Operation & Maintenance Best Practices Guidelines (Version 6.0)

The Asset Owner has ultimate legal and moral responsibility for ensuring the health and safety of people in and around the solar plant, the security of the site, and the protection of the surrounding environment. The practical implementation is normally subcontracted to the O&M service provider. In some cases, the Asset Manager can provide or prescribe the systems, which are then implemented by the O&M service provider. This chapter will investigate specific areas of Health, Safety, Security, and Environmental (HSSE) policy and coordination that relate to O&M service providers. For a general overview of the fundamentals of HSSE coordination, please refer to SolarPower Europe’s Lifecycle Quality Guidelines V 1.0.

2.1. Healthy, Safety and Security

Managing the risks that solar plants pose to the health and safety (H&S) of people, both in and around the plant, is a primary concern of all stakeholders. Solar plants are electricity generating power stations and pose significant hazards which can result in permanent injury or death. Risks can be mitigated through proper hazard identification, careful planning of works, briefing of procedures to be followed, and regular and well documented inspection and maintenance (see also Power plant security). 

The dangers of electricity are well known and can be effectively managed through properly controlled access and supervision by the O&M service provider. Any person accessing a solar PV power plant should expect some form of introduction to ensure they are briefed on any hazards and risks. Staff working on electrical equipment must be appropriately trained, have sufficient experience, and be supervised. It is also key that others working around the equipment - for example panel cleaners - are equally aware of the potential risks and have safe methods of working around HV and LV electricity.

Hazardous areas and equipment should carry appropriate markings to warn personnel of possible hazards and wiring sequence. Such markings should be clear and evident to all personnel and third parties (and intruders) entering the plant premises.

As well as the inherent dangers of a typical solar plant, every site will have its own set of individual hazards which must be considered when working on the plant. An up-to-date plan of hazards is important for the O&M service provider to manage their own staff and provide third party contractors with adequate information. It is usually the case that the O&M service provider holds the authority and responsibility for reviewing and, where necessary, rejecting works taking place in the plant. Failure to carry this out properly has important consequences for general safety.

Besides workers on the solar plant, it is not unusual for other parties to require access to it. This may be the Asset Owner, or their representative, the landowner, or, in some situations, members of the public. It is important that the plant access control and security system keeps people away from areas of danger and that they are appropriately supervised and inducted as necessary.

The Asset Owner is ultimately responsible for compliance with H&S regulations within the site/plant. The Asset Owner must make sure that the installation and all equipment meet the relevant legislations of the country and, that all contractors, workers, and visitors respect the H&S Legislation by strictly following the established procedures, including the use of established personal protective equipment (PPE).

At the same time, the O&M service provider should prepare and operate their own safety management systems, previously agreed with the Asset Owner, that take into account site rules relating to H&S and the potential hazards involved in the works. The O&M service provider should ensure that they, and all subcontractors, comply with H&S legislation.

The Asset Owner will expect the O&M service provider to assume the role and duties of the principal contractor under the relevant national regulations governing H&S. This involves the O&M service provider proving that they are competent and are able to allocate enough resources to fulfil these duties.

Before starting any activity on-site, the Asset Owner will deliver a risk assessment and method statements to the O&M service provider who will provide a complete list of personnel training certifications and appoint a H&S coordinator. During the whole duration of the contract the O&M service provider will keep the H&S file of each site up to date.

The O&M service provider must have their personnel trained in full compliance with respective national legal and professional requirements. This generally includes obtaining certification necessary for working in a variety of environments, such as MV and/or HV electrical plants. Within Europe, referral to European Standards is not sufficient (examples of standards used today are ISO 14001, OHSAS 18001 etc).

To achieve a safe working environment, all work must be planned in advance. Normally written plans are required.

Risk assessments which detail all the hazards present and the steps to be taken to mitigate them need to be produced. 

The following dangers are likely to exist on most solar plants and must be considered when listing hazards and identifying risks. The severity of any injuries caused are exacerbated by the terrain on which solar plants are built and their remoteness.

1. Medical problems: It is critical that all personnel engaged in work on solar plants have considered and communicated any pre-existing medical problems and any additional measures that may be required to deal with them
2. Slips, trips, and falls: The terrain, obstacles and equipment installed on a solar farm provide plenty of opportunities for slips, trips and falls both at ground level and whilst on structures or ladders; and for roof-top or carport systems, fall-protection and additional equipment is required when working at heights
3. Collisions: Collisions can occur between personnel, machinery/vehicles and structures.  The large areas covered by solar farms often necessitate the use of vehicles and machinery which, when combined with the generally quiet nature of an operational solar plant, can lead to a lack of attention. General risks such as difficult terrain, reversing without a banksman and walking into the structure supporting the solar panels require special attention
4. Strains and sprains: Lifting heavy equipment, often in awkward spaces or from uneven ground, presents increased risk of simple strains or longer-term skeletal injuries
5. Electrocution: Operational solar plants, whether energised or not, present a significant risk of electrocution to personnel. This risk is exacerbated by the nature and voltage of the electricity on site and the impossibility of total isolation. Staff engaged in electrical work obviously suffer the greatest risk but everybody on site is at risk from step potential and other forms of electrocution in the event of a fault.  Specific training needs to be given to all those entering a solar farm on how to safely deal with the effects of electrocution. In addition to general electrical safety, common issues for solar PV power plants include arc-flash protection when working on energized circuits; and lock-out-tag-out to ensure circuits are not unintendedly energised
6. Fire: Several sources of combustion exist on a solar farm, the most common being electrical fire. Others include combustible materials, flammable liquids, and grass fires. Safe exit routes need to be identified and procedures fully communicated. All personnel need to be fully aware of what to do to avoid the risk of fire and how to act in the event of a fire  
7. Mud and water: Many solar farms have water travelling through them such as streams and rivers, some have standing water, and some are floating arrays. Mud is a very common risk particularly in winter as low-grade farmland is often used for solar farms. Mud and water present problems for access as well as electrical danger
8. Mechanical injury: Hand-tools, power tools, machinery, and mechanisms such as unsecured doors can present a risk of mechanical injury on site  
9. Weather: The weather presents a variety of hazards, the most significant of which is the risk of lightning strike during an electrical storm. Due to the metal structures installed on a solar farm an electrical storm is more likely to strike the solar array than surrounding countryside. A solar farm MUST be vacated for the duration of any electrical storm. Working in cold and rainy weather can cause fatigue and injury just as working in hot sunny weather presents the risk of dehydration, sunburn, and sun stroke. Working during sunny days for undertaking maintenance and/or testing on site can lead to sunstroke. To avoid this, drinking sufficient water and staying in the shade is recommended
10. Wildlife and livestock: The renewable energy industry is proud to provide habitats for wildlife and livestock alongside the generation of electricity. Some wildlife, however, presents dangers. There are plants in different regions which can present significant risk, some only when cut during vegetation management. Animals such as rodents and snakes, insects such as wasps, and other wildlife and livestock can present significant risks. The nature of these risks will vary from place to place, and personnel need to be aware of what to do in the event of bites or stings. Snakes, spiders, ticks, bees, and bugs are common and pose a number of hazards where snake bites could be lethal, spider bites can cause pain and inflammation, tics bites could result in tick bite fever, bees can cause allergic reactions and bugs could fly into people’s eyes. It is therefore important that all precautions are taken to prevent or manage these incidents. Storage and application of pesticides, herbicides, and rodent poisons also introduce health and safety hazards. For example, Glyphosate was very common in controlling vegetation at solar PV power plants and has been found to be carcinogenic. Mowing has several hazards including flying objects. Every job at a solar PV site should have safety precautions identified and implemented

Everyone entering a solar farm, for whatever reason, should have been trained in the dangers present on solar farms and be trained for the individual task that they will be performed. They should have all the PPE and tools necessary to carry out the work in the safest way possible. The work should be planned, and everyone concerned should have a common understanding of all aspects related to the safe execution of their task. Different countries will mandate written and hard copy paperwork to meet legislation, but best practice is to exceed the minimum requirements and to embrace the spirit of all relevant legislation.

Best practice in H&S sees the ongoing delivery of training and sharing of lessons learned. By increasing the skills of persons involved in the industry, we can make the industry safer and more productive.

As a best practise, it is advised to create and implement Life-Saving Rules as part of the Health and Safety programmes. Life-Saving Rules are a set of non-negotiable guidelines designed to prevent severe injuries or fatalities in workplaces. These rules address high-risk activities such as working at heights or controlling hazardous energy, focusing on behaviours and practices that, if violated, have the potential to lead to serious harm.

It is advised conducting a Last Risk Assessment, a final, real-time evaluation of potential hazards and risks immediately before beginning a task or activity. A Last Risk Assessment ensures that workers assess the current environment, conditions, and potential changes that could impact safety.

Electrical Safety

Electrical safety in solar photovoltaic (PV) plants is crucial for both worker protection and plant efficiency. This is governed by strict standards such as IEC 60364 and EN 50110, which ensure the establishment of a clear and effective safety framework. Key roles are defined for Low Voltage (LV) and High Voltage (HV) systems, including responsibilities for LV and HV responsible persons, as well as an overarching Electrical Safety Manager (QEPIC). These roles are supported by rigorous appointment procedures, documentation, and regular reviews to maintain safety competence.

Additionally, safety practices like work permits for high-risk electrical tasks, PPE usage, and systematic switching procedures are critical for reducing electrical hazards. Comprehensive training and fostering a strong safety culture within the plant are necessary for ongoing risk mitigation. Maintenance and inspections, along with the adoption of advanced technologies, help identify and address potential electrical issues.

For those seeking more detailed information on electrical safety protocols, Annex A is included that provides deeper insights into best practices, safety documentation, and the specific requirements for ensuring electrical safety across all systems and operations in solar PV plants.

2.2. Environment

Renewable energies are popular because of their low environmental impact, and it is important that solar plants are operated and maintained to minimise any adverse effects. Environmental problems can normally be avoided through proper plant design and maintenance – for example, bunds and regular inspection of HV transformers will reduce the chances of significant oil leaks – but where issues do occur the O&M service provider must detect them and respond promptly. Beyond the environmental damage there may be financial or legal penalties for the Owner of the plant.

Legal obligations to be fulfilled by the O&M service provider (or the Technical Asset Manager) may include long-term environmental requirements to be implemented either onsite or off-site. Typical requirements can be, amongst others, water tank installation, tree clearing, drainage system installation, amphibian follow-up, edge plantation, and reptile rock shelter installation. Such requirements should be implemented and managed by the O&M service provider to comply with the relevant regulations. As a best practice, the O&M service provider’s environmental preservation activities can go beyond legal obligations.

Other aspects that need to be considered as best practice, are recycling of broken panels and electric waste so that glass, aluminium and semiconductor materials can be recovered and reused, and hazardous materials disposed of in a safe manner, complying with legal requirements. In areas with water scarcity, water use for module cleaning should be minimised.

In many situations, solar plants offer an opportunity, where managed sympathetically, to provide opportunities for agriculture and a valuable natural habitat for plants and animals alongside the primary purpose of generation of electricity. A well thought out environmental management plan can help promote the development of natural habitats, as well as reduce the overall maintenance costs of managing the plant’s grounds. It can also ensure the satisfaction of any legal requirements to protect or maintain the habitat of the site. In any case, environmental requirements from building permits should be complied with. Maintenance services should comply with things such as the proper application of herbicides, pesticides, and poisons used to control rodents. The use of solvents and heat-transfer fluids should also be controlled. Cleaning agents (soap) should be environmentally friendly (no chlorine bleach) and applied sparingly to avoid over-spray and run-off.

The SolarPower Europe Solar Sustainability Best Practice Benchmark discusses how to make sure that biodiversity is increased on a solar PV power plant:

• Local best practices should be considered

• Decision frameworks and decision support tools should be used

• Local experts should be consulted

By doing this and after discussion of various management methods, a management plan should be decided, which defines certain objectives concerning biodiversity and describes the activities by which to achieve them. Some typical measures are:

• Categorically forbidding the use of herbicides

• Reducing the frequency of vegetation cutting to the necessary minimum (not all areas need the same frequency)

• Cut vegetation in different phases to make sure that there are always untouched parts

• Limit the number of sheep per hectare to avoid over-grazing (if sheep are part of the management plan)

• Planting hedges with local species at the borders of the plant

• Creating piles of stones as microbiotopes for reptiles

• Arranging heaps of dead wood

• Keeping specific surfaces vegetation-free

• Removing cut grass in specific areas

These activities should be accompanied by regular surveys by local experts, to control evolution of biodiversity. They shall propose changes to the management plan if this is necessary for achieving the objectives.

2.2.1. Transitioning from O&M to End-of-life (EoL) management

Based on the growth of solar PV installations, we can estimate that about 1-1.2 million solar PV modules are installed every day around the world. With this in mind and with an estimated average annual failure rate of 0.2% in the field, we may anticipate today ~8 million solar PV modules to fail every year, corresponding to a weight of 144 kt of potential annual solar PV waste from solar PV failures only. Adding also other solar PV waste sources and streams, such as the decommissioning of solar PV modules due to end of service lifetime, repowering, insurance claims, etc., the cumulative solar PV waste is expected to reach up to 8 Mt by 2030.

Reported field experiences show that, most solar PV modules with diagnosed/classified failures that are decommissioned, follow a linear EoL management approach: they enter the waste stream and are either disposed as waste (the majority of the time) or recycled. Currently less than 10% of decommissioned modules are recycled. However, experts from the IEA PVPS Task 13 and the CIRCUSOL project estimate that 45%-65% of them, can be diverted from the disposal/recycling path, towards repair and second life solar PV (re-use) or, as aforementioned, revamping.

To ensure the technical-economical bankability of solar PV re-use and second life solar PV, within the O&M framework and the overall solar PV value chain, it is important to:

• Identify the addressable “target volume”, i.e., the failed solar PV modules (or strings), the repair of which is technically feasible, and the occurrence or distribution of such failures.

• Determine the post-repair efficiency and/or post-revamping reliability of these modules.

• Integrate optimal sorting-repair-reuse and logistics procedures in the current solar PV O&M

value chain, embracing circular economy business models.

Transitioning from PV O&M to EoL management requires streamlined PV triage and qualification methods, as well as efficient PV repair strategies. These are essential for preparing PV modules for reuse and ensuring a viable second-life PV market.

Current industry practices and insights into these areas are inconsistent and scarce, with a lack of standardisation. On this basis, we identify certain future R&D pathways and challenges to be addressed, to support the development, growth, and bankability of second life solar PV and circular PV O&M business:

• Industrialisation and qualification of new solar PV module designs-for-circularity: including “repair-friendly” solar PV components, modular designs, and deployment of repair technology solutions in upscaled re-manufacturing lines

• Identification and tracking solutions (e.g. RFID) at solar PV components/modules/system level,

to facilitate reverse logistics, sorting/inventory of solar PV and warehouse operations

• (Automated) detection, diagnostics, and classification (incl. recommendation) of repair or reuse operations in solar PV asset management tools for solar PV plants

• Standardisation/technical specifications for on-site quality control and sorting, as well as off-site

design qualification and type approval protocols, towards solar PV reuse-repurposing-recycling

• Synergies of solar PV Asset Owners and O&M service providers, with innovators in supply chain/reverse logistics technologies, also leveraging AI/machine learning aided logistics, sorting, warehouse operations, inventory management for circular solar PV economy.

The recently published report End-of-Life Management Best Practice Guidelines by SolarPower Europe provides detailed insights and guidelines concerning the transition from operations to EoL. It refers notably to the PV reuse market landscape, second-life business models and the “preparing for reuse” technical framework for PV panels and other balance-of-system (BOS) components.