GreenBOOT Energy Services Company registered in India would like to introduce a hybrid Solar Fish
Drier which is to harnesses the Power of the Sun and the use of agro-waste fuel to increase the real-time drying efficiency of Vegetables, agro produce, and fish like Omena and other fish products
within Lake Region.

When our company successfully installed a Fish and Sea Weed drier in Zanzibar, Our partners felt
that Kenya especially the Lake Victoria regions should not be left out. And this is how we have
landed in Kenya to replicate the same. Our drying process improves the storage life of the products.
Perishable foods cannot be consumed at once when produced. Small fish around Lake Victoria are
available in all seasons and are harvested every day. The only fishermen’s challenge is the
preservation and real-time distribution. Their traditional method only Sun drying has met several
setbacks. The chain of distribution only depends on a volatile sun-drying process that at times
becomes uncertain throughout the year.

To satisfy the demand for Omena fish we need to preserve the fish and this is where hybrid solar
drier becomes handy and we have come up with a breakthrough technology as a possible remedy.
We believe this would be the only viable alternative to traditional drying. Our Hybrid Solar drier will
combine the use of Sun and biomass briquettes or agro waste which is available all through the
seasons from Sugar factories and farms.

What is contained in our Solar and Hybrid Dryer?
Solar dryers will use Solar Energy and hot air generated from the uses of agro waste fuel heat to dry substances. Solar dryers use the heat from the sun to remove the moisture of the food substance. As per our technology, there are two types of solar dryers i.e.

Direct and Indirect drying processes:-
Direct Solar Dryers (Traditional) expose the substances to be dehydrated to direct sunlight. One modern type of solar dryer has a black absorbing surface that collects the light and converts it to heat; the substance to be dried is placed directly on this surface. These driers may have enclosures, glass covers, and/or vents to increase efficiency as per the picture below.

In Indirect Solar Dryers, the black surface heats incoming air rather than directly heating the
substance to be dried. This heated air is then passed over the substance to be dried and exits
upwards often through a chimney, taking moisture released from the substance with it. They can be
very simple, just a tilted cold frame with black cloth to an insulated brick building with
active ventilation, and as per our proposal, this will include a backup heating system most likely
come from agro-waste products i.e. Biomass briquette or any other agro-waste readily available
within the Counties around the Lake Basin.

One of the advantages of the indirect hybrid system is that it is easier to protect the food, or other
substance, from contamination whether wind-blown or by birds, insects, or animals whose activities
can chemically alter some foods making them less appetizing.

Solar drying is mostly carried out with hot air around 50 to 80 degrees Celsius. Solar dryers such as
Vyom and many other models now use polycarbonate sheets or UV preventive glass so that UV rays
of the sun do not penetrate the food which leads to degradation during the drying process. HybridSolar dryers not only make the drying faster, but it also prevent dust, pathogens, bird droppings,
and interference from external agents. With his system, one can work around the clock.

Food items such as fish, fruits, vegetables, spices, and other items once dried in solar can be stored
for longer periods assisting the stakeholders and enhancing the chain of distribution.
Solar energy produces hot air in the solar collectors. Increasing the temperature in a given volume of
air decreases the relative air humidity and increases the water absorption capacity of the air. A
steady stream of hot air into the drying chamber circulating through and, over the drying substances
results in continuous and efficient dehydration/drying.

Our Dryers have an immediate response to the following needs:-

• Food security and preservation
• Value addition
• Reduced waste
• Community-based Small-scale Traders/farmers.
• Fishermen-food producers
• Efficient Value chain and food distribution

TYPES OF SOLAR DRYERS:
There are a variety of solar dryers in our designs. Principally, solar dryers can be categorized into
three groups:

Natural Convection Dryers
Solar dryers use the natural vertical convection that occurs when air is heated. Generally, natural
convection dryers are sized appropriately for on-farm use. The structure consists of three main
components: a solar collector, a drying bin, and a solar chimney. Natural convection dryers that are
smaller in scale are wooden boxes with vents at the top and bottom. Food is placed on screened
frames thar slide into the boxes. Air enters the bottom of the solar air heater and is heated by the black
metal absorber. The warm air rises past the food and out through the vents at the top. While operating,
these dryers produce temperatures of 130–180° F (54–82° C), which is a desirable range for most
food drying and also for pasteurization. With these dryers, it’s possible to dry food in one day, even
when it is partly cloudy, hazy, and very humid. Inside, some shelves will hold 35 to 40 medium-sized
apples or peaches cut into thin slices.

Forced Convection Dryers
The convection is forced over the food through the use of a fan. In the case of forced convection
dryers, the structure can be relatively similar. However, the forced convection dryer requires a power
source for the fans to provide the airflow. The forced convection dryer doesn’t require an incline for
the air flow however, the collector can be placed horizontally with the fan at one end and the drying
bin at the other end. In addition, the forced convection dryer is less dependent on solar energy as it
provides the airflow itself; this allows the design to work in weather conditions in which the natural
convection dryer doesn’t work. As inadequate ventilation is a primary cause of loss of food in solar
food dryers and is made worse by intermittent heating, it is essential to realize proper ventilation.

Tunnel dryers
The structure of a tunnel dryer is relatively simple. The basic design components of a tunnel dryer are
the following, a semi-circular solar tunnel in the form of a poly house framed structure with
UV stabilized polyethylene sheet by the selection of drying conditions and equipment.

Parameters need to be considered for Solar Dryer:-
Moisture Content. The foodstuff after drying must be at moisture content suitable for storage. The
desired moisture content will depend on the type of food, duration of storage, and the storage
conditions available. The drying operation is also essential in minimizing the range of moisture levels
in the batch of food as portions of under-dried food can lead to the deterioration of the entire batch.

Mold growth. This is very critical in fish drying, the rate of development of micro-organisms in Fish
is dependent on the food moisture content, temperature, and the degree of physical damage to the
food.

Appearance and smell of the fish. For example, the color of Omena and the smell can be adversely
affected if the Omena has not undergone real-time drying as opposed to a traditional drying process.
This is why we introduce a well-maintained operated hybrid solar dryer with a biomass base hot air
generator.

Socio-economic benefits of Our Hybrid Solar Drier. One of the main issues facing developing
countries today is the issue of food security. The solar food dryer can improve food security by
allowing the longer storage of food after drying compared to food that hasn’t been dried.

The solar dryer can save fuel and electricity it replaces dryer variations that require an external
energy source in the form of electricity or fossil fuel.

Solar food dryers cut drying times in comparison to sun drying. While the fossil fuel or electrically
powered dryers might provide certain benefits (more consistent airflow and higher temperatures),
the financial barriers that these technologies provide might be too high for marginal farmers within
the community.

Fruits, vegetables, and meat dried in a solar dryer are better in quality and hygiene compared to
fruits, vegetables, and meat dried in direct sun-drying conditions.

In rural areas where farmers grow fruits and vegetables without proper food drying facilities, the
farmers need to sell the food in the market shortly after harvesting. When food production is high,
the farmers/fishermen have to sell the food at a low price to prevent the food (Fish Omena) from
losing value through fermentation and decomposition.

Solar food dryers will prevent financial losses in these situations.
Drying food equally reduces its volume and weight. Therefore, with these combinations of longer
storage times, the food is also easily packed and transported after drying which potentially opens up
additional markets to the Omena distributors.

Our Hybrid Solar Dryers:
Solar heating has limitations of time and climatic conditions to overcome such difficulties we have
designed a hybrid solar drying system using additional types of fuel such as Biomass briquettes,
firewood, Coffee husks, Ground nuts husks, firewood, and maize cobs.

Components of Solar cum Hybrid Dryers:-

• Close a polyester chamber as per the capacity of the dryer,
• Solar air heaters,
• Hot air circulation Blower with connecting piping,
• Inside air circulation fans,
• Internal temperature control system,
• Internal humidity management system with exhaust fans,
• Renewable Solid waste base hot air generation system for the continuous supply of hot air
  when sun rays are not available,
• Control panel,
• MS racks to hold the Stainless Steel trays, etc.