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Expression Of Interest: Conversion Of U.S.G Residences To On-Site Solar (July 21, 2022)
July 21, 2022


The US Embassy in Pretoria issues this expression of interest for the Conversion of U.S. Government Residences to On-site Solar Photo-Voltaic Electricity Generation coupled with safe on-site Battery Storage System and therefore issues a brief explanation of our requirement.   Kindly be advised that a formal Solicitation will be advertised once this project is ready for release.



EOI no. EOI US 001/07/2022
Description of the works The US Embassy hereby invites submissions for the appointment of Electrical Contractors to convert U.S.G. owned residences to On-site Solar Photo-Voltaic Electricity Generation coupled with safe on-site Battery Storage System
Class of work Electrical
Eligibility criteria Respondents who are qualified Electricians and who can issue COC’s, who are tax compliant and are willing to subject their company and staff to the US Embassy’s applicable security vetting procedures are eligible to submit a response to this EOI.
EOI issue date 20 July 2022
Access to the EOI documentation Documentation relating to this EOI can be accessed via the US Embassy’s business ops website using the link contained in the EOI advertisement and will not be made available in hard copy format.

Respondents must submit their documentation to the US Embassy via the following email addresses:

ThompsonM1@state.gov and KriekJX@state.gov

Closing date and time The closing date and time for receipt of responses is:          

5 August 2022 at 12:00. Late submissions will not be accepted.


1.               Interpretation of this EOI

1.1 Clarification requests by respondents

Respondents may request clarification for purposes of preparing a response to this EOI, only via the email address provided in the Standard Notice and Invitation to submit an Expression of Interest.

1.2. Communication protocol

Respondents must refrain from contacting any of the US Embassy’s personnel regarding this EOI. Any communication with the US Embassy must be via the email address provided in the Standard Notice and Invitation to submit an Expression of Interest.


2. Evaluation of EOI submissions

2.1. Manner of evaluation

Respondent’s submissions will be evaluated by a technical evaluation panel (COR).

2.2. Security and vetting

Respondents who participate in this EOI process must note that personnel, contractors, sub-contractors and independent contractors of the successful tenderer will be subjected to the US Embassy’s security vetting processes.

2.3. Tax compliance

Respondents who participate in this EOI process must be tax compliant.  In the case of a respondent which is a joint venture, each joint venture partner must be tax compliant.

2.4 No obligation

Nothing in this EOI should be construed as creating an obligation on the US Embassy to proceed to issue a RFQ in respect of the works described in the EOI.

2.5. Costs

All costs incurred during the preparation and compilation of a respondent’s submission will be borne exclusively by the respondent.

The following documents are required upon submitting your responses:

  • Company Profile on a Company Letterhead
  • Letter of Good Standing
  • Accreditation and Certification Documents
  • 3 x Reputable References with Contact names and numbers


Mission South Africa seeks a solution to convert U.S. Mission residences to on-site solar photo-voltaic electricity generation coupled with a safe on-site battery storage system to meet fully each residence’s electricity consumption requirements.  This will include residences in Pretoria, Johannesburg, Durban and Cape Town.

Work Site – At residential locations (precise addresses to be provided) located in:

  • Pretoria = 250 x residences
  • Johannesburg = 55 x residences
  • Cape Town = 40 x residences
  • Durban = 10 x residences

Minimum Requirement – 5 residences

Maximum Requirement – 400 residences

Installation – per residence


  • Warranty
    • 10 years on Battery System
    • 25 years on solar charge controller system
    • Electrical Certification of Installation Upon System Installation to ensure conformance to applicable South African and applicable United States electrical codes.
  • Equipment
    • All major components such as battery system, charge controllers and solar PV panels shall be of U.S., European, Canadian, Japanese, or Korean manufacture
    • Circuitry between panels and major components shall be Alternating Current (AC) to ensure system safety.


Most residences are serviced with balanced 3-phase electricity supply backed up with residential diesel-powered generator (genset) with Automatic Transfer Switch (ATS), we seek a vendor to provide:

Three separate single-phase power wall systems in each residence, connected to one, two or three separate phases.  Most residences shall be three-phase installations.


Phase one – Essential circuits to include the following


a. Socket outlets for alarm system, microwave, freezer, refrigerator, and kettle, excluding dryer and washer

b. All interior lights

c. Alarm system

d. Security lights

e. Automatic garage doors

f. Automatic gate motor

g. Electric Fences


Phase Two – AC units

a. Bedrooms

b. Living Room depending on size of AC unit


Phase Three – Non-Essential Circuits

a. Stove

b. Geysers

c. Dryer

d. Washer

Priority shall be given to Phase One – Essential Circuits to ensure optimal solar PV generation and longest-term, off-grid supply possible.  Phase Two and Phase Three circuits can be balanced to ensure optimal performance and maximum essential circuit run time.


Battery Storage System Specifications

  1. 5kw usable power
  2. 9kw peak power
  3. 14kwh lithium-ion battery pack with built-in inverter
  4. Must be allowed to be monitored remotely “in live time”


a. Residence must be able to run on the PV system, off the grid and charge the battery pack when needed during the day, only to return to the grid when set battery parameters have been depleted.

b. System should be able to be set to charge the battery pack from the grid during off-peak hours, if needed and as necessary, to supplement daytime solar PV charging.


Solar Requirements

a. 4.3kwp for each specified battery system

b. Solar PV panels for Phase One — Essential Circuits shall be installed in the “prime area” of the residence roof to ensure maximum charging rate

c. Each solar PV panel shall be fitted with an intelligent inverter connected to prevent high-amperage Direct Current (DC) voltages flowing to gateways or other peripheral components

d. Solar PV panel system should be mounted in a manner to prevent/minimize drilling into roof tiles


Generator Requirements

  1. Residential diesel generators do not need to be supplied or installed, but already shall be at each residential location and be tied into system in the following precedence hierarchy:
    1. (Primary power generation):  Solar PV Panel to Battery Storage System/Residence
    2. (Secondary) Battery Storage System to Residence
    3. (Tertiary) Automatic Transfer Switched Municipal Mains Power to Battery Storage to Residence
    4. (Quaternary) Automatic Transfer Switched Diesel-powered Residential Generator to Battery Storage to Residence

As some residences are clustered in security compounds and serviced by a single, shared generator, existing electrical service connections shall remain in place, but have the solar PV and battery systems put into each residence between the ATS and each residence’s main electrical panel.


Requirements Office verifies equipment requiring three-phase power currently is in use at the residences.

Proposal Scope


1. Roof-mountable solar PV panels

    1. IP-65 or better rating for continual exterior use and element exposure,
    2. Preference given to U.S./European components and manufacture, or South African manufacture made with U.S./European components,
    3. 7-year warranty, preference given to longer warranty periods.


2. Roof-mounting system of solar PV panels

    1. IP-65 or better rating for continual exterior use and element exposure, including wind
    2. Five-year warranty for roof penetrations, if necessary
    3. Appropriate grounding


3. Solar Charge Control System/Inverter/Backup Gateway

    1. All necessary hardware required to convert generated electricity to 240v AC (alternating current)
    2. All necessary hardware to direct generated electricity to stable, 240v AC current to existing main Distribution Board
    3. All necessary hardware to direct generated electricity to on-site storage vessel/battery
    4. All necessary hardware to switch to emergency power from existing municipal power/diesel generator backup system
    5. Appropriate system grounding, as applicable
    6. Preference given to U.S./European manufacture or equally to South African manufacture with U.S./European components


4. Storage Vessel/Battery System

    1. Capacity greater than current existing residential requirements divided by the number of electrical phases present at property
    2. Ability to provide (through battery capacity, software configuration or both) continual 240v AC electricity to residence without regard to day/night
    3. 10-year warranty
    4. Ability to mount outdoors in elements or indoors
    5. Mounting hardware
    6. Appropriate grounding, as applicable
    7. Preference given to U.S./European manufacture or equally to South African manufacture with U.S./European components
    8. Integrated Home Energy Monitoring System through an app available to resident
    9. Centralized real-time home energy monitoring system available to U.S. Mission personnel charged with monitoring collective system efficacy.