19th Oct 2017 11:07:05 AM

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Children of Fire

The LFE system: Lights for everybody

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 firechildren@icon.co.za 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? YES !

By making use of wind generators and solar panels that convert the sun’s 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 plug ).

Q) What makes this system different from other systems available today ?

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 grid.

The system can tap into the national electrical grid ( if necessary ), due to its SABS rating.

Environmentally friendly; Low maintenance; Easy to operate.

Q) What are the disadvantages of this system?

A) Initial construction and installation costs are high.

Qualified electricians are required to install the system to ensure that SABS ratings are guaranteed.

Solar power

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 source).

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 quality one).

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 maintain.

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 (August 2002)

Wind power

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 attention.


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
fuels. Wind energy is also non-polluting

Cattle can graze under wind turbines, and sheep look for shelter around them

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 safe.

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.
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 year.

Are there enough wind resources?

Wind Energy is abundant.
Example: South African West Coast has a 10 000 MW potential
Huge off-shore potential worldwide

Is Wind Energy Expensive?

Wind energy is inexpensive.
Is the least expensive, and most effective.
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
Expected to be the cheapest by 2050

How much land is required to site wind Turbines?

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
- solar cells uses less land than bio fuel but still use 1.4 hectares; wind only uses 0,0036 hectares of land.

Can wind energy be used in developing countries and does it create jobs?

Wind energy is an ideal developing country technology.
Made locally
Easily installed
No fuel needs to be transported
locally serviced
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

R 4987

1 x Wind Turbine

R 5700

16 x Light bulb fittings

R 1600

4 x Step up transformer

R 280

Insulated copper wiring assuming the dimensions of an average 2 roomed house)

R 770

16 x Light bulbs

R 640

16 x Light switches

R 128

Installation cost (performed by a qualified electrician according to SABS standards)

R 1800

   

TOTAL

R15905

Total (that each house would pay (eight houses)

R 1988

Further research and development would diminish costs

Classes of wind power

Wind Power
Class*

Wind Power Density (W/m2)

speed (km/h)

1

100

15.84

2

150

18.36

3

200

20.16

4

250

21.6

5

300

23.04

6

400

25.2

7

1000

33.84






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