**1. Introduction**

Sustainable development is about achieving a more sustainable global future so that future societies face fewer challenges arising from resource scarcity and accumulating atmospheric pollutants. Sustainable development is a powerful development concept as it integrates the economic, societal and environmental aspects and the interrelationships among the energy, environment and societal concerns. Developing sustainably ensures that the availability of critical resources such as energy, water and food is available to both present and future generations and emphasizes mitigating the scope of the environmental problems across both geographic and generational boundaries [1]. However, the transition towards sustainability is still at an early stage in developing economic regions while economies around the world have been struggling to balance their economic growth priorities without deteriorating the natural resources. Developing economies and regions

**Citation:** Nepal, R.; Phoumin, H.; Khatri, A. Green Technological Development and Deployment in the Association of Southeast Asian Economies (ASEAN)—At Crossroads or Roundabout?. *Sustainability* **2021**, *13*, 758. https://doi.org/10.3390/ su13020758

Received: 26 November 2020 Accepted: 12 January 2021 Published: 14 January 2021

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are expected to be hit hard by climate change due to their more limited adaptation capabilities even though they have produced relatively small amounts of greenhouse gases. The COVID-19 pandemic brings further uncertainty in adapting sustainability reforms to combat climate change given the economic downturn and border closures in many regions affecting resource mobility. Nonetheless, the role and importance of green technology as a climate change adaptation vehicle has always been crucial in providing a new perspective on sustainable development.

Developing economic regions like Southeast Asia currently face paramount challenges as well as opportunities in matching its increasing energy demand due to rising incomes, industrialization and urbanization with sustainable energy supply considering the transition to a lower-carbon economy. Greenhouse gas emissions have been rising rapidly at an average annual rate of 5% in recent decades among major Southeast Asian economies such as Indonesia, Malaysia Philippines, Thailand and Vietnam [2]. The region is poised to become a net energy importer of fossil fuels such as oil due to growing population, industrialization and urbanization despite the slowdown in economic growth [3]. The total population in the Association of Southeast Asian Economies (ASEAN) region will increase to 715 million by 2025 with the economy growing by more than 5% per year and therefore explaining a rapid rise in energy demand of at least 4% annually [4]. The overall growth in energy demand of more than 80% since 2000 has been met by a doubling in fossil fuel use engendering severe energy security concerns such as rising import dependence and environmental concerns due to an increase in energy-related carbon dioxide (CO2) emissions [3]. For instance, the share of this geographic region to global emissions increased to 4% in 2018 (3% in 2010), while the number of deaths linked to outdoor and household air pollution in Southeast Asia is expected to spike to more than 650,000 a year by 2040, which is an increase from around 450,000 deaths in 2018 [5]. The average temperature in ASEAN is also rising by 0.1 to 0.3 degree Celsius per decade in the last 50 years and is projected to increase by 2–4 degrees Celsius by the end of the 21st century [6]. The electricity demand in the region is growing at an average of 6% and remains among the fastest in the world, while the region's demand for electricity is projected to double by 2040 [3]. In 2016, the ASEAN economies set a target of 23% to have its primary energy supply secured from renewable sources by 2025 [4]. However, it is also likely that the overall energy demand will grow by almost 50%, while the power generation will double by 2025 [3]. Some countries in the region will have to at least double their share of renewable energy every year, but a doubling of renewable capacity alone may not be enough to combat climate change. The rising energy demand and related CO2 emissions in the ASEAN, therefore, implicates the heightened need for transitioning towards the development and deployment of greener energy sources as a necessary climate change adaptation strategy in the region.

There is also an ongoing discourse in the ASEAN to devise policy strategies to mitigate and adapt to climate change threats and to balance the trade-offs between economic development and environmental sustainability given the region's heavy reliance on fossil fuels. For instance, the power generation mix of the ASEAN is dominated by fossil fuels, which accounted for almost 80% in 2017 and are expected to account for 82% in 2050 in the absence of the region not transitioning to cleaner energy systems [7]. Therefore, the need to develop, deploy and adopt green technologies is imminent for Southeast Asia to address the twin challenges of rising energy demand and increasing emissions in ensuring energy sustainability as well as to mitigate the adverse impacts of climate change. The ASEAN economies should increase their share of renewables in the energy mix to 70% by 2040 to meet their sustainable development goals [8]. However, the progress towards the adoption of green technology such as renewables in Southeast Asia is slower than the anticipated potential across many Southeast Asian economies. Renewable energy only meets around 15% of demand with the rapid increase in hydropower and modern use of bioenergy in heating and transport [9]. Solar and wind power being the most abundant energy resources in the ASEAN only contribute negligibly to the power mix [7]. The large potential of sustainable use of modern bioenergy remains untapped in the region, although

electricity from hydropower production has quadrupled since 2000. The Southeast Asian economies are yet to perform globally in renewable energy deployment due to various challenges despite having huge potentials for sustainable energy sources [10]. However, policymakers across Southeast Asia are intensifying their efforts in achieving a common goal of a secure, sustainable and affordable energy sector even though the region is diverse and dynamic [8]. The diversity in energy mix in the region also offers a viable opportunity to accelerate regional physical interconnections of power grids and make greater use of the resource and demand complementariness [11]. Boosting regional power grids in the ASEAN has also been a well-advocated energy policy agenda in the past [12].

The objective of this study is to analyze and review the energy–economy–environment in the ASEAN from an energy sustainability perspective in the context of green energy development and deployment as a powerful climate change adaption policy in the region. In doing so, the study recognizes the inevitable economy–environment tradeoffs between regional economic growth and adverse climate change impacts as a policy tool for policymakers to emphasize. The study assumes that successful energy transition in the ASEAN is only possible by increasing the share of renewables and clean energy and fuels. Therefore, based on our impartial and unbiased analysis using secondary data sources, we propose that the policymakers need to formulate and implement proper policies that are of short-term, medium-term and long-term nature. These policy proposals include scaling of renewable energy deployment, focusing on energy efficiency improvements, discouraging the use of fossil fuels by undertaking energy pricing reforms and embracing hydrogen, carbon capture, utilization and storage technologies. However, significantly accelerating the deployment of renewable energy in the region is challenged by greater levels of investment and financing requirements, which the region needs to overcome alongside managing the energy governance and financial risks.

Our study is also one of the limited studies focused on the deployment and advancement of green energy technologies as a necessary climate change adaption strategy in the context of sustainable development in the ASEAN. The findings of our study are significant to the ASEAN governments and policymakers in crafting a sustainable energy policy through the development and deployment of alternative greener energy options apart from the conventional renewable sources in adapting to adverse impacts of climate change in the region. We undertake a case review of the ASEAN region as a whole as a case-specific analysis based on a secondary data as a suitable approach to examine policy problems that do not easily lend themselves to rigorous quantitative analysis or that cannot be analyzed using econometrics due to the unavailability of disaggregated data [13].

The remainder of the paper is structured as follows. Section 2 is a brief literature review on the deployment of conventional renewable energy in the context of green growth and energy transition and also portrays the current status of conventional renewable energy deployment in the ASEAN. Section 3 discusses green energy innovation and alternative green energy options for the ASEAN in adapting to climate change. The three major proposed policy recommendations are discussed in Section 4. Section 5 concludes the paper.
