The importance of good spares management

When equipment is offline due to spare parts, it has a negative impact on energy generation. Good spares management can be the difference in a client losing or saving millions of pounds of revenue and potentially avoiding months of downtime. As an O&M provider for nearly 100 solar projects globally, maximising energy generation is something that is extremely important to us which is why we have developed a novel and sophisticated parts management process to help our client’s sites perform more efficiently.

Across the solar portfolio that we manage, we have found that inverter replacements are causing the most downtime. This is partly because they are one of the most intricate parts on the site, so most likely to fail, but also because many sites haven’t historically been serviced by operations and maintenance programmes. With inverters being one of the most expensive parts to replace, with the longest lead times (often months), this can lead to a large amount of generation loss.

Following discussions with the inverter OEMs we realised that having guaranteed stock levels and dispatch time was something no one was able to offer let alone achieve. This is why for one client we signed an agreement to own over 1,000 spare parts that are compatible with their inverter fleet and deliver these on-demand within a guaranteed time period.

When combined with our O&M service, the centralised parts management provides uninterrupted performance for solar assets at a much lower cost than the traditional approach. To give an example of the benefit of this service, on one occasion a manufacturer was quoting a lead time of three months for a highly critical component. However, we were able to supply this overnight avoiding three months of downtime. To date, we have provided over 100 orders all meeting their delivery timeframes of 48 hours – with 75% being delivered within 24 hours.

This unique multi-vendor spares management service gives clients more security in their ongoing operations. Knowing that inverters can be back into service following a breakdown within 48 hours gives a great sense of security towards ongoing generation and meeting their expected budgets.

We also ensure that a reliability study is carried out to help highlight which parts are essential to ensure the availability and maximum performance of the asset – a £5 solar part could be critical to the entire plant. Whereas most traditional solar O&M strategies focus more on visual inspections, RES’ reliability management service also focuses on diagnostic testing to systematically assess and mitigate risks and compliment the traditional methods. At the end of the Reliability Risk Assessment, owners have a clear picture of the failure risk over the plant lifetime, measured in financial value, and a list of options to reduce the risk including a business case. Mitigation steps typically involve contingency planning for repairs, proactive purchasing of replacement parts, enhanced monitoring and inspection or upgrading of components. This proactive approach to maintenance helps to optimise the allocation of maintenance resources, reduce plant downtime and reduce investment in the wrong spares or in activities that add little value. To give an example of the benefit of this, we made a 12% performance savings for one of our clients across a portfolio of eight UK-based solar farms that we manage.

Good spares management can be the making or breaking of a solar farm. We are looking at ways to build on our parts management process and to continue to improve the service we provide. For instance, we are considering expanding the offering to include in-house repairs and other parts of the solar farm. Whilst for clients this ensures maximum energy generation, it also ensures that more green energy is being fed to the grid helping us achieve our vision of a future where everyone has access to affordable zero carbon energy.

Author: Matthew Newbury, Senior O&M Manager

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