Engineering, Procurement & Construction Best Practice Guidelines (Version 2.0)

This chapter describes the procedures for properly transferring the O&M activities of a PV plant from the EPC to the O&M service provider. After the FAC, when the Asset Owner takes over the full contractual responsibility for the plant operation, it is industry practice to hand over the long-term O&M activities to specialised third-party O&M service providers. These specialised service providers are organised to provide best in class O&M activities. Their technical departments are designed to provide high level remote monitoring of failures and performances, timely on-site maintenance activities, project management services, and strategic spare parts management etc. (For more information and best practices, please refer to SolarPower Europe’s O&M Best Practice Guidelines.)

The handover process between the EPC service provider’s O&M phase and the specialised O&M service provider is critical and must be properly managed by the Owner. This avoids loss of information, prevents possible underperformance, and avoids hidden costs. The handover includes several steps, which are mainly attributed to three macro-categories of activities:

• Providing documentation such as drawings, specifications, projects, diagrams, policies, standards, procedures, parts lists, and reports of construction monitoring, commissioning tests etc. in appropriate file formats, necessary for the functional, safe, and efficient operation of the system (see also Annex C “Documentation set accompanying the solar PV plant” of the O&M Best Practice Guidelines)

• Granting access to the plant site, to familiarise the O&M service provider with the facilities and the equipment and components installed. One should allow the O&M service provider sufficient time on site to explore the facilities and perform all the required measurements, to avoid hidden issues afterwards

• Starting the O&M activities including the set-up of a proper organisational structure, including control room service, project managers, site technicians, subcontractors, etc. The O&M service provider must also handle the related logistics such as warehouses, provision of spare parts, and relations with third parties such as the security service provider, and grid operator, as described in the O&M Best Practice Guidelines.

When the O&M contract includes guarantees, such as availability or PR, it is essential to have enough historical performance data to get a proper understanding of component status at take-over, and avoid the risk of paying liquidated damages. The availability of centralised, cloud-based data collection and analysis systems are an emerging best practice which allows data (both historical and real-time) to be consistently captured, shared, and used by all stakeholders.

In the following sections, best practices for handovers are described.

10.1. Transfer of the documentation

A proper and complete set of documentation is crucial to ensuring proper management of the lifecycle of a PV plant. The O&M service provider will use it for O&M while the Asset Owner may need it for administrative or commercial purposes. Therefore, at this stage it is best practice to involve the Asset Owner, or a representative, to make sure all parties have full copies of the documentation.

A list of all required documents can be found in Annex F and Annex C “Documentation set accompanying the solar PV plant” of the O&M Best Practice Guidelines. It is important to underline the file format that must be used. All the technical drawings should be received both as a PDF with stamp and signature and as an editable format (.dwg). Having an editable format of the drawing has two main benefits: (1) it makes it simple for the O&M service provider to update the as-built documentation following any major interventions or revamping, (2) it limits the extra cost for the Asset Owner of redoing of the documentation. Unfortunately, often much of the plant engineering information is provided in formats such as PDF, JPEG, TIF instead of AutoCAD. While these formats are useful for human readers, they are of limited value to modern O&M systems as they require conversions or manual data entry to convert unstructured documents. Data integrity problems often follow, which can result in operating mistakes.

In addition to the documentation package described above it is important to give full visibility to the O&M work done during the warranty period. Therefore, the following list of information should also be handed over:

• Maintenance reports done by the EPC service provider

• Hourly production data of each inverter and meter

• Hourly irradiation values measured on site

• Description of any force majeure event that occurred, such as thefts, grid failures or outages, equipment replaced under warranty

• Output of any measurement test conducted

10.2. Transfer of existing contracts

Contracts require special handling during handovers. They may have been executed with subcontractors such as local field electricians, companies who take care of the vegetation, specialised support companies, internet service providers etc. Further examples include service contracts with manufacturers of inverters or security systems.

The transfer of contracts is critical because the obligations and responsibilities therein are also transferred. Furthermore, the new service provider cannot choose counterparts and renegotiate conditions easily. Therefore, the transfer of contracts needs some time; three months is a reasonable period. In some cases, a contract needs to be terminated and a new service provider needs to be found.

It is best practice for contracts to include a clause about this kind of transfer from the beginning. This helps avoid degradation of contract conditions as a result of the handover. A common inspection with the new contract parties should allow for better understanding of the current situation and help define priorities for the coming period.

10.3. Access to monitoring and communication systems

Adequate time for the transfer of Monitoring and communication systems should be factored into any handover. Common problems include passwords not being given to the new O&M service provider and proprietary code in the Programmable Logic Controllers (PLC). Another problem may be the use of the EPC service provider’s communication infrastructure for certain functionalities. For example, the use of the EPC service provider’s VPN to give secure access to network devices.

The most problematic point is probably the existence of proprietary PLC codes. Even if the EPC service provider agrees to give access to this code (which is normally not the case), it will be difficult for the new O&M service provider to understand and develop it further. This requires thorough documentation of the existing code, and the EPC service provider would have to agree to hand this over to the new O&M service provider. If this is not the case, the only solution is to replace the existing PLCs with those of the new O&M service provider.

As an alternative, one could use a monitoring service supplier from the beginning. In this case the transfer of the Monitoring System can be handled like the transfer of a service contract. Or, if the contract is with the SPV, the transfer would involve the provision of user ID and password to the O&M service provider. On the other hand, this alternative has inherent disadvantages like a different cost structure, and less flexibility.

Using open solutions with open interfaces, freely accessible documentation and specialised support companies is best practice. However, this still needs to be developed on a large scale.

Due to the complexity of the handover or migration of the Monitoring and communication systems, a sufficiently long transition period should be planned, for example 6 months. During this period, the EPC service provider should be obliged to cooperate with the new O&M service provider. The conditions of this cooperation should be described in the EPC contract.

10.4. Organisation of an inspection

On-site technical inspections are an essential step of the handover process because they allow the O&M service provider to document and assess the PV plant’s status. These procedures go beyond the as-built consistency checks, which are based on the set of documents accompanying the PV plant (see the complete list of documents in Annex F). These inspections are also useful for familiarising the O&M service provider with a site’s geographical features, logistics, and surroundings. 

From a technical perspective, handover inspections (in compliance with the inspection criteria defined in the IEC 62446-1:2016), despite their similarity to the inspections done during (re)commissioning, have a slightly different approach and focuses on the aspects below.

To ensure an accurate and complete inspection on-site, the EPC service provider and the Asset Owner should allow the O&M service provider sufficient time to perform all the detailed checks that are requested. This means that the handover inspection may last several days, depending upon the size and characteristics of the plant. As best practice, O&M and EPC service providers should plan the inspection well in advance, agreeing upon a written schedule for the activities to be performed on-site, with an indication of the role that the personnel of each party will have during the visit.

The inspection should at least cover the following aspects.

Health & Safety check

Checks should be aimed at ensuring the safety of field personnel while maintaining the uninterrupted operation of the plant. This must be considered a minimum requirement and must be performed following the regulations of the jurisdiction where the plant is located.

Consistency of plant construction with as-built project documentation

As a minimum requirement, the inspection team of the O&M service provider shall check the entire site. The team should review all the main installed components and materials to verify the correctness of the as-built project documents. In the case of a discrepancy, the EPC service provider should update the as-built project documentation. If drones were used to undertake construction monitoring and reporting (as per best practice), the documentation generated through this serves as a useful asset to refer to.

Identifying potential issues with contractual guarantees

One of the main purposes of the O&M service provider inspection is to ensure that the performance guarantees included in the service contract can be achieved properly. As specified in Chapter 10 on Key Performance Indicators and Chapter 11 of the O&M Best Practice Guidelines on the Contractual framework, this may include Availability and Response Time and, in some cases, PR guarantees.

SolarPower Europe’s O&M Best Practice Guidelines highlight the potential shortcomings of including a PR guarantee in the O&M service contract  and suggest possible alternatives, such as Availability and Response Time guarantees. However, the decision on what types of guarantees to include ultimately needs to be negotiated between the Asset Owner and the O&M service provider prior to the handover. If a PR guarantee is included, as a best practice, the O&M service provider should be invited to attend the Final Acceptance tests, so they can get an accurate idea of the plant’s actual PR. Alternatively, if the O&M service provider is unable to attend the Final Acceptance tests, the PR should be recalculated during the handover as precisely as possible. Proper calculation of PR is especially relevant because the O&M service provider will carry on the risks of a project.¹ 

Subcontracted services

It is common practice for large O&M service providers to make use of local specialised companies to carry out activities such as vegetation control, module cleaning, HV substation maintenance and security and surveillance. As mentioned previously, these companies could be the same as those already in charge of such activities during the EPC phase. As best practice they should be involved in the handover inspections to advise the main O&M service provider on their specific area of responsibility.

Collect verbal information from current operator

Although not a formal activity, the site visit should be used to confirm information included in the O&M reports that are provided as described in section 10.1 Transfer of the documentation. This should be done by asking the hosting personnel of the EPC service provider about details of extraordinary events and major repair/substitution interventions that occurred in the past, security related aspects (e.g., theft), force majeure events (e.g., flooding and drainage issues) and component related issues (e.g., serial defects on modules). Best practice assumes full transparency between the EPC service provider and the new O&M service provider.

Visit and access to the warehouse used by the EPC service provider

To set up the spare part management strategy as described in section 10.6. Set up of strategic spare parts warehouse, a visit to the warehouse used by the EPC service provider should be part of the inspection. Moreover, the inventory of material and components will be made available to the O&M service provider for its activity.

Additional inspections

The handover by the EPC service provider generally does not require extremely detailed component inspection if they are new and the manufacturer guarantee is still valid. However, PV modules are the core producing units of a PV plant and could have hidden problems that do not show up immediately. As minimum requirement, visual inspections of all the modules (the inspection procedures in IEC 61215-1:2016 may be useful reference) are recommended. Aerial infrared thermography (in compliance with IEC TS 62446-3:2017) should be used for this as best practice. For the O&M service provider and Asset Owner, having a comprehensive aerial visual and thermographic inspection report serves as a valuable baseline against which future performance of the PV plant can be benchmarked. In addition, further inspection techniques²) should be done on a representative sample of modules.

Retrofitting and revamping/repowering opportunities

Given that these Guidelines consider the handover of the O&M activities after FAC, it is unlikely that the plant requires retrofitting or revamping/repowering. However, it is recommended that site evaluations should be done with a prospective view on how to extend an asset’s lifetime and increase its productivity. This can be translated into mid- to long-term plans for retrofitting and revamping interventions.

^{1 - As recommended by O&M Best Practice Guidelines, section 10.3.4, the PR formula should be corrected for temperature to neutralise short-term fluctuation due to temperature variations from STC (25°C). As a best practice, temperature should be registered with a granularity of up to 15 minutes and the average temperature should be calculated by weighting the mean temperatures according to the specific yield of the period.}

^{2 - For an overview of relevant international standards, see Annex A.}

10.5. Preliminary Handover Report and Punch List

The handover on-site inspection produces a detailed report that includes a Punch List. This document is a technical report that describes all the existing issues and inconsistencies that were discovered and defines a simple pass criterion for each plant component. This report is of great importance to the handover process because it might trigger important conversations with the Asset Manager or the Asset Owner to tailor or amend the O&M contract (e.g., price negotiation). A standard handover report should contain the following information:

10.6. Set up of strategic spare parts warehouse

Spare parts management is a key activity to ensure a high level of availability and minimise downtime and is typically included in the O&M service provider’s scope of work. The starting point of this process is the setup of a strategic spare parts warehouse. A detailed description of this process can be found in Chapter 8 of the O&M Best Practice Guidelines on Spare Parts Management. Below is a summary of it.

Spare parts should be bought by the EPC service provider together with all the other components for the installation of the power plant as this ensures maximum efficiency. Typically, the initial spare parts should last at least for two years from Commercial Operation Date (COD). The volume should be in line with the requirements of the Asset Owner and O&M service provider, as the O&M service provider might recommend additional spares that they deem necessary to meet contractual obligations (e.g., availability guarantees). Generally, it is not economically feasible to stock spare parts for every possible failure in the plant. Therefore, the O&M service provider, together with the Asset Owner, should define the stocking level of specific spare parts that make economic sense (Cost-Benefit Analysis). For a minimum list of spare parts, see the table below. This list is not exhaustive and system requirements and technology developments can lead to this list being updated following discussion with manufacturers, amongst others.

TABLE 4 - MINIMUM LIST OF SPARE PARTS (NON-EXHAUSTIVE)

Another aspect to be considered is the warehouse location and condition: components leftover from construction such as structural elements and electrical boxes may not be needed regularly and can be stored in a remote warehouse. However, most useful components should be stored on site or be easily accessible in case of need.

During this preliminary stage it is also important to identify equipment requiring particular storage conditions, such as controlled temperature and humidity, so that the O&M service provider can organise the warehouse accordingly.

Once the preliminary list is agreed, it is best practice to allow the O&M service provider to operate the plant for a period of 3 months before defining a final list of spare parts. During this period the O&M service provider shall evaluate the progress of equipment degradation and recurrent outages.

10.7. Training of Asset Owner and O&M service provider

As already highlighted in paragraph 8.2.8., the EPC service provider should arrange an introduction to the site and a specific training program for the Asset Owner and the O&M service provider as part of the handover process. This is even more important when handing over to a third-party O&M service provider. In this case, as best practice, this process should be structured in two parallel streams:

• HSSE training: the O&M service provider’s staff and the Asset Owner HSSE coordinator should be involved in a dedicated on-site visit where the EPC service provider explains and shows all the H&S procedures. During this, the O&M service provider’s staff and the HSSE coordinator can identify additional hazards and implement new procedures if necessary. It is common for O&M service providers or Asset Owners having stricter HSSE standards than the regional regulations. For this reason, the inspection before the handover is beneficial for all parties

• O&M manual and procedure: The O&M service provider’s staff need to be trained on specific site requirements. Therefore, having training sessions in which the EPC service provider explains the content of the O&M manuals for major systems and equipment is recommended

10.8. Confirmation of the Punch List and KPIs after 3 to 6 months from start of O&M

The transition period (i.e., the initial period of the O&M contract during which the O&M service provider becomes familiarised with the site) ends after 3 months as a minimum requirement. However, a 6-month period is recommended as best practice. At the end of the transition period a final Handover Report is drafted by the O&M service provider. This should include the final revision of the Punch List and compare current plant KPIs with historical ones. Other elements or information resulting from the observation and the events that occurred during the transition period can be added, if required.