Public Call for Tender nb. 91175996 Procurement request for supply and installation of solar system and earthing system 21.2202.6-003.00 PART II

GIZ PART II project aims at supporting Palestinian Refugees to participate in shaping their own socioeconomic conditions at community level. Despite the vast array of challenges facing Lebanon and its residents, PART II is acting at various levels to ensure sustainability of this support. These actions include the project’s backing to local initiatives with the aim to enable a better environment, supporting the community to improve their living conditions during the ongoing economic plight.

In spite of the dire conditions people in Lebanon are facing, PART II project strives to support their partners and initiatives on several tracks to be able to support in return the Palestinian refugees in the community to stand their ground.

The major electrical outage, among other things, had a negative impact on several projects and partners' fixed overhead costs. As a result, PART II began its support with the purchase of solar panel systems for partners in 2022 and will continue to support some initiatives in a similar manner so that they can continue their projects and, in return, be able to support their community, generate employment opportunities, and strengthen their sense of community.

In this framework, the services of a service and goods provider are requested to contribute to the support of PART II project to their supported initiatives (Bybee and Al Ard) and safety earth/grounding system for their partners who were supported previously from the project with the procurement process.

1. Scope of work

The supplier shall deliver the below mentioned goods for the beneficiaries in the following locations:

ByBee- Tyre, South lebanon

Al Ard- Tyre, South Lebanon

Sekke- Saida, South Lebanon

Initiate- Tyre, South Lebanon

WPA- Tripoli, North Lebanon

Al Hesbe- Saida, South Lebanon

 A free standing or stand-alone backup PV System is made up of a number of individual photovoltaic modules (or panels) with power outputs of between 500 and 600+ watts each. These PV panels are then combined into a single array to give the desired power output.

A simple stand-alone PV system is an automatic solar system that produces electrical power to charge batteries (for use at night when the sun’s energy is unavailable) and to power the associated place.

Stand-alone PV systems are ideal for remote rural areas and applications where other power sources are either impractical, unreliable or simply are unavailable to provide power for lighting, appliances and other uses.

A stand-alone photovoltaic (PV) system is an electrical system consisting of and array of one or more PV modules, conductors, electrical components, and one or more loads.

While a major component and cost of a stand-alone PV system is the solar array, several other components are typically needed. These include:

• The inverter is often referred to as the brain of a solar system because it converts solar radiation into useful energy. Grid-tied inverters, off-grid inverters, and hybrid inverters are the types available in the market. In order to pick the right inverter, it is important to list your needs.

The one you choose primarily depends on your solar installation and energy consumption. Among these, off-grid invertors do not have any contact with the utility grid. In short, an off-grid inverter draws DC power from a battery source that is charged using solar arrays. Hence the prime advantage is that it can operate even if grid failure occurs. These inverters are also known by the name stand-alone inverters. 

• Fuses and Isolation Switches – These allow PV installations to be protected from accidental electrical shorting of wires allowing power from the PV modules and system to be turned “OFF” when not required saving energy and improving battery life.
• Inverter –  Inverters are used to convert the 12V, 24V or 48 Volts direct current (DC) power from the solar array and batteries into an alternating current (AC) electricity and power of either 120 VAC or 240 VAC for use in the domestic office like space or commercial facility to power AC mains appliances such as computers, printers, lighting, TV’s, kitchen appliances, etc.
• Batteries – Batteries are an important element in any stand-alone PV system but can be optional depending upon the supplied facility load profile and peak load demand. Batteries are used to store the solar-produced electricity for night time or emergency use during the day when the grid power is unreliable with repetitive cutouts. Depending upon the solar array configuration, battery banks can be of 12V, 24V or 48V with many hundreds of amperes hours in total depending on the required supply and/or backup time.

For facilities with reduced instantaneous power consumption, batteries are an important element and the heart of the stand-alone solar power system, whether that is one using a large array of panels to power a small to medium residential, office like space or commercial facility. In case of the main line power cutout, Batteries become essential to remedy to the fluctuating nature of the output being delivered by the PV panels or array. They also convert the electrical energy into stored chemical energy for use when the solar array is not producing power.

During the hours of sunshine, the PV system electrical yielded power is directly fed to the load, with excess electrical energy being stored in the batteries for later use.

 During the night, or during a period of low solar irradiance, such as a cloudy, rainy days, the electrical energy is supplied to the load from the battery. So battery storage allows a stand-alone PV system to be run when the solar panels are not producing enough energy on their own with the battery storage size tied to the electrical usage. There are basically two types of batteries used for solar energy storage: deep cycle batteries and shallow cycle batteries. Deep cycle lead acid batteries are generally used to store the solar power generated by the PV panels, and then discharge the power when energy is required. Deep cycle batteries are not only rechargeable, but they are designed to be repeatedly discharged almost all the way down to a very low charge.

Deep cycle batteries are ideally designed for storing energy generated by a stand-alone PV system and then being drawn upon for power on a consistent, daily basis.

• Wiring – The final component required in and PV solar system is the electrical wiring. The cables need to be correctly rated for the voltage and power requirements.
• Earthing / grounding system

A “stand-alone PV system” of this type offers independence from the electricity grid and power companies. However, the batteries will eventually discharge if used for long periods or there is no backup power source so stand-alone systems should be coupled with a small gas or diesel generator for extended no-sun periods or to recharge the batteries when they fall below a 60 to 80 percent depth of discharge.

Stand-alone AC systems on the other hand use an inverter, charge controller, batteries, fuses for protection and related wiring. The batteries provide power to the inverter that produces the required 120 VAC or 240 VAC in order to be utilized by the facility AC appliances.

This is typical of most small to medium residential, office like space or commercial facility. photovoltaic energy systems. There are two types of inverters: sine wave and non-sine wave inverters. Non-sine wave inverters are cheaper and can be used in stand-alone systems for non-critical power requirements like lighting, power tools and pumps for pumping water etc as their output waveform is non-sinusoidal.