What is a National Grid System?

1. What is a National Grid System?
National grid is a transmission network consisting of the high voltage electrical power that
covering a whole country or a national by connection of power stations as well as the power
substations by ensuring the power generated is transmitted to consumer to satisfy the consumer
demands. The National grid majorly is for the distribution of the electricity within the country. It
connects the generating stations to factories, homes and commercial centers country wide. It is
composed of the overhead power transmission lines, pylons and underground cables. The system
is in use of bulk electrical energy transfer from the power stations to substations then to the
consumer.1
Advantages of the National grid
i. Electricity can be consumed from any power generating station in order to cater for the
demand anywhere in the country
ii. The power plants can be constructed near the available natural resources as well as far
away from urban centers.
iii. Extra electrical power can be used in generation of Hydro electrical power by pumping
water up hill
iv. If on power station may failure or switched for maintenance the consumer can continue
receiving electricity from the supplier.
v. Keeping of pollution far from the cities
Disadvantages of the national Grid
i. Some of the power is wasted due to the heating the cables
ii. It costly to build the national grid infrastructure system for the whole country if the
underground cable connection is used.
iii. The national grid system promotes monopoly, which may lead to laxity of quality service
delivery to the consumer.
iv. The overhead as well as their electrical supporting towers may bring an eyesore in some
areas.
v. The national grid system if connected to the internet and the system is hacked, it can
bring the whole national into a total electrical blackout for instance when Turkish
national grid was hacked the whole country was put into an electrical black out.
2. What is alternating current and how it is produced?
Alternating current is usually produced as a result of the change of the charges flow direction
periodically. Due this effect, the levels of voltage also reverse with current along the line. The
alternating current is generated using a device known as the alternator. An alternator is a special
device that designed to generate alternating current by the spurning a loop wire inside of the
1 Godfrey Boyle
Renewable electricity and the grid: the challenge of variability ( 1. edn Earthscan 2012 ) 144.

magnetic field, that causes inducement of the current along a wire. This is usually done though
the rotation of the magnetic field at around stationary set coils of wire by the turning of the shaft.
Advantages of alternating current
i. Alternating current can be transmitted over a long distance.
ii. The alternating current can be easily produced
iii. It is cheaply generated when compared to dc.
iv. The generators of ac have higher efficiency than dc.
v. The alternating current can be easily stepped up or down by transformers.
vi. The value of the alternating current can be easily decreased without excess loss of
energy.
vii. It produces better lighting
viii. It can easily generate a waveform
Disadvantages of alternating current
i. It can cause heat and spark which can result electric fires or shocks.
ii. It can create impractical in transmission in undersea cables for it needs a substation
nearly after every four hundred miles. In underwater, the substations cannot be built
there.
iii. The need of insulation at high power makes it difficult to handle it because it can result
electrocution to the operator if not well handled.
iv. It is expensive when used in cars because of its impracticability in cost terms.
v. It needs more cables to transport making it expensive when compared to dc.
3. What is Hydropower?
Hydropower is the generation of electricity due to water moving which is harvested in a reservoir
or dam and falls due to gravity to rotate turbines. The water flow creates energy that can be
harnessed and used. The widely used method is of a dam constructed on the river channel to keep
water in the reservoir. The stored water at the reservoir is released to cause rotation of the
turbines which in turn rotates the magnetic magnets to induce current along the coils of the
wires. The power generated is the harnessed and connected to the step up transformers for
stepping up for transmission.
Advantages of Hydropower
i. It is a form of renewable energy
ii. It is a source of alternative and environmental friendly energy
iii. Hydropower is reliable and stable provided there rivers available.
iv. It needs a low operating cost
v. It easily matches with the current demands dep2ending the river regime.
2 James Kirtley
Electric power principles: sources, conversion, distribution and use ( 1. edn Wiley 2011 ) 10-80.

vi. The water used for Hydropower can be used for other applications such as irrigation.
vii. The dam constructed can be used for recreational activities such as canoeing
viii. The hydropower station can attract tourists.
Disadvantages of hydropower
i. It can lead to environmental damage due to water flow interruption.
ii. It is expensive to build it.
iii. The exploitation of hydropower may lead to droughts in some areas.
iv. It can lead to floods at lower regions of the water flow.
v. It can cause water supply shortages
vi. The site of constructing hydropower can result displacement of people and wild life from
their habitats.
vii. Accidents caused by dams are deadly to the lower regions of the dam.
viii. It does not provide consistent power due to drought sometimes.
4. What is Wind power?
It is the power produced by harvesting the wind energy to generate electricity or mechanical
power. The mechanical energy can be employed for grinding cereals or water pumping. The
Mechanical energy is convertible into electricity by use of a generator. The wind rotates the
turbines which are connected magnets, and then a rotating field is produced that leads to induced
current at the coils of the wires. Wind movement has kinetic energy. Thus, high velocity wind
will result high power produced by the wind power plant. So when there is slow wind velocity
small power is generated.
Advantages of wind power
i. Promotion of energy cost effectiveness
ii. It revitalizes the rural economies as it is built in rural areas.
iii. It reduces dependence on fossil fuels which are exhaustible in nature.
iv. It is environmental friendly because it does not pollute air and water.
v. It is a renewable energy resource.
vi. Wind is a free fuel to be exploited.
vii. Promotes price stability in energy sector.
viii. It promotes job creation.
ix. It discourages energy subsidies from the government.
x. It has negligible greenhouse effects on the environment.
Disadvantages of Wind power
i. It only when the wind is blowing a turbine can produce electricity.
ii. The aesthetic to people when seeing the wind power.
iii. The shadow flickering which may alter the light to residents near the wind farm.