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Cristina Serrano 31-Mar-2022 08:45:00 5 min read

The danger lurking beneath your solar investment

To assure the design life of a solar PV project, all potential risk factors require careful consideration.

Corrosion may not be at the forefront of your mind when contemplating risks, but it is essential to consider when assessing the lifetime of a solar structure.

Underestimating corrosion could lead to irreversible problems that may shorten the lifetime of your solar project. To establish the likelihood of corrosion, you need to understand the process and all the factors involved.

 

Underground Corrosion could be reducing your solar structure’s lifetime

Advancing corrosion underneath PV module structures can be particularly dangerous because the foundations are often out of sight but remain exposed to the soil’s corrosive properties.

Specific corrosion-related risks to be considered within a solar farm include copper earthing systems and galvanised steel piles that can lead to galvanic corrosion. Galvanic or bimetallic corrosion occurs when two different metals are in electrical contact in an electrolyte. In this case, the soil acts as the electrolyte where the more noble metal (e.g., copper) is protected, and the more active metal (e.g., zinc or steel) tends to corrode, compromising the structural integrity of the whole underground structure. As corrosion advances, material that was originally part of the pile is chemically transformed and eventually removed. This reduces the amount of material that provides support for the structure, which results in weaknesses in the load-bearing base material. Without proactively assessing and monitoring the solar structure, this can lead to catastrophic consequences for the site.

 

The cost of corrosion

While it is hard to estimate the economic consequences of a corroding solar plant, it is essential to assess and monitor corrosion risk and be ready to implement mitigation measures when deemed necessary. As soon as corrosion has broken through the galvanised layer and affected the steel, you can no longer rely on the design calculations to assume the structure is safe. Acting too late could reduce the lifetime of your investment or require a complete replacement of the PV panel structure, essentially a plant rebuild.

 

Did you know?

A galvanisation warranty only accounts for the galvanisation thickness, not the rate at which a structure loses its coating and begins to rust.

The EPC will typically estimate the likelihood and timescale of corrosion based on soil properties at a site. Module support structures have an average expected lifespan of between 25-30 years, but exposure to pollution, soil-related corrosion and extreme environmental conditions can challenge component durability. Specific to the UK, the earthing systems are all copper – you may find an underestimation for the speed of corrosion due to an oversight of the interaction of copper with galvanised steel.

 

Helping to reduce the impact of corrosion – asset life extension

It is the responsibility of fund managers to mitigate and manage risk. Corrosion can lead to expensive problems if not identified and dealt with appropriately. Our comprehensive desktop analysis services will establish your corrosion risk levels. We determine your most at-risk sites and collaborate with corrosion industry leaders to create a personalised action plan to address your corrosion prevention and protection methods.

Once corrosion is present in a structure, there is no reversal process. It is vital to act fast to work proactively rather than at a reactive rate. By collaborating with our experts to produce predictive risk assessments, you can reduce the risk of your assets not achieving their expected lifetime.

 


 

Corrosion is just one challenge that may impact the lifespan of your solar portfolio.

We work to ensure all the components of a PV plant can function optimally to achieve their predicted lifespan. Ongoing analysis and predictive assessments are effective ways to keep track of developments and potential issues. If you are looking to establish mitigation methods to keep your solar portfolio functioning optimally, contact us to find out how we can support you.

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Cristina Serrano

Cristina is an engineer specialising in renewable energies. She applies her comprehensive project management skills to boost the performance of PV plants for Quintas Advisory clients.