Countries around the world are currently implementing clean, environmentally friendly energy in order to face the transition to technologies that allow for the decrease of greenhouse gas emissions. Solar, geothermal, wind, hydrogen, biomass, and other new renewable energies have all been widely used to lessen reliance on fossil fuels, which emit a lot of CO2. Hydrogen is one of the renewable energy sources that is seen as promising for the future. Because it is storable, transportable, and utilisable, hydrogen offers immense potential for industrial and transportation applications. Hydrogen can be created from a variety of resources using a variety of materials, technological pathways, and both fossil fuels and new renewable energy. The storage technique is important to the growth of hydrogen energy. High gravimetric energy density, volumetric energy density, and low temperature and pressure are all features of good hydrogen storage. Indonesia has a lot of potential for hydrogen energy development. The application of hydrogen energy as a source of power generation is the most appropriate in Indonesia nowadays. In Indonesia, the transportation sector that uses hydrogen energy is currently underdeveloped. Hydrogen in transportation has been unable to compete with electric vehicle technology, which is far safer than hydrogen as a vehicle fuel source. Hydrogen generation requires large-scale storage devices with high gravitational and volumetric energy densities, as well as moderate temperatures and pressures. Based on present conditions, the liquid organic hydrogen carrier (LOHC) is the optimum storage technique in Indonesia. Hydrogen is the lightest and most basic element, with only one electron and one proton, and it is colorless, odorless, and combustible. Hydrogen has been used as a source of energy for over 200 years. Hydrogen gas is produced by the interaction of sulfuric acid and iron, according to Swiss scientist Paracelcus. Myelin also stated that hydrogen gas was burned in the seventeenth century. In the past, many raw materials were used to discover hydrogen. The use of hydrogen as an energy source has also been tested in the area where Sir William Robert Grove first created the hydrogen-powered fuel cell. In 1900, hydrogen was also employed to keep aircraft buoyant. Furthermore, the Soviet Union launched the first space shuttle, which used liquid hydrogen fuel, in 1981. Because of its flammability, hydrogen is frequently associated with risk. On May 6, 1937, the Hindenburg tragedy occurred, killing 36 passengers. The German airplane, which had 211,890 m2 of hydrogen gas in 16 camps or cells, was destroyed in a fire in just a few minutes. On the LZ 10 Schwaben aircraft, a fire broke out due to hydrogen being ignited by a spark created by static charge accumulating in the gas bag. This incident resulted in the injuries of 34 soldiers. On February 21, 1922, a US military plane crashed into a high-voltage power wire near Langley Field in Hampton Roads, Virginia, killing 34 people. The United States government decided not to develop hydrogen-powered aircraft.

The shifts of the climate have been encountered by lots of people from coast to coast, time to time and it’s also coming from human activities since the 1800s from the burning of fossil fuels. Greenhouse gas emissions are the main substances that make climate change which include methane and carbon dioxide. The prime emitters are mostly coming from fossil energy electric power plants, transport, buildings, industries, agriculture fields and farms, and land-use sectors [1]. The gasoline that most people use for their cars is one of them. All living creatures on Earth especially wild animals and humans themselves must put on their survival mode to survive from the impact of climate change. It can be seen from the intense and constant changes in environmental conditions such as recurring droughts, storms, heatwaves, rising sea levels, melting glaciers, and warming oceans [2]. In Indonesia, where the whole country’s main food depends on the availability of rice can also be impacted which will worsen the food supply. The study showed on South Sumatra and Great Malang on the indication of climate changes’ impact on the production of paddy/rice, that the agriculture system is very fragile to climate change, and it leads to the decline of paddy production in a few places in both regions. The study calculates the temporal data from 1980 – 2030 also shows a prediction that the paddy production will be grossly declined by 1,37% per year [3]. Global Climate Risk Index 2021 from Germanwatch listed Indonesia in 14th of a climate risk index for 2019 scored 24.83 with fatalities in 2019 ranked in 3rd position. This data shows that Indonesia has a high potential to be badly affected by climate change if there’s no prevention action taken soon. Seroja tropical cyclone that occurred in East Nusa Tenggara, West Nusa Tenggara, and around East Timor from 3rd April to 12th April 2021 was one of the most destructive tropical cyclones after Kenanga cyclone in southern Java back in 2008, told by the National Disaster Mitigation Agency of East Nusa Tenggara (BNPB) [4]. The cyclone that killed at least 222 people, declining production of paddy, and high-risk of climate change fatalities; future proof that climate change affects and will vanish more people. The climate disasters that happen from past to future create high susceptibility to climate change fatalities. The susceptibility itself can be determined by the infrastructure, food supply, and economic framework conditions. World Risk Report 2021 shows that Indonesia is ranked 40th in high risk, scoring 10.39 in the 7.59 – 10.75 range. The susceptibility of Indonesia is classified as medium, but Indonesia still faces an exceedingly high exposure component in which is determined as the risk of getting earthquakes, storms, floods, drought, and sea-level rise.

Indonesia is a marine country, meaning it is made up of islands with a land area that is almost equal to the amount of sea. Indonesia's enormous seas make it one of the world's countries with the greatest potential for creating energy in water, particularly in the sea. Marine energy is one of the most promising renewable energy sources, with plentiful resources and a low environmental impact. Indonesia's waters supply renewable energy sources with a large potential of roughly 60.98 GW scattered across the country's oceans. This can be developed to be utilized as an energy source to replace fossil fuels that have been used in the past. In accordance with the President's decision, renewable energy's contribution to the overall national primary energy mix must be boosted to 17 percent by 2025. With Indonesia's potential as a maritime nation, marine energy is gaining traction as a way to boost electrical energy consumption and contribute considerably to the country's primary energy mix. Tidal energy is a type of marine energy that can be used as a new renewable energy source. Tides are a natural occurrence in which sea levels rise and fall on a regular basis due to a combination of gravity and the attracting force of astronomical objects, particularly the sun, earth, and moon. Tides are caused by gravitational attraction as well as the centrifugal force. The centrifugal effect is a push to the outside of the rotational axis. The tidal cycle occurs twice a day, with two low tides (semidiural) or simply once a day (periodic). In Indonesia, there is a total of 41 GW of tidal energy potential scattered across Medan (North Sumatra), NTB, NTT, Riau Province, West Kalimantan, North Sulawesi, Moluccas, and West Papua, with an average change in sea level of roughly 3-5 meters between highs and lows).

Indonesia is one of the world’s most populous nations. The growing population and middle-upper class demand farmers to produce more food. However, the lack of proper storage pre-and post-consumer results in massive amounts of food waste. These wastes are often transported to landfills, where it will decompose and produce methane gas. As food waste gain more attention, both scientists and citizens have paid more attention to this grave situation. Incineration is one of the methods widely used, where food wastes are burnt to produce energy and generate electricity. However, this process releases harmful gases, including dioxins. One of the alternatives for incineration is anaerobic digestion. Anaerobic digestion is deemed most suitable because it is relatively easy and cheap to install. There are several types of reactors, with the most optimum reactor being the semi-continuously mixed reactor. In cases where the microbe environment is unstable due to low food diversity, co-digesters such as manure can be used. The application of anaerobic digestion allows us to kill two birds with one stone: reducing greenhouse gas emissions and generating clean energy. As anaerobic digestion gains more popularity, it is expected that it will contribute to Indonesia’s nationally determined contribution (NDC) targets.

There has been much concern about a massive increase in the world’s population. It causes the scarcity of resources such as food, health, and energy. Increasing of energy needs, limitation of fossil-fuel-based energy resources, fluctuation of fossil fuel global price and environmental and human health issue of greenhouse gases (GHG) emission have led management energy crises in Indonesia and forced the Government of Indonesia (GOI) to increase fossil fuel import and price (Mayasari, et al, 2019). Biofuels can be an alternative to fossil fuels. Compared to fossil fuels, biofuels have lower carbon emissions. Biofuels can help in reducing the emission of greenhouse gases (Rasool and Hemalatha, 2016). Fuels derived from plants come under renewable sources and can be grown anywhere. Biofuels are defined as liquid or gaseous fuels that derive from biomass materials. Biofuel (Rasool and Hemalatha, 2016) are mainly obtained from biological materials, mostly from plants, animals, wastes and microorganisms (Datta, et al., 2019). Biofuels can be used alone or in combination with other fossil fuels such as petrol (Rasool and Hemalatha, 2016). Primary biofuels are mostly fuel wood, wood chips, pellets and organic materials which are generally used for heating generation, cooking or electricity purposes in a crude appearance. Secondary biofuels which are acquired from cultured biomass and consist of liquid biofuels that are extensively used in transportation and industrial purposes. The third-generation biofuels are fuels that would be produced from algal biomass, which has a characteristic growth yield as compared with conventional lignocellulosic biomass (Datta, et al 2019).

Fossil fuel is one of the most important energy sources in Indonesia and is widely used both in transportation, industry, and households. Fossil fuel is a fuel formed by natural processes such as the anaerobic decomposition of buried dead organisms and their resulting fossil fuels typically have an age of millions of years. Energy consumption in Indonesia, based on data from EIA (Energy Information Administration) from 1980 to 2018, has been rising sharply as a result of the high population. This condition is certainly a serious concern because if new energy reserves are not found, Indonesia is going to have an energy crisis. Forecasting primary energy production and consumption markets is critical for efficient energy policy implementation. More precise forecasts of energy consumption and production are vital when consumption growth rates are greater than production growth rates as in the case of Indonesia. To understand the future of energy consumption and production, we utilize machine learning algorithms, Holts Winter forecasting, Seasonal Autoregressive Integrated Moving Average (SARIMA), and Autoregressive Integrated Moving Average (ARIMA) model. We trained and evaluated the model using annual data from 1980 to 2018. The Holts Winters model and SARIMA outperform the ARIMA. The prediction shows that the supply of dry natural gas and coal is secure, whereas the supply of petroleum is in jeopardy. Coal is the safest energy source, according to forecasted predictions, with considerable production, growing 23% from 2018.

Optimization of the utilization of renewable energy (EBT) must be carried out as part of an effort to raise sustainable development in order to meet the energy mix objective by 2025. Biomass is one of the renewable energy sources with considerable potential for development. Biomass is a carbon-based substance that can release heat when oxidized. When used as an energy source, biomass has various advantages, one of which is that it is renewable, allowing it to be classified as sustainable energy. However, the current use of biomass as an energy source is still very low, at 1,895.7 MW, or around 5.8 percent of its potential of 32.6 GW. The government began to devise and implement several strategies, one of which was the cofiring program. Co-firing is the use of a certain ratio of coal and biomass as fuel while maintaining power plant quality and efficiency. In Indonesia, the co-firing program is stated in the 2019-2038 National Electricity General Plan (RUKN) as part of the Energy Conservation Roadmap on the energy supply side in power plants. The goal is to enhance the renewable energy mix. Because PLN's PLTU capacity is relatively substantial, 31 GW or 50.3 percent of the country's installed capacity, it has the potential to be used more effectively to reach the target. PLN intends to make transition of 114 PLTUs to co-firing by 2024. This co-firing approach will be enable building of a large scale biomass industry having capacity of consistently supplying of co-firing fuel ranging from 4 to 9 million tons per year. It is envisaged that this co-firing initiative will help Indonesia bridge the gap between the aim and the actual implementation of a renewable energy mix. The solution is co-firing or co-combustion, which is the simultaneous combustion of coal and biomass in the combustion chamber of an existing large-scale power plant. An existing and operating coal fueled PLTU is more ideal for co-firing if its location is not too far from biomass source (less than 50 km to 80 km), lowering the cost of transporting biomass. Co-firing is more advantageous for low-quality coal, which is widely available in Indonesia. It is also more environmentally friendly. Meanwhile, co-combustion is proven to be more costeffective for electricity generation. Furthermore, the combustion system at PLTU in Indonesia is generally suited for co-firing with biomass. According to the combustion operation, there are at least two methods of co-firing: direct cofiring and indirect co-firing. Direct co-firing combustion process is simpler, coal and biomass are burned at the same time. While in indirect method, biomass gasification process needs to be done, prior to the mixing of those fuels in the combustion chamber. Theoretically cofiring with biomass does not add GHG, while the biomass grown in its natural state earlier, CO2 was absorbed during photosynthetic process of vegetations and trees. During co-firing combustion, in turn, CO2 then released to the air.

In the recent decade, the potential energy of new and renewable energy (EBT) has attracted the attention of the world's leaders. Emissions of carbon created by burning fossil fuels are viewed as something that should be reduced as far as possible, and one method to do so is to transition to more ecologically friendly EBT. Nuclear is one of non-carbon releasing power generation. To ensure energy security and nuclear energy sustainability (sustainability), the globe began to turn to thorium as a material fuels nuclear option in the late 1990s. Thorium is an element that, when absorbed by neutrons, becomes fissile U-233, which can be used as a material fuel in nuclear reactors to initiate a reaction cycle. Indonesia's future hopes are pinned on this new form of energy source. In Bangka, West Kalimantan, and West Sulawesi, the thorium content is predicted to be between 210,000 and 270,000 tons. The rare earth of thorium phosphate mineral monazite (CeLa-Y), which contains roughly 12% ThO2, has the highest thorium concentration of any mineral. ThO2 is present in about 6 to 7% of the population on average. Thorcon International Pte.Ltd. claims to be the first in the world to build ThoriumFueled Power Plant (PLTT) with a capacity of 500 Megawatts (MW). BATAN (National Nuclear Energy Agency) already has the technology to process thorium ore, including the separation of thorium from the mineral monazite. According to research from 2015, the country has thorium reserves of up to 130,974 tons, as well as uranium reserves of 74,397 tons. Thorium's potential as a key for new energy source and the core of the clean energy revolution has been an enticing notion for many years. Extracting nuclear energy in a cost-effective manner remains a challenge that will necessitate a significant investment in research and development. However, if the energy source is actually present within Indonesia's soil, it is reasonable for this country to take advantage of its potential in order to ensure the country's clean energy supply in the following decades, which ensures no damage to the environment or its people.

Indonesia is currently targeting the acceleration of national energy development in accordance with PP. 79 of 2014. Regarding that target, the government is starting to empower many of potential EBT sectors, such as PLTBm. Biomass sector is targeted to contribute in some portion of our energy supplies around 2% - 5% by 2025. With its geographical location on the equator, Indonesia’s tropical climate allows biodiversity to nourish, enriching the variety of biomass sources as alternative supplies in this emerging biomass energy cultivation. On the other hand, Indonesia is also a country with the largest crude palm oil (CPO) production in the world, with a total production of 47 million tons in 2019. Regarding this fact, researches nowadays are focusing on waste based-biomass from empty oil palm bunches as an alternative, despite the high cost pre-treatment process, uniformity of composition, and low calorific value. To be able to use it as a fuel, it is necessary to have a method to improve its quality. This biomass contains 55% - 60% lignocellulosic material, and has a proximate energy value over 4,492.11 Kcal/ton. Torrefaction is a thermochemical pre-treatment process for biomass materials, an adjusted pyrolysis method for organic-based materials that is partially controlled and generally occurs at a temperature range of 200-300 ° C in atmospheric pressure. This process is widely used for the necessity to upgrade biomass quality to higher heating value, energy density, combustion efficiency and lower humidity. The torrefaction process on empty fruit bunches may utilize residual heat from low pressure steam effluent system. Oil palm’s empty fruit bunches with high humidity level around 70% are torrefied with Heat Air Dryer (HAD) and Superheater Steam Dryer (SSD) unit before being used as biomass fuel. During the drying process, empty fruit bunches experience a decrease in water content through heating process by hot air or steam. In the HAD unit, the output can achieve a humidity level of 57% and with a total efficiency level of 92.7%. On SSD units, the output can achieve up to 18% moisture reduction with an efficiency rate of 90.2%. The combination of the torrefaction process through HAD and SSD by utilizing waste heat from steam can maximize the quality of biomass. This method ,in exchange of additional capital cost, will yield a promising higher return resulted from lower transportation cost and longer boiler lifetime.