Solar PV Hybrid Systems: Integrating Solar with Other Renewables in Indonesian Islands

Solar PV Hybrid Systems are innovative solutions that combine solar panels with other energy sources, such as storage batteries or the PLN grid, to ensure a more stable and efficient electricity supply. The system allows users to optimally utilize solar energy by storing excess energy for use when solar production is low, such as at night or during cloudy weather. The main components in the system include solar panels (PV) that convert sunlight into DC electricity, hybrid inverters that convert DC electricity into AC and manage the flow of energy between solar panels, batteries, and the grid, storage batteries to store excess energy, and an energy management system that manages the distribution and use of energy to make it more efficient. A hybrid generation system is a generation system that uses more than one type of primary energy source for the same load. The main purpose of developing a hybrid plant is to ensure the supply of primary energy sources to the plant, so that electricity production is also guaranteed. On the other hand, with this hybrid system, the generation system will also become more efficient and economical.

The need for Solar PV Hybrid Systems in Indonesia is increasingly urgent to improve the electrification ratio, especially in remote areas not yet covered by the main grid. These systems allow the combination of solar power with other renewable energy sources, such as wind and micro-hydro, thereby improving the efficiency and reliability of electricity supply. In addition, the implementation of hybrid systems can reduce dependence on fossil fuels, help reduce carbon emissions, and support the government's target of increasing the renewable energy mix to 35% by 2034, with an additional 17 GW of solar capacity. With unique geographical challenges, Solar PV Hybrid Systems are a practical solution for remote area electrification, in line with Indonesia's efforts to achieve more sustainable energy security.

Indonesia, as an archipelago, faces significant challenges in providing reliable and affordable electricity. Many small islands still rely on diesel generators to meet their electricity needs. This reliance leads to high operational costs due to fluctuating fuel prices and expensive transportation costs. In addition, limited infrastructure such as roads and bridges hinder efficient energy distribution, especially in remote areas. Equitable access to electricity and electricity quality is in accordance with the national energy policy, PP 79/2014, which clearly states that the national energy policy aims to create national energy security and independence. One of the priorities in the KEN is to prioritize energy development, utilizing existing resources in the country for people or parties who have not yet gained access to energy, both electricity and others.

However, Indonesia has abundant renewable energy potential that can be utilized to overcome these challenges. Solar energy, for example, is highly potential with high sunlight intensity throughout the year. In addition, the potential for wind, micro hydro, and biomass energy is also scattered in various regions, offering alternative sustainable energy sources. Currently, the development of EBT refers to Presidential Regulation No. 5 of 2006 concerning National Energy Policy. The Presidential Regulation states that the contribution of EBT in the national primary energy mix in 2025 is 17% with a composition of 5% biofuels, 5% geothermal, 5% biomass, nuclear, water, solar, and wind, and 2% liquefied coal. For this reason, the steps to be taken by the Government are to increase the installed capacity of Micro Hydro Power Plants to 2.846 MW in 2025, installed capacity of Biomass 180 MW in 2020, installed capacity of wind (PLT Bayu) of 0,97 GW in 2025, solar 0,87 GW in 2024, and nuclear 4,2 GW in 2024. The total investment absorbed by renewable energy development until 2025 is projected at 13,2 million USD. The implementation of hybrid systems that integrate various renewable energy sources is an effective solution. By combining solar, wind, micro-hydro and biomass, these systems can provide a more stable electricity supply and reduce dependence on fossil fuels. In addition, hybrid systems can reduce operational costs and support the development of more efficient energy infrastructure in the Indonesian archipelago.

To meet the need for reliable and sustainable energy in island areas, Solar PV Hybrid Systems are an effective solution. These systems combine various renewable energy sources such as solar, wind, micro-hydro and biomass with advanced energy storage and management systems. With this approach, the electricity supply becomes more stable, reduces dependence on fossil fuels, and improves energy use efficiency. Here are the main components and technologies that support solar hybrid systems:

1.     Main Components of Hybrid System

• Solar PV as the main energy source

  o   Converts sunlight into electricity through photovoltaic cells.

  o   Used directly or stored in batteries for later use.

• Storage battery for power stabilization

  o   Lithium-ion: More efficient, lightweight, high energy density.

  o   Lead-acid: Cheaper, shorter lifespan than lithium-ion.

  o   Serves as backup power when the main source is unavailable.

2.     Other Renewable Energy

• Wind

  o   Capitalize on the steady wind speeds in coastal and island areas.

  o   Wind turbines generate additional electricity for hybrid systems.

• Micro hydro

  o   Uses small rivers and mini waterfalls as an energy source.

  o   Suitable for areas with constant water flow.

• Biomass

  o   Uses organic waste such as wood, rice husks, or agricultural residues.

  o   Generates electricity through combustion or gasification.

3.     Energy Control and Management System

• Smart Grid: Optimizing energy distribution with smart grid systems.

• Internet of Things (IoT): Remotely monitor and control system performance.

• Artificial Intelligence (AI): Analyzing energy usage data to improve efficiency.

Solar PV Hybrid Systems provide major economic, environmental and energy security benefits, especially for Indonesia's islands and remote areas. From an economic perspective, these systems are able to reduce operational costs that previously depended on expensive and unstable diesel fuel. By adopting solar energy and other renewable energy sources, the cost of electricity production can be reduced, thus reducing the burden of government subsidies for remote areas. In addition, the utilization of renewable energy helps improve energy efficiency and ensures more stable electricity availability, reducing the risk of frequent blackouts due to dependence on a single energy source. From an environmental perspective, solar hybrid systems contribute to reducing carbon emissions and the negative impacts of burning fossil fuels, thus helping to mitigate climate change. The use of locally available renewable energy, such as solar, wind and biomass, is also more environmentally friendly than fossil fuels. In addition, the social benefits of these systems are significant, as stable access to electricity allows communities to develop new businesses such as seafood refrigeration, small industries, and other electricity-based services, which were previously difficult due to limited energy supply. Thus, the implementation of Solar PV Hybrid Systems not only improves the quality of life of communities, but also promotes more inclusive and sustainable economic growth.

The implementation of Solar PV Hybrid systems in Indonesia faces various technical challenges that need to be overcome to ensure their reliability and efficiency. One of the main challenges is the intermittency of solar power, where electricity production varies depending on weather conditions and time of day. Therefore, energy storage technologies, such as lithium-ion batteries, are required to stabilize the electricity supply. In addition, grid stability is also an important issue, especially in managing multiple renewable energy sources simultaneously to avoid power fluctuations that can disrupt system operations. Another challenge is installation and maintenance in remote areas, which often face limited infrastructure, difficult transportation of equipment, and a lack of local experts who can properly handle these systems. In addition to technical challenges, non-technical aspects also factor into the successful implementation of hybrid systems. Supportive regulations and policies, such as electricity tariff schemes for renewable energy and PLN's role in the management of hybrid projects, are essential to ensure the sustainability of these systems. In terms of economics, high initial investment costs are often a barrier for local governments and private investors in developing these projects. Therefore, innovative funding models, such as Public-Private Partnerships (PPPs), subsidies or tax incentives, are needed. In addition, human resources (HR) is also a challenge, given the lack of experts skilled in the installation, operation and maintenance of these systems. To address this issue, training programs for local communities are needed to increase their capacity to operate hybrid systems independently.

In addition to the implementation in Indonesia, various countries have also successfully implemented hybrid renewable energy systems to improve electricity reliability in island regions. One interesting example is the Philippines, which has many islands with similar electrification challenges to Indonesia. Internationally, the Philippines has successfully implemented a hybrid system by combining diesel power generation and battery energy storage systems (BESS). One of the leading energy companies in the Philippines, AboitizPower, operates a hybrid BESS system that functions to maintain the security of the electricity grid. When there is an imbalance in the grid, this system can immediately function by running the battery fully for the first 13 minutes, then releasing 49 MW to allow the diesel engine to achieve increased power. After this period, the discharge from the battery adjusts until the diesel engine reaches full load. This implementation shows how the integration of energy storage technology with conventional energy sources can improve the stability and reliability of electricity supply in island regions. AboitizPower operates various power generation facilities covering both renewable and non-renewable energy sources, with a total installed capacity of 4.482,13 MW as of Q3 2023. In an effort to support the energy transition in the Philippines, AboitizPower is committed to balancing its energy portfolio by targeting a 50:50 ratio of renewable and thermal capacity by 2030. The company plans to invest approximately ₱190 billion in the next decade to add 3,700 MW of renewable energy capacity through various projects, including the development of solar and geothermal power plants.