VREs (variable renewables) like wind and solar power are vital in achieving net-zero emissions. However, lifecycle analysis reveals that manufacturing and waste disposal of the material requires attention to make sure that there are no detrimental costs borne by society.
VREs Lifeline to Reach Net Zero and Why Does It So
Numerous global reports emphasize the significant role of variable renewables (Wind and solar power) in achieving the net-zero emissions target by the mid-century. The World Energy Outlook report by the International Renewable Energy Agency (IRENA) highlights that over 60% of the decarbonization efforts in the power sector required to achieve net-zero emissions will be dominated by variable renewables. To meet the net-zero emission targets, the installed capacity of solar photovoltaic (PV) needs to scale up to 5200 GW by 2030 and 14.000 GW by 2050 [8]. Similarly, the installed capacity of onshore wind is projected to reach 3000 GW by 2030 and reach 6170 GW by 2050. [8]
It is unsurprising that variable renewables (VREs) energy sources have gained considerable attention as critical solutions in the battle against climate change. Performance-wise, VREs such as wind and solar photovoltaic (PV) have witnessed significant advancements. Notably, the efficiency of solar panels has shown notable progress, increasing from less than 5% in the early 1990s to approximately 23-24% in the present day [1]. Similar advancements have been observed in the realm of wind turbines. Performance enhancements can be observed through various parameters, including the increase in turbine height, & rotor diameter. For instance, the average rotor diameter of newly installed wind turbines worldwide exhibited a consistent growth trend from an average of 43.2%, from 67.4 meters in 2005 to 95.9 meters in 2014 [5]. Furthermore, current wind turbines height is taller than ever, as evidenced in 2012, In the United States, the average height of installed wind turbines has been approximately 280 feet, equivalent to 80 meters. Before 2006, there were only a limited number of wind turbines surpassing the height of 280 feet [4].
In addition to their performance increases, the Levelized Cost of Energy (LCOE) associated with variable renewable energy (VREs) sources plays a significant role in their future deployment. Solar photovoltaic (PV) and onshore wind power technologies offer the most cost-effective options compared to other alternative generation technologies. Currently, the LCOE of onshore wind power stands at 7.5 USD cents per kilowatt-hour (kWh with a projected decrease to 5 USD cents per kWh in 2050, representing a 30% reduction from its current price in 2030 [6]. Similarly, solar PV demonstrates an even lower LCOE, with prices currently at 6.7 USD cents per kWh and projected to decrease to an exceptionally low of 3.3 USD cents per kWh by 2050 [6]. Both of VREs LCOE, are cheaper compared to other fossil fuel-based generating technologies like open-cycle gas turbine plants and diesel plants. Additionally, they exhibit lower costs than other renewable energy counterparts, such as geothermal, hydropower, and waste incineration power plants.
However, the increasing performance of renewable energy technologies, which leads to cost reductions, only considers the input-output effect and costs throughout the plant’s lifetime. It does not consider how raw materials are extracted, processed, and transformed into a single solar panel or wind turbine unit. Additionally, it fails to account for the potential damage caused by wind turbines and solar panels once they end their operational life. Thus, as we become increasingly dependent on these technologies, it is paramount not only to map out system improvements to enhance efficiency and cost-effectiveness but also to ensure that the low-cost advantages do not come with hidden detrimental environmental effects in the long run, as the burden of these costs will ultimately be borne by society.
The Unseen Sides of VREs Manufacturing and Waste
An encompassing approach to assessing the environmental impact discussed above is called Life Cycle Assessment (LCA). This evaluation method aims to uncover the environmental consequences associated with all stages of a project, thereby revealing the hidden costs inherent in developing and utilizing a technology over its entire lifespan. In the case of VREs, conducting a lifecycle analysis enables a comprehensive examination of the various phases of the product’s lifespan, offering opportunities for improvements that can further enhance its environmental performance. While the typical LCA assessed the full lifecycle of given projects ranging from the extraction of raw material to the end of life, thus, Since VREs are inherently clean in their operational nature, the analysis primarily focuses on the extraction of raw materials, manufacturing processes, and waste disposal.
One study analyzed the lifecycle impact of integrating Variable Renewable Energy (VRE) on the overall power system lifecycle. The lifecycle studies carried out in 2020 by Bouman, a researcher from the Norwegian Institute for Air Research (NILU), sought to assess the consequences of greater adoption of renewable energy sources in the European Union’s 27 member countries [2]. This investigation quantified environmental factors, such as global warming potential, freshwater eutrophication, particulate matter formation, terrestrial acidification, freshwater ecotoxicity, and land occupation.
The study findings indicated that pursuing an improved energy mix in the EU-27 from 2005 to 2018 would lead to offsets of gross avoided impacts relating to global warming potential, particulate matter formation, and terrestrial acidification. However, it was acknowledged that these offsets would come with potential risks associated with freshwater eutrophication and land occupation, which are consequences of the development of Solar PV technology. The eutrophication effect observed can be attributed to the manufacturing process of panels, which utilizes various metal ions (mainly copper), and chlorine, known for their significant contribution to ecotoxic impacts.
In addition to the aforementioned findings, it has been discovered that substances employed in the manufacturing processes of silicon refining and the pretreatment of solar panels, such as Hydrofluoric Acid and Sodium Hydroxides, require strict regulation due to their highly corrosive nature. These substances pose a risk of severe burns upon contact with human skin, necessitating careful handling and precautionary measures. Moreover, in the context of assessing the ecological consequences throughout the complete supply chain, it is crucial to acknowledge the environmental impact associated with the extraction of quartz, which functions as the impure manifestation of silicon exposes miners to various risks, notably the potential development of respiratory ailments, such as silicosis.
In the field of wind turbines, a study conducted by Bounou, A. in 2016 aimed to perform a lifecycle assessment of the environmental impact associated with producing 1 kWh of electricity from wind turbines with a 2.3-3 MW capacity [3]. The research estimated, that approximately 6 to 10.9 grams of CO2 equivalent emissions are emitted per kWh of energy produced by the wind turbine. The results of the lifecycle assessment also emphasize that, among the mentioned emissions, the majority of impacts stem from the extraction and production of materials. This stage accounts for over 79% and 70% of the climate change impact for onshore and offshore wind turbines, respectively.
It is not surprising that the majority of lifecycle emissions associated with wind turbines are attributed to the manufacturing process. Particularly noteworthy is the prevalent use of steel as the primary material in wind turbine manufacturing. The steel industry is widely acknowledged for its high carbon intensity, mainly stemming from its heavy reliance on coal as a primary energy source. Furthermore, although approximately 85% to 90% of wind turbine components are recyclable, the turbine blades pose a challenge due to their complex carbon fiber composites, which are difficult to separate using current recycling methods. Consequently, wind turbine blades accumulate in landfills. While the disposal of these materials in landfills does not directly harm the environment, the significant size of the blades occupies landfill space that could otherwise be utilized for other waste in a given region. According to Liu and Barlow (2017), it is estimated that the global mass of retired wind turbine blades by 2050 could reach as high as 43 million tons.
Innovate to Mitigate
It is not surprising that the majority of lifecycle emissions associated with wind turbines are attributed to the manufacturing process. Particularly noteworthy is the prevalent use of steel as the primary material in wind turbine manufacturing. The steel industry is widely acknowledged for its high carbon intensity, mainly stemming from its heavy reliance on coal as a primary energy source. Furthermore, although approximately 85% to 90% of wind turbine components are recyclable, the turbine blades pose a challenge due to their complex carbon fiber composites, which are difficult to separate using current recycling methods. Consequently, wind turbine blades accumulate in landfills. While the disposal of these materials in landfills does not directly harm the environment, the significant size of the blades occupies landfill space that could otherwise be utilized for other waste in a given region. According to Liu and Barlow (2017), it is estimated that the global mass of retired wind turbine blades by 2050 could reach as high as 43 million tons.
Nevertheless, it is noteworthy that all stakeholders and institutions actively push the boundaries of what is deemed feasible to reduce the impact of the lifecycle of wind turbines and solar PV systems. VEOLIA, employs a unique method to recycle turbine blades. Blades, which are mainly composed of fiberglass and balsa wood, undergo a process of shredding into minuscule pieces that can then be utilized in cement production [7]. The utilization of shredded turbine blades for cement production holds the advantage of reducing the number of raw materials conventionally employed by cement manufacturers, consequently resulting in a decrease in greenhouse gas emissions.
However, there are differing opinions regarding the suitability of shredding wind turbines and incorporating them into cement production. As previously mentioned, wind turbines contain a significant concentration of high-energy materials. Consequently, directly incinerating them, as done in the cement manufacturing process, would eliminate the potential for future repurposing and would not justify the energy expended in their initial manufacturing. Consequently, several measures have been undertaken to explore alternative avenues for repurposing wind turbines.
Re-Wind, an association focused on wind power materials, has pioneered the repurposing of turbine blades. They have developed conceptual applications such as using turbine blades as foundations for a pedestrian bridge in Ireland [10]. Re-Wind also has plans to repurpose blades for cellphone towers and fencing. This repurposing effort is not limited to Re-Wind, as artists and businesses have also engaged in similar practices. In the Netherlands, discarded turbine blades are used to create child-friendly playgrounds and monuments. Siemens Gamesa, a leading offshore manufacturer, has repurposed turbine blades into parking shades for bicycle storage facilities in Denmark [7].
In improving the lifecycle of solar plants, the prevailing solar panel technology is crystalline silicon, which currently holds the majority market share. These panels contain an aluminum frame, glass, copper wire, polymer layers, silicon solar cells, and a plastic junction box. Several of these components can be effectively recycled. Glass, which constitutes a significant portion of the panel’s weight (approximately 75 percent), already benefits from a well-established recycling industry [13]. Materials such as aluminium frame, copper wire, and plastic junction boxes are also easily recyclable.
One of the challenges in recycling solar panels lies in the strong adhesive properties of the polymer layers that bond the crystalline silicon and the presence of valuable materials such as internal copper and silver. as developed technologies that efficiently separate materials within end-of-life photovoltaic panels. They can recover ultrapure silicon from the solar cells and the silver fingers used for electrical current collection in each cell. The recycling processes employed by ROSI Solar utilize physical, thermal, and soft chemistry mechanisms to extract these materials while minimizing energy consumption [12]. Besides solar panel recycling, ROSI Solar also contributes to improving the efficiency of photovoltaic plants, specifically by reducing silicon waste resulting from wafer cell cutting processes [11].
The Take
Extensive deliberation has been devoted to the subject of Variable Renewable Energies (VREs), and it holds true that renewable energy sources represent a cost-effective and environmentally friendly alternative to electricity generation. Nonetheless, a comprehensive examination reveals that although VREs may appear operationally clean and economically advantageous when evaluated from a lifecycle perspective, certain detrimental costs must be considered. However, it is essential to clarify that the purpose of this article is not to criticize VREs or undermine their promising future impact. Instead, the article’s function is simply to shed light on what is currently unseen effects by some people.
On the other hand, it is also noteworthy to observe that stakeholders, ranging from businesses to academia, advocate for breakthroughs and new business models to reduce the overall impact and disposal of VREs. Collaboration and supervision among these stakeholders are necessary and can be facilitated by the government. As a regulator, the government can establish a legal platform, such as setting standards for toxicity waste disposal, enforcing recycling obligations on VRE operators, and providing incentives for innovative recycling businesses that can help mitigate the lifecycle impact of VRE production.
If all of these measures can be achieved, not only are humans promised a cost-effective future shift to renewables, but also a responsible circular future in utilizing, producing, and disposing of the generating technology we employ, thereby creating an all-positive value chain for all, in order to propel civilization to its new heights.
Author: Aditya Perdana
References
[1] Blakers, A. Zin, N. Mc Intosch, K. Fong, K. 2013. High Efficiency Silicon Solar Cells. Energy Procedia Volume 33 (1-10)
[2] Bouman, A. 2020. A Life Cycle perspective on the benefits of renewable electricity generation. ETC/CME report 4/2020
[3] Bounou, A. Laurent, A. Olsen, S. 2016. Life Cycle Asessment of On Shore and Offshore Wind Energy Theory to Application. Appl Energy 180:327–337. doi: 10.1016/j.apenergy.2016.07.058
[4] EIA. 2017. Wind Turbine Heights and Capacities Have Increased Over the Past Decade. U.S. Energy Information Administration – EIA – Independent Statistics and Analysis. Accessed on 10th May 2023.
[5] Gonzales, J. Arantegui, R. 2016. Technological Evolution of Onshore Wind Turbines – A Market-Based Analysis
[6] IESR. 2023. Making Energy Transition a Succeed, An Update of The Levelized Cost of Storage and Levelized Cost of Electricity.
[7] Insider Business. 2022. Why Wind Turbine Blades are So Hard to Recycle | World Wide Waste. (273) Why Wind Turbines Blades Are So Hard to Recycle | World Wide Waste – YouTube. Accessed on 10 June 2023
[8] IRENA. 2022. World Energy Transitions Outlook. International Renewable Energy Agency. Abu Dhabi, UAE.
[9] Liu, P. Barlow, C. 2017. Wind Turbine Blade Waste in 2050. Journal of Waste Management, Volume 62 (229-240)
[10] Re-Wind. 2023. Construction and Cost Analysis of BladeBridges Made from Decomissioned FRP Wind Turbine Blades. https://www.re-wind.info/journal-papers/2023/2/12/ruane-et-al-2023-construction-and-cost-analysis-of-bladebridges-made-from-decommissioned-frp-wind-turbine-blades . Accessed on 10 June 2023
[11] ROSI. 2023. Silicon Kerf Recycling. Kerf recycling | ROSI (rosi-solar.com). Accessed on 11 June 2023.
[12] ROSI.2023. Photovoltaic Modules Reycling. https://www.rosi-solar.com/photovoltaic-modules-recycling/ . Accessed on 11 June 2023
[13] US EPA. 2023. Solar Panel Recycling. https://www.epa.gov/hw/solar-panel-recycling . Accessed on 11 June 2023.
[14] USGS. 2023. What Materials are Used to Make Wind Turbines. What materials are used to make wind turbines? | U.S. Geological Survey (usgs.gov) . Accessed on 10 June 2023
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