Solar Dryers For Coffee In Kenya

Solar dryers for coffee in Kenya by Grekkon Limited improve the drying efficiency of harvested coffee cherry. In Kenya, harvested cherry is largely manually open dried which takes 10 – 14 days depending on the location and the prevailing temperatures. Open coffee drying is done on wooden raised table structures with a wire mesh bed laid out where the coffee cherry is spread thinly. The coffee cherry is dried by direct solar radiation and wind movement

Cost of solar dryers for coffee in Kenya

The overall cost of a solar dryer depends on the size. The average price of a large solar dryer for coffee in Kenya is Kes 1,200/M square

Challenges of open coffee drying

• it is labour intensive. This is needed to turn it over every 45 minutes to 1 hour on the bed to ensure eveness of drying, covering it in the evening or on rainy days with a polythene cover to prevent moisture entry
• quality degradation as a result of moisture entry, dirt and other contaminants
• it requires lots of space because the beds cannot be designed in a storeyed manner
• none uniformity of drying because it is turned over by hand on the raised drying beds

Open drying of coffee cherries in a coffee factory in western Kenya

The key advantage of open sun drying of coffee is that it is cheap, and has zero CO2 emissions

The coffee is dried from 60% to 10% – 11% moisture level. There are six stages in cofee drying

1) Skin drying. Moisture 55-45%.
2) White Stage drying. Moisture 44-33%.
3) Soft Black stage. Moisture 32-22%.
4) Medium Black Stage. Moisture 21-16%
5) Hard Black Stage. Moisture 15-12%
6) Fully dry coffee and conditioning. 11-10%

Coffee drying is a post-harvest handling process where the coffee quality is preserved instead of improving it. Different temperature limits are allowed for differet coffee processing methods. Moisture level are checked to prevent moulding on the drying coffee

Solar dryers for coffee in Kenya by Grekkon Limited provide a low cost, efficient, zero CO2 emissions, and a clean way to dry cofee cherry. The use of solar dryers mitigates against the challenges faced under open sun drying.

How does a solar dryer for coffee work?

1. Air in the dryer in contact with the coffee is heated through solar radiation

2. Mositure in the coffee beans rises and is expelled through a ventilation

The temperature in the coffee solar dryer is on or about double that of the ambient temperature

Benefts of a solar dryer for coffee

• the coffee beans are not tuned over manually to achieve eveness of drying. This cuts out the huge labor cost coffee factories incur during coffee drying. Eveness of drying is well achieved as hot air dries every bean uniformly
• there is no external mositure entry especially from rain. This removes any occurence of moulding or mildew
• coffee dries at half the time or less that it would take under direct sun drying. This reduced drying time saves on operational costs
• there are no external contaminants

The exterior of a solar dryer built in a coffee factory by Grekkon Limited

• the polythene paper cover used has UV block treatment which preserves the quality of the coffee bean. It also has anti-drip attributes, so that dew does not form on it, then drop on the coffee
• space is eficiently used because the drying racks are stacked up over each other, unlike in open sun drying where each coffee cherry must make contact with the sun’s rays to dry
• in areas where coffee theft in factories is rampant, the solar dryer can be locked to prevent entry. This is not possible under open sun drying
• drying goes on even in hazy, cloudyor rainy conditions. Coffee is thus dried anytime of the year

Demerits of a dryer for coffee

• it is expensive to isntall
• the polythene cover has to be changed every 3 -4 years when the UV block treatment has worn off
• it is uncomfortable to work in during the day as the internal temperature is high
• where care is not taken, over-drying of coffee may happen, which reduces its quality and its subsequent market price. A moisturemeter should always be used in the drying process to prevent this
• it requires maintainance

A coffee solar dryer working principle

A coffee solar dryer can be enhanced with solar module powered extraction, and exhaust fans. This will further improve on the drying time as moisture is extracted faster. However, due to the large size of the unit, it is an expensive undertaking. It is largely used in smaller fish, herbs, spices,vegetable and fruit solar dryers

How to install solar dryers for coffee

• create raised tables from timber or galvanised steel not more than 1M in width. The length is as much as can be done. These tables can be storeyed upto 3 levels with vertical gaps of 0.75M – 1M between the levels. The horizontal distance from a table to another is 0.5M
• lay a food grade wire mesh over the tables to hold the coffee. A shade net or insect net can be used. The reason a perforated membrane is laid is to allow for free drying air movement on the beans
• construct the galvanised steel framework over these tables to amaximum mid height of 5M
• lay the greenhouse polythene paper over the steel frame
• place an insect net in the air entry and exit points.An insect net prevents entry of insect pests

A 2 level table bed coffee dryer by Grekkon Limited in Kagumoini area, Nyeri county

Grekkon Limited provides training on proper coffee drying in a solar dryer, and also on the maintainance and managemnt of the solar drying unit after installation to coffee societies in Kenya
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Metallic Greenhouse Price In Kenya

Every metallic greenhouse price in Kenya by Grekkon Limited is determined by the greenhouse type, and size. All metallic greenhouses in Kenya by the company are made from galvanised steel. They are built to last for decades under intense crop production

Metallic Greehouse Price In Kenya

Our metallic greenhouse price in Kenya is provided in the tabulations below by cost and size for galvanized metallic greenhouse tunnel-type structures. Each unit has a drip irrigation kit, side roll-ups, and an entry pouch. We offer a crop support structure, a 1,000L tank, PPE kits, fertilizer, and seeds package at an extra cost. Consideration is made for a grower’s greenhouse budget. These prices include all greenhouse materials in Kenya

Completed units of metallic greenhouses by Grekkon Limited in Heni area, Nyandarua county

How much does a metallic greenhouse cost in Kenya?

A. Small

B. Medium

C. Large
From 800M square. Kes 900 per meter square. We customise our price according to size, and your greenhouse budget

Metallic Greenhouse Price In Kenya

5 Key Factors That Determine Greenhouse Cost

1. unit size. The larger it is, the costlier it becomes for the reason that it take in more material and labour. The choice a greenhouse of size is determined by; land area, water availability, and a grower’s budget
2. design. A tunnel type greenhouse is less costly than a vented type. This is because the latter has a larger roof surface area. Tunnel type greenhouses are for cooler highland locations, while the vented types are for warmer mid to low altitude areas. co-joined units are less costly than single units. For intance, 3 units measuring 30M x 8M built separately are more expensive than contructing them as one co-joined unit measuring 30M x 24M
3. greenhouse construction frame material of the unit. Grekkon Limited as a top greenhouse construction company in Kenya, has an option of a low cost greenhouse constructed from timber. This is referred to as a wooden greenhouse, or the option of the more pricey metallic greenhouse. Both serve the same purposes
4. frame treatment undertaken. Timber for greenhouse construction in Kenya is either treated with light organic solvent preservative (LOSP), or with used motor oil. These treatments protect the timber from termite attack. LOSP treatment is costlier, and preserves the wood longer. Motor oil has to be re-applied every so often and should not be in contact with the crop. Steel is either galvanised with zinc, or an aluminum paint coat is applied on the surface. In this too, the former treatment is costlier, and remains for long
5. greenhouse crop type. our greenhouse construction cost in Kenya for each of these types is determined by the crop type. For instance, an indeterminate crop that requires an internal crop support system will have a more costly greenhouse than a short strawberry crop. The greenhouse installation cost of a plant propagation unit with misters and foggers is higher than a herbs and spices unit without such

Metallic Greenhouse Price In Kenya

These are the materials used in metallic greehouses in Kenya installations

I. UV treated greenhouse polythene with anti drip properties

This is the key material that protects the crop from the elements of weather; sun, wind and rain. It creates the ‘greenhouse effect’, and minimises disease and pest incidences on the crop. It is either clear or yellow in color. Clear greenhouse polythene for fruiting crops, or in ornamentals, bi or multi colors. This is because it allows in more light which these need for photosynthesis, the process that makes food for the plants. Yellow is for vegetative crops, and mono color ornamentals. In mono color ornamentals, it intensifies the color

II. Galvanised steel bars

They provide structural support to the greenhouse, and also to the crop as ‘crop support structures’ for tall indeterminate crops such as; tomato, peppers, and cucumbers

III. UV treated high density insect nets

These nets keep away insect pests. They are for self pollinating (do not require external pollinators such as insects and birds) greenhouse crops

IV. Bird nets

These are only used in greenhouse crops that require insect pollination from bees, butterflies, hornets and many other pollinating insects. They allow in the insects, but keep away bird pests. An example of such a crop is strawberry

V. Profiles

They are screwed onto the galvanised steel bars so that the greenhouse cover is tucked in them

VI. Wiggle wires

Once the greenhouse cover is tucked in the profile, wiggle wires keep it in place so that it is not removed by wind or other physical force. Wiggle wires have a plastic covering to prevent damage to the greenhouse paper the are in direct contact with

Wiggle wires hold in place a clear greenhouse polythene sheet tucked in a profile

VII. Screws

The join the profiles to the galvanised steel structure

VIII. Concrete

This is what supports the metallic greenhouses in Kenya structures on the ground and keeps them upright

Humidification through misters in a seedlings propagation greenhouse

Successful greenhouse farmers in Kenya grow both none food and food crops in our metallic greenhouses. Common greenhouse food crops are; tomato, peppers, strawberries, and cucumber.  Galvanised steel bars, insect netting, screws, and profiles are our greenhouse construction materials. With labor addition, all now constitute your final greenhouse cost

Grekkon Limited’s metallic greenhouse price in Kenya will include; a drip irrigation system for crop production, or a misting/ fogging system for seedlings propagation, and labour. Sprinkler irrigation systems are not installed in greenhouses

A bird’s eye view of a metallic greenhouse for seedlings propagation under construction by Grekkon Limited at the ICIPE institute in Kasarani area, Nairobi county

Hybrid Solar Dryers For Sale In Kenya

1. Solar powered. These units have a solar powering system that runs the extraction and exhaust fans. The fans provide better movement of air within the dryer, and removal of the moisture from the drying produce. This hastens the drying process
2. Biomass powered. They have a biomass burning unit connected on the exterior. Biomass in the form of brickettes or charcoal heats water which produces steam that travels in tubes within the dryer. This heats up the air in the dryer, accelerating the dring process. Biomass powered dryers can be used at night or on cloudy, rainy or cold days when there is insufficient sunshine to dry

Hybrid Solar Dryers For Sale In Kenya

Solar Dryer Materials

• Light UV treated translucent polythene paper to allow heat and light. The paper also has anti-drip treatment to prevent dew formation which causes moulds to form on food
• Heavy UV treated geomembrane to conserve heat
• Steel bars galvanized with food-grade aluminum or zinc for food safety
• UV treated heavy gauge netting to prevent insect pests from entering

A hybrid solar dryerwith both an external biomass heating units, and a solar power system

 Hybrid Solar Dryers For Sale In Kenya

I. What is hybrid solar dryer?

II. What are the three types of solar dryers?

• Natural / conventional solar dryers. These dry using only the power of the sun
• Forced  / active dryers. They are augmented versions of the conventional solar dryers
• Portable or fixed solar dryers

IV. What does a solar dryer do?

Grekkon Limited’s solar dryers reduce the moisture content to less than 12% in these products;

• Plantation crops; coffee, rice, cassava
• Vegetables; tomato, onion, garlic, brassicas, hot peppers
• Cereals; sorghum, and millet
• Herbs; moringa, mint, rosemary
• Oil crops; groundnuts, sunflower, macadamia, cashew nuts
• Others; mushrooms, fish, beef, mutton

V. How do you dry vegetables with solar?

• Wash the vegetables to remove all dirt
• Ensure there are no insect pests present
• Remove any diseased parts or produce
• Cut or grind them into smaller pieces to increase the drying surface area

Place them in the solar dryer holding trays

Dry cassava chips

VI. What is the most popular use of solar dryers?

To dry fruits, mushrooms, vegetables, herbs, spices, coffee, cassava, banana and fish. Banana and cassava are further processed into food flour. A solar dryer ensures that the food is free of any external contamination

VII. What are the main applications of a solar dryer?

Besides vegetables and fruits, commercial solar dryers in Kenya are for fish, root crops and mushroom drying. Commonly dried foods in Kenya through our solar dryers are:

i. Banana, cassava, pumpkin, millet, and sorghum to make food flour. Dried cassava is also processed for industrial starch manufacture

ii. Moringa as a medicinal herb

iii. Tomato, capsicum, traditional vegetables, kales, and spinach  as vegetable nutrients

iv.  Mango, papaya, as dried fruits for snacking

v.  Omena which is the silver cyprinid fish for both human consumption, and as additive to animal feed

vi. Coffee so that it’s suitable for milling. Coffee solar dryers are the largest, each holding over 5 tons of berries per drying session

Low Cost Solar Dryers

Grekkon Limited is the largest supplier of  low cost solar dryers for agricultural products in Kenya .  These low cost solar dryers work on solar strength, and are also augmented with a biomass heat unit if so desired by the client. Our agricultural solar dryers design is according to the product, location, and drying volume per session. These passive or active solar dryers for fruits and vegetables are fixed or portable as the user needs it. The fixed ones are large and impractical to move about, while the portable one are small domestic drying units

Solar dried mango slices

Low Cost Solar Dryers in Kenya

Grekkon limited designs and constructs both passive/ natural circulation, and active/ forced circulation low cost solar dryers for agricultural products. The passive solar dryers have no additional mechanical input, while the active dryers do. Active solar dryers are also know as hybrid solar dryers. Their additional mechanical inputs are;  a biomass heating unit, or solar powered exhaust plus extraction fans, and synchronizers. A hybrid solar dryer will have one (solar system or biomass heater) of these enhancements, or both. These enhance drying time by 30% to 100% compared to passive drying. Attached biomass heating units allow for night time drying, or on cloudy/ rainy days.

Solar Dryer Materials

• Light UV treated translucent polythene paper to allow heat and light. The paper also has anti-drip treatment to prevent dew formation which causes moulds to form on food
• Heavy UV treated geomembrane to conserve heat
• Steel bars galvanized with food-grade aluminum or zinc for food safety
• UV treated heavy gauge netting to prevent insect pests from entering

A simple portable solar dryer under construction by the Grekkon technical team at Rusinga Island, Homa Bay county. The local community will dry bananas for processing into flour

Below are 2 videos: The first one is of a farmer in Homa-bay county, western Kenya using a community passive/ natural circulation solar dryer to add value to banana produce. The second one is of a mango processor in Taita Taveta county at the county’s coast with an active/ forced circulation dryer. Both solar dryers are by Grekkon Limited.

Video 1.   Video 2.  

Our low cost solar dryers have shelves at different levels depending on the volume or weight of food crops to dry per session.

Low Cost Solar Dryer Design

What is the working principle of a solar dryer?

1. Passive/ Natural Circulation Food Solar Dryer

Grekkon Limited solar dryers work in the following steps;

i. Capture & collect the sun’s heat

ii. Create a ‘greenhouse effect’ which causes moisture loss from the produce

iii. Air coming into the dryer exits with this moisture from the vent

2 Active/ Forced Circulation Food Solar Dryer

In addition to what takes place in the passive solar drying unit, the fans force in hot air from outside, and force out hotter air combined with moisture from inside the dryer. At night or on cloudy/ rainy days, the biomass unit supplies the drying heat.

Pros and cons of a low cost solar dryer in Kenya

1. Speed of drying. Food dries four to five times faster.
2. Quality. As the sun’s UV rays do not get into direct contact with the drying food, the food’s; color, taste, scent, and nutritional value is unaffected
3. Cleanliness. The food is free from dust, sand, or other external contaminants
4. No pests. Insect, bird, or mammalian pests have no access to food in the dryer, so no attack occurs
5. It is more expensive to build and maintain than open-air drying

Solar dried chilli peppers

 Low Cost Solar Dryers

FAQs

III. What do a low cost solar dryers do?

Grekkon Limited’s solar dryers reduce the moisture content to less than 12% in these products;

• Plantation crops; coffee, rice, cassava
• Vegetables; tomato, onion, garlic, brassicas, hot peppers
• Cereals; sorghum, and millet
• Herbs; moringa, mint, rosemary
• Oil crops; groundnuts, sunflower, macadamia, cashew nuts
• Others; mushrooms, fish, beef, mutton

IV. How do you dry vegetables with solar?

• Wash the vegetables to remove all dirt
• Ensure there are no insect pests present
• Remove any diseased parts or produce
• Cut or grind them into smaller pieces to increase the drying surface area

Place them in the solar dryer holding trays

Dry cassava chips

V. What is the most popular use of low cost solar dryers?

To dry fruits, mushrooms, vegetables, herbs, spices, coffee, cassava, banana and fish. Banana and cassava are further processed into food flour. A solar dryer ensures that the food is free of any external contamination

VI. What are the main applications of a solar dryer?

Besides vegetables and fruits, commercial solar dryers in Kenya are for fish, root crops and mushroom drying. Commonly dried foods in Kenya through our solar dryers are:

i. Banana, cassava, pumpkin, millet, and sorghum to make food flour. Dried cassava is also processed for industrial starch manufacture

ii. Moringa as a medicinal herb

iii. Tomato, capsicum, traditional vegetables, kales, and spinach  as vegetable nutrients

iv.  Mango, papaya, as dried fruits for snacking

v.  Omena which is the silver cyprinid fish for both human consumption, and as additive to animal feed

vi. Coffee so that it’s suitable for milling. Coffee solar dryers are the largest, each holding over 5 tons of berries per drying session

Irrigation Company In Nairobi

In 2017 through 2018, Grekkon Limited was an irrigation company in Nairobi servicing small to medium scale holders. The company’s focus was on irrigation and allied services. these are;

• Irrigation. drip, overhead, and sub surface irrigation systems
• Dam liners. for irrigation water harvesting and conservation
• Greenhouses. steaal and wooden types
• Borehole drilling
• Water pumps. solar, electric, petrol and diesel types
• Solar dryers. for post harvest crop loss management
• Agricultural nets. bird nets for bird pests, shade nets for , and insect nets for insect pests
• Trays. seedling trays for seedling propagation, and hydroponic trays for hydroponic fodder production
• Coco peat. a non soil media for use in seedling trays
• Mulch paper. to manage field water loss through evaporation, weed and pest control

While improving the clients’ overall yield, and income from farming. The company focuses on this smallholder, and medium holder niche because of the presence of large irrigation service providers in the country. These companies clientele are the large ornamental, cereal and vegetable growers. Smaller growers had to fend for themselves because they were never a priority for these large corporates. A hallmark of the company is the free 4 month agronomy training programs for all their farmers. Grekkon Limited is the only company that offers this free service to farmers in Kenya

The company organizes ‘training days’ in various regions of the country. Growers come to learn of new and existing technologies.

The other objective was to do further by offering expert irrigation, greenhouse, water pumps, and dam lining expertise to these small scale to medium scale commercial farmers, who had no professional entity to consult for such. This was through physical site visits to carry out assessments, provide advice, and carry out irrigation project reviews afterwards. And so, Grekkon Limited – Irrigation Hub was born. It is headquartered in Athi River, with outlets in other key agricultural zones in Kenya

Two years after establishment, Grekkon won the coveted Most Preferred Irrigation Systems Company of the Year award in 2019. This was at the prestigious Agribusiness Excellence Awards ceremony. The farmers in their votes had finally spoken!

Irrigation Company In Nairobi

1. Irrigation Products

1. Drip kits. For both vegetable and fruit tree/ forestry irrigation. This includes; drip tape, 16mm HDPE pipe, starter connectors, off-takes, drip to drip connectors, button or online drippers, and end caps
2. Rain hose kits. It has; rain hose pipe, off-takes, connectors, and an end cap. Rain hose kits are best utilised where drip irrigation systems cannot be installed such as is pasture, or crop nurseries
3. Sprinkler systems. There are various types;

3.1. Pop up sprinklers. These are sub-surface sprinklers for lawns, golf course, football pitches, and gardens

3.2. Rain gun sprinklers. These are metallic high pressure, high volume sprinklers for use in all crops. They are well utilised in larger acreage because they have a wide area of spray

3.3. Impact sprinklers. They are plastic and range from 1/2″ to 1″. Mostly used to irrigate small vegetable farmes, or pasture

3.4. Meganet sprinklers. These are plastic sprinklers that range from 1/2” to 1”. They are a suitable alternative to impact sprinklers

3.5. Butterfly type sprinklers. They are for lawns and small gardens like the kitchen garden

3.5. Micro sprinklers. They irrigate individual fruit tree plants, just like button drippers. However they cover a wider area, and provide better humidity around the crop’s root zone

In this video below, a smallholder farmer who was an early adapter of Grekkon’s rain hose kits. She speaks about her growing experience

4. Misters and foggers. Used in greenhouses for seedlings watering, and humidity control

Solar water pumps by Grekkon Limited

5. Water pumps;

As an irrigation equipment supplier, every irrigation system is backed by the following types of water pumps to draw water from a source, to supply the irrigation system

i. Solar water pumps. These are either surface or submersible types. Submersible water pumps work under water, while surface water pumps are ground based

ii. Electric water pumps. Like solar water pumps, they’re surface and submersible options

iii. Diesel generator water pumps. They run on diesel powered engines. They are portable or fixed types. The latter are larger in size

iv. Petrol water pumps. They run on petrol powered engines, and are smaller than diesel water pumps

6. Irrigation pipes

6.1. HDPE pipes from 16mm through 280mm diameter. The pipe thickness is from PN6 through PN25

6.2. PV pipes from 20mm through 280mm diameter. The pipe thickness is from PN6 through PN25

6.3. Suction pipes for supply with water pumps

6.4. Delivery pipes as either canvass or PVC material

Irrigation Company In Nairobi

Water pump accessories

Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, adaptors, splicing kits, control boxes, invertors (for DC to AC converstion) cables,  cable ties, solar panels (for solar pumps), and a solar panel support structure

Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, and adaptors

Every irrigation system has a main, and/ or sub-main pipes. We advice on the right pipe thickness, size and type based on

• Land size; determines pipe size. Large pipes for large acreage. Our pipe sizes range from 16mm to 180mm in diameter
• Irrigation system adopted; any of the 1 to 3 above
• Land ownership system; leased or owned? HDPE for the former, PVC for the latter

These pipes have specific fittings which are; elbows, tees, valve sockets, ball valves, couplings, adaptors,sockets,saddle clamps, and end caps by type and size

Drip irrigation system under installation by Grekkon Limited using PVC pipes as main and sub-main lines

Irrigation Company In Nairobi

Installation Service

Our irrigation service team conducts systems installations service in east Africa. We offer advisory services to manage the system well for many years

A client’s irrigation system installation by a company technician

Irrigation Company In Nairobi

Key Attributes

Innovation

Grekkon Limited in its innovation introduced the rain hose irrigation system. This new product solved many irrigation challenges for commercial vegetable and corn farmers. The company is the market leader in research and commercialization of natural solar dryers, each unit designed to meet the product or market drying requirements

Today, Grekkon Limited is the largest supplier of natural solar dryers within the east Africa community states

In 2024, Grekkon Limited introduced the first color coded drip tapes in the Kenyan market

Team

Grekkon Limited’s resounding success is largely due to its team of field professionals who provide engineering, commercial, and technical services

Country Wide Presence

As an major irrigation company in Kenya, Grekkon Limited has offices in; Athi River, Nairobi, Kisumu, Eldoret, Nyeri, and Nyahururu

Where to buy dam liners in Kenya

Where to buy dam liners in Kenya is from Grekkon Limited. The company offers the best UV-treated black high density polyethylene (HDPE) dam liners manufactured for tropical climates. Our pond liners for sale in Kenya line the walls and floors of water harvesting reservoirs. This is to prevent water loss through seepage into the soil. Changing rainfall patterns and unpredictable seasons are increasingly becoming a norm in Africa. This is why the need for agricultural water conservation is growing amongst farmers. Every farmer practicing irrigation has a water source

Where to buy dam liners in Kenya

Water pans lined with dam liners are a source of irrigation water storage. This water is from a larger source such as a lake, river, or borehole water, and also harvesting rain and run-off water. Besides irrigation of your crop, the pond liners on your water pan allows  for commercial or subsistence fish rearing; the former to boost household income, the latter to supplement household protein

Where to buy dam liners in Kenya

Dam liners are available in the companies 6 branches located in; Athi river, Nairobi, Kisumu, Eldoret, Nyeri and Nyahururu. We supply pond liners either as rolls of 110M x 8M, 0r cut and welded into the client’s water pan’s specifications

Dam liner rolls by Grekkon Limited

HDPE pond liners cut from a roll and welded to tailor it to the water pan dimensions

Where to buy dam liners in Kenya

Positioning Your Water Reservoir For Irrigation

This depends on:

i. The source of water going into the water pan. If  the source is from a lower altitude water source such as a river or lake, the water pan is at an elevated position so that with a water pump, the water is reticulated through irrigation water pipes to the water pan. If the water source is from rain water falling on the roofs or run-off, the water pun is positioned at a lower gradient

ii. Preferred irrigation method. If by sprinkler  irrigation or rain hose kits which require high pressure from a water pump, the water pan will be situated at any point. If by low gravity pressure say for drip or button drip irrigation, then it will be at the highest point of the farm

Water harvesting using dam liners

Where to buy dam-liners in Kenya

How to Harvest Water Using Dam Liners

Factors to consider

1. Land size

The amount of water required for half an acre is less than that needed for 20 acres. The latter will harvest more water to irrigate the greater acreage, and the former will have less water harvested. The bigger the volume of water reserved, the larger the dam liner size

2. Location

The amount of rain fall is different in every climatic zone. Growers in the cool wet highlands have just a few dry months in the year, while farmers in the dry zones have more dry months than wet. In regions where the interval between rains is long, larger reservoirs are built for the same acreage as that in the cool wet location. Again, dry locations have very high  water loss through evaporation. In this case, it is advised to set up a shade net over the water reservoir to manage this water loss

3.  Ground Elevation

The farm gradient determines the location of the water pan. Some choose to have it at the lowest part so as to capture run-off water. If it is for crop irrigation, this water is either pumped uphill to a tank from where it flows back by gravity to the crop. Or it is pumped directly to the crop from the water reservoir. Others choose to locate the water pan on the highest point of the farm so that the water, through gravity flows out to the crop. In this case, the farmer does not retain run-off  rain water from the farm. On a flat terrain, irrigation water is physically pumped out to either a high storage tank for onward gravity flow to the crop. Or directly to the crop

A low reservoir that collects run-off rain water

4. Farming System

The size of the water pan will differ for irrigation, compared with aquaculture or livestock production

5. Crop Type

Some crops are more water demanding such as leafy vegetables, than others such as herbs. Then some crops  like onion are densely spaced while others are like avocado are sparsely populated in the farm. This will determine the water requirement

6. Irrigation System

Every irrigation system has it’s own unique water use. Drip irrigation conserves water while overhead irrigation through sprinklers or rain hose kits spends huge water volumes

7. Surface Texture

The surface texture of the water pan determines the dam liner thickness to install. For a smooth surface, a 0.5mm dam liner is ok. Where the surface is stony or rocky, then the 0.75mm or 1mm dam line is better

Before harvesting your water using dam liners, ensure that the water pan’s surface is free of debris as much as is possible. This will be stones, rocks, tree stomps, or sticks. This reduces the danger of your dam liner tearing as a result of perforation caused by the weight of the water squeezing the material against these particles

Trench 0.75M to 1M along the perimeter or circumference of the water pan. This trench is 1ft wide and 2 ft deep. Your dam liner edges will be tucked in here and covered with soil, gravel or stones to anchor it in place. Alternatively, use sand bags along the edges to hold your dam liner in place

Where to buy dam liners in Kenya

How Are Dam Liner Sizes Calculated?

Before determining the dam liner size, one must understand the size of the reservoir or tank. This is by measuring the length, width, and depth/ height (for rectangular or square shaped reservoirs/ tanks). For circular or cylindrical tanks/ reservoirs, measure the diameter, and the depth/ height. The reason this is key is because our dam liner material comes in rolls. To make out the shape of the water pan or tank, the dam liner is cut  in large bits from the roll and joined together. This is to create the 2 dimension size of the water reservoir or tank. For example; if the width of the dam liner on the roll is 8M, and the water pan requires a width of 15M. Then 2 pieces, one measuring 8M and another 7M in width from the roll are cut and joined to create the 15M width

How Do I Calculate How Much Dam Liner I Need?

The dam liner calculator is adapted to the shape of the irrigation water reservoir as illustated in the 3 different shapes below

1. Sloped sides reservoir

The slope of the dam wall is shown as slanting length (SL) or slanting width (SW) in the dam liner calculator tabulation shown later in this page

2. Cylindrical circular tanks

3. Straight side reservoirs

Where to buy dam liners in Kenya

Pond Liner Calculator Table

If your totals include a decimal say 120.3sq, round it up to the nearest whole number, in this case 121M sq. The +0.6M in the ‘circular liner’ and is the overlap. So is the 2M in the straight side liner’

“D” is the maximum depth which is the center-most point of the reservoir

Where to buy dam liners in Kenya

How much overhang should a pond liner have?

An overhang is the extra liner material that holds the main liner in the reservoir or tank. This excess material is held against the external wall of the tank, or tucked in a trench all around the reservoir to support the dam liner in place. It is covered with soil or stones in the trench.  Another alternative to trenching is to lay sand bags on it. The weight of the sand bags holds the dam liner in place

After excavation, it is necessary to compress the mould of soil roundabout the water pan before making a trench

See below

Where to buy dam liners in Kenya

How To Weld Dam Liners

1. Factory welding. Depending on the dam liner size, weld it whole or partially in the factory. The weight and volume of the welded material must be easily portable on site.  The latter factor guides on how much of the dam liner material will be put together in the factory
2. Site  or field welding. This is done on site at the point of dam liner installation. It is the joining together of the partially welded dam liner pieces from the factory. Site welding is done when the entire dam liner could not be wholly put together in the factory. This is as a result of weight or bulkiness, which limits lifting and transportation of the bulky and heavy material. The weight size of the portable material depends on the thickness of the dam liner. The thicker it is, the less it is
3. A wedge welding machine or a heat gun/ heat blower is the equipment that does dam liner welding. A wedge machine is what does it in the factory. The heat gun is highly portable, and so is best for field joinery

Dam liner welding involves melting the liner material under high temperature at the point of joining them. Once melted, the 2 layers are laid one over the other and as they harden, become one unit

Factory wedge welding of a 1mm  thick dam liner

Joining 2 dam liner pieces with a heat gun

Both equipment run on electric power. In off grid electricity locations, Grekkon Limited provides a generator to power the heat gun or wedge welding machine

Where to buy dam liners in Kenya

A Step by step procedure on how to install dam liners

To learn how to install dam liners in your water pan or tank, consider the following factors

1. Determine if;

1.1.  It is a water reservoir

or

1.2  A water tank

Each storage unit has a different way of calculating the dam liner

2. Define the shape of the water pan or tank;

2.1. Is it circular/ oval or square/ rectangular?

2.2  Are the rectangular/ square sides steep or slanted?

The dam liner calculation formulae is different for each shape as illustrated later in this article

The second stage in how to install dam liners is to work out the dam liner size

A Grekkon Limited technician installing a dam liner in a water reservoir

Small Irrigation Equipment Supplier

Grekkon Limited is a small irrigation equipment supplier in east Africa. Domiciled in Kenya, we serve farmers in; Cameroon, DRC, Ethiopia, Kenya, Nigeria, Rwanda, Somalia, South Sudan, Tanzania, Uganda and Zambia. Our irrigation materials, tools and equipment vary with the system adopted by a grower. Below is our irrigation equipment list

Double emitter drip tapes pioneered in Kenya by Grekkon Limited

Small Irrigation Equipment Supplier

Types of Irrigation Equipment

1. Drip kits. For both vegetable and fruit tree/ forestry irrigation. This includes; drip tape, 16mm HDPE pipe, starter connectors, off-takes, drip to drip connectors, button or online drippers, and end caps
2. Rain hose kits. It has; rain hose pipe, off-takes, connectors, and an end cap. Rain hose kits are best utilised where drip irrigation systems cannot be installed such as is pasture, or crop nurseries
3. Sprinkler systems. There are various types;

3.1. Pop up sprinklers. These are sub-surface sprinklers for lawns, golf course, football pitches, and gardens

3.2. Rain gun sprinklers. These are metallic high pressure, high volume sprinklers for use in all crops. They are well utilised in larger acreage because they have a wide area of spray

3.3. Impact sprinklers. They are plastic and range from 1/2″ to 1″. Mostly used to irrigate small vegetable farmes, or pasture

3.4. Meganet sprinklers. These are plastic sprinklers that range from 1/2” to 1”. They are a suitable alternative to impact sprinklers

3.5. Butterfly type sprinklers. They are for lawns and small gardens like the kitchen garden

3.5. Micro sprinklers. They irrigate individual fruit tree plants, just like button drippers. However they cover a wider area, and provide better humidity around the crop’s root zone

In this video below, a smallholder farmer who was an early adapter of Grekkon’s rain hose kits. She speaks about her growing experience

4. Misters and foggers. Used in greenhouses for seedlings watering, and humidity control

Solar water pumps by Grekkon Limited

5. Water pumps;

As an irrigation equipment supplier, every irrigation system is backed by the following types of water pumps to draw water from a source, to supply the irrigation system

i. Solar water pumps. These are either surface or submersible types. Submersible water pumps work under water, while surface water pumps are ground based

ii. Electric water pumps. Like solar water pumps, they’re surface and submersible options

iii. Diesel generator water pumps. They run on diesel powered engines. They are portable or fixed types. The latter are larger in size

iv. Petrol water pumps. They run on petrol powered engines, and are smaller than diesel water pumps

Small Irrigation Equipment Supplier

Water pump accessories

Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, adaptors, splicing kits, control boxes, invertors (for DC to AC converstion) cables,  cable ties, solar panels (for solar pumps), and a solar panel support structure

Accessories that accompany motor powered pumps are; foot valves, clips, suction pipes, and adaptors

Every irrigation system has a main, and/ or sub-main pipes. Our irrigation pipes are HDPE and PVC. We advice on the right pipe thickness, size and type based on

• Land size; determines pipe size. Large pipes for large acreage. Our pipe sizes range from 16mm to 180mm in diameter
• Irrigation system adopted; any of the 1 to 3 above
• Land ownership system; leased or owned? HDPE for the former, PVC for the latter

These pipes have specific fittings which are; elbows, tees, valve sockets, ball valves, couplings, adaptors,sockets,saddle clamps, and  end caps by type and size

Drip irrigation system under installation by Grekkon Limited using PVC pipes as main and sub-main lines

Small Irrigation Equipment Supplier

Installation Service

Our irrigation service team conducts systems installations service in east Africa. We offer advisory services to manage the system well for many years

A client’s irrigation system installation by a company technician