2. East Africa’s largest solar park
Williamson Tea’s 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 it’s 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 factory’s 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 that has
‘solar fuel saver’ (SFS) 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 emerging economies where grid
power is unstable and standby generators are relied on for power.
Construction of the solar power system began in February 2014; the official launch
and connection to the grid took place in May 2014.
Location
Changoi, Bomet County
Size
1 MWp
Annual generation
1,600,000 kWh
Lifetime CO2 savings
30,000 tonnes
2 3
3. 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 sun’s energy is guaranteed as the
sun shines every day, and will never run out.
Location
Kenya is the 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 alternative
Like 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.
4
Costs
In 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.
5
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Electricity Savings
Solar Generation
Load/Demand
Purchase from utility
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Year
Combined revenue and savings, first 10 years
Value of di
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-4
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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 park.
“
4. Project timeline
Solarcentury 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 – using solar PV to
reduce costs, safeguard the environment and help Kenya
compete on the world stage.”
Dr Christian Turner, the British High Commissioner to Kenya,
speaking at the launch of Williamson Tea solar park.
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 Solar Fuel
Saver is installed
(read more
overleaf)
Ths system is
commissioned
and launched
6 7
“
5. How the Changoi solar park 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 isn’t shining. This
kind of system, seen here, is known as a Solar Fuel Saver.
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.
Utilising Solar Fuel Saver technology means that solar PV
systems can run alongside diesel generators without the
need for expensive batteries. The Solar Fuel Saver 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 Solar Fuel Saver 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
Solar Fuel Saver can be used to switch off the inverters
when reverse power flow is about to happen.
Dr Daniel Davies
Director, East Africa
Solar Fuel Savers
Solar working in parallel with the grid or diesel:
Main
distribution
board
Loads
DC to AC
inverter
Solar
generator
Grid
Utility
electricity meter
M
Solar
generation
meter
G
Diesel
generator
Solar with a standby generator
When the grid is available the PV operates in parallel with the grid.
Cost of
diesel generated
electricity
F
Changeover switch
20 km of DC cable
8 9
6. Solar home systems
Solar 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 park 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 don’t 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.
9 10
About Solarcentury
Solarcentury 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 world’s 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 Italy, The Netherlands, South Africa and Kenya,
as well as a growing presence in Latin America. Solarcentury East
Africa is headed up by one of Solarcentury’s 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.
7. Find out more
Call
+254 (0)701 918683
Email
internationalenquiries@solarcentury.com
Visit
www.solarcentury.com
Solarcentury is in business for a purpose
to 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 our sister charity SolarAid, which aims to
eradicate kerosene lamps from Africa by 2020.
SCK007-0514
Solarcentury East Africa Ltd,
Marula Manor, Marula Lane, Karen,
Nairobi, Kenya
PO Box 15097,
00509,
Nairobi, Kenya
Registered in Kenya no. CPR/2013/109535
London | Helmond | Milan | Johannesburg | Nairobi
