Call for Proposal- Design, Supply, Installation, Commissioning and Maintenance of Solar Photovoltaic (Hybrid) Systems for 11 Schools in the Tigray Region, Ethiopia
Location: Addis Ababa, Ethiopia
Organization: SOS Children’s Villages International (SOS CVI)
Deadline: 30 July 2026
Job Description
CALL FOR PROPOSALS
Design, Supply, Installation, Commissioning and Maintenance of Solar Photovoltaic (Hybrid) Systems for 11 Schools in the Tigray Region, Ethiopia
Who we are
SOS Children’s Villages in Ethiopia is an International Non-governmental organization and a member of SOS Children’s Villages International Federation. We started our humanitarian work in Ethiopia with the opening of our first Village in Mekelle, Northern part of Ethiopia in 1974. Since then, we have expanded our programs to different regions where there are significant needs for intervention and where we believe we can work in partnership with all relevant actors to bring sustainable positive outcomes for children’s and young people.
Today, we have grown significantly to meet the persistent challenges that confront Ethiopian children who have lost parental care and those that are at risk of losing their parental care. Working in close collaboration with international donors, local government and community-based organizations across eight program locations; we aspire that every child grows up with love, respect and security.
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Our Commitment to Safeguarding
At SOS Children’s Villages, safeguarding isn’t just a policy, it’s a foundational value embedded in everything we do. We are unwavering in our commitment to protecting the children, young people, adults, and communities we serve, as well as our workforce and resources.
We cultivate an environment of trust and accountability where every voice is heard and respected. All successful candidates will be expected to champion our holistic safeguarding principles, actively upholding our Child & Youth Safeguarding Policy, Code of Conduct, and regulations against sexual misconduct, fraud, and corruption.
By joining our team, you commit to integrating these vital standards into your work, ensuring the highest levels of safety, ethics, and integrity in every action and partnership.
Together, we create a world where everyone feels safe, respected, and protected
Join Our Mission:
We are looking for a qualified contractor (or consortium) to deliver, on a turnkey basis, solar PV hybrid systems with battery storage that reliably meet the defined share of each school’s energy demand, and to maintain those systems over an agreed operation and maintenance period.
Tender at a Glance
| Item | Detail |
| Issuing organisation | SOS Children’s Villages in Ethiopia |
| Assignment | Turnkey EPC of solar PV hybrid systems for 11 schools |
| Location | Tigray Region, Ethiopia (final site list per Annex C) |
| Contract type | Design, Supply, Install, Commission & Maintain (turnkey EPC with O&M) |
| Eligibility | Open internationally (only international firms) |
| Publication date | 02 July 2026 |
| Site visit | Not required / not arranged |
| Proposal submission deadline | 30 July 2026, 17:00 EAT |
| Submission method | Email (Procurement@sos-ethiopia.org) |
| Evaluation basis | 70% technical / 30% financial |
| Budget ceiling | None disclosed – bidders to quote competitively |
| Validity of proposal | 90 days from submission deadline |
SOS Children’s Villages Ethiopia is a child-focused, non-governmental organisation working to ensure that children at risk grow up within a caring family environment and have access to quality education, health care and protection. As part of its commitment to improving learning conditions, SOS Ethiopia is seeking to electrify 11 schools in the Tigray Region using reliable, clean solar energy. Many schools in the region experience unreliable or absent grid electricity, which limits the use of digital learning equipment, lighting and connectivity. This project will equip 11 schools – comprising primary and secondary schools – with solar photovoltaic (PV) hybrid systems and lithium iron phosphate (LiFePO₄) battery storage to provide dependable power for laptops, interactive displays, lighting and network equipment. SOS Ethiopia hereby invites qualified and experienced companies to submit technical and financial proposals for the design, supply, installation, commissioning and maintenance of these systems.
Objective and Scope of Work
Objective
To procure a qualified contractor (or consortium) to deliver, on a turnkey basis, solar PV hybrid systems with battery storage that reliably meet the defined share of each school’s energy demand, and to maintain those systems over an agreed operation and maintenance period.
Scope of work
The selected contractor shall be responsible for the full turnkey delivery, including but not limited to:
- System design and engineering for all 11 schools, based on the load profiles provided (Annex A) and any site-specific conditions.
- Supply of all equipment, including PV modules, LiFePO₄ batteries, inverters/hybrid inverters, mounting structures, protection devices, cabling, metering and balance-of-system components.
- Installation, testing and commissioning of complete systems at all 11 sites.
- Integration with the existing grid connection where available (grid + battery hybrid configuration), including appropriate changeover/control and safety equipment.
- Training of designated school/SOS staff on safe operation and basic monitoring.
- Operation and maintenance (O&M) for a defined period after commissioning, including preventive and corrective maintenance and performance reporting (see Section 4.6).
- As-built documentation, test certificates, manuals and warranty documentation.
System architecture
The required configuration is a grid-connected solar PV hybrid system with battery storage (grid + PV + battery). The PV array and battery shall supply the defined share of demand; the existing grid connection serves as a complementary/backup source for charging and for periods of low solar generation. Systems must be designed to operate safely and automatically during grid outages.
Technical Requirements and Specifications
Energy coverage requirements
The solar PV hybrid systems must cover, as a minimum, the following share of each school’s annual energy demand (kWh/year), based on the load profiles in Annex A:
| School type | Minimum solar coverage of annual energy demand | Reference annual demand* |
| Primary schools | ≥ 90% | ≈ 13,950 kWh/year per school |
| Secondary schools | ≥ 84% | ≈ 111,770 kWh/year per school |
Resulting minimum solar-supplied energy: primary ≈ 12,555 kWh/year per school; secondary ≈ 93,887 kWh/year per school. Bidders must clearly state the modelled coverage percentage achieved by their proposed design for each represented school, with supporting PVsyst simulation output,
Battery storage – mandatory technology
Battery storage must use lithium iron phosphate (LiFePO₄ / LFP) chemistry. Other lithium chemistries (e.g. NMC), lead-acid or gel batteries are not acceptable. Battery sizing must be justified against the load profile and the required autonomy/backup strategy described by the bidder. Battery banks must meet or exceed the following minimum specifications:
| Parameter | Minimum requirement |
| Battery chemistry | Lithium iron phosphate (LiFePO₄) |
| Nominal voltage | 51.2 V |
| Operating voltage range | 40 V – 60 V |
| Depth of discharge (DoD) | ≥ 90% |
| Cycle life | > 6,000 discharge cycles |
| Battery Management System (BMS) | Integrated, with relevant safety certification (e.g. IEC 62619 / UN 38.3) |
Component Standards
- PV modules: monocrystalline, with valid IEC 61215 and IEC 61730 certification.
- Inverters / hybrid inverters: suitable for grid-interactive operation with battery storage, with relevant IEC/EN safety and EMC certification and appropriate protection functions.
- LiFePO₄ batteries: with integrated/compatible Battery Management System (BMS) and relevant safety certification (e.g. IEC 62619 / UN 38.3 for transport).
- Cabling, protection and mounting: compliant with applicable IEC standards and suitable for local environmental conditions; surge/lightning and over-current protection to be included.
- All equipment must be new, unused and of current production.
Inverters / hybrid inverters must meet or exceed the following minimum specifications:
| Parameter | Minimum requirement |
| Euro efficiency | ≥ 96% for primary school and ≥ 98% for secondary school |
| Max. PV input voltage | ≤ 1000 V |
| Start-up voltage | ≤ 125 V |
| Remote monitoring system | Mobile app and web browser based cloud access |
PV Panels must meet or exceed the following minimum specifications:
| Parameter | Minimum requirement |
| Efficiency | ≥ 22% |
| Power tolerance | ≥ 2W |
| Annual degradation level | ≤ 0.5% |
| Temperature Coefficient of Pmax(y_Pmp) | ≤ -0.300% / °C |
Mounting structures and balance of system
Mounting and racking structures must be engineered to the same quality and design life as the rest of the system (i.e. a structural design life of at least 25 years, matching the PV modules). They must meet or exceed the following minimum requirements:
| Parameter | Minimum requirement |
| Material | Hot-dip galvanised steel (to ISO 1461) and/or anodised marine-grade aluminium (e.g. 6005-T5); all fasteners stainless steel (A2/A4) |
| Corrosion protection | Designed for ≥ 25-year service life under local environmental conditions; no dissimilar-metal contact (galvanic isolation) |
| Structural loading | Engineered to withstand site-specific wind and (where relevant) seismic loads per Eurocode EN 1991-1-4 or equivalent; stamped structural calculations to be submitted |
| Mounting type | Suitable for roof- and/or ground-mount as applicable; roof fixings to be non-penetrating or fully weather-sealed; tilt/orientation optimised for site latitude |
| Warranty | ≥ 10-year manufacturer product warranty on the mounting system |
| Certification | Manufacturer test/quality certification and compliance with applicable IEC/EN standards |
Minimum warranty requirements
Proposals must meet or exceed the following minimum warranties. Warranties exceeding these minimums are encouraged and will be considered favourably during technical evaluation. Warranty terms must be stated per item in the Bill of Quantities (BoQ) and substantiated by manufacturer documentation.
| Component | Minimum specs / warranty | Notes |
| PV modules | ≥ 25 years product / ≥ 30 years linear output | Performance warranty to define guaranteed output retention over 30 years |
| Inverters / hybrid inverters | ≥ 10 years | Full product warranty |
| LiFePO₄ batteries | ≥ 10 years | State warranty period AND throughput/cycle guarantee and retained-capacity threshold |
Operation & maintenance (O&M)
Bidders shall propose an O&M package covering preventive and corrective maintenance after commissioning, including response times, scheduled servicing, spare-parts strategy, remote monitoring (if offered) and periodic performance reporting to SOS Ethiopia. The proposed O&M period, scope and pricing shall be clearly stated.
Proposal Submission Requirements
Each proposal must contain the following. Incomplete proposals may be rejected. The submission may be in English.
Technical planning for at least two schools
Bidders must provide detailed technical planning for at least two representative schools – one primary school and one secondary school – based on the load profiles in Annex A. For each of the two schools, include:
- System design and sizing (PV array capacity in kWp, battery capacity in kWh, inverter rating in kW).
- Energy yield / coverage calculation demonstrating the required minimum coverage (≥ 90% primary, ≥ 84% secondary), with supporting simulation or calculation.
- Technical drawings, including: single-line/electrical diagram, system layout, array/mounting arrangement, and battery & inverter installation layout.
- Description of grid integration, protection and safety concept, and behaviour during grid outage.
Bills of Quantities (BoQ)
Two BoQ documents ( one for primary school and one for secondary school) must be submitted. A complete, itemised BoQ covering all items (equipment, materials, installation, transport, O&M, etc.). The BoQ must explicitly include the warranty term for each of the following: PV panels, batteries and inverters. Prices should be itemised and shown per school and as a project total where applicable.
Data sheets
Manufacturer data sheets for all quoted items (PV modules, LiFePO₄ batteries, inverters, mounting, protection devices, metering, etc.), confirming the technical specifications and certifications referenced above.
Company and compliance documents
- Company profile and legal registration/trade licence(s).
- Evidence of relevant experience (reference projects of comparable scope, ideally solar PV with battery storage for institutions).
- Contactable references: at least three reference clients for comparable projects, with contact person, organisation, email and telephone, which SOS Ethiopia may contact directly.
- Relevant certifications/qualifications of the firm and key technical staff.
- Proposed project team and implementation/delivery schedule, with CVs of named key team members (e.g. project manager, lead/design engineer, site supervisor) detailing their qualifications and relevant project experience.
- Financial statements for the last three (3) years, to demonstrate the firm’s size, financial standing and capacity to deliver a project of this scale.
Eligibility
This call is open to all qualified national and international firms (and consortia/joint ventures) able to demonstrate the legal capacity, technical competence and financial standing to deliver the assignment. Consortia must nominate a lead entity. International bidders must be able to deliver, install and maintain in the Tigray Region of Ethiopia and comply with all applicable Ethiopian import, customs and operating requirements.
Evaluation of Proposals
Proposals will be evaluated on a combined technical and financial basis with a weighting of 70% technical and 30% financial. Only proposals meeting the mandatory requirements (LiFePO₄ batteries, minimum coverage, minimum warranties and complete submission) will proceed to scoring.
Indicative scoring framework
| Criterion | Weight | Category |
| Technical design quality & achieved energy coverage | 25% | Technical |
| Quality of equipment, certifications & warranties offered | 20% | Technical |
| Relevant experience & references | 10% | Technical |
| O&M approach, team & delivery schedule | 15% | Technical |
| Financial proposal (price) | 30% | Financial |
| Total | 100% |
SOS Ethiopia reserves the right to request clarifications, to accept or reject any proposal, and to annul the process at any time without incurring liability
Timeline and Key Dates
| Milestone | Date / time (EAT) |
| Publication of Call for Proposals | 26 June 2026 |
| Deadline for clarification questions | 30 June 2026, 17:00 |
| SOS responses to clarifications | On a rolling basis until 1 July 2026 |
| Proposal submission deadline | 3 July 2026, 17:00 |
| Evaluation & award (indicative) | [to be confirmed by SOS] |
No site visit is arranged for this tender. Bidders are expected to base their designs on the load profiles provided and any publicly available site information
Submission Instructions
Complete proposals (technical planning, BoQs, data sheets and company/compliance documents) must be submitted in a single email submission – technical and financial documents together – to reach SOS Ethiopia by the deadline.
| Field | Detail |
| Submit to (email) | [Procurement@sos-ethiopia.org] |
| Email subject line | SOS-ETH/SOLAR-TIGRAY/2026-01 – [Bidder name] |
| Format | PDF (drawings may be PDF; BoQ may additionally be provided as Excel) |
| Deadline | 30 July 2026, 17:00 EAT |
| Clarification questions to | [Procurement@sos-ethiopia.org / Maheder.Getahun@sos-Ethiopia.org] |
Proposals received after the deadline may be rejected. Bidders are responsible for ensuring their email (including attachments) is successfully received; very large files should be split or shared via a secure link as agreed with the contact person.
Technical and financial documents together – to reach SOS Ethiopia by the deadline.
General Terms and Conditions
- This Call for Proposals does not commit SOS Ethiopia to award a contract or to pay any costs incurred in preparing a proposal.
- All information provided by SOS Ethiopia is confidential and to be used solely for preparing the proposal.
- SOS Ethiopia applies a zero-tolerance policy on fraud, corruption and child safeguarding violations; bidders must comply with SOS Child Safeguarding and anti-corruption standards.
- Awarded contracts are subject to satisfactory due diligence and signing of SOS Ethiopia’s standard contract terms.
- Prices must remain valid for 90 days from the submission deadline.
Annex A – School Load Profiles
A.1 Primary school load profile
| Appliance | Qty | Power (W) | Total (W) | Hours | Energy (kWh/day) |
| HP 200 G2i Laptop | 40 | 65 | 2,600 | 08:00–20:00 | 31.20 |
| Light fitting | 6 | 72 | 432 | 08:00–20:00 | 5.18 |
| USW-16-POE Switch | 1 | 18 | 18 | 24 h | 0.43 |
| Dream Machine Pro | 1 | 33 | 33 | 24 h | 0.79 |
| U7 Lite Access Point | 2 | 13 | 26 | 24 h | 0.62 |
| Total | 3,109 | 38.22 |
2. Secondary school load profile
| Appliance | Qty | Power (W) | Total (W) | Hours | Energy (kWh/day) |
| HP 200 G2i Laptop | 300 | 65 | 13,500 | 08:00–20:00 | 234.00 |
| Light fitting | 24 | 72 | 1,728 | 08:00–20:00 | 20.74 |
| Samsung Flip Pro 85″ | 6 | 528 | 3,168 | 08:00–20:00 | 38.02 |
| Dream Machine Pro | 1 | 33 | 33 | 08:00–20:00 | 0.79 |
| U7 Lite Access Point | 16 | 13 | 208 | 08:00–20:00 | 4.99 |
| USW-Pro-24-POE Switch | 4 | 50 | 200 | 24 h | 4.80 |
| USW-Pro-48-POE Switch | 2 | 60 | 120 | 24 h | 2.88 |
| Total | 18,957 | 306.22 |
Estimated annual demand: ≈ 111,770 kWh/year. Minimum solar coverage required: 84% (≈ 93,887 kWh/year).
Annex B – Submission Checklist
Bidders should confirm that the following are included before submitting:
- Technical planning for at least two schools (one primary, one secondary), incl. system sizing
- Technical drawings (single-line diagram, layout, mounting, battery & inverter installation)
- Coverage calculation showing ≥ 90% (primary) and ≥ 84% (secondary) of annual demand
- Confirmation that batteries are lithium iron phosphate (LiFePO₄)
- Complete itemised BoQ for all items
- Warranty term stated in the BoQ for panels, batteries and inverters (meeting minimums)
- Manufacturer data sheets for all quoted items
- Company profile, registration/licence and reference projects
- Three contactable client references for comparable projects
- CVs of named key team members
- Financial statements for the last 3 years
- Proposed team, implementation schedule and O&M package
- Signed validity declaration (90 days) and acceptance of terms
Annex C – List of Schools (to be completed by SOS Ethiopia)
The project covers 11 schools in the Tigray Region. SOS Ethiopia to insert the final list below (school name, type – primary/secondary – and location). The load profiles in Annex A are representative of the primary and secondary school categories respectively.
| No. | School name | Type (Primary/Secondary) | Location / Woreda |
| 1 | Axum secondary school in Axum, Tigray, Ethiopia. | secondary school | Axum, Tigray, Ethiopia. |
| 2 | Axum alumni secondary school in Axum, Tigray, Ethiopia. | secondary school | Axum, Tigray, Ethiopia. |
| 3 | Kedamawi Minilik secondary school in Axum, Tigray, Ethiopia. | secondary school | Axum, Tigray, Ethiopia. |
| 4 | Aste Kaleb secondary school in Axum, Tigray, Ethiopia. | secondary school | Axum, Tigray, Ethiopia. |
| 5 | Nigiste Saba II comprehensive secondary school in Adwa, Tigray, Ethiopia. | secondary school | Adwa, Tigray, Ethiopia. |
| 6 | Guya secondary school in Guya, Tigray, Ethiopia. | secondary school | Guya, Tigray, Ethiopia. |
| 7 | SOS secondary school in Mekelle, Tigray, Ethiopia. | secondary school | Mekelle, Tigray, Ethiopia. |
| 8 | Mesebo secondary school in Mekelle, Tigray, Ethiopia. | secondary school | Mekelle, Tigray, Ethiopia. |
| 9 | Alene secondary school in Mekelle, Tigray, Ethiopia. | secondary school | Mekelle, Tigray, Ethiopia. |
| 10 | Fire sweat preparatory & secondary school in Samre, Tigray, Ethiopia. | secondary school | Samre, Tigray, Ethiopia. |
| 11 | Samre secondary school in Samre, Tigray, Ethiopia. | secondary school | Samre, Tigray, Ethiopia. |


