FV3985 Dissertation - Fire safety strategies for Offshore Renewable Substations

 

CHAPTER 1 GENERAL INTRODUCTION

 

1.1 Introduction

The offshore renewable energy industry is rapidly expanding and offshore substations play a critical role in facilitating the transfer of energy generated from offshore wind farms, tidal turbines, and wave energy converters to the grid. However, fire incidents in offshore substations can have catastrophic consequences, leading to loss of life, damage to the environment, and disruption of power supply. Therefore, developing effective fire safety strategies for offshore renewable substations is crucial to ensure safe and sustainable offshore renewable energy operations.

 

1.1.1 Rationale

The growth of the offshore renewable energy industry has brought attention to the need for developing effective fire safety strategies for offshore substations. Despite the critical role of fire safety in offshore substations, there is limited research on this topic. Most of the existing research has focused on fire safety in onshore applications, and there is a need to develop specific fire safety strategies for offshore substations due to the unique challenges posed by the offshore environment. Moreover, there are currently no offshore safety standards that are specifically tailored to meet the needs of offshore environments. These standards are heavily based on oil and gas standards. Consequently, there might be a need for unnecessary fire safety provisions, which will increase the cost of providing clean energy solutions.

 

1.1.2 Nature of the Problem

The offshore environment presents unique challenges to fire safety, including limited access for emergency services, harsh weather conditions, and the need for self-contained fire suppression systems. Moreover, given the fact that offshore platforms often contain flammable materials, there is an increased risk of fires occurring due to the distance at which these substations are located. Therefore, it is essential to identify these challenges and develop specific fire safety strategies for offshore renewable substations to ensure the safety of personnel and the protection of the environment. In Qatar, offshore renewable energy has become increasingly important due to the political commitment to promote regenerative energy sources and carriers. The operating conditions for offshore renewable energy are harsh and unstable, resulting in significantly higher costs. The Qatari Civil Defence (QCD) must develop comprehensive guidelines for fire prevention at offshore renewable substations since there is a requirement for their availability. It is imperative to implement fire protection strategies for all personnel and facilities when operating offshore renewable substations to avoid fire-related hazards. In addition to these objectives, fire protection strategies should also be taken when erecting the substation. It is necessary to take alternative measures for fire prevention and timely firefighting before structural and technical fire protection strategies are put into operation during construction if they are not ready to go into operation yet.

 

1.1.3 Scope of Investigation

This dissertation aims to develop effective fire safety strategies for offshore renewable substations. The study will review the existing regulations and guidelines for fire safety in offshore substations and identify the unique challenges of fire safety in offshore renewable substations. A review of the literature and relevant case studies will be carried out as part of this research to develop and evaluate strategies to overcome these challenges as well as to evaluate the effectiveness of the developed fire safety strategies in the end. Finally, the study will provide recommendations for the implementation of the developed fire safety strategies in offshore renewable substations.

 

1.1.4 Limitations

This study will focus on fire safety strategies for offshore renewable substations and will not cover fire safety in other offshore installations such as oil and gas platforms. The study depends on the DNV-OS-D301, which is a widely recognized and adopted guideline by the offshore industry and regulatory bodies. However, the standard may be more inconvenient than what is required in the field of renewable energy. However, this is because the offshore environment presents unique challenges and risks that are not typically encountered in the renewable energy field. In addition, the study will explore fire safety strategies from a theoretical perspective without conducting physical experiments.

1.2 Aim and Objectives

The aim of this dissertation is to develop effective fire safety strategies for offshore renewable substations. The objectives of the study are:

1. To review the literature on fire safety in offshore substations, including the current regulations and guidelines.
2. To identify the unique challenges of fire safety in offshore renewable substations and develop strategies to overcome these challenges.
3. To evaluate the effectiveness of the developed fire safety strategies through studying previous case studies.
4. To provide recommendations for the implementation of the developed fire safety strategies in offshore renewable substations.

 

The following key questions will be addressed in this dissertation:

1. What are the unique challenges of fire safety in offshore renewable substations?
2. What are the current regulations and guidelines for fire safety in offshore substations?
3. What are the best practices for fire safety in offshore renewable substations?
4. How effective are the developed fire safety strategies in preventing and managing fire incidents in offshore renewable substations?
5. What are the practical considerations for the implementation of the developed fire safety strategies in offshore renewable substations?

 

1.3 Research Methodology

The methodology for this dissertation involves a combination of bibliographic research and qualitative research. The bibliographic research will identify the current state of knowledge on fire safety strategies for offshore renewable substations, including existing regulations and guidelines, the effectiveness of different fire detection and suppression systems, and the challenges of emergency response. The qualitative research will involve conducting a survey with respondents from different areas of offshore renewable substations, including individuals involved in the design, construction, operation, and maintenance of offshore renewable substations, regulatory authorities, and emergency response teams. In order to conduct the survey, different areas of offshore renewable substations from different countries would be surveyed, such as France and Germany, as Qatar is still seeking to establish its first offshore renewable substation by 2030. The respondents included a wide array of professionals involved in the design, construction, operation, and maintenance of offshore renewable substations and regulatory authorities as well as emergency response teams. The survey will focus on current fire safety practices, perceptions of the effectiveness of existing fire safety strategies, and areas for improvement. Ethical considerations will be taken into account, and the results will inform the analysis of the effectiveness of different fire safety strategies and the development of recommendations for improving fire safety in offshore renewable substations. The combination of these two research methods will provide a comprehensive understanding of the current state of fire safety in offshore renewable substations and identify best practices for improving fire safety in these settings.

 

1.4 Past Investigations

Previous studies in fire safety strategies have focused on fire safety in onshore applications, such as commercial and residential buildings, and offshore oil and gas platforms. However, there is limited research on fire safety in offshore renewable substations. Some studies have investigated the effectiveness of fire suppression systems in offshore wind turbines, but there is a need for more comprehensive research on fire safety strategies for offshore renewable substations.

One such investigation is DNV-OS-D301, developed by DNV GL, which provides guidelines the design of fire zones and barriers, the selection of materials and equipment, and the development of fire protection systems and procedures, and fire protection in offshore installations. The standard also provides guidance on fire prevention and detection measures, fire suppression systems, emergency response plans, and training and education for personnel. The standard outlines fire protection requirements for different parts of an offshore installation, including the substation, and provides guidance on the design, installation, and maintenance of fire protection systems.

In order for offshore substations to be designed to meet certain requirements, an industry standard named DNV-ST-0145 has been developed. According to the standard, the substation must be sufficiently safe from fires, explosions, and other hazards, as well as be capable of responding to emergency situations. According to the standard, offshore substations must be designed to be safe, reliable, and able to operate in harsh environments, and that is why the standard was developed.

Vds 3522: Offshore Wind Power developed by the German Insurers (GDV e.V.), is another investigation that focuses on loss prevention in offshore wind power. The investigation provides guidelines for the design, installation, and maintenance of fire protection systems in offshore wind power installations, including substations. The guidelines also include recommendations for fire risk assessment and emergency response planning.

Overall, these past investigations have provided valuable insights into the challenges of fire safety in offshore renewable substations and have helped to inform the development of regulations and guidelines for fire safety in these settings. These investigations have contributed to the development of effective fire safety strategies for offshore renewable substations and have provided a basis for future research in this area.

 

1.5 Structure of the Dissertation

This dissertation consists of six chapters. Chapter 1 provides an introduction to the research topic, the rationale for the study, the objectives, hypotheses, and the structure of the dissertation. Chapter 2 provides a comprehensive review of the literature on fire safety in offshore substations, including the current regulations and guidelines. Chapter 3 identifies the methodology used for this study to address relevant responses to the research questions. Chapter 4 evaluates the effectiveness of the developed fire safety strategies. Chapter 5 analyzes the results obtained through the literature review and the survey. Finally, Chapter 6 provides the conclusions and recommendations of the study.

 

1.6 Main Achievements

This dissertation aims to develop effective fire safety strategies for offshore renewable substations to ensure the safety of personnel and the protection of the environment. The study will review the existing regulations and guidelines for fire safety in offshore substations, identify the unique challenges of fire safety in offshore renewable substations, and develop strategies to overcome these challenges. In addition, the study seeks to evaluate the effectiveness of the developed fire safety strategies through simulations and case studies, and provide recommendations for the implementation of the developed fire safety strategies in offshore renewable substations. The study will contribute to the development of best practices for fire safety in offshore renewable substations and provide a basis for future research in this area.

 

Chapter 2 Literature Review

 

Introduction

Offshore renewable energy generation is a rapidly growing industry that offers a promising solution to the challenges of climate change and energy security. Offshore renewable substations are essential platforms in the transmission of electricity generated by offshore wind turbines or other renewable energy sources. However, the presence of high-voltage electrical equipment and flammable materials on these substations increases the risk of fire incidents. Fire incidents at offshore renewable substations can cause significant damage to the environment, lead to production shutdowns, and pose a significant risk to the safety of workers. Therefore, it is essential to have effective fire safety strategies and guidelines in place to ensure the safety of workers and the environment.

The purpose of this literature review is to provide an overview of the current research on fire safety strategies for offshore renewable substations. The review will begin by examining the fire risk at offshore renewable substations, including the potential sources of ignition and the factors that can contribute to the spread of fire. The review will then discuss the existing fire safety guidelines for offshore renewable substations, including the relevant international standards and regulations. The literature review will also explore the various fire safety strategies that can be employed to minimize the risk of fire incidents at offshore renewable substations.

This literature review aims to provide a comprehensive understanding of the current state of research on fire safety strategies for offshore renewable substations. The review will contribute to the development of effective fire safety guidelines and strategies that can ensure the safe and sustainable operation of offshore renewable energy generation.

 

Fire Risk at Offshore Renewable Substations

Offshore renewable substations are vulnerable to fire incidents due to the presence of high-voltage electrical equipment, combustible materials, and fuel sources such as diesel generators (Finn and Sandeberg, 2019). In addition, the harsh offshore environment, including wind, waves, and saltwater, can also contribute to fire incidents. Studies have shown that fire incidents can result in severe damage to the substation equipment and may cause power outages, environmental damage, and even loss of life (BSEE, 2022).

 

Fire Ignition Sources in Offshore Renewable Substations

Uadiale et al., (2014) conducted a study on the fire risk at offshore renewable wind turbines and found that the risk of fire increases due to the presence of multiple ignition sources such as electrical arcing, overheating of equipment, and diesel engines. Furthermore, they found that the harsh offshore environment could also contribute to fire incidents by causing corrosion and damage to electrical equipment, which can lead to electrical arcing.

The BSEE Report (2022) investigated the common factors of ignition sources within offshore substations, and the report highlights three main factors “lightning strikes, hot work, and human error”. The report highlights that “lightning strikes are the most common ignition source and may cause dielectric faults, cable insulation breakdown, and electrical surges”. Moreover, the components of the substation that could lead to fire hazards include “the control container, gas-insulated switchgear, step-up transformer, shunt reactors, high-side, and low-side bus duct and air-core reactor”. Transformers are identified as the component with the largest fuel load and the most significant fire hazard.

In a study conducted by Ragheb (2011), the researcher concluded that the presence of highly flammable materials within offshore renewable turbines is a significant contributing factor to the fire problem in substations. These materials are often stored alongside potential ignition sources, including electrical connections and hot surfaces, creating a high risk of catastrophic fires. Moreover, once a fire begins in a renewable substation, the situation can quickly become more dangerous due to the high wind speeds commonly experienced in such locations. The wind not only increases the supply of oxygen to the fire, but also allows it to spread rapidly. Lindsay et al. (2016) reported that more than 90% of offshore renewable energy substations that have been studied experienced turbine or major component failures resulting in complete loss.

Even if a fire is detected early, firefighting efforts can be significantly hindered due to the height of the turbines. In many cases, it is not feasible to respond immediately to offshore wind substation fires, as the response teams must be dispatched to the location, as noted by Uadiale et al. (2014). Moreover, in situations where the wind is extremely strong, burning debris may fall from the turbine and cause fires to spread or damage nearby properties, as warned by CFPA-E (2012).

 

Fire Safety Guidelines for Offshore Renewable Substations

Several fire safety guidelines have been developed to ensure the safety of offshore renewable substations. The International Electrotechnical Commission (IEC) has developed IEC 61892-3, which provides guidelines for the design, construction, and operation of offshore substations, including fire safety measures. The guidelines recommend the installation of fire detection and suppression systems, emergency lighting, and escape routes. In addition, the guidelines also recommend the use of non-combustible materials and the implementation of proper ventilation systems to reduce the risk of fire incidents. The IEC guidelines emphasize the importance of risk assessments and hazard identification during the design and construction phases. The guidelines recommend that the substation should be designed in such a way that it is easy to access for fire-fighting personnel and that fire-fighting equipment should be located in easily accessible areas. Furthermore, the guidelines recommend that regular maintenance and testing of the fire safety systems should be carried out to ensure that they are in good working condition.

In this study, the primary reference for fire protection strategies in contemporary offshore renewable substations are the DNV-OS-D301 and DNVGL-ST-0145. These guides outline the most common strategies for fire protection and provide detailed information on their main provisions. The strategies discussed include passive and active fire protection methods, firefighting systems, and fire detection and alarm systems, which form the foundation of fire safety strategies.

The provisions covered by these guides include both passive and active fire protection strategies, as well as firefighting systems and fire detection and alarm systems. Passive fire protection strategies are designed to minimize the spread of fire and prevent it from spreading to other parts of the substation. This can include measures such as using fire-resistant materials in construction and the installation of fire-resistant barriers.

Active fire protection strategies, on the other hand, are designed to quickly detect and extinguish fires. This may involve the installation of automatic fire suppression systems or manual firefighting equipment, such as extinguishers or hoses. The guides also cover the design and installation of fire detection and alarm systems to ensure that any fire is detected quickly, and the appropriate response is initiated.

DNV-ST-0145 is a standard that provides requirements for the design of offshore substations. The standard covers various topics, including safety, fire and explosion protection, and the response of the substation in emergency situations. The aim of the standard is to ensure that offshore substations are designed to be safe, reliable, and capable of operating in harsh environments.

Compared to DNV-OS-D301, another offshore standard that addresses fire protection, DNV-ST-0145 provides more comprehensive requirements specifically for offshore substations. While DNV-OS-D301 focuses solely on fire protection, DNV-ST-0145 covers a broader range of topics, including safety and emergency response. Additionally, DNV-ST-0145 takes into account the unique challenges and risks associated with offshore environments, which are not addressed in DNV-OS-D301. By following the requirements set forth in DNV-ST-0145, offshore substations can be designed and constructed to withstand the challenges of offshore environments and operate safely and effectively.

In addition, the (BSH SD) is a set of guidelines that provide specific requirements for the construction of offshore structures and wind turbine nacelles that are located beyond 12 nautical miles from the coast of Germany. The guidelines cover a range of topics related to the construction of offshore structures and wind turbine nacelles, including structural design, stability and seaworthiness, environmental loads, fatigue and corrosion, and electrical and mechanical systems. The guidelines are intended to ensure that offshore structures and wind turbine nacelles are designed and constructed to meet the highest standards of safety, reliability, and environmental sustainability.

One of the key objectives of the BSH SD guidelines is to minimize the risk of accidents and incidents that could result in harm to people, damage to the environment, or loss of property. To achieve this objective, the guidelines specify detailed requirements for the design and construction of offshore structures and wind turbine nacelles, including the use of high-quality materials and components, rigorous testing and inspection procedures, and the implementation of robust safety and environmental management systems.

In addition to these technical requirements, the BSH SD guidelines also include provisions for ensuring compliance with relevant international and national standards and regulations, as well as requirements for monitoring and reporting on the performance of offshore structures and wind turbine nacelles.

The CFPA-E standard on renewable substation fire protection (CPFA-E, 2010), which was adopted by the VdS guideline (Vds 3522, 2016), emphasizes the potential risks of fires at offshore renewable energy substations and provides recommendations on how to prevent, detect, and suppress wind turbine fires. This standard is designed to establish a common European guideline for fire protection measures.

In addition to this, the US standard NFPA 850 (NFPA 850, 2020) has a specific chapter that deals with fire safety design procedures for offshore wind energy facilities that are susceptible to fires. This chapter provides detailed guidance on fire prevention, detection, and suppression systems, as well as other fire safety measures that need to be implemented to ensure the safety of offshore wind energy facilities.

Finally, the BSEE stated that the BSHSD and DNV-ST0145 are the only two guidelines that are applicable to offshore renewable substations. In their regulations, the BSEE requires that offshore renewable energy facilities, including substations, comply with applicable industry standards and guidelines for safety and environmental protection. Both standards are important in ensuring the safety and reliability of offshore renewable energy facilities. BSHSD sets requirements specific to offshore wind turbine construction and operation beyond the German coastline, while DNV-ST0145 provides comprehensive requirements for offshore substation design, including fire protection strategies. Both standards aim to prevent and mitigate risks associated with offshore renewable energy production, ensuring the safety of personnel and the environment.

 

Fire Safety Strategies for Offshore Renewable Substations

Various fire safety strategies have been proposed to reduce the risk of fire incidents at offshore renewable substations. One such strategy is the use of passive fire protection measures, such as fire-resistant materials and fire barriers, to prevent the spread of fire. Active fire protection measures, such as fire detection and suppression systems, are also essential to ensure the safety of the substation. Studies have shown that the use of water mist systems is an effective method for suppressing fires in offshore renewable substations (Vds, 2016; McNiff, 2002; Glushakow, 2007). Glushakow (2016) conducted an experimental study on water mist suppression of diesel fuel fires in an offshore substation and found that the water mist system was effective in suppressing the fire. They also found that the use of water mist systems reduced the amount of water required for firefighting and minimized the potential damage to the equipment.

Emergency shutdown systems are another important fire safety strategy for offshore renewable substations (DNV-OS-D301, 2021). These systems can quickly shut down the substation in the event of a fire, thereby preventing the spread of fire and minimizing the potential damage to the equipment. Furthermore, proper training of personnel in fire safety procedures can also contribute to reducing the risk of fire incidents.

Another fire safety strategy that can be employed is the use of fire-resistant coatings on the electrical equipment (BSH 2015; DNV-OS-D301, 2021; DNV-OS-D301, 2021; DOS, 2016; CFPA-E, 2012; VDS, 2016). These coatings can prevent the ignition and spread of fire and can reduce the damage caused by fire incidents. Furthermore, the use of fire-resistant coatings can also improve the durability of the equipment, thereby reducing the need for frequent maintenance and replacement.

Fire Detection Strategies Offshore Substations

According to (BSEE), Fire detection strategies for offshore substations require careful consideration due to the complex architecture and various components installed on the topside structure. Different containers house various electrical transmission equipment, which can be conditioned or unconditioned. The recommended fire detection technology for offshore substations includes aspirating smoke detection for control containers and “point heat detectors for electrical transmission and miscellaneous containers that are unconditioned”. Visual radiant energy detectors are “recommended for exposed open areas of the substation, such as the step-up transformer and helipad”. However, “beam smoke detectors and linear heat detectors are not recommended due to the complex, small, and congested architecture. The use of aspirating smoke detection is advised for enclosed transformers. ROR heat detectors could also be provided for the step-up transformers and shunt reactors” (BSEE, 2022).

Fire Suppression Strategies for Offshore Substation

According to (BSEE, 2022), the first step in the selection of fire suppression systems for offshore substations is to compare and select the appropriate fire risk mitigation measures. Powder suppression systems are generally “not recommended for offshore substations because they can cause inadvertent damage to sensitive electronic equipment by the aerosolized particles” (BSEE, 2022). The benefit gained by “active suppression systems of equipment and processes on the open platform deck is minimized due to exposed weather conditions and hindrance to substation operation. Therefore, water-based suppression systems are more suitable for the protection of various areas of the offshore substation” (BSH 2015; DNV-OS-D301, 2021; DNV-OS-D301, 2021; BSEE, 2022).

Water sprinkler systems are a suitable option for offshore substations, but their “practicality is decreased by the large water storage tank requirement or addition of a seawater fire pump, as well as the potential for inadvertent damage to surrounding electrical equipment by corrosive seawater” (BSEE, 2022). “The very small water particulates can suppress the fire and minimize water damage. However, any water-based suppression technology must be protected from freezing weather conditions” (BSH 2015; BSEE, 2022; DNV-OS-D301, 2021).