Power Factor (In Detail) #3

Related Posts
Power Factor #1
Power Factor #2

From our previous discussion we saw that Power Factor can be defined in 3 definitions. ie

• The cosine of an angle between Voltage (V) and Current (I)
• True Power / Apparent Power
• Resistance / Impedance

Please note that in the above expressions, the value of Power Factor can never be greater than 1. A good power factor is always 0.9 or 0.89

In this post we are going to look into detail the Power Factor of angle between Voltage(V) and Current (I)


The power factor PF is mathematically defined as the cosine of the phase angle between voltage and current. True power is defined by the equation . The graphical representation produces a product of the voltage and current. This product is represented as a sine wave, which is twice the frequency of the voltage and current and represents the instantaneous power and its direction. If the power sine wave is completely on the positive side of the axis, it shows that the power in the system is traveling only in one direction, toward the load.

The area under this power sine wave curve represents the amount of energy delivered to the load. If the power sine wave is shifted, the difference in area between the positive and the negative sides represents the power delivered to the load. The negative side of the power sine wave represents the reflected power from a reactive load.

A lagging power factor is one in which the current is lagging behind the voltage and is characteristic of an inductive load.

A leading power factor is one in which the current is leading the voltage and is characteristic of a capacitive load. If the phase angle were to be shifted to be greater than 90 degrees in either direction, the load would effectively become the source.

Power Factor Correction
A power factor of one (1) or "unity power factor" is the goal of any electric utility company since if the power factor is less than one (<1) , they have to supply more current to the user for a given amount of power use. In so doing, they incur more line losses. They also must have larger capacity equipment in place than would be otherwise necessary. As a result, an industrial facility will be charged a penalty if its power factor is much different from 1.

Industrial facilities tend to have a "lagging power factor", where the current lags the voltage (like an inductor). This is primarily the result of having a lot of electric induction motors - the windings of motors act as inductors as seen by the power supply. Capacitors have the opposite effect and can compensate for the inductive motor windings. Some industrial sites will have large banks of capacitors strictly for the purpose of correcting the power factor back toward one to save on utility company charges.

First Green Energy Centre to be set up in Nairobi, Kenya

Kenyans are set to reap the rewards of a new initiative to help local companies develop and set up climate friendly technologies that will create thousands of jobs.
World Bank’s Special Envoy for Climate Change Andrew Steer announced that the world’s first Climate Innovation Centre (CIC) will be established in Nairobi.

Mr Steer made the revelation yesterday during a conference at the Danish Embassy, Nairobi, dubbed "Green Growth in Kenya" which will focus on the private sectors role in promoting green growth in the context of the country’s changing climate.

The CIC is spearheaded by the Royal Danish Embassy and the Banks Information for Development Program and is expected to help Kenya’s private sector boost industry competitiveness, job creation and cut effects of climate change.

Climate technology
"The creative spark of private Kenyans and African entrepreneur can transform climate challenges into market opportunities. This Climate Innovation Center will provide the help to make it happen," he said.In the first five years, the CIC is expected to create more than 70 climate technology businesses, generating some 4,600 direct and indirect jobs.

"The private sector has a pivoted role in the economy, contributing to 80 per cent of Kenyans GDP. It is expected that 1.7 million informal SMEs will be assisted by CIC," said Geert Aagaard Anderson, the Danish Ambassador to Kenya.Meanwhile, Prime Minister Raila Odinga has said Kenya must take a green development path if it is to realise faster economic growth.He said the energy sector, which drives the country’s economic growth, has the potential to generate renewable energy of up to 7000MW, if fully exploited.

Kenya to build local power transformer plant

Kenya is set to construct the first electricity transformers manufacturing plant in the region to boost electricity distribution in the country.
According to the Kenya Power and Lighting Company the plant will manufacture and assemble transformer for local as well as regional market.

In a paid up advert in local dailies the company is calling interested firms to help in carrying out a study on the viability of such a project.

Late last year the company raised 9.8 billion shillings through a rights issue, which KPLC says was meant for upgrading its systems in the country.

KPLC has invited prequalification bids for a viability study on building a local transformer manufacturing plant to help meet the country's growing demand for power.

 Kenya suffers regular power failure owing to insufficient electricity generation capacity and a dilapidated transmission network which have been largely blamed on investor flights and high power bills.....

3phase blog is 1 year old

The 3phase blog is celebrating 1 year old since it was created.It has been a long journey especially the SEO (Search Engine Optimization) part.To all who have taken the time to comment or even read the posts....A big Thank you.

Not to forget all bloggers out there whom we have exchanged ideas and back links on how to make this site better better by day.Especially the synctum blog..thanks

Kudos to the dot tk (.tk) team who freely provided me with the .tk domain (www.3phasepower.tk) thus reducing the long domain name provided by Google guys.
Finaly thanks to Adobe for creating Adobe Photoshop which has enabled me edit my images to taste.

Thank you guys for the wonderful, inspiring and courageous comments...


Where We Came From

This was the first header when the blog was new.

A few months after I landed on the Google Search I changed the header to this.Was too big so didn't last long.

The best so far.Was put up soon after the FIFA World Cup kicked off.

Sudan : Power & Energy

The Republic of Sudan is Africa's largest state by land area( 2,505,810km sq.) and tenth largest in the world.
Despite being the 17th fastest growing economy in the world with new economic policies and infrastructure investments, Sudan still faces formidable economic problems, as it must rise from a very low level of per capita output. Since 1997, Sudan has been implementing the macroeconomic reforms recommended by the IMF
This country has serious problems of Desertification since most of its terrain is flat and open to soil erosion.
However the Blue and White Nile flow through this vast state.
The Blue and White Niles meet in Khartoum to form the River Nile, which flows northwards through Egypt to the Mediterranean Sea. Blue Nile's course through Sudan is nearly 800 km (497 mi) long and is joined by the rivers Dinder and Rahad between Sennar and Khartoum. The White Nile within Sudan has no significant tributaries.There are several dams on the Blue and White Niles. Among them are the Sennar and Roseires on the Blue Nile, and Jebel Aulia Dam on the White Nile. There is also Lake Nubia on the Sudanese-Egyptian border.

Energy and Power

Sudan has a total electrical consumption of  1700GWh of which 77% is supplied by Hydro power.

Installed Capacity: 1100MW++
-----Thermal Power: 760MW
-----Hydro Power: 320MW

Main Hydro Power Plant: Roseires Dam - Blue Nile Southeast of Khartoum.[210MW]
Country's Power Responsibility: National Electricity Corporation.

In 1996 Sudan and Ethiopia were linked by a transmission link. Sudan is to build a hydroelectric and irrigation dam on the Nile north of Dongola. The $300 million project will be financed predominately by China, with Sudan contributing $75 million. In addition, transmission lines will be built to Marawi, south east of Dongola, and Wadi Halfaa in the north.In Sudan about 70% of generated power is consumed in Khartoum.Rural Sudan is without electricity except for diesel generators at the responsibility of Local Authorities.

Two electric power stations have been inaugurated in June 2004 and they are estimated to have a combined capacity of 330 MW. two facilities that would participate in the supply of power. The El Jaili Power project is a power plant that has been constructed by the National NEC in the vicinity of Khartoum. El-Jaili combined cycle power station also known as Plant 1. The Dit Kilo X power station is powered by diesel and has a working capacity of a 257 MW. The project consisted of 7 diesel units that were interconnected at the existing Kilo X substation where bays for injection of 110 KV have been made available. It was Sudan's first Independent Power Production (IPP) project that was completed in 2004. There also exist the 300-MW Kajbar hydroelectric facilities in northern Sudan.

The government aims to boost the country’s electrical power generation capacity over the next few years. Several additional power stations with a total capacity of 700 MW have been planned for completion before 2008.
Sudan is seeking funding from China and Malaysia to finance the construction of the Kajbar and Merowe hydroelectric stations. Development of these hydro projects will cost approximately 1.5 billion (US$). The two plants will have capacities of 300 MW and 1000 MW respectively. Construction of the Malakal run-of-river project, with one or two 10 MW stations, and the Atbara Rumela, also run-of-river, with a 30 MW station, is being reviewed .

Is Kenya Ready For Nuclear Power?

The Kenyan Government has announced plans of starting a nuclear power facility come 2017, but the questions on most Kenyans is " Is Kenya Ready For Nuclear Power" Nuclear Power comes in large quantities and also we could have enough to sell to our neighbours.Thats the advantageous side now do we have the capacity to dispose the nuclear waste? What if something goes wrong then we end up with a local Chenobyl Disaster?

The Project
The Kenyan government has identified construction sites for a nuclear power plant — potentially the first on the continent outside South Africa.Rolex Kirui, a senior engineer for the Kenyan government, says that one site has been identified near the Kenyan coast and construction is scheduled to begin once an ongoing environmental study has been completed. He says that a second potential site has been identified in western Kenya, bordering Lake Victoria.

Kenya has a shortage of 3,000 megawatts of electricity for the country. Kenya generates just 1,100 megawatts of electricity per year and its electricity production is ranked twenty-second in Africa.

The project will cost an estimated 80 billion Kenyan shillings (US$1 billion).But it will take at least five years before the plant is operational as extensive inspection must be carried out by authorities such as the Radiation Protection Board and the National Environmental Management Authority. Construction could begin as early as September 2010 once a feasibility study is complete

South Africa is the only African nation to have a fully operational nuclear power plant. Egypt and Nigeria are in the process of planning their own plants but Kenya is the first to both identify a site and undergo an environmental study.

Kengen to shut down Emergency Power Generators

The Kenya Electricity Generating Company, KenGen: Kenya's largest power producer is ready to switch off Emergency Power Generators. These power generators were commissioned last year (2009) during the period of acute shortage in power caused by low rainfall and low water levels in the hydroelectric dams.

The Emergency Power Generators which produce 150MWinto the grid, produce power from Diesel fuel resulting in the high electricity costs for Kenyans. The Power Relief cost the government 1.7Billion Ksh and have been running since the commissioning.

The expected switch off of these fuel guzzlers will take place on 6th January 2010.This will mean less power bills in the coming future as the government calls investors to explore the rich energy potential of Kenya. On the other hand, The Kenya Power & Lighting Company, KPLC - The Largest distributor of power, said consumers have been pointing a finger on them blaming them of huge power bills. KPLC has reassured its customers that they have to charge a higher Fuel Levy because of the Emergency Power generators.

A recent survey of the power in Kenya shows that the countries over-reliance of Hydro Power has seen massive shortage of power once the rains falls. It is because of this that Ken Gen has embarked of an expansion of its Geothermal Power at Olkaria, Naivasha.

Ngong Wind Power - Kenya

Installed Capacity: 5.1 Mega Watts

Commisioning Year: 2009

Wind Turbines: 6

Output of each turbine: 850kW

Model: Vestas V52

Main Contractor TPF-Econoler SA (Belgium)

Location:Ngong Hills, 22km SW of capital, Nairobi - Kenya.

Standing tall at a height of 50m from the ground, the wind turbines rotate at the winds pace in a bid to generate Kenya's source of Wind Power.The Ngong Wind Power Project which was commissioned in August 2009, is Kenya's largest Wind Power Station but will come second once the Lake Turkana Wind Power Project (LTWP) is completed.

The 6 Turbines, each with a maximum output of 850kW produce a total of 5.1MW of clean energy into the grid.For the Vestas V52 Model turbines, KenGen executed a contract for the implementation of Ngong Hills Wind Power project with TPF-Econoler SA (TPFE) of Belgium on 29th October 2007.

Kenya receives sh.3.79 Billion to finance regional energy projects

Kenya has recently aquired  a 3.97billion loan form the African Development Bank. This is part of a regional grids of five countries.The five countries include Uganda, Burundi, DRC, Congo & Rwanda. Speaking during the signing ceremony, at The Treasury building, Finance minister Uhuru Kenyatta, said the project will enhance cross border sharing of electricity and development at low cost power resources. The loab deal was signed by AfDB representative: Mrs. Domina Buzingo.

This loan will facilitate:

1. Upgrading of 769km of 220kV and 110kV Power lines.
2. Construction & Reinforcement of 17 transformers to interconnect the grids of the Nile Equatorial Lake Countries.
3. Construction of a 220kV double circuit transmission line from the border of Uganda to the substation at Lessos - which shall be expanded with additional transformers & switchgear
4. Uganda - Rwanda interconnection, upgrading of the Burundi, DRC and Rwanda interconnection lines.
5. Operational Costs.

One of the major potential sources of power is the Iinga Dam in DRC which has a potential of 40GW

How your neighbourhood transformer works

Generally as one of the most preyed upon units in the electric industry, the domestic or neighborhood transformer serves a crucial role in ensuring that we get a constant flow of electricity.In the electric industry it is commonly referred to as a Step-down transformer since it does exactly that at all times besides protecting consumers.

The main purpose of these electrical machines is to provide a step-down mechanism for the incoming voltage from the primary substation, located away from consumers.It should be noted that it steps down voltage and steps up current to feed the consumer directly.It is the last in the line of machines that modify the voltage or current before going to small consumers.

In countries that use the BS 240/415V Standard, their transfomers usually receive and incoming supply of 11kV from the overhead feeders.It is then from this 11kV is is able to step it down to 240/415V 3phase voltage.
One major drawback of these machines is the heat energy generated therefore it does not operate at full efficiency.It is also prone to vandalism, because it houses a rather rare expensive oil that is used as a cooling mechanism. One good as advantage of this machine however is that it does not require regular maintenance and can withstand the weather elements as long as the mounting is mechanically sound.