000 panel however, is a Siemens product that comes with a 20 year guarantee
Small wind turbines are mainly used for rural energy in developing
countries. Rural electrification of houses, villages, farms and small
industries can often be done less expensively and more quickly with renewable
energy, such as wind power than by extending the national grid.
Q) How does a wind turbine work?
A) The wind turbine, which is at the top of a tall tower, accumulates
wind energy and changes it into electricity. The electricity is then used to
charge batteries. Since the wind is uneven, some sort of storage is usually
included in the system and back-up generators are often used.
Q) Are wind turbines too "high-tech" for rural people?
A) The high technology of a wind turbine is in just a few manufactured
components such as the blades. A wind turbine can actually be much simpler than
a diesel engine. It also requires much less attention and maintenance. The
turbines, for example, have only three moving parts and do not need any routine
maintenance. They can operate for five years or more, without any
Q) What are the advantages of using a wing turbine?
A wind turbine can pay for itself within 3-4 months, all the
energy used to construct and maintain it, compared to the decades for fossil
and nuclear plants. Wind energy is limitless unlike fossil
energy is also non-polluting
Cattle can graze under wind turbines, and sheep look for shelter
While birds tend to collide with man-made structures such as
electrical power lines, or buildings, they are very rarely affected directly by
wind turbines. Total impact on birds is trivial compared with power lines.
Wind energy does not make any dangerous pollution. No one has
ever been hurt by wind energy installations, and there is 0% risk of large
scale catastrophic accidents being caused by wind turbines unlike the nuclear
power station in Chernobyl in the Soviet Union in 1986. Wind energy is
Wind turbines use 0.002% of the water used in traditional power
generation (Water is only used to clean turbine blades to keep them operating
at peak efficiency). Installing wind farms rather than new fossil and nuclear
plants will help preserve scarce water resources.
Renewable energy is an alternative to other energy sources
Q) What are the disadvantages of using a wind turbine?
Renewable energy cannot solve all our energy problems.
Wind turbines are unreliable (they are only effective in places
where the wind direction is constant and wind speed is consistent)
Wind turbines are noisy (they make a whispering sound).
Wind turbines are dependent on wind.
Wind turbines spoil the scenery, for some people.
Do Wind Turbines really save energy?
Wind energy is clean and effective.
Are there enough wind resources?
2 to 3 months to recover all
energy that was used to built and operate it.
1 MW turbine saves 87 million
litres of water per year.
1 MW turbine saves 35 000 tons of coal per
Wind Energy is abundant.
Is Wind Energy Expensive?
Example: South African West Coast has a 10
000 MW potential
Huge off-shore potential worldwide
Wind energy is inexpensive.
How much land is required to site wind Turbines?
Is the least expensive, and most
But is dependent on how windy the site is
In Denmark energy
cost per kilowatt hour is predicted to fall by 20 per cent by 2005
to be the cheapest by 2050
Wind Energy uses land resources sparingly and 99 per cent of the land
can be used for farming or grazing as usual. Land requirements to produce 1.5
million kW/a: - bio fuel plant uses 154 hectares of valuable land
Can wind energy be used in developing countries and does it create
cells uses less land than bio fuel but still use 1.4 hectares; wind only uses
0,0036 hectares of land.
Wind energy is an ideal developing country technology.
No fuel needs to be transported
Creates four times more jobs than fossil fuel plants; ten times
more jobs than in a nuclear power
40 000 jobs altogether worldwide:
Example Danish Wind Turbine Manufacturers Association, targets to create a
total of 1.7 million jobs worldwide .
Q )How much would my system cost?
A) Assuming that the system would power sixteen 11 Watt
fluorescent light bulbs the costs for construction and installation would be as
follows, (This would be the equivalent of providing eight dwellings with 11
Watt fluorescent light bulbs/ two bedroom dwellings
Description of costs
Cost in Rands
1 x 75Watt Solar Panel
1 x Wind Turbine
16 x Light bulb fittings
4 x Step up transformer
Insulated copper wiring assuming the dimensions of an average 2
16 x Light bulbs
16 x Light switches
Installation cost (performed by a qualified electrician
according to SABS standards)
Total (that each house would pay (eight houses)
Further research and development would diminish costs
Classes of wind power
Wind Power Density (W/m2)