Invitation to Bid (ITB) - Supply and Installation of 103.5 kW Solar PV System for the Banz Town Water Supply Facility in Jiwaka Province, Papua New Guinea

New amendment added #3: Addendum No.3 is made to extend the bid submission deadline to 27 Aug 2025, 5:00 PM (local POM time).

New clarification added: QUESTION:We would like to respectfully raise a concern regarding the requirement stated in BOQ Tab S2.1, Item 15.1.1:“225 kWh Liquid Cooling BESS c/w integrated PCS”We understand the importance of thermal management in battery systems; however, we would like to request clarification on whether air-cooled or passively cooled BESS solutions — which are widely deployed and proven globally for systems of this scale — would be acceptable in place of liquid cooling.Our key concerns with liquid-cooled systems at this scale (225 kWh):Reliability & Maintenance: Liquid-cooled systems introduce higher maintenance complexity, including coolant circulation, leak management, and monitoring subsystems — often requiring specialist intervention over time.Suitability for Remote Sites: In smaller, decentralized, or rural applications like Banz, serviceability over a 10–15 year lifecycle becomes a significant challenge.Proven Alternatives: For BESS systems up to and even beyond 500 kWh, air-cooled lithium-ion systems are widely used internationally — offering simpler integration, fewer moving parts, and a lower long-term risk profile.Liability Risk: As a contractor, taking on a liquid-cooled system in this class introduces long-term liability for servicing and performance that may be disproportionate to the size of the installation.Our Request:Could UNOPS kindly confirm if:A high-quality, air-cooled BESS solution (225 kWh) would be accepted, provided it meets all safety, performance, and integration standards?Alternatively, would UNOPS be open to a performance-based specification (e.g., maintaining cell temperature within safe operating limits) rather than mandating a specific cooling method?We are committed to delivering a robust, low-maintenance, and cost-effective solution aligned with the project's long-term sustainability goals.ANSWER:No, the design for this project, including the cooling system for the BESS, has already been approved. Bidders are required to submit prices as per the BoQ items and design standards, and are not allowed to change any part of the design or any items in the BoQ. 

New clarification added: QUESTIONS:Can you please confirm that the commissioning test will evaluate the performance of the entire solar PV system, rather than individual panel outputs?Will the commissioning performance test focus on system functionality and energy yield, rather than achieving full nameplate capacity (103.5 kWp) under field conditions?Is it acceptable to provide factory flash test reports for each panel as proof of compliance with the “no negative tolerance” requirement?Will the system’s actual performance during commissioning be assessed based on environmental conditions at the time (irradiance, temperature), rather than ideal test conditions?Can we use energy yield modeling tools (e.g. PVsyst or equivalent) to provide an expected performance baseline, to which actual commissioning results can be compared?Is there a required performance ratio (PR) or minimum energy output benchmark that the installed system must achieve during the commissioning test?ANSWERS:The successful bidder will be required to conduct commissioing test of the entire Solar PV system for performace verification. We would not test each individual panel output on site to see if they are performing to the stated rated capacity or not. The performance of entire system will be tested to ensure each component functions as per design when connected to the whole system.The contractor is expected to conduct a commissioning test to ensure that all system components are performing according to design standards and that the entire solar system achieves the Performance Ratio (PR).The Factory flash test reports (delivered with the modules and showing ≥ rated Wp with no negative tolerance) will be accepted as fulfilling this requirement.The contractor is expected to provide commissioning reports demonstrating the actual performance of the system based on the environmental conditions at the time (irradiance, temperature).The energy yield simulation has already been performed by the design consultant and will be used as a benchmark for performance verification. Therefore, the contractor is not required to carry out a separate yield simulation.The minimum required Performance Ratio (PR) for the installed system shall be ≥ 75% during the commissioning test.

New amendment added #2: Addendum No.2 is made to adjust the performance security requirement.Please see the highlighted on page 10 - 11 of the file named "ITB_Small Works_Sections II, III, IV, V_Rev.1".

New clarification added: QUESTION:We are writing to seek clarification regarding Returnable Schedule 1.2: Details Provided by the Contractor, specifically in relation to the section where the contract value is to be entered. Our query concerns the separation of the pricing section into Lot 1 and Lot 2. We are submitting a bid for both Lot 1 and Lot 2, with one (1) Preliminary & General Item Cost covering both Lots for which we have a combined contract value for the two Lots. Kindly clarify how we should enter the contract value in the schedule:Should we split the combined contract value proportionally between Lot 1 and Lot 2 and enter values separately under each Lot?Or should we provide the total combined contract value under one of the Lots (or in an additional section), and clearly indicate in a note that it covers both Lots?Alternatively, is there a preferred format or instruction we should follow in this case?ANSWER:The bidders are requested to submit separate pricing for Lot 01 and Lot 02 as specified in the financial offer. Bidders submitting offers for both lots may also provide a combined total value. UNOPS will decide whether to award separate contracts for Lot 01 and Lot 02 or a single contract to one bidder, based on the evaluation criteria, or the lowest technically compliant bid for each lot or the combined value. Please complete Schedule 1.2: Details Provided by the Contractor as per the guidelines provided in this form.

New amendment added #1: Addendum No.1 is made to upload the following documents:Onsite pre-bid meeting minutesOnline pre-bid meeting minutes and slidesWTP Site A-001 _ Mark up 001..PV02 - Site Reticulation Layout _ Mark up 002..The tender timeline has also been extended as per the details below:Extending the clarification deadline to 18 Aug 2025, 5:00 PM (local POM time)Extending the bid submission deadline to 22 Aug 2025, 5:00 PM (local POM time)

New clarification added: QUESTIONS:The BoQ provided contains 2 x carports-2 & 1 x Carport (Total 3 Nos.), whereas the provided overall WTP station drawing shows only 1 carport-1 & Carport-2. Could you please clarify?Both of the transformers mentioned in the BoQ refer to only Installation but not supply. Is the supply of transformers also in the bidder's scope? Please clarify.The pole heights for 11 kV and 415 V are not mentioned in the BoQ, can we assume the AZ/NZS standards for this?ANSWERS:Refer to Addendum No.1, the layouts of all three carports is shown on Drawing No. "WTP Site A-001 _ Mark up 001..".The scope of the Supply and Installation of 103.5 kW Solar PV System for the Banz Town Water Supply Facility includes supply and installation of both transformers.The pole heights for the 11kV lines shall be 10m minimum, details to be per AS/NS Standards. 

New clarification added: QUESTION:Are you aware as to whether there are to be any specific equipment specification requirements, such as certain items of equipment being manufactured to any particular country standards & regulations?Everything we use is whilst manufactured overseas, the equipment is normally fully approved to PNG and Australian/New Zealand Standards.ANSWER:All equipment, if not specified in the relevant specifications document supplied, shall be A/NZ Standard quality and manufactured to A/NZ Standard.  

New clarification added: QUESTION:Please confirm who is providing the Generator?ANSWER:The scope of this tender includes the supply, installation and commissioning of the 110kVA genset. 

New clarification added: QUESTION:Who will be providing the Carports?We ask because the carports are drawn as regular carports in the floorplan of the files provided, so, is UNOPS supplying the carports and we are required to work within the confines of the provided carports?Or are the plans guides for us to provide the whole carport?ANSWER:The scope of the Supply and Installation of 103.5 kW Solar PV System for the Banz Town Water Supply Facility includes construction of the three carport structures under Lot 1. All required drawings are provided, the civil, the architectural and the structural all provide the details for the construction of these carport structures. 

New clarification added: QUESTION:Your Excel BOQ form indicates that the BESS load requirements are a, "225kWh Liquid Cooling BESS c/w integrated PCS".Can we propose an alternative without liquid cooling, which we feel will be more appropriate for monitoring and maintenance in PNG?ANSWER:Bidders are not allowed to change any design or any items in the BOQ lines. There had been considerable time and resources spent during the design phase. There are reasons why these specific items are being specified here and the ITB requirements prohibit any changes to the design in any form. 

New clarification added: QUESTION:We would like to seek clarification regarding the following requirement in the Solar PV System Technical Specification:“The modules are to have no negative power tolerance (i.e. the actual Wp capacity of the panels, at commissioning, is to be equal to or higher than their rated Wp capacity). Flash test results for each panel are to be provided to the Client’s Engineer on delivery of modules.”We fully understand and support the intent to verify module performance; however, we would like to point out that:Flash testing of panels under STC (Standard Test Conditions) cannot be reliably or accurately conducted on-site at the time of commissioning, due to real-world environmental variations (irradiance, temperature, etc.).The only valid and industry-standard flash test results are those provided by the manufacturer, under factory-controlled conditions, and are typically printed on the panel’s test label and included in the module’s flash data sheet.Therefore, we respectfully request clarification on whether:Factory flash test reports (delivered with the modules and showing ≥ rated Wp with no negative tolerance) will be accepted as fulfilling this requirement.The term “at commissioning” refers to the submission of these factory reports, rather than requiring field-based Wp verification under non-standard site conditions.We appreciate your clarification on this matter to ensure full compliance with technical expectations and avoid any misinterpretation during commissioning.ANSWER:Factory flash test reports (delivered with the modules and showing ≥ rated Wp with no negative tolerance) will be accepted as fulfilling this requirement.However, the successful bidder will still be required to undertake testing of the whole setup/system. We would not test each individual panel on site to see if they are performing to the stated rated capacity but it's the whole system that we are to test to ensure each component functions as designed when connected to the whole system. Should there be any test results being unacceptable or below acceptable/expected values, then the contractor will need to test each component, per the specifications, to identify the faulty panel/eqpuipment and replace with a good working panel/equipment. All test readings of the whole system should be as per the specificaitons.