DESIGN, SUPPLY AND INSTALL A HYBRID SOLAR FOR LIVESTOCK FARMERS

CALL FOR EXPRESSION OF INTEREST (EOI) – DESIGN, SUPPLY AND INSTALL A HYBRID SOLAR FOR LIVESTOCK FARMERS.

Background information.

Kilimo Trust Rwanda (KTR) is Non-Governmental Organization (NGO) working on agriculture and agribusiness that specializes in the design and implementation of sustainable agribusiness solutions in Rwanda and across East Africa. Kilimo Trust has worked collaboratively with agricultural value chain actors to co-develop interventions that enhance farm productivity, improve postharvest management, expand access to finance and appropriate technologies.  

Kilimo Trust Rwanda (KTR) is of one the implementing partners of Power for Food Partnership (P4FP) Project. The P4FP promotes the integration of Regenerative Agriculture (RA) with the Productive Use of Renewable Energy (PURE) across six districts of Rwanda including Nyagatare, Kayonza, Rwamagana, Bugesera, Rutsiro and Rubavu. The project aims also to increase farmers’ productivity, strengthen climate resilience, enhance market access, and accelerate the adoption of regenerative agriculture powered by clean energy technologies. 

Kilimo Trust Rwanda invites qualified and experienced solar technology suppliers to submit Expressions of Interest (EOI) to design, supply and install a hybrid solar system for livestock farmers to promote sustainable use of green energy for livestock framers.

Overview of the assignment

This call aim to design, supply and install a hybrid solar PV system designed to support Chaff cutter and auxiliary electrical loads with battery backup and grid integration. The proposed solution is designed to promote the use of clean, renewable energy by maximizing solar power generation while reducing dependence on conventional grid electricity. It features high-efficiency solar PV modules, advanced lithium battery storage, and a hybrid inverter with intelligent energy management and grid backup capability. This integrated system delivers a reliable, efficient, and sustainable power supply for the intended application.

System objectives.

The proposed systems are intended to:

• Provide reliable energy for chaff cutter motor and auxiliary loads 
• Maximize daytime solar energy utilization 
• Provide night-time battery backup for auxiliary loads 
• Utilize the utility grid as supplementary backup.
• Ensure stable and efficient system operation.

Load requirements.

Chaff Cutter (11KW) + Auxiliary Loads 13KW. 

• System sizing calculations (Daily Energy Consumption):

1. Schaff Cutter: 11KW X 2Hrs =22KWh (Only at Daytime)
2. Cooler: 2KW X 15Hrs= 30KWh
3. Milking system: 2.2KW X 0.3=0.66KWh
4. Mixer: 1200W X 0.3Hrs=360Wh=0.36KWh  
5. Lighting: 150W X18Hrs= 27000Wh=2.7KWh

Daily Total Energy= 22+30+0.66+0.36+2.7= 55.72KWh/day   

Factor in System inefficiency

Solar system experience energy losses from Inverter conversion, Wiring and Battery heat. Assuming a standard 80% system efficiency (20% loss), divide the daily energy requirement by efficiency. 

Total Required Generation=55.72KWh/0.80=69.65KWh 

Determine Solar Array Size

Solar Panels only produce peak power during sunlight hours. Assuming an average of 4 peak sun hours per day in Eastern Province, divide the total required generation by the sun hours. 

Solar Array Size=69.65KWh/4Hours= 17.41KWp

Size of Battery storage

The battery must power the load when the sun is not shining (roughly 12 hours a day) and handle the cloudy days.

• Assuming Nighttime Consumption: 2.15KW X 12hours =25.8KWh (all lights and cooler)
• Lithium Battery Sizing (80% Depth of Discharge): To keep the battery health must not drain it completely. Battery Capacity= 25.8KWh/0.80=32.25KWh 

NOTE: The Chaff Cutter will only operate during the day time, the battery capacity will only consider nighttime load

Inverter Sizing

The inverter Converts DC power into AC power. It must handle the PV power and the potential startup surges from the Chaff Cutter and Other Inductive Loads.

Chaff Cutter + Auxiliary Load

• Solar PV Array: 17.4 kWp 
• Hybrid Inverter Capacity: 20kW  
• Battery Storage: 32 kWh 

1. System configuration

Solar PV Array

The PV array will consist of high-efficiency monocrystalline solar modules mounted on a durable support structure designed for optimal energy production.

1.1 Key Features:

• High conversion efficiency 
• Long operational lifespan 
• Weather-resistant design 
• Surge and overvoltage protection 

2. Hybrid Inverter System

• The hybrid inverter manages:
• Solar energy conversion 
• Battery charging/discharging 
• Grid synchronization 

2.1 Features:

• Pure sine wave output 
• Intelligent energy management 
• Automatic grid transition 
• Remote monitoring capability 

3. Battery management integration

Battery Energy Storage System

Lithium battery technology is proposed for both options due to:

• High cycle life 
• Deep discharge capability 
• Fast charging performance 
• Low maintenance requirements 
• High operational efficiency 

3.1 preliminary energy analysis

Parameter Option A

Solar PV Capacity - 17 kWp

Inverter Capacity - 20 KW

Battery Storage - 32 kWh             

Total Load Capacity - 16.55 kW

Chaff Cutter Load - Only Run Daytime

Estimated Backup Duration - 12 hrs

Grid Integration - Yes

Mandatory documents for submission

Interested and eligible bidders must submit:

• Expression of Interest letter addressed to Kilimo Trust Team Leader Rwanda
• Financial and technical proposal for the proposed sizes and specification of solar system.
• Company Registration Certificate
• Rwanda Revenue Authority (RRA) Tax Clearance Certificate which is valid
• Rwanda Social Security Board (RSSB) Clearance Certificate which is valid
• Certificates of Completion Related to this works
• 2 Recent Contracts of similar goods/services (within the last 5 years)
• Delivery Timeline
• Warranty & After-Sales Support.

Submission and Deadline 

All required Bid documents must be written in English and submitted on this platform not later than Friday 11th September 2026 at 5:00PM Rwandan Time. Late bids will be rejected.

Note: Only selected bidders will be communicated.