**2. Current Status of Renewable Energy Deployment in the ASEAN**

Historically, the development and deployment of conventional green technologies have mostly been carried out in the context of national green growth strategies and energy transition. This is because economies around the world have set challenging targets to reduce greenhouse gas emissions and renewable energy technologies that offer decarbonization pathways and possibilities. Many developing countries have started to adapt strategies related to green growth into their economic development agenda. The gap between the technologies and the capabilities has been addressed on the basis of literature on technology transfer as well as industry insights across the technology lifecycle. Heuristics have been shown to be crucial when it comes to deployment of clean technology from a policymaker perspective, while technology-specific green growth strategies also depend on countries with different income levels as well as their requirements [14]. However, several challenges in the energy sector have been identified to meet the renewable energy targets that were set by ASEAN economic community between 2010–2015 [15]. For instance, there has been little progress in terms of regional cooperation in critical areas like physical infrastructure, while various financial constraints, regulatory differences and technological gaps are challenging energy security.

Governments in Indonesia, the Philippines and Singapore have focused on the institutionalization of sustainable energy by aligning with the domestic systems of renewable energy based on an analysis of their sustainable energy policies between 2000 and 2016 [16]. Li et al. [17] in 2020 found a tremendous mismatch between resources and energy demand despite the huge potential for renewable energy in the research about the energy transition in East and Southeast Asia. In another article of 2019 by Lee et al. [18], the impact of fossil fuel aerosols on air quality in Southeast Asia under varying hypothetical fuel consumption scenarios were examined. The results showed that the replacement of coal by natural gas in the power generation and industry sectors would lead to a 25% reduction in sulphate in the Southeast Asia region. Substituting biofuels by natural gas in the residential sectors would lead to a 42% reduction in black carbon concentration. The importance of clean air in the Southeast Asian region is also articulated under the findings of the International Energy Agency (IEA) [8] where energy-related air pollution death will rise to 650,000 by 2040 from an estimated 450,000 in 2018. Taghizadeh-Hesary and Rasoulinezhad [19] determined how energy transition patterns depend in 45 Asian economies when classified as per their income levels for the period of 1993–2018 using the generalized method of moments (GMM) estimation approach. The results showed that an increase in population slows the energy transition process across all income levels with economic growth, generating a positive relationship with the energy transition, while CO2 emissions negatively influence energy transition.

There has also been increasing debate about the effects of energy transition in the form of broader global biodiversity threats. Studies have shown that renewable energy facilities can be land-intensive as well as impact conservation areas. Rehbein et al. (2020) [20] assessed that the extent of current and likely future development of renewable energy related to onshore wind, hydropower and solar photo-voltaic generation intervenes with the protected biodiversity areas. It was found that lack of proactive measures like nonremoval of subsidies of fossil fuels and barriers to regional market integration by the ASEAN governments will act as barriers to the region in achieving the ambitious target of 23% renewables in the primary energy mix by 2025 [9].

The Table 1 below shows that studies focused on the deployment and advancement of green energy technologies in the context of green growth and energy transition are limited for Southeast Asia. Our review study attempts to extend this strand of literature by reviewing the specific case of the ASEAN economic region in search of viable climate change adaptation strategies. Existing studies have mostly focused on the technical and environmental aspects of conventional renewable energy with much disregard for innovative fuels like hydrogen and carbon capture and storage. Our research will contribute to the crafting of sustainable energy policy by the ASEAN governments through the deployment of innovative green technologies in fighting climate change as well as achieving sustainable economic growth in the region.

The ASEAN region is expected to achieve an accelerated economic growth over the next decade and experience 50% rise in energy demand. Importantly, the region is targeted to source 23% of its primary energy from renewable sources [4]. The global economic and energy indicators show that ASEAN region is becoming a net importer of fossil fuels given the rapidly growing economies in the region and increasing population size. Oil is likely to continue to dominate the road and transport demand in ASEAN. Similarly, coal demand will increase, driven by strong policy settings by countries to meet the economic growth targets. IEA estimated that more industrial consumers than the power plants drive the demand of natural gas although the increase in imports of oil is making sources such as Liquefied Natural Gas (LNG) less price competitive in the ASEAN.


**Table 1.** Literature Summary.

About 120 million people (around 10% of ASEAN's overall population) still do not have access to electricity in Southeast Asia, and the rural areas face a critical challenge in accessing the power [21]. There are about 45 million people in the region who rely on biomass as a fuel for cooking [8]. There is a tremendous potential for renewable energy, but renewable energy only accounts for 15% of the energy demand. On one hand, hydropower has increased by four times since 2000 along with the increase in the suse of bioenergy in heating and transport [3]. On the other hand, the share of solar photovoltaics and wind is small, although the costs have been declining in recent years. An efficient market-based energy efficiency framework could strengthen in their deployment but such framework is missing.

Southeast Asia's overall energy demand is also expected to grow by 60% by 2040 based on a stated policies scenario developed by IEA in 2019. The projection assumes that the size of the economy will double over the period and the majority of the population will be concentrated in the urban areas experiencing an increase of 120 million [22]. A structural economic shift towards less energy-intensive manufacturing and services sectors is expected along with greater energy efficiency improvements, which will lower the rate of energy demand compared to previous decades, although it will represent 12% of global energy rise by 2040. The oil demand will exceed 9 million barrels per day (mb/d) by 2040, which is currently at 6.5 mb/day [3].

However, Southeast Asian nations also have a geographic advantage in terms of natural resource endowments to produce renewable energy. For example, Indonesia and the Philippines have substantial geothermal energy potential, while Vietnam, Cambodia, Laos and Myanmar have large-scale hydropower potentials. Similarly, most areas in these countries have at least 12 h of sunshine on average and are suitable for solar electrification. The global renewable energy generation capacity stood at 2179 GW by the end of 2017, with the hydro sector holding the largest share with an installed capacity of 1271 GW. In the same period, Asia alone accounted for 64% of the global share in new renewable capacity. The majority of the growth in installed renewable capacities is driven by the new installations of solar and wind energy in the ASEAN (around 85% of all new renewable capacity installed). Thailand was one of the distinguishable countries in the ASEAN region that had the second-highest share in bioenergy capacity (430 MW). Indonesia topped the

list in expanding the geothermal energy capacity by 306 MW and is soon approaching a 2 GW total geothermal capacity [23]. Similarly, Malaysia is the third-largest producer of photovoltaic cells in the world while solar is responsible for sourcing the majority (47% in 2017) of the grid-connected renewable power generation in Malaysia [24].

Likewise, Laos has around 80% of its primary energy demand sourced through renewable energy, and the country has realized its potential. Biomass energy, which comes from forestry and agricultural waste, comprises 68% of its energy and is used for household cooking and small-scale rural production. The remaining 12% is sourced from the hydropower sector. The commercial methods to utilize biomass in Laos includes direct combustion, gasification, anaerobic digestion and hybrid system [25]. Laos also took advantage of the 300 days of annual sunlight, which enabled its economy to equip 13,000 rural homes with solar panels. In Indonesia, the government has taken the initiative to build a large-scale floating power plant, which has opened doors for 60 other reservoirs across the country [26]. The country has huge potential for wind, and a 100-hectare wind farm was opened in South Sulawesi that has a capacity to power around 70,000 households [27].

The Philippines has the largest potential for wind energy in Southeast Asia, although a significant proportion of the population does not have access to electricity, compelling them to use alternate methods for cooking and lighting. Green start-ups have played a major role in the Philippines by benefitting from the natural energy resource endowments. A Filipino startup named Sustainable Alternative Lighting came up with a saltwater solution-powered lamp product that retains power for up to eight hours. Furthermore, the disposable component of the lamp lasts for 6 months and is also not expensive to replace. Around 51% people use firewood or charcoal in the Philippines [28].

Figure 1 shows that the region's energy demand is expected to rise to 60% by 2040. This expected rise in energy demand is far lower compared with the energy demand of the previous decades. The renewable share in power generation is expected to rise from 24% in 2020 to 30% by 2040. However, the expected rate of progress in renewable energy is still short of levels reached by other emerging economies such as China and India under the stated policies scenario. The hydropower sector that accounts almost 80% of the renewable share is the cornerstone of ASEAN's energy portfolio and the rise of wind and solar energy as well as biofuels, and bioenergy from waste products is likely to deliver promising growth. Furthermore, innovation in hydrogen carbon technologies could positively change the energy landscape of ASEAN [7].

**Figure 1.** Primary Energy Demand in the Association of Southeast Asian Economies (ASEAN) (2018–2040). Source: Adapted from IEA [3].

Figure 2 portrays the economic and energy outlook of the Southeast Asian region in the global context. While the region is experiencing one of the highest increases in electricity demand at an average of 6% per year, the numbers of power systems in the region face major financial backlash. The use of overall energy demand cannot be undermined either, as the overall energy demand has grown by more than 80%, with fossil fuel use doubling. The renewable energy capacity potential in Southeast Asia is significant enough and is continuously growing as observed in Figure 2. Nevertheless, only 15% of the region's energy demand is met at present from renewable energy sources, although the scope for renewable energy in the region is tremendous. The falling costs of solar photovoltaics and wind could be encouraging news for supporting their deployment, especially for the small economies in the region such as Myanmar, Cambodia, Vietnam and Laos.

Hydropower output has also quadrupled in Southeast Asia since 2000 [3]. The costs for solar photovoltaics (PV) have been falling over time, but the share in total energy remains small. IEA [3] data also show that there has been a shift towards low energy-intensive manufacturing and services given the projected rate of energy demand growth is lower than the past two decades, which holds 12% share of the projected rise in global energy use to 2040. Figure 3 below also shows that space cooling is set to drive the growth in household electricity demand in the ASEAN by 2040.

Achieving a clean energy future in the ASEAN requires electrifying the transport sectors by deploying green technologies like electric vehicles. However, the congested roads and lack of proper infrastructure make it difficult to scale up and replace oil consumption. The rise of middle income and the increasing demand for household space cooling has increased the energy use for air conditioners in ASEAN by 7.5 times in the past 30 years. Indonesia, which is the most populated country in ASEAN, only has about 10% of its households with air conditioning, and less than 20% of households in the whole ASEAN region have air conditioning. However, these numbers are likely to keep growing, and an additional 200GW of capacity needs to be added by ASEAN countries by 2040, which will increase demand by 30% [29]. There are opportunities, at the same time, to increase energy efficiency policies, which could in turn enhance efforts to improve the building and equipment efficiency. Policymakers must understand that hydrogen is one of many alternatives available to fossil fuels, given the high significance in energy storage, longerdistance driving and faster filling [7].

**Figure 3.** Household electricity demand growth in the ASEAN (by appliance source). Source: Adapted from IEA [3].

#### **3. Green Innovation and Alternative Energy Options in the ASEAN**

Meeting the energy-related sustainable development goals (SDGs) in the ASEAN requires deploying multiple technologies and policy approaches in the energy sector. As there are no silver bullets, international experiences of energy transitions can offer valuable guidance and insights in the development and deployment of green energy technologies in the ASEAN, considering that fossil fuels have dominated the planet for centuries and will continue to do so. While the removal of carbon from the atmosphere is urgent, innovative energy solutions should be adapted considering the environmental, technological and economical aspects. Policymakers need to have a practical orientation towards the frameworks that are being developed internationally towards the deployment of green technologies so that the energy transition becomes smooth. A report by IRENA showed that Southeast Asia has the highest share of jobs in renewable energy (83%), whereas it is the lowest in terms of energy efficiency jobs (only 7%) [30]. Renewable energy technology varies significantly across the member states in ASEAN, although there has been some significant progress made in renewable energy development.

#### *3.1. Nuclear Energy*

Nuclear power systems are comparatively clean and a reliable source of energy with the potential to contribute towards hydrogen economy. Many countries in Southeast Asia have also expressed increasing interest in nuclear energy given the economic benefit as well as low-carbon emissions for electricity supply [31]. In addition to renewables, the technological advancement of nuclear reactors is already considered to have the possibilities of transforming the clean energy sector in Southeast Asia [32]. The substantial possibility for cost-effective, efficient and large-scale hydrogen production utilizing heat derived from nuclear power station already exists. For example, the US Department of Energy introduced the Advanced High-Temperature Reactor (AHTR) technology build for hydrogen production with high-temperature water electrolysis or thermochemical cycles [33]. Several studies on the thermochemical cycle have delivered thermal-to-hydrogen energy efficiencies of, e.g., 50% for the adiabatic UT-3 cycle and 52% for the sulphur-iodine cycle [34]. Hence, economically sound and technologically superior hydrogen production capacities could be sourced from nuclear energy. Nuclear energy sector has also gained favor from international organizations like Intergovernmental Panel on Climate Change (IPCC) as an important energy option to attain the "zero emissions". However, there have been accidents like the Fukushima nuclear incident in Japan that have changed the political

environment and perceptions towards nuclear energy. The commitment to mitigating greenhouse gas (GHG) was revised in Japan as a response. Although Japan committed to a 25% reduction in emissions from 1990 levels by 2020, it only decreased by 3.8% from 2005 levels, translating to a 3.1% increase in GHG from 1990 levels [35]. However, the nuclear reactors in Japan also restarted their operations since 2015 despite the lack of public acceptance.

An increase in global nuclear power production of about 80% is required by 2040 to achieve the sustainability target in which 85% of the global electricity needs to come from clean sources by 2040 compared with the existing 36%. The use of nuclear power has reduced carbon dioxide (CO2) emissions by over 60 gigatons, which is equivalent to two years' worth of global energy-related emissions [3]. Hence, it would be much harder to achieve a sustainable energy system without a proper nuclear investment. Furthermore, nuclear plants also help to keep the power grids stable by limiting the seasonal fluctuation impact from other renewables and reduce dependence on imported fuels, which has been prevalent in major ASEAN countries. However, public acceptance and trust needs to be garnered by informing the public about the importance of the energy source as a viable energy technology to address societal needs.
