Revamping and Repowering of Solar PV: Challenges and Opportunities

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Solar PV is widely recognized as one of the most utilized technologies in renewable power generation, with over 1,000 GWp installed globally across numerous countries. Over the past two decades, the development of this technology has progressed differently in various regions around the world. Countries such as Japan, Germany, and the USA can be considered pioneers in this field, having established a significant number of experimental and commercial installations in the early 2000s. During the same period, Europe experienced a surge in solar PV technology, aided by incentives, leading to Germany, Spain, and Italy emerging as the frontrunners. Meanwhile, China has now become the leading country in terms of installations. Experienced professionals and companies born in those countries fostered expertise and rapid technological advancements that have spread to Eastern Europe, the UK, Latin America, Southern Africa, the Mediterranean, the Middle East, Australia, and the Asia Pacific region.

According to data provided by local authorities, in France, Germany, Italy, Spain, and the UK, over 70GWp of solar energy were installed over a decade ago, representing nearly 40% of the total power capacity in these countries, with Italy leading at 60%. Similar situations can be observed in countries outside of Europe such as Japan, the United States, and China, where approximately 70GWp total of solar energy were installed more than a decade ago.

The lifespan of a utility scale power plant is typically estimated to be between 20 and 30 years, influenced by factors like PV module defects, efficiency decline, and technological advancements. However, variations in local conditions and product quality can significantly impact the actual lifespan of these plants. Recent advancements in product quality have made the insurgence of defects in newer modules less common compared to those manufactured in the past 10 years.

Another crucial aspect to consider is the significant increase in efficiency of average crystalline silicon PV modules, which is nearly double the efficiency achieved by technology 10 or 15 years ago. In 2010, the most commonly available module in the market was a polycrystalline silicon 60 cells module with a peak power ranging from 220Wp to 240Wp. However, the current modules of similar size surpass 400Wp in power, and if the installation allows for replacement with 144 semi-cell modules, the power can exceed 500Wp. Although these slightly larger modules are more readily available in the market.

In the past, typical utility scale plants built 10 or 15 years ago had a total peak power ranging from 1 to 5 megawatts, with a few cases exceeding 10MWp. The size of the typical utility scale solar plant constructed in temperate areas in the northern or southern hemispheres was approximately 2 to 3 hectares for each installed megawatt peak. Considering the current efficiency, only half of the terrain would be sufficient to install the same power. The size of land required to build these plants has been a major concern raised by critics of solar power production, as it involves significant land usage, especially in specific areas that are more favourable for installations, which may lead to the concentration of clusters. In response to this concern, public administrations have implemented measures and regulations to restrict the construction of new solar facilities in those areas.

In this scenario, technology has developed innovative solutions to simplify and accelerate the repowering process. The increase in power of string inverters, along with the integration of monitoring and control features, now allows for a seamless one-to-one replacement of old DC combiner boxes. This is particularly common in cases of centralized inverters with DC combiner boxes, where 12 to 16 strings can now be collected with a single string inverter handling 24 strings. The old, DC cables running from the combiner box to the cabins housing the centralized inverters can be easily swapped out for AC cables. In many instances, existing pipes can be reused, minimizing the need for excavation. Additionally, the old cables can be sold as "dirty-copper," as the price of this material has doubled in the last 5 years. Within the cabins, the centralized inverters and DC parallel switchboards are removed, making way for new AC parallel switchboards. Transformers are either replaced or new ones are installed to accommodate the additional power, taking into account both technical requirements and permit restrictions.

It is crucial to highlight that the revamping of solar facilities, which includes the disposal and recycling of old solar modules and other electrical and electronic equipment waste (WEEE), presents both a challenge and an opportunity that must be effectively managed in order to maximize benefits and prevent negative impacts. Solar modules can be almost entirely recycled, offering economic advantages with the current available technologies. The module frame, made of recyclable aluminium, along with the front tempered glass, can be completely recycled. Additionally, materials such as silicone, copper, and rare metals like Indium or Gallium can be recycled up to 95% through melting and chemical processes. While it is true that the number of facilities capable of implementing these processes is limited and concentrated in specific countries, the rising costs of energy and raw materials are attracting private investments, leading to the approval and construction of new facilities.

These opportunities present new possibilities for the upcoming years. The development of larger solar facilities exceeding 100MWp is becoming more common, making them comparable to other types of power plants such as thermoelectric, combined cycle, dam hydro, or small nuclear plants. However, the significant investments required limit the number of potential investors, and the permitting process for these facilities remains lengthy, often facing opposition from local stakeholders. As a result, many medium-sized investors, private funds, and Independent Power Producers (IPPs) are turning their attention to the repowering and revamping of existing plants. This allows them to expand their presence in the energy market with a more secure and manageable investment, ensuring short-term revenues. Repowering and revamping projects are also supported by various public authorities in different countries, offering simplified permitting processes and encountering less resistance from local stakeholders. Furthermore, it is worth noting that in most cases, these plants will still be eligible for full or partial incentives that were originally granted to the facility, and in some instances, new incentives may be available as well.

Vector Renewables, with its extensive experience in the majority of thriving solar markets, is closely monitoring the progression of this phenomenon. It has already established a strong presence in countries such as Italy, Spain, and Japan where the topic of full revamping is discussed and applied recurrently in the last couple of years. Moreover, Vector Renewables is well-equipped to provide its strong expertise in identifying the most promising opportunities both in active and emerging repowering markets. This includes assisting with technical decision-making, analysing regulatory frameworks, permits, and incentive schemes, as well as coordinating the engineering aspects of comprehensive revamping solutions.