Williamson Tea 1MWp solar farm

Changoi, Bomet County, Kenya

East Africas largest solar farmWilliamson Teas solar photovoltaic (PV) system is nestled amongst the hills in the Kericho District of Kenya. Owned and funded by Williamson Tea, a publicly listed company in Kenya, it is the largest solar installation in East Africa.

Williamson Tea is forward thinking and committed to sustainable farming and creating a greener future for tea production in Kenya. They chose solar since its a clean and sustainable energy source which will enable the company to significantly reduce its spend on non-renewable energy such as diesel, and lower its carbon footprint.

Solarcentury designed a solar PV system to provide approximately 30% of the tea factorys electricity needs. When the national grid is working, the solar power system will work in parallel with the grid and reduce the amount of grid electricity imported. When the grid is unavailable, the solar power system will work together with the standby diesel generators, significantly reducing the amount of diesel consumed.

The solar PV system at Changoi is one of only six systems in the world using this technology. The design enables the solar power system to operate in parallel with a standby generator and creates a stable power supply, negating the need for batteries. This makes solar an economically viable solution for many factories, farms and other businesses in locations where grid power is unstable and standby generators are relied on for power.

Location Changoi, Bomet CountySize

1 MWpAnnual generation

1,600,000 kWhLifetime CO2 savings

30,000 tonnes

Why did Williamson Tea choose solar?The world is currently highly dependent on fossil fuels for energy. There are three major issues which make this unsustainable. First, fossil fuels are very expensive, with the price set to rise even further. Second, fossil fuels are finite and will eventually run out. Third, when burned they release large volumes of CO2 into the atmosphere, causing climate change and hazardous weather. Solar power is simple, clean and cost-effective. Unlike fossil fuels, the suns energy is guaranteed as the sun shines every day, and will never run out.

LocationKenya is an ideal location for solar electricity; being on the equator where the sun is high in the sky all day provides great conditions for getting the most out of a solar system.

The solar alternativeLike many businesses, Williamson Tea is supplied with power from the grid, but also uses on-site diesel generators during power cuts.

Solar power can be used to reduce the power demand on the grid, whilst reducing electricity bills, and reduce the amount of diesel which is consumed by the on-site generators.

Reducing electricity and diesel bills by using solar has a direct benefit to the bottom line, improving profitability and gaining a competitive edge.

CostsIn Kenya, the cost of diesel is US $1 per litre (fuel costs per kWh of diesel-generated power can exceed US $0.30 per kWh). The cost of grid power for businsses is $0.20 per kWh.

In comparison, the cost of power from a solar PV system is generally $0.10-0.15/kWh, depending on finance costs and radiation.

Adding a solar PV system to the local network to offset diesel and grid consumption will significantly reduce overall energy bills for Williamson Tea. Cost of energy is the most significant business expense, which is typical of many rural businesses, so there is great potential to boost profits and give a competitive advantage.

The solar PV system will also support the grid by improving the power factor of the factory and providing voltage support at the end of the supply line.

Like all renewable energy technologies the up-front investment is the major cost item. However, once a PV system is installed there are no on-going costs besides cleaning and inspection.

In the example below, we sized a solar system to be as large as possible but limited the size so that the business owner would be able to make use of all the electricity produced. The result is a 1MWp system that will produce 1,600,000 units of electricity per annum. Over 25 years, with no upfront cost, the business will save over $10m.

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Our ministry is considering the introduction of net metering, which allows residential and commercial customers who generate their own electricity from solar power to feed electricity they do not use back into the grid,

Davis Chirchir, Energy Secretary, speaking at the launch of Williamson Tea solar farm.

Project timelineSolarcentury was on site for just over two months, through March and April.

The official launch and connection to the grid took place in May 2014.

This innovative low carbon solar power solution is a perfect example of the multiple benefits that can be achieved by

Britain and Kenya working together. Solar PV can help reduce costs, safeguard the environment and enable Kenya to compete on the world stage.

Dr Christian Turner, the British High Commissioner to Kenya, speaking at the launch of Williamson Tea solar farm.

October Contract signed

March The solar PV construction begins

February Tea cleared and site prepared

April Installation of the PV modules, inverters and cabling

May The hybrid system is installed (read more overleaf)

Ths system is commissioned and launched

How the Changoi solar farm works

New control strategies enable large solar PV systems, such as the one

at Williamson Tea, to be operated in parallel with diesel generators, which act as a back-up power source for when the sun isnt shining. This kind of system, seen here, is known as a hybrid PV system.

Operating solar PV systems alongside diesel generators presents a number of challenges including ensuring a stable power supply with the solar PV operating in parallel with the generator, and ensuring the generator never runs below 35% part load, which can damage the machinery. The hybrid technology means that solar PV systems can

run alongside diesel generators without the need for expensive batteries. The control system manages the output from the solar PV system to ensure that the diesel generator operates at a minimum, and also so that the diesel generator can be deployed if loads rapidly increase or if clouds momentarily reduce the solar output.

One of the most common hybrid applications is where solar PV is being used to reduce the off-take from the public grid in places with expensive and intermittent power, and then to use the same system to work in parallel with the standby generators. This reduces fuel consumption without removing the essential back-up of the diesel generator for night-time operation or when the sun is not shining. Where local utilities do not allow reverse power flow into the distribution network, the control system can be used to switch off the inverters when reverse power flow is about to happen.

Dr Daniel Davies Director, East Africa

Solar hybrid technologySolar working in parallel with the grid or diesel:

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meter

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Solar with a standby generatorWhen the grid is available the PV operates in parallel with the grid.

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electricity

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Changeover switch

Solar home systemsSolar is flexible, and as well as large-scale utility power systems, solar PV can benefit those using domestic energy. Solarcentury was pleased to donate solar home systems to several employees living at the farm at Williamson Tea, whose homes are not connected to grid power.

These simple, effective solar PV systems were formally presented to the employees by the UK Minister of Energy and Climate Change, Greg Barker during his tour of the solar farm in April 2014.

The clean solar electricity generated by the solar home systems reduces the employees consumption of costly kerosene which gives off fumes that can cause health problems. As well as reducing the risk of fire, using solar electricity rather than kerosene means employees can read, study, and do sewing or other income generating activities in the evenings, as well as charge their mobile phones and listen to the radio.

It makes financial sense too, since the employees dont have to spend so much on kerosene. Research in 2012 by SolarAid, the charity founded by Solarcentury, found that families in Kenya using solar lights reduce kerosene use by an average of 77% and save 74 per year.

Solar home lights the facts: Reliable, safe and cost-effective. Charge during the day to give clean, free light at night. Do not require costly installation or maintenance. Provide instant light in remote rural areas the electricity grid might never reach.

About SolarcenturySolarcentury is one of the most respected solar companies in the world. Founded in 1998, it has been around since the early days of the solar industry and has been part of the evolution that has made PV the attractive investment it is today. Solarcentury has put solar on a greater variety of sites than any other company in the industry, including the worlds largest solar bridge in London, Blackfriars, winning multiple awards for its project and product innovation.

We are excited about the opportunity to work with the various renewable energy stakeholders in Kenya. We have worked with the Kenya Renewable Energy Association on the initial draft on a set of Kenyan PV Installation Guidelines. The Kenyan Association of Manufacturers is now developing this with the assistance of UK Department for International Development.

The development of standards for training and regulation of suppliers and installers is key to building a safe and reliable solar industry, this has been recognised by the Kenyan Energy Regulator the Energy Regulatory Commission, ERC, who have imposed a requirement for those companies selling and installing solar sytsems to be licenced. Solarcentury is proud to have completed this registration process and carries the ERC C1 Licence.

Here at Changoi, Solarcentury were the designers, suppliers and installation contractors. We developed the concept design during the early phase of the project and supported the developers with designs and system modelling. We were then contracted to do the detailed system design and installation and will be operating and maintaining the site.

Our business is global and growing, with our headquarters in London UK, and offices in Germany, The Netherlands, South Africa, Kenya, Ghana, and Latin American countries.

Solarcentury in East Africa is headed up by one of Solarcenturys founders, Dr Dan Davies based in Nairobi, Kenya. Dr Davies is one of the few solar engineers in Kenya to hold a T3 Solar Technician Licence.

Find out more Call

+254 (0)701 918683

Email

internationalenquiries@solarcentury.com

Visit

www.solarcentury.com

Solarcentury is in business for a purposeto make a big difference in the fight against climate change through widespread adoption of solar power.

We are a big believer in helping solar change our world for the better, and we contribute 5% of our net profits every year to SolarAid, the charity we founded, which aims to eradicate kerosene lamps from Africa by 2020.

SCK

007-

0514

Solarcentury East Africa Ltd,Marula Manor, Marula Lane, Karen,Nairobi, Kenya

PO Box 15097,00509,Nairobi, Kenya

Registered in Kenya no. CPR/2013/109535