SAJC Cluster 1 Lecture 7 Notes (Renewable Energy)

St. Andrew’s Junior College H2 Cluster 1: Development, Economy and Environment (Topic 1.1) H2_Cluster 1_Lecture 7_2024/pg 1 Lecture 7 Managing Resources (I): Renewable Energy KEY QUESTION: How do we manage the use of renewable energy sources? With the completion of this lecture, attached readings and tutorial, you should be able to discuss: - Potential of solar power and hydropower to reduce dependence on fossil fuels as energy sources - Limitations of solar power and hydropower in providing energy security - Trade-offs associated with solar power and hydropower: economic, environmental and social considerations Lecture Outline 7.1 Energy security and the role of renewable energy 7.2 Solar Power 7.2.1 Potential of solar power to reduce dependence on fossil fuels 7.2.2 Limitations of solar power in providing energy security 7.2.3 Trade-offs associated with solar power (a) Economic considerations (b) Environmental considerations (c) Social considerations 7.3 Hydropower 7.3.1 Potential of hydropower to reduce dependence on fossil fuels 7.3.2 Limitations of hydropower in providing energy security 7.3.3 Trade-offs associated with hydropower (a) Economic considerations (b) Environmental considerations (c) Social considerations Reading 1: Why hasn’t solar energy in Singapore taken off in a big way after so long? Reading 2: The cost of Laos’ quest to be Southeast Asia’s ‘battery’, and the World Heritage town at risk Workers installing solar panels on the roof of a house during a hot day in Singapore.

St. Andrew’s Junior College H2 Cluster 1: Development, Economy and Environment (Topic 1.1) H2_Cluster 1_Lecture 7_2024/pg 2 7.1 Energy security and the role of renewable energy • Energy security is defined as the reliable supply of energy at reasonable prices. Energy security can be studied in these aspects: o long-term energy security mainly deals with timely investments to supply energy in line with economic developments and environmental needs. o short-term energy security focuses on the ability of the energy system to react promptly to sudden changes in the supply-demand balance. • Globally, fossil fuels are burned to supply more than 80% of the world’s energy (see Fig. 1). There are many reasons to explain their continued adoption by countries to ensure energy security (see Table 1). These include their already ready availability which is further aided by how technology helps to find more of these sources (e.g. hydraulic fracturing for shale gas) as well as relatively stable prices (such as for coal). • However, emissions of carbon dioxide from fossil fuel combustion and industrial processes contributed about 78% of total greenhouse gas emission increase between 1970 and 2010. Our heavy reliance on burning fossil fuels such as coal and oil for electricity generati on has encouraged the release of carbon dioxide into the atmosphere much faster than the Earth can reabsorb them into carbon sinks (such as forests). (More on this in Cluster 3) • Coupled with our ever-increasing demand for electricity, it is easy to predict that carbon concentration in the atmosphere will only intensify unless environmentally -friendlier sources of energy are found. • Much attention has thus been cast on sources of energy that will release less carbon than the burning of fossil fuels would. Renewable energy sources could significantly reduce greenhouse gas (GHG) emissions. Many are already proven and effective sources of energy, but at only 11%, remain dwarfed by consumption of coal, oil, and gas (see again Fig. 1). • In this lecture, we examine the potentials of renewable energy sources as a solution to energy security, using solar power and hydropower as our case-studies. We also consider the reasons for their relatively slow acceptance by countries despite the benefits that they can bring. Fig. 1

St. Andrew’s Junior College H2 Cluster 1: Development, Economy and Environment (Topic 1.1) H2_Cluster 1_Lecture 7_2024/pg 3 Table 1. Advantages and Disadvantages of Fossil Fuels Fossil Fuels Advantages Disadvantages Oil • Indispensable in road transport • Petrochemical industries generate various products and by products which are valuable raw materials for other industries • Leading tradable commodity • Flexible use – can be distilled into different fuel products • Easy to transport and store fuel • Cleaner and easier to burn than coal • Most economical source of energy • Non-renewable – takes millions of years to form • Burning oil generates CO2, a GHG • Sulphur from oil combines with moisture in atmosphere to produce acid rain • Not as clean or efficient in use as gas • Serious oil spills from super tankers and pipelines • High price volatility • Geopolitical tensions in areas with the largest reserves • Market is dominated by leading oil-producing countries and large TNCs • Concerns that ‘peak oil’ (i.e. when global oil extraction goes into decline, creating shortages and price hikes) is not far away Natural Gas • Cleanest of fossil fuels • Flexible and efficient fuel for power and heat generation • Increasing proven reserves from unconventional sources (reassessment of speculative reserves and shale gas) • Reserves increasingly off shore or in more remote areas • Large investment requirement for gas transport and distribution • Increasingly long supply routes with high infrastructure costs Coal • Wider geographical distribution and more plentiful reserves • New technologies to improve environmental performance • Stable prices • High emissions of carbon, particulates and other pollutants • Environmental mitigation such as carbon capture (use) and storage (CCS/CCUS) have a negative impact on energy efficiency 7.2 Solar Power • Solar energy is the technology used to harness the sun's energy and make it useable. In 2019, the technology produced about 1% of global energy demand (see Fig. 1). • Photovoltaic (PV) cells, or solar panels, are required to help with the conversion process. When sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity. (See Fig. 2) • Current solar energy reaching the Earth’s surface (198 W/m2) far exceeds all current energy requirements. Solar energy can be used for heating of buildings, be converted into electricity with photovoltaic cells on solar panels. However, use of solar energy requires site characteristics, e.g. site must have “solar access” – not having buildings or vegetation block the Sun. Fig. 2

St. Andrew’s Junior College H2 Cluster 1: Development, Economy and Environment (Topic 1.1) H2_Cluster 1_Lecture 7_2024/pg 4 7.2.1 Potential of solar power to reduce dependence on fossil fuels • Solar power is a clean energy source that produces no direct greenhouse gas emissions during operation. By transitioning to solar energy, countries can mitigate the environmental impacts associated with conventional fossil fuel-based power generation. The reduction in carbon emissions supports efforts to combat climate change and promotes a more sustainable and secure future. • Solar power derives energy from the sun, which is an abundant and renewable resource. Recall from Lect 5 that solar energy is infinitely renewable. This means that solar power can provide a consistent and sustainable source of energy for the long term, reducing dependence on finite fossil fuel resources. • Solar panels have also benefitted from production technology advances, which have made it cheaper and easier to produce these panels. As can be seen in Fig. 3, the prices of electricity from solar are now just as competitive as electricity derived from fossil fuels. Fig. 3

St. Andrew’s Junior College H2 Cluster 1: Development, Economy and