While the transition to a cleaner energy sector is underway in Pacific Island Countries and Territories (PICTs), there are still many challenges that need to be overcome from demand, energy, chemical, and technological perspectives. The composition of the Pacific region makes it highly compatible with the movement towards small-scale, decentralized, and on-demand production of chemicals (for direct use as well as acting as an energy storage vector). Power-to-X, being the conversion of electricity into a range of different chemicals and fuels, has immense potential to offset reliance on imports, fossil fuels, as well as decrease transportation requirements. The emerging Power-to-X technologies have potential to address many of the struggles in transforming to a renewable sector. This chapter examines the transition to clean energy generation technologies, focusing on those emerging technologies which are close-to-market level implementation and have the potential to transform the Pacific region. The prospects and limitations, including the diversity of the region from both a generation and storage perspective, as well as the chemical demand, and its reliance on fossil fuel-based derivatives and imports are discussed.
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Decentralized renewable Power-to-X technologies have the potential to facilitate the energy transition in Pacific Island Countries and Territories.
18.1 Introduction
The energy transition within the Pacific is well underway. Many Pacific Island Countries and Territories (PICTs) have plans and roadmaps to increase access to electricity, as well as transition towards renewable energy-based systems. These roadmaps are framed toward the transition to (1) increasing electrification, (2) decreased reliance on fossil fuels, thus reducing greenhouse gas emissions, and (3) a more autonomous, lower-cost and more resilient energy sector. The framework as PICTs transition to a more sustainable and equitable society has been discussed extensively in Chaps. 3 and 12. However, as aptly posed by the International Energy Agency (IEA), “more than just renewables and efficiency will be required to put the world on track to meet climate goals and other sustainability objectives” (IEA 2020a).
Across PICTs there remain significant barriers to achieving energy sustainability and autonomy. These were outlined in detail by the UN Economic and Social Commission for Asia and the Pacific and include (Johnston 2013):
The lack of energy resources in PICTs, as well as the limited range of resources.
The population distribution, with many in remote areas, and the high cost of developing new energy resources.
The lack of energy data, including the trends associated with end-use.
The lack of local knowledge and skills.
The weak bargaining positions with petroleum suppliers.
The historical dependence on international agencies for infrastructure.
The low electricity cost and subsidies which have been below cost price meaning there are limited funds for maintenance and upgrading.
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While there is a significant push by governments and development partners and agencies to increase electrification, this increased electrification requires ongoing consideration such as grid connectivity, environmental footprint, capital investment, and specific energy and feedstock requirements. Particularly in the rural regions of the Pacific, connection to the grid is not the most economically viable option. The establishment of a more diverse range of off-grid solutions, tailored to the environment and needs of specific areas is essential.
Globally, new technology developments, increased consideration on environmental impacts and sustainability, as well as increasingly empowered consumers and communities are all spurring a shift toward distributed, decentralized energy production. This means a greater number of energy generation centres, more competition and a more diverse range of generation and storage approaches. The advantages of this shift are significant. The increased competition, reduced infrastructure and transportation costs, the lower barriers to entry and the more tailored approach, means more efficient usage of resources.
This global shift has potential to be hugely beneficial in the Pacific region. In step with global shifts, the decentralized, off-grid production of energy, in particular for the Least Developed Countries and Small Island Developing States (LDCs and SIDS), has significant potential to transform the region.
The LDCs and SIDS face unique barriers toward the successful implementation of renewable energy projects. These include the isolated market with small sizes and small population base resulting in low economies of scale, the narrow range of resources, remote locations, and economical and ecological vulnerability (Lomaloma, n.d.).
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For the transformation of the Pacific region, as outlined in this volume (Chaps. 3 and 12), the shift toward renewable energy (such as wind, solar, and geothermal), as well as enhancements in energy efficiency are a great starting point. The employment opportunities, low environmental footprint, and increased energy autonomy and security are particularly advantageous.
This chapter focuses on emerging technologies which are not quite at deployment stage yet, however if implemented, hold the potential to transform the PICTs transition to a clean energy future. Power-to-X is an increasingly common term in the emerging research technologies space. Power-to-X is the conversion of electricity, particularly renewably produced electricity such as through photovoltaics (PV), hydro, and geothermal energy, to a range of different chemicals and fuels.
While the inherent nature of PICTs provide barriers to a transition to a more sustainable, reliable and accessible energy future, the region is uniquely situated to transition to the small scale, decentralized production of electricity and chemicals in an on-demand manner. The emerging technology in this space has potential to transform the region.
18.2 Energy Generation Technologies
The Pacific region is diverse. PICTs exist along a large spectrum of development levels, from the most developed, Australia and New Zealand, to the LDCs. Further, the natural resources, in particular with respect to fossil fuels and land mass, geothermal/wind power suitability, vary drastically across the region. Australia, Timor Leste, and Papua New Guinea all have fossil fuel reserves whereas many of the other nations do not.
The Melanesian countries can be characterized by large, mountainous islands with considerable natural resources in the form of fertile soils, mineral deposits, and large forests. In the Polynesian and Micronesian countries, the mid-sized island states have limited land resources and low amounts of tradable natural resources. The small and low island states of Micronesia have very limited land and oil with their resources mostly limited to the ocean. Given this vast variability across the region, an in-depth review of the scope of energy generation throughout the region is difficult. However, the focus of this chapter is on near-to-market technologies which can be exploited across the region, in particular those that are capable of transforming energy into applications which are suited to diverse applications throughout the Pacific.
The transformation to renewable electricity generation is well underway throughout the Pacific region (Chap. 12). There has been a significant increase in solar and wind power plants over the 2000 to 2018 timeframe (UNESCAP 2019).
Renewable energy generation throughout PICTs is on an upward trajectory (Norojono et al. 2018) with some nations having a 100% renewable penetration target by 2030. As outlined in Chaps. 3 and 12, solar, wind, geothermal, bioenergy and hydro are all playing significant roles in the generation of energy throughout the Pacific. While this generation of electricity through variable renewable energy has many advantages, including energy autonomy, reduced emissions, reduced reliance on imports, and increased compatibility with off-grid energy solutions, it come with its limitations. These limitations include intermittency of renewables (specifically for solar PV) and typically higher capital investment requirements that may make the adoption of renewable electricity unfeasible.
Section 18.3 will address the near-to-market technologies that have the ability of overcome the variable renewable energy generation.
18.3 Emerging Technologies for Transformation and Storage
This volume has aptly demonstrated that energy poverty throughout PICTs, in particular within the LDCs and SIDS, is widespread. It has been estimated that approximately 70% of households throughout the Pacific region do not have access to electricity. Further, 85% of households are also estimated to have limited access to clean cooking technologies.
Both the population distribution and the geography of the Pacific region, in particular SIDS, make the transition towards decentralized solutions a potential driver for economic development. For example, in areas throughout PICTs of low population density, the cost of establishing off-grid systems is lower than extending the grid to households. In Fiji, it was determined that the cost of grid extension was close to four times higher than installing an off-grid diesel generator (Matakiviti and Pham 2003). Thus, for SIDS, the cost of installing off-grid systems is likely to be lower than if grids were extended.
Variable renewable energy refers to renewable energy that is inherently fluctuating in nature, such as wind and solar as opposed to dispatchable power such as hydroelectricity. While electricity generation through variable renewable energy sources may be increasingly feasible, the direct use of this electricity presents unique issues due to its intermittency. Further, the storage of this energy can be difficult and costly, particularly over timescales longer than the minute to hour. The storage of electricity, particularly variable renewable energy to load balance for production and demand, requires significant planning and investment (European Commission 2017). Power-to-X, being the conversion of electricity (and in this case power trapped within resources such as plastics and biodegradable waste) has potential to overcome the intermittency, load balance, and produce valuable chemicals and fuels.
This section will focus on new close-to-market technologies for the transformation, storage, and usage of variable renewable energy, which are well-suited for the Pacific region. This suitability includes being relatively low cost, or with low capital requirements, compatible with small scale, off-grid, decentralized production, as well as exploiting key waste products for the region.
18.3.1 Batteries
While the generation of electricity through variable renewable energy is established and the transition to a variable renewable energy system is well underway throughout PICTs, there remains significant issues in terms of energy storage and balancing supply and demand. Energy storage is often needed to manage short-term peaks as well as load balancing.
Many islands and off-grid regions in PICTs are powered by diesel generation, and thus the integration of variable renewable energy/battery storage presents a unique opportunity. These diesel generators are often oversized, operate below 30% capacity, and are emission intensive. However, diesel generators have the benefit of flexibility and rapid responses to variable energy demand that can fluctuate dramatically on an hour-to-day time scale as well as seasonally. Battery storage systems have been shown to be capable of delivering reliable power at approximately 30% of the cost of diesel generators (Stock et al. 2015). Additional, battery power is not hindered by oil price supply chain issues like diesel supply is (Puliti and Bazilian 2019). Beyond this, the use of variable renewable energy/battery systems overcomes the inherent pollution and health impacts associated with diesel combustion. If capital expenditure is included, it is estimated that diesel generators cost approximately 0.352 USD/kWh. In contrast, renewable power generation has been estimated at a levelized cost of 0.15 + / 0.10 USD/kWh.
Consequently, PICTS present a unique and promising opportunity for battery storage. The technology can help to integrate renewable energy (Balza et al. 2014), reduce reliance on fossil fuels generation, and has been postulated to be capable of lowering costs in some cases. Given their technological maturity, and the limited requirement for infrastructure, safety issues, and upskilling, batteries are likely to dominate as the key energy storage approach in the Pacific region. This transition is expected to begin as separate stand-alone storage in small scale decentralized systems, then to minigrid systems, and finally in grid connection.
To date, the high costs associated with battery energy storage has been the key deterrent to the implementation of variable renewable energy sources. However, costs of storage systems are rapidly declining thanks to both technological advancements and scaling benefits.
The progress of battery technology, in particular with respect to costing, is more advanced than that of electrolysers (see Sect. 18.3.2). The cost of lithium-ion batteries in particular has decreased (from USD1000/kWh from 2009 to USD200/kWh in 2019) as a consequence of increased production rather than major technological advancements (IRENA 2017). This is expected to decrease to USD90/kWh by 2030 due to technology improvements and fierce competition among major manufacturers. The Cook Islands have approximately half of their islands under the process of being converted from mostly diesel power to solar and battery storage only. For example, Rarotonga, the Cook Islands largest island, has a 1 MW Te Mana Ra solar farm installed by NSW-based MPower and is in the process of incorporating a 5.6 MWh battery system (Vorrath 2018). This example illustrates the increasing deployment of renewable coupled battery microgrids in PICTs.
18.3.2 Hydrogen
Hydrogen is widely considered as “the fuel of the future”. As shown in Fig. 18.1, hydrogen is increasingly being utilized as a clean energy carrier as well as feedstock for various chemical manufacturing. Hydrogen has vast benefits over carbon-based fossil fuels, including its ease in production and its zero-emission nature when utilized. Hydrogen can be produced through a number of pathways, such as by reacting fossil fuels with steam or oxygen using Steam Methane Reforming (SMR) or coal gasification (CG) to generate grey hydrogen or through renewable energy driven water electrolysis to generate green hydrogen.
The global hydrogen demand is growing (Fig. 18.1). As of 2018, demand was around 73 million tonnes and is projected to increase to 300 million tonnes by 2050 (Deloitte 2019). Much of this demand is currently met via SMR. At present, industrial hydrogen production accounts for approximately 6% of global natural gas consumption and 2% of coal consumption, and thereby is a major contributor of global carbon emissions, emitting over 830 million tonnes in 2018 (IEA 2019a, b). As a result, there is a concerted effort to produce renewable hydrogen, which can facilitate decarbonization and sustainable economic development (Saeedmanesh et al. 2018). It is expected that with future declining cost of generating renewable hydrogen, the alternate clean fuel will see more adoption as an energy vector in sectors such as transportation, heat and electricity generation, and in steel manufacturing (Staffell et al. 2019). This viewpoint is echoed by the Australian government and the country’s National Hydrogen Roadmap has proposed that “clean hydrogen is a versatile energy carrier and feedstock that can enable deep decarbonization across the energy and industrial sectors.” One of the key benefits of green hydrogen production and storage is its ability to overcome the intermittency in energy from the renewable sector, providing a longer term storage solution compared to battery storage systems.
A stacked bar graph plots global demand for pure hydrogen versus years from 1975 to 2018. It has data for, refining, ammonia, and other. The graph has an increasing trend. The highest fraction of refining, ammonia, and other is in the year 2018.
Fig. 18.1
Global demand for pure hydrogen as a function of end usage across time (IEA 2019a, b)
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18.3.2.1 Production
The production of grey hydrogen generates significant carbon emissions, and both blue and grey hydrogen require typically large infrastructure and upkeep. Aside from the conventional, thermochemical route to hydrogen production, electrochemical hydrogen production through water splitting is being increasingly considered a viable route. Currently, a much smaller proportion of hydrogen is produced via electrolysis of water owing to higher production costs. Nevertheless, this approach has various benefits as it is both sustainable and highly compatible with small scale delocalized production of hydrogen. Electrocatalytic hydrogen production provides a flexible storage solution which can be built for purpose, and that can be scaled according to demand (IEA 2020a). Hydrogen production through electrolysis offers opportunities to load balance renewable energy technologies such as solar and wind, and offset the intermittency challenge.
Electrochemical hydrogen production uses an electrical current to split water to produce hydrogen and oxygen. For the pathway to be viable from a low carbon perspective, it requires low/zero emission electricity. It is inevitable that the ramping of hydrogen electrolyser value chain is leading to a reduction in their costs and allowing greater application of delocalized hydrogen production in emerging markets.
Of the electrolyser technologies, both alkaline electrolysers (AE) and polymer electrolyte membranes (PEM) are commercially available while the solid oxide electrolyser (SOE) is still under lab-scale development. AE is reported to be economically more viable (due to its low capital costs), although recent developments in PEM technology illustrate its potential to compete with AE within a few years. Ultimately, the cost of hydrogen production from both AEs and PEMs is predicted to be significantly reduced as the technology develops, plants scale-up from 1 to 100 MW and with declining electricity pricing. Thus, with the greater uptake of these technologies and with any sort of incentive for reduced emission electricity, renewable hydrogen is anticipated to become increasingly competitive with production costs predicted to reach $2.29–2.79/kg by 2025 (CSIRO 2019).
PEM and AE require a catalyst, electrolyser and, importantly, a pure (fresh) water feed (with pH adjustment) to produce hydrogen. Producing hydrogen from neutral electrolytes, in particular seawater, without the need to add strong acids or bases, provides a promising route from an implementation perspective. Further, the requirement and use of fresh water poses problems. Fresh water is a scarce and precious commodity throughout the Pacific (see Chap. 2), with complimentary and interlinked priorities between water, energy, and food needed. Exploiting this necessary commodity for energy therefore poses a difficult ethical and resource allocation dilemma. The ability to exploit seawater to produce hydrogen, however, will have direct benefits to PICTs given their proximity to the ocean (Fig. 18.2) and with the majority of households located in close coastal proximity.
A map of the coast in 22 P I C T Ss marks the proportions of households. The legends are, % pop less than 1, between 1 and 5, between 5 and 10, and more than 10 kilometers from the coast. The regions are Micronesia, Melanesia, and Polynesia. Households with less than 1 kilometer have the maximum proportion.
Fig. 18.2
Pacific regional map, adapted from UN Geospatial (2023)
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There are significant challenges associated with utilizing seawater to directly produce hydrogen. Material development for direct seawater use has been difficult, leading to low hydrogen production. In addition, seawater contains numerous impurities that will hinder stability. While this technology is not yet at a commercial deployment stage, it is clear the potential benefits, specifically for PICTs, are promising. Further, by recombining the hydrogen and oxygen to produce electricity, purified water can also be produced, offering additional benefits.
18.3.2.2 Storage
One of the key benefits of exploiting hydrogen is its ability for long-term storage of renewable power. This storage lifetime has the potential to be longer than batteries, albeit there are safety and engineering challenges. The highly explosive and low-density nature of hydrogen storage presents significant technical barriers which needs to be overcome before renewable hydrogen can penetrate the market as an alternative to battery storage. At present, hydrogen can be stored through four approaches: (1) compression, (2) liquefaction, (3) transformation, and (4) solid-state storage. While experiencing ongoing research, the ideal approach to large-scale hydrogen storage is yet to be determined.
Of the different storage routes, the most common storage approach for hydrogen is compression via pressurization and storage within carbon/steel composites. Compression storage can also include underground storage and line-packing. Despite its popularity, hydrogen compression is restricted by low volumetric density. Line packing has potential in regions with already established natural gas infrastructure, which is promising in New Zealand and Australia, but is inherently limited throughout the rest of the Pacific region. Papua New Guinea may also present a unique case as pipeline supply of natural gas to major centres might be feasible if natural gas infrastructure is established from the well-head or via a branch line from the existing pipeline to Port Moresby.
Liquefaction can be done through both cryogenic and cryo-compressed tanks, in both these cases hydrogen is cooled to −253 °C, resulting in low evaporative losses with a high volumetric storage capacity. While both these technologies are promising, they are costly and require expensive storage materials and infrastructure.
Transformation covers the conversion and storage of hydrogen as other carriers such as ammonia and methane. The difficulty associated with these transformations mostly arises from the back conversion to hydrogen and the need for considerable infrastructure. However, if they can be utilized directly (such as through methane for cooking or ammonia for fertilizer), there is potential for significant economic benefit. It should be noted that the conversion to methane will result in carbon emissions when utilized. There is also potential to blend hydrogen into existing natural gas infrastructure to lower the overall carbon output.
Solid-state storage involves the use of metal composites such as metal hydrides to store hydrogen and is gaining increasing research interest. While they are yet to be proven for large-scale commercial applications, recent results and costing reveal that metal hydrides can cost below 0.02 AUD per kW. This amounts to one-tenth the cost of lithium storage competitors and buying power from the grid, making solid-state storage highly competitive (Hannam 2020).
18.3.2.3 Transport and Utilization
Hydrogen can be utilized in a range of ways, some which require extensive infrastructure, others that need no/little adjustments to current infrastructure. In its simplest form, hydrogen can be recombined with oxygen to release energy (and produce water as the only by product). This stationary use of hydrogen, through fuel cells and gas turbine supplementation, can be used to produce electricity, thus balancing the production/demand curves for intermittent renewables. Hydrogen can also be used in portable applications, such as in transportation through fuel cell vehicles for material transport, as well as for passenger cars. Figure 18.3 displays the IEA’s data surrounding policy support and incentives for hydrogen deployment as a function of use type around the world. It is clear that most countries are focusing on hydrogen deployment to decarbonize the transportation sector. With the exception of Australia, land masses and the need for extensive land-based transport of energy in PICTs are limited, with delocalized hydrogen generation more suited in this instance.
A horizontally stacked bar graph plots hydrogen using areas versus the number of countries. The data is for, incentives without targets, targets without incentives, and combined incentives with targets. Passenger cars have the highest value with the highest fractions of incentives without targets and combined incentives with targets. Electrolysers have the highest fraction of targets without incentives.
Fig. 18.3
Current policy support for hydrogen deployment. It is seen that a number of countries have developed favourable policies to encourage hydrogen fuel cell driven transportation (IEA 2018)
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18.3.2.4 Summary and Applicability
Exploiting clean hydrogen can assist in decarbonizing a range of sectors and aid PICTs in improving their energy security. Hydrogen holds the ability to support the integration of renewables into the sector, allowing the storage of energy in week to month timeframes. Ultimately, continued research efforts and scaling-up systems will see the costs of technologies for producing, storing, and utilizing clean hydrogen drastically reduced.
The world is increasingly looking toward hydrogen as a potential fuel for the future. Global North nations, such as Japan and Germany, are playing instrumental roles in driving this transition. For example, as part of the 3E+S (energy security, economic efficiency, and environmental protection, plus safety) strategy, Japan plans to establish a “hydrogen economy” by 2050. While Global North countries are driving the change, countries in the Global South (such as the LDC and SIDS) have potential to “be the big winners” in the shift toward the hydrogen economy (Zhai 2019). On both the supply side as well as export potential, Global South countries have the ability to exploit renewable energy resources to produce hydrogen.
Island nations have been proposed as ideal demonstration sites for the realization of the hydrogen economy, including emerging hydrogen technologies. This is because hydrogen has the potential to promote energy autonomy, be used at scales ideal for island nations, and its low emission nature means it can aid in preserving the pristine environments across PICTs (Barbir 2010). In 2011, a demonstration unit of renewable power-driven hydrogen generation, storage and utilization system was established in the remote Aegean Island of Bozcaada, Turkey by a consortium of United Nations Industrial Development Organization (UNIDO), and the International Centre for Hydrogen Energy Technologies (ICHET) (Hydrogenics 2011). The system comprised a 20 kW solar photovoltaic array, a 30 kW array of wind turbines and a 50 kW electrolyser with a hydrogen storage system. The system is capable of subsequently converting hydrogen back to electricity using a 20 kW fuel cell and a genset engine (3 kW). The system was designed to supply 20 households (or equivalent) with uninterrupted electricity for up to 24 h (Barbir 2010).
Currently the uptake of hydrogen as an energy vector within PICTs is low. With the exception of both Australia and New Zealand, who have comprehensive and ambitious hydrogen plans, the smaller PICTs as well as the LDCs and SIDS have no established plans. In fact, many of the “Energy Roadmaps” for the LDCs and SIDS do not even mention hydrogen (Government of the Republic of the Marshall Islands 2018). In 2010, a joint venture between the Cook Islands and UNIDO-ICHET proposed a $3.38 million hydrogen plant on Aitutaki in the Cook Islands. The proposed project was planned to account for less than 10% of the island’s energy demand. However, the proposed project was postponed on grounds of excess capital expenditure which outweighed the benefits to the island (Cook Island News 2011).
On continuing to advance the knowledge, capability, reduce the cost, and increase the safety of renewable/hydrogen systems, their ability to make real impact within PICTs exists. Ultimately, reducing the capital costs of electrolyser systems, as well as increasing the infrastructure surrounding hydrogen use, can advance the use of hydrogen as an energy vector in the Pacific. One particular technological advancement, the use of direct seawater electrolysis, has potential to transform the energy makeup on PICTs.
18.3.3 Hydrocarbons as a Vector
Methane (CH4) is the primary component of natural gas and arguably is the cleanest combusting fossil fuel. Natural gas is often liquified for transportation and storage, as liquid natural gas (LNG). Liquid petroleum gas (LPG) consists mostly of propane and butane. All PICTs already use LPG, mainly for household cooking (Oil and Gas Today 2019).
The combustion of fossil fuels for cooking and heating produces CO2 emissions, however in comparison to alternative approaches (burning biomass or kerosene), using LPG and LNG is a cleaner alternative offering significantly lower environmental and health impacts. Honourable David Day Pacha (the Minister of Energy, Mines and Rural Electrification) in the Solomon Islands, addressed a conference in 2016 stating that the transition to LPG would have “benefits to communities [that] are significant as it enables activities to be performed at night including education, avoiding time spent collecting traditional fuels and removing the risks associated with open fires such as respiratory diseases” (Posts 2020).
For over 50 years, LPG has been supplied to the Pacific, through Origin Energy, for use in domestic, commercial, and industrial applications. Fiji is currently the largest LPG market in the Pacific, consuming around 13,000 tonnes of LPG per annum. There are two LPG carriers operated by Origin Energy, which are capable of supplying 28,000 tonnes per annum to 19 ports within the Pacific region (16 of which are serviced by Origin) (Oil and Gas Today 2019).
The use of LNG and LPG within PICTs sees the region rely on their import and is impacted by fluctuating prices associated with fossil fuels. As a result, local decentralized production of hydrocarbons may improve the security and stability of energy production in the region. As discussed in Chap. 12, biofuels and waste-to-energy approaches are currently being utilized in the PICT. Section 18.3.4.1 will focus on near-to-market technologies for these approaches which have the potential to hold significant benefit, particularly in the Pacific.
18.3.3.1 Onsite Hydrocarbon Production
The production of methane as a fuel (biogas) from waste is becoming increasingly popular, particularly in Global South countries. Biogas consists mostly of biomethane (50–70%), along with carbon dioxide (25–45%) and traces of other gases including hydrogen sulphide, water vapor, and ammonia. From biogas, purification can be used to produce biomethane by removing the other components.
Globally in 2018, 35 million tonnes of oil equivalent (Mtoe) of biogas and biomethane was produced where their assistance in transforming the energy sector worldwide is a strong prospect. In PICTs the use of biodigesters has been mostly restricted to small demonstration sites, majorly focused on piggeries. Thus, current utilization rates in PICTs represent only a small fraction of their potential.
Biogas is typically produced by anaerobic digestion (microorganisms breakdown biodegradable feedstocks in the absence of oxygen). The digestion produces biogas and digestate. The digestate is a solid, sludge like material rich in nutrients that can be used as a fertilizer, as an alternative to chemical fertilizers—helping to secure agricultural food sources and reduce commercial fertiliser purchase and import costs.
A wide range of feedstocks can be exploited for biogas production (IEA 2020b). This allows significant versatility, as site-dependent feedstocks can be exploited in PICTs. The most common feedstocks are animal waste and crop residue. However, municipal solid waste and industrial waste can also be utilized. Smaller, decentralized facilities can be utilized for individual homes while larger facilities can be used across multiple homes as a cooperative project. Another significant benefit is, once established, digesters have minimal cost and upkeep requirements.
If properly established, digesters can aid in reducing environmental footprints through the prevention of greenhouse gas emissions. It has been estimated that biomethane can suppress the emission of ~ 1,000 million tonnes of greenhouse gases by 2040 (IEA 2020b).
To maximize biogas production, research has examined pre-treating the feedstock. Pre-treatments include physical milling, extrusion, heat treatments, microwave treatment, and acid/base treatments. (Achinas et al. 2017) The treatments have been shown to significantly (5–20%) increase methane yield by increasing the biomass surface area and breaking down ligands, aiding in digestion. The pre-treatment technologies can enhance yield; however, they add cost and complexity to the process. There remains a current gap between the research and how it translates into commercialization.
18.3.3.2 Onsite Hydrocarbon Utilization as an Emerging Fuel Source
The biogas can be stored and used directly, this being a particularly feasible route in the LDCs. It is becoming increasingly common to upgrade the produced biogas. The direct utilization of biogas is typically accompanied with a simple pre-treatment to remove hydrogen sulphide by passing the gas through water. The gas can then be combusted directly. The biogas can used for power, heating, or as a clean alternative to the solid biomass used in cooking in LDCs. Depending on the feedstock and digestion conditions, this can result in significant carbon dioxide emissions.
18.3.3.3 Barriers to Entry for Hydrocarbons as a Vector
According to the IEA (2020b), the Asia/Pacific region holds the greatest opportunities for utilizing biogas. This can be attributed to the decentralized nature of the PICTs, as well as rising natural gas/LPG import and consumption.
One of the biggest inhibitors to the implementation of this technology is the lack of knowledge and knowhow. In particular, the lack of knowledge on the attainable biogas levels and optimum digestor conditions for a given feedstock is a significant deterrent (Ward 2013). It has been estimated that the quantity of biogas that can be attained from taro crop residues throughout Samoa is approximately18 million cubic meters per annum.
18.3.4 Ammonia
Globally, approximately $60 billion worth of ammonia is produced every year for utilization, mostly in the form of fertilizers. Recently, ammonia has been gaining attention as a hydrogen carrier for the hydrogen economy. Ammonia stores close to double the energy of liquid hydrogen (on a volume basis) and is simpler to transport and distribute compared to hydrogen.
The commercial Haber–Bosch process for producing ammonia was developed in the early Twentieth Century. The process necessitates high pressures (150–250 atmospheres) and temperatures (400–500 ºC). Additionally, relatively high purity hydrogen and nitrogen feeds are required. Consequently, the process consumes a significant amount of energy and is fundamentally incompatible with small scale, decentralized ammonia production and accommodating renewable energy is unfeasible. PICTs have limited ammonia production capacity via this route and thus limited potential. However, as technology develops and ammonia production moves away from large scale, high capital requirements, LDCs within PICTs will have an increasing role to play. The potential options for ammonia use as an energy vector include in transport (particularly for heavy vehicles), directly in power generation, and as distributed energy storage. Within PICTs, beyond a potential energy vector, ammonia has the ability to enhance food security. Sweet potato is an important crop for the food security, particularly in the island countries in the South Pacific (Hartemink et al. 2000). In Papua New Guinea approximately 60% of the total dietary energy requirements is met by the consumption of sweet potato tubers. Further, cocoa is a significant export vector in Papua New Guinea as well as many countries throughout PICTs (Fidelis and Rajashekhar Rao 2017). These demonstrate that much of the food, and export within the LDCs in the PICTs rely heavily on agriculture, where the ready availability of fertilizer can play a significant role.
18.3.4.1 Ammonia Generation and Utilization
In recent years, technology development towards renewably powered small-scale delocalized production of ammonia rapidly evolved. While the direct synthesis of ammonia electrocatalytically is far from at a stage of commercialization, there remains promise in the emerging technologies, such as the Li-intermediary approach.
As previously discussed, throughout PICTs, diesel generators are key energy sources, supplemented by variable renewable energy (solar and wind). It has been proposed that small to medium scale generators can run effectively on ammonia that is produced and stored locally, in a decentralized on-site and on-demand manner. The direct use of ammonia, as a fuel to substitute diesel can already be seen in small-scale engine demonstrations. For example, a 3.5 kW power generator has been adapted to run in a dual-fuel mode coupled with (and substituting ammonia) for diesel with an ammonia content of up to 80% (Macfarlane et al. 2020). While this has not been directly employed in PICTs to date, the potential to substitute diesel with green ammonia remains an emerging opportunity.
Alternately, ammonia can be produced as a feedstock for hydrogen storage. New technology, developed by CSIRO, can extract hydrogen from ammonia, allowing the ammonia, which is simpler and cheaper to store and transport, to be used as an energy vector (Dolan 2017). The CSIRO technology has the potential to produce hydrogen from ammonia at 5 kg/day (Dolan 2017).
18.4 Energy Production from Waste Plastic
PICTs have a significant issue in dealing with plastic waste. While plastic waste is recycled in many developing countries, landfill and open disposal is common practice in PICTs (Mamad et al. 2018). Over 300,000 tonnes of waste plastic is generated by PICTs per annum, with much of it ending up in coastal water (Australian Government 2020). Plastic is essentially unavoidable in today’s society, however the impact the waste has on PICTs is amplified by the regions reliance on fishing and tourism (Lebreton et al. 2018). Thus, there exists an avenue to exploit this waste as a resource.
Plastics are comprised of petrochemical-based hydrocarbons with stabilizing additives, thus making them difficult to degrade. The plastics can be utilized as raw materials, where the pyrolysis of waste plastics into fuels has potential use as a resource for the decentralized electricity production throughout the region while simultaneously reducing plastic waste.
The pyrolysis of plastic waste involves its thermal degradation into fuels (solid, gas and liquid) where it is heated at high temperatures (300–900 °C) in the absence of oxygen (Miandad et al. 2019). The plastic breaks down and produces a range of gases (hydrogen, methane, carbon dioxide, carbon monoxide, etc.), as well as liquid oil products with different chain lengths (Dayana et al. 2016).
Demonstration plants for waste plastic pyrolysis are beginning to be built throughout PICTs, including the Solomon Islands. The technology reduces both plastic waste and emissions associated with direct combustion of plastic waste while producing fuels for direct use in cooking and electricity generation.
Nufuels have built an integrated system which uses pyrolytic conversion to produce energy for cooking, as well as electricity from waste plastic bags and bottles. The system has potential to be extended to biomass conversion in a similar manner discussed above (in Sect. 18.3.3). The Nufuels integrated system, shown in Fig. 18.4, is simple to use and can be operated and maintained by locals.
A photograph has a man working on a plant for plastic pyrolysis to produce energy. It has various containers connected with pipes. There is a building and trees in the background.
New technology developed by the University of Sydney, Cat-HTR, has potential to improve yields for plastic pyrolysis. Cat-HTR uses water, high pressure, and high temperature to convert plastic into gases for cooking, as well as liquid fuels. In 2019, the Government of Timor-Leste began preparing a memorandum of understanding with Mura Technology to begin developing the use of Cat-HTR technology in the region (Government of Timor-Leste 2019). The proposed plant will be capable of processing 20,000 tonnes of plastic waste annually, while producing 17,000 tonnes of synthetic fuels. The process will include a pay-for-plastic system where the people of Timor-Leste will contribute to “safe and clean drinking water in schools and improve sanitation, provide essential resources for education, and provide low-cost energy from renewable energy sources in rural areas” (Government of Timor-Lest 2019).
18.5 Conclusions and Outlook
This chapter has outlined emerging technologies that have potential to aid in the transition to a clean energy future in the Pacific region. The current global trend driving movement away from centralized, fossil fuel-driven electricity production is being driven by increased environmental awareness, desire for national independence from fluctuating fossil fuel supplies and prices, as well as a decreasing supplies of finite fossil fuels. This has led to a substantial increase in research toward (1) renewable electricity generation and (2) conversion of energy (both renewable electricity, known as Power-to-X, as well as energy held within plastics and biodegradable waste, Waste-to-X) into a range of energy carriers for use and storage.
While the growth of research toward these decentralized energy generation, distribution, and utilization approaches is being driven from a global approach, the potential implications for the Pacific region are vast. As identified in Chap. 12, a transition to renewable energy in the Pacific region is evident, although there remains a continued reliance on fossil fuels to satisfy growing energy demand. Significant scope exists for newly developed, near-to-market technologies to expedite the transition in this region. The nature of PICTs is characterized by a large degree of variability in terms of development; energy, food, and water security; and resources. The low energy security, and lack of access to electricity and clean cooking technologies, which defines the SIDS and LDCs throughout the region also indicates that rapid change is needed. The nature of the region presents barriers to the transformation of the sector as well as a range of advantages, such that the sector is uniquely positioned to drive the transformation.
Battery technology is arguably the closest to market technology for load balancing in the use of variable renewable energy in PICTs. The increase in battery research, novel material engineering approaches, as well as the impact of scaling from increased production means prices are becoming more competitive. Unfortunately, the limitation in terms of short storage timescales, high capital costs, and required “knowhow” hampers direct implementation. The development of hydrogen technologies, in particular, the further-from-market hydrogen production directly from seawater has a unique opportunity in the Pacific region. While there are limitations from a technological development perspective, as well as barriers to entry from a capital expenditure perspective, there remains promise for implementation.
The conversion of waste (biodegradable and plastic) into solid, liquid, and gaseous fuels, has significant potential within the Pacific region as well. This technology is rapidly developing and cheap to install with low maintenance costs. New developments in catalyst incorporation to tune the ratio of the products, post-treatment technologies (to upgrade the gases produced), and the incorporation of water in high pressure pyrolytic upgrading has been shown to increase yields significantly.
Ultimately, the Pacific region is uniquely positioned to aid in the transformation to delocalized, sustainable, tailored energy generation, storage, and utilization. As the technologies continue to develop, the suitability for their implementation in the region follows. With the appropriate policy and incentive frameworks there is much optimism for energy security in the Pacific.
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