Quality-control testing at PV project due for 2016 completion

Renewable-energy consulting and engineering firm Enertis is conducting factory inspections and independent quality- control tests at the Mulilo Sonnedix Prieska photovoltaic (PV) project, in the Northern Cape.

The company tells Engineering News that testing started in May and will be completed in February next year.
The 75 MW solar PV project is part of the third round of South Africa’s Renewable Energy Independent Power Producer Procurement Programme (REIPPPP), located at the Copperton/Kronos substation, about 50 km south-west of Prieska.

Enertis South Africa country manager Álvaro Velasco says it is important to perform thorough due diligence when buying PV panels, as PV modules are the key components in a solar PV plant, typically representing more than 40% of the total cost of a solar PV project.

Velasco adds that a large number of units are required for such a project and that the logistics involved in such installations are delicate. Further, business models for these projects are drafted with the consideration that the installations will perform for at least 20 years.

He further points out that the PV installations are done with a relatively small capital investment reserved for substituting the modules should they need to be replaced during the lifetime of the plant.

“The performance of a specific module affects the performance of those connected to it. Further, the electrical performance and mechanical resistance of modules throughout their lifetime are directly related to the components and processes used during their manufacturing,” adds Velasco.

PV Module Testing
Velasco explains that a thorough purchase advisory and PV module testing process includes reviewing the warranty conditions and testing the modules manufactured with the specific components that will be used for the project in simulated conditions.

These tests include a dynamic load-testing cycle, potentially induced degradation resistance testing, low-irradiance characterisation, an analysis of any key aspects that might affect the stability of the quality levels of the PV modules during the manufacturing of different batches, and regular audits of the manufacturing process.

The testing also includes preshipment and preinstallation testing that entails flash tests, electroluminescence tests, lamination tests and gel-content tests.

Velasco notes that it adds great value if some testing is performed in an independent third-party laboratory for what is considered objective results.

Manufacturing Audit
A standard manufacturing audit aims to verify whether the final product and the production process of the PV modules comply with the quality requirements signed in the modules supply agreement between the buyer and the manufacturer.

Velasco adds that the auditing procedure includes monitoring all the processes involved in the manufacturing and logistics of the solar PV panels, which could impact on the modules’ quality.

It also includes ensuring the adequacy of certificates involving the factory and modules, receiving and storing raw materials, reviewing the use of the agreed bill of materials, and properly implementing the standard operation and in-process quality-control procedures.

The manufacturing audit also ascertains whether production is carried out according to industry standards and buyer requirements.

“Before the shipment, and in addition to supervising loading and shipment, a randomly selected sample of the modules is typically tested by an external laboratory or at the same factory. This is supervised by a third-party inspector to randomly verify the quality of the final product,” explains Velasco.

Improved Quality
Velasco says it is beneficial for local PV module manufacturers to submit their products to this type of testing process, as it improves the quality of their products: “They are pushed to improve their systems and correct any production deficiencies.”

Therefore, small-scale and embedded- generation users, as well as major developers, also benefit from improved quality, Velasco adds.

He says the allocations made by the Department of Energy in the third round of the REIPPPP in 2013 made South Africa one of the most dynamic solar markets in the world, adding that local PV modules are expected to play a key role in its development.

The South African solar market has grown into a mature industry that can create much-needed energy-generation capacity, local employment and a competitive renewable-energy environment that attracts investments from major international players, Velasco adds.

This has prompted international PV modules manufacturers, such as Jinko Solar and JA Solar, both of China, and ILB Helios, of Switzerland, to move to South Africa, as they recognise the market potential.

Velasco adds that the preferred REIPPPP bidders have committed to South Africa’s local-content requirements, which he believes will not be met if locally manufactured PV modules are not used.

“Factories are being built, dozens of complex pieces of equipment installed, hundreds of people trained, and quality-control systems and practices put in place,” he says.

The future performance of PV plants operating across South Africa depends on several factors, including adequate planning and engineering, correct construction and operation of the assets, as well as the selection of appropriate equipment.