News in SHP
Small Hydro Dower
in Nigeria
Messr Idris Mohammad (National Electric Power Authority, Nigeria)
Ikpo Kalu Ochu(Electrical lnspectorate Services, Federal
Ministry of Power & Steel, Nigeria)
In partial fulfillment of the requirement for the completion of the training
course on SHP, this presentation is made to briefly introduce our representative
countries, the availability of SHP in our countries, training experience and
possible areas of co-operation in SLIP. The importance of SHP projects (to be
initiated in our countries) cannot be overemphasized. This renewable approach
to power supply is a lucrative and promising future prospect of energy development
that de-serves a closer attention. As we de-liberate along we will discover
a few suggestions that would add more flesh to the entire presentation.
1 BRIEF INTRODUCTION OF NIGERIA
The total area of Nigeria is 923,770 square kilometers, bounded in the east
by Cameroun (1690 km) and in the west by Benin Republic (773 km) and in the
north by Niger Republic (1497 km) and Chad (8 km ) bringing the total land boundaries
to 4,047 km.
There are two seasons: the wet season which runs from May through October and
the dry season which prevails from November to April.
Nigeria is rich with several highlands, lowlands, rivers, mountains, plateaux,
with various vegetations from one season to another. Prominent among the rivers
are River Niger and River Benue. About 65% of the population earn their living
from the land, mainly as subsistence farmers. Agriculture has been the mainstay
of the national economy until the discovery of crude oil in the late 50's. Petroleum
has become the backbone of the nation's economy with Nigeria as the sixth largest
producer of oil in the world.
Nigeria is a multi-ethnic secular state with a great variety of languages spoken
in the country. There are about 230 tributes with over 250 dialets in Nigeria.
The three major tributes are the Housas (north), Igbos (East) and the Yorubas
(West). English is the official languages in Nigeria.
Nigeria is the GMT+ 1 hour time zone, with twelve months of 30 days (September,
April, June, November) 31 days (January, March, May, Au-gust, October, December)and
28 days for February (or 29 days during leap years).Nigeria uses 220 volts norminal
AC voltage at 50Hz frequency.
Nigeria's population is estimated at 124 million with average growth rate of
3.05% and the capital city of Nigeria is ABUJA. The head of state, commander
in chief of the armed forces of Nigeria is Chief Olusegun Obasanjo. There are
36 state in Nigria apart from the Federal capital territory. Nigeria practices
the presidenatial system of government. Elections are held every 4 years for
new leaders to emerge. Next Nigeria election is due by the year 2003. There
are 3 tiers of Government, namely executive, legislative and the judiciary.
Members of the national assembley are elected from their constituencies by the
electorates.
Nigeria is rich in tourism attractions. The Temperate climate during the two
seasons affords tourist maxi-mum comfort from the outstanding moderately cold
plateau state (temp between 12~C and 20~C) to the shiny northern and southern
state ( temp between 18~C and 37~C). Some tourists attractions and where the
could be located in Nigeria are as follows.
(1) Obudu cattle ranching in Cross River state (East)
(2) Olumo rock in Abeokute , Ogunstate (West)
(3) Osun shrine in Oshogbo, Osun state (West)
(4) Ikogusi warm and cold water spring (Mid West)
(5) Argungu fishing festival, Kebbi state (North)
(6) Yankari games reserve Baauchi state (North)
(7) National Museum at Onikan, Lagos state (West)
(8) Kainji/Jebba/ Shiroro dams Niger state (North Central)
(9) Mambila plateau - Taraba state (North East)
(10) National Theatre at Iganmu, Lagos state (West)
(11) Usman DanFodio tomb, Sokoto state (North)
There are about 7 major cities in Nigeria with average population of 5 million
people in each. Hospitality industries are ridily available, from the luxurious
Hilton and Sheroton hotels to the tourist - class hotels. All tourist hotels
offer a choice of modem hotels with state-of-art com-
munications facilities.
The local currency in Nigeria is the Naira made up of 100 Kobo = 1. There are
denominations of (500, 200, 100, 50, 20, 10 and 5) naira notes. Visitors may
import unlimited amount of foreign currency, providing declarations of such
currency is made to customs officials on arrival. Visitors are able to change
unused Nigerian currency back to the foreign currency of their choice before
departure at the airport in company of currency declaration form and receipt
for exchange transactions.
2 AVAILABILITY OF SHP STATIONS IN OUR COUNTRY
Though our report is suppose to be in small hydro power which is not available
in our country we have taken Shiroro hydro power as a
case study.
Shiroro hydro electric power station is one of the 7 power stations in Nigeria.
It belongs to national electric power authority (NEPA), which is situated in
Niger state, 550m down stream of the confluence of Kaduna River with its tributary,
the Dinya River about 60km northeast of Minna, the state Capital.
HISTORY
The story of the hydro electric project in Nigeria dates back to 1951 when with
the growth of industries and rapid urbannisation the de- mand for electricity
was rising faster than the suppler. The decision to build a dam across, river
Kadnna in the area of Shiroro a small farmers village near minna in niger state
that gives its name to the gorge where the project is located has its origin
in the survey carried out in 1951 and relevant to the exploitation of the energy
potential of the Nigeria fiver sys- tem. As a result of the reports of the survey,
the niger dam project committee (made up of representatives of the Federal government,
the government of the former northern Nigeria and the former electricity corporation
of Nigerai) recommended that an initial development near Kurwasa followed by
development at Shiroro and Jebba would be most beneficial to Nigeria. The Shiroro
power station in the Kaduna river is of 600 MW.
The final design of the whole project was prepared for NEPA by chas T main international
inc. of Boston Mass, USA who were also responsible as Engineers for the super-vision
of all the contracts required for its implementation while the contracts for
the construction of the civil works was awarded by NEPA to an Italian firm TORNO
SPA towards the end of 1978.
Other components of the project where awarded to different companies, which
included the Austrian firm VOESt ALPINE for the supply and installation of the
hydraulic turbine and governs, INGRA RADE KONCAR of the federal republic of
Yugoslavia for the supply and installation of the generator and exciation system,
MITSUI/TOSHIBA of Japan for the generator -transformers and GEC of UK for the
projective relay and control equipment. High volt-age switchgear and other switchgear
equipment where supplied by Siemens AG of the Republic of Ger-many while CEI
of Italy handled electrical installation and auxiliary plant Items. A Spannish
company, BYNSA supplied the project cranes. In a similar vein both the power
intake and spillway gates together with the associated electro-hydraulic control
equipment were supplied by Tampella of Finland.
DAM
The Dam is of a rock-fill type and stands 115m high above the original river bed-elevation, across Shiroro gorge for a crest length of 700 metres. The width of the dam at its toe is over 300 metres whilst its crest, which accommodates a service road is 7.5m wide. The crest of the dam has a heavy reinforced concrete parapet wall, more than 5 m high, which is also designed to protect top of the dam from the waves that will build up in the lake under wind pres-sure.
POWER INTAKE
The 60m high reenforced concrete tower of the power in take with a 44m by 15m
rectangular plain is located on the right bank in the proximity of the spillway's
structure. At the bottom the are four openings 5.50 m wide and 10m high through
which, and a transition area in the concrete structure, the water from the reservoir
enters the circular penstock to be finally conveyed to the turbines in the power
house. The bottom of the tower has 1.5m diameter water re-lease out let to maintain
the flow when the turbines are not turning to be used by people living along
river down stream from the dam.
The intakes can be short by means of gates operated by hydraulic hoists located
on the chamber of the top of the tower which is accessible from the dam crest,
through a steel bridge.
SPILL WAYS
The spillway is at the right abutment of the dam and is a reinforced concrete
structure about 100m long on its center line, which includes 4 openings 15m
wide and 16.65m high. The openings are con- trolled by means of hydraulically
operated tainter gates. The capacity of the spillways is7,500 cubic metres per
second. Downstream from the structure a concrete chute 50m wide and 360m long
built within the right bank, takes the spilled water to the bucket at its end
and finally into the plunge pool which has been provided by the excavating the
existing river bed.
PENSTOCKS
The penstocks are made up of t steel barrel with a diameter of 6.3m and have
a total developed length of 1,400m in four lines of varying individual lengths
, the total weight is 4000 tons. The penstock lines, partly horizontal and partly
inclined are fully encased in reinforced concrete.
POWER HOUSE
The main building of the power house, which is 100m long and about 40m wide
house the 4 ~150MW units. It is a massive rein-forced concrete structure most
of it within the rock with a structural steel superstructure which supports
the roof as well as the rails of the 210 tons over head traveling cranes used
for the erection of the turbines and generators and for their major maintenance.
The maximum height of the building from the foundation level to the rooftop
is 51m. From the power house the water flows back into the riverbed a downstream
from the dam, through steel lined draft tubes and eight opening which can be
short by means of the gates, controlled by another gantry crane of 30 ton capacity.
INSTALLED CAPACITY
Shiroro hydro power has a total capacity of 600MW from the 4 generating units
rated at 150MW each at a head of 97m, each unit comprise of a vertical francis
hydraulic turbine unit controlled by an electro hydraulic governor. The turbine
drives a synchronous generator of salient pole construction having a net output
of 150MW. The generator is excited by a static self excitation sys-tem. The
speed of rotation for the unit is 150 rpm. These turbine generators are capable
of independent operation.
GENERATION
Power is generated at 16kV volt- age levels. A generator-trans-former steps
up the voltage to 330kV level for connection to national grid via the agency
of a 330kV switch yard The national grid constitutes a power pool to which all
the power stations and load centers are connected. The stations annual energy
generation is 2230GWh. This accounts for a plant utilization of about 42%.
TRANSMISSION
Shiroro power station has 4 ~ 200 MVA, 16-330kVpower trans-formers through which
4 short span feeders. Fedtwo (2) 330kV buses 1 and 2. In between these buses
1 & 2 are a breaker and half system comprising of SF6 circuit breaker and
motor operated disconnect switches (Isolators). From the 2 buses emerge 4 ~330kV
feeders (2) between Shiroro and Jebba and (2) between Shiroro and Kaduna. The
arrangement of the buses allow for multiple sources of power utilizing the 4
lines. Provision for double circuit to Abuja has been made and partially equipped
for future supply to Abuja at 330kV. Within the switch yard there is a provision
of 2 ~ 150MW, 330/132/33 kV auto grid transformers for the provision of the
following transmission voltage levels.
a) 132 kV transmission lines
i)Double circuit 132 kV to Minna which also supplies Suleja, Abuj a and Bida.
ii) Single circuit 132 kV Shiroro Tegina which also supplies Contagora substation.
b) 33 kV transmission lines
i) Single circuit from Shiroro to Gwada and Kuta.
ii) 33 kV supply to 2~ 15 MVA 33/11 kV transformers.
c) 11 kV distribution network
i) 2 ~ 11 kV feeders to the power station for power station auxiliaries.
ii) 1 ~ 11 kV feeder to the senior camp.
iii) 1 X 11 kV feeder to the operators and junior camps with T-off to Zumba
resettlement village.
iv) 1 ~ llkV feeder to the switchyard auxiliaries.
v) 11 kV Supply to the supple-mentary National Control Center.
SPECIAL FEATURES OF SHIRORO
a) The station runs on 4 No Francis Turbines which are suites for the medium
head reservoir operation of Shiroro lake.
b) Quick start from cold and quick load pick-up are also special features of
the machine in the Shiroro power station.
c) Each of the 4 Shiroro machines can boost power supply to the National Grid
by 150 MW in just 6 minutes.
This is one of the most important special features of Shiroro power station
which makes the station vital in handling emergencies resulting from sudden
increases in load demand or sudden loss of the machine in an-other station.
UNIQUE ACHIEVEMENTS AND
A WARD WINNINGPERFORA/IANCE
a) Shiroro power station has remained the most reliable power station in the
country's electricity net-work.
b) Shiroro power station operates at 100% capacity.
c) Its units are the fastest in boosting power supply to the National Grid.
d) In emergencies National Electric Power Authority (NEPA) of Nigeria falls
balk on Shiroro power station for bulk production of electricity.
e) It generates 25% of Nigeria electricity demand.
IMPACT OF THE DAM ON ITS EN- VIR ONMENT
Although the power station project involves the relocation of families, it also
offers benefits to the local communities. The creation of the dam led to the
change of climatic condition in and around the lake area. It modified the relative
temperature of the catchment area resulting in cold/warm zone in the Shiroro
lo- cal government area. The northern area where the lake is situated has a
colder temperature than the southern part of the local government.
1) ECONOMIC & SOCIAL IM- PACT
a) The dam and the switchyard constitutes a tourist centre where people from
all works of life visit for tourism during holidays and week- ends.
b) The presence of the dam has created job opportunities at various levels for
the indigenes and non-indigenes as well.
c) The indigenes feel a sense of belonging by way of contributing to national
development through power generation from Shiroro power station.
d) The station represents a unique engineering finn for students on excursion
and provides a good training ground for industrial training of students of engineering
and allied courses of study.
e) The station contributes immediately towards science education by providing
higher institutions with instructional materials like old trans-formers, electric
motors, pumps e.t.c..
f) The construction of Shiroro dam has resulted in improved revenue generation
for the state and lo-cal government through taxis from civil servants and various
levies from other settlers.
2) FISHING
Fishing activities around Shiroro dam on the river Kaduna was almos none existent
before the creation of the dam. After the construction of the dam, fishing has
since commenced resulting in more than fort) fishing villages located along
the banks of river Kaduna and its major tributaries mainly rivers Munye, Sarkinpawa,
Dinya and Guni. The creation of the dam has attracted immigrants from distant
areas such as Edo state, Sokoto state, Borno state, and even Niger and Mall
countries out- side Nigeria.
The construction of Shiroro dam has therefore given rise to the following.
a) Commercial fishing activity.
b) Improved nutritional value on the diet of the villagers.
c) Altemative commercial activities and source of income instead of the usual
farming activity alone.
d) Improved social status since additional income is generated.
e) Improved social interaction with the immigration of people from far and wide
settling among the local people.
3)AGRICULTURE
Before the impounding of the lake, the vegetation of the land along the Kaduna
river was mainly savanna, with patches of few wood lands along its tributaries
of Guni, Muye, e.t.c.. However, the construction of the dam has improved the
fol-lowing agricultural activities in large scales.
a) Livestock production.
b) Fadama farming.
c) All year round farming by irrigation from the lake.
d) Normal raining season fanning, the major crops grown in the lake catchment
area include maize, rice, yam, cassava, millet, potatoes and guinea corn. The
Fadama area yields the following crops: sugarcane, vegetables, tomatoes, pepper,
e.t.c..
3 EXPERIENCE DURING THE TRAINING COURSE ON SHP IN CHINA
1)LECTURES TECHNOLOGY
Small hydro-power is a new tech- nology which has not been praticed in our country.
During the training the technological aspect of SHP were thoroughly taught and
un-derstood. Areas covered under SHP were hydrology, geology, power, protection,
control, construction and metering systems. All these aspects were taught by
different research engineers/specialists in details theoretically and later
followed by practical explanation during site visit outside HRC training center.
The Automation of electrical energy is also an important aspect that was taught.
This automation made technology easier operationally, though it has a disadvantage
of creating unemployment in the country. Since research is the back bone of
any developing country, redundant workers caused by automation can be transferred
to reaserch centers in order to discover more technologies or improve on the
existing ones.
INTERNATIONAL TRADE
The main aim of this training is technical cooperation which cannot be achieved
without international trade among developing countries. During the training
some of the international trade terms were high- lighted and explained in details.
These terms assist both the import/buyer and the exporter or seller. Some of
these terms are FOB, FCA, CPT, CIP, etc. All these terms are provided to guide
both the importer and exporter, so when ever our country is ready to import
something from China, we have been taught during this training how to make use
of these terms. If these terms are properly defined by both the importer and
exporter at the beginning of the business the would be no difficult in resolving
dispute if it occur at the end of the business. For example if CPT (carriage
paid to destination) agreement is made and exporter failed to pay for the carriage,
CPT term would be refered to and law will be enforced on the exporter to fulfill
the agreement.
GENERAL
There are other experiences or trainings acquired during this course period
apart from technology and international trade experience.
During the site seeing, it was discovered that Chinese government converted
some wonders of nature in and outside Hangzhou to recreational and tourist centers.
This at-tracts many people within China and other parts of the world to come
as tourists or for recreation. It also pro-vides revenue for the government
and job opportunities for the citizens. There are natural places like those
of China in our country which could be utilized in the same way or even better.
From the knowledge we have acquired through the training, this will be conveyed
to our country and similar recreational centers shall be constructed. Some of
these places are West Lake, Fish/Animal zoo, where rocks were excavated to house
animals and fish. There are other places visited outside Hangzhou where foot-path
was provided over a long hill of about 2km which also has water falls
at different elevations. This also brings revenue to the government as one of
the recreational and tourist centre in China.
2) NEW DIMENSIONS
Small hydro construction has led to new dimensions in the field of technology.
Presently there is no SHP in our country, but from the knowledge acquired we
have seen the importance of SHP and some new dimensions taken by China in the
field of technology. Some of these new dimensions include pumped storage power
stations, used to balance loads at base and peak periods. This could also be
used to maintain generation at low water head in the dam by pumping water from
the down stream to the upstream of the dam.
The decentralization of power control and independent power stations practiced
in China is also some-thing that brings about the stability of power supply
in the country. This is possible because of the construction of many SHP stations
at different localities to supply particular or specific communities. This will
pre-vent a whole nation from experiencing total blackout due to failure from
a station or line. SHP can be as many as possible because it is pollution free
and has lower maintenance costs than others.
3) WELFARE 1N CHINA
In the area of welfare, HRC has done a lot to make us comfort-able at all times
both in and outside HRC. Site seeing was regularly organized from time to time
in and outside Hangzhou city. The coordinators of the course were always ready
to accept our complaints. Whenever we required anything outside HRC premises,
they would describe the place to us and many times accompany us to the place.
None of the HRC staff has ever frowned at us despite our continues request of
one thing or another, instead they laughed and joked with us, thereby making
us to always fill at home. We shall really miss all of our coordinators after
departure to our various countries, be-cause they treated us like their own
brothers especially messrs Pan, Yan Shen, and Zhao. We promise to continue communicating
with them after returning to our respective countries, and probably make a visit/business
trip to China via HRC.
4) RECOMMENDATIONS
The knowledge acquired during the training on SHP has exposed us to many fields
of technology. The following recommendations are therefore important for our
country to be implemented.
a) Construction of SHP projects to improve the stability of power supply.
b)Construction of pumped storage hydro power stations to minimize non-generation
due to water shortage.
c) Decentralization of national control centre to minimize total blackout due
to loss of a unit or line.
d) Construction of independent SHP stations at different localities to sup-ply
particular or specific communities.
e) Sending personnel to developed or developing countries to participate in
the construction of SHP stations.
4 POSSIBLE AREAS OF CO-OP-ERATION ON SHP BETWEEN OUR TWO COUNTRIES
The training programme on SHP in China can be described as an eye opener. The
availability of the much needed electrical energy through SHP exploitation in
China provides a great lesson to be learnt by an inquiring mind. The need to
pre-serve our much treasured forests and wild life by providing alternative
means of fuel for daily domestic uses, the need to pull our resources together
to fight desert encroachment in the northern part of our country through construction
of SHP dams, and the need to establish cottage industries in the rural areas
as abundant SHP energy will be readily avail-able, thereby decreasing rural-urban
,drift make it abundantly necessary that areas of possible co-operation between
our two countries should be diligently sought and established. This measure
will in the nearest future make Nigeria benefit from the gains of SHP projects
that is being enjoyed by China presently.
1) CO-OPERATION THROUGH EDUCATION
Information dissemination
The two countries ~an cooper- ate to a great extent depending on the level of
information that is available to both the government and the governed. Information
on avail- ability of small hydro power alternatives and its gains will normally
rouse attentions especially if the present means of power supply is unsatisfactory.
Creating awareness through the media or radio/TV adverts, newsletters and publications
will greatly afford everyone an opportunity to com-pare and contrast, and thereby
make positive contributions towards the establishment of SHP protects in the
country.
Educational materials in form of journals, correspondence courses and possible
integration of SHP courses in the curriculum of Nigerian higher institutions
will greatly enhance co-operation on SHP between the two countries.
2) TECHNICAL CO-OPERATION
Special technical training programme may be signed between the two countries
whereby technical personnel will be sent to China from Nigeria to be trained
on the rudiments of SHP technical know-how. These trained personnel subsequently
work closely with experts from China in the course of consulting, planning,
construction and execution of SHP projects in Nigeria. This aspect of possible
co-operation will also involve equipment supply and maintenance. Since China
has fully developed and automated the manufacture, operation and control of
SHP technology, it becomes a lot easier to also train some team of technical
personnel from Nigeria within the same industries in China.
There is possibility of systematic technology transfer in the area of SHP exploitation
in Nigeria from China since the latter has a complete and comprehensive package
of this lucrative renewable energy. Provision of spare parts, useful result-oriented
solutions and proper maintenance culture will not pose any problem. China is
fully equipped and appears ready for any
proposals from our country.
3)GOVERNMENT POLICIES
The government of Nigeria is known for polices that are both people oriented
and intergovernmental-friendly. As a democratic government, the welfare of the
governed constitutes the major aspect of the government's programme. Provision
of steady and uninterrupted power
supply has been one of the outstanding feats the present government seeks to
achieve. Introduction of such policies in China (to the government of Nigeria)
that created enabling environment for SHP projects and sup-ply to thrive is
a very useful tool that can bring about real co-operation on SHP.
The policies of government of Nigeria greatly favour foreign investments in
Nigeria. Chinese government can fully use this oppommity to invest on SHP in
Nigeria and become a major shareholder. This will be a most desirable venture
in Nigerian economy. Chinese government stands to gain a lot form this joint
venture co-operation.
4) ECONOMIC CO-OPERATION
Goods and services abound in China of which our two governments can co-operate,
SHP project being a priority presently. Economic liberalization in Nigeria opens
doors for this exchange of goods and ser- vices between the two countries.
The volume of economic trans- action between the two counties will further increase
public confidence in future areas of co-operation, this time around, on small
hydro power generation.
More bilateral agreements could be advocated between the two countries on such
areas as project executions, intermediate technology development or other aspects
of technical co-operation.
5) CONTINUITY OF CO-OPERA- TION
The consolidation and sustenance of the different possible areas of co-operation
between the
two countries so far discussed will further create greater opportunities. This
means that the co-operation enjoyed by the present generation will be transferred
to the next. This continuous co-operation will gradually transform into inter-governmental
co-operation of unimagined proportion.
This will bring about lots of mutual benefits between the two countries.
5 CONCLUSION
China has gone a long way in establishing an SHP industry and its subsidiaries.
The prospects are very high for China to exploit the abundant opportunities
for constructing SHP stations in Nigeria.
The Nigerian Government attaches a lot of priority to stable and un-interrupted
power supply. These two Governments can cooperate at this level to enable China
deliver her packaged energy potentials on the one hand, and afford Nigeria the
opportunity of realizing her dream of
abundant power supply for economic prosperity on the other hand. These cooperations
in our opinion should take immediate effect.