Of the millions of wells drilled, approximately 3.5 million are now abandoned, with some being properly plugged and others left unplugged. Unplugged wells can emit greenhouse gases, contaminate surrounding environments, and pose safety hazards. Orphaned wells, which lack a responsible operator, become the financial responsibility of the government and taxpayers.

Access to clean cooking fuels is crucial for gender equity and poverty alleviation. Currently, billions of people lack safe and affordable energy sources for cooking. Women and girls bear a disproportionate burden in collecting and processing polluting fuels, affecting their well-being and opportunities. Clean cooking energy reduces cooking time, allowing women to engage in other activities like childcare, work, and household chores.

As of January 2023, 575 utility-scale biopower plants were operational globally, with a total capacity of over 29,000 MW, less than 0.5% of worldwide power generation. An additional 6,000 MW are under construction. China is believed to significantly underreport its true biopower capacity, perhaps as high as 22,000 MW, primarily from agricultural residues and waste-to-energy facilities. Brazil, another major player, relies largely on sugarcane byproducts.

The world energy system is experiencing seismic shifts, with a rapid expansion of low-carbon fuels and energy efficiency. However, fossil fuels still dominate investments despite the need to reduce greenhouse gas emissions. Different countries prioritize energy RD&D in diverse ways, and state-owned enterprises play a significant role.

The safety of nuclear reactors is a subject of debate. While incidents like Three Mile Island, Chernobyl, and Fukushima have had impacts on human health and the environment, the overall risks of radiation exposure are considered small. Advancements in technology and regulations have significantly reduced the frequency of core damage incidents. Nuclear power is an important low-carbon energy source, but opinions differ on its safety compared to fossil fuels and renewables.

Biopower is electricity generated from renewable organic materials, such as plants and animals. Different countries rely on various biomass sources, including sugarcane, trees, and municipal waste, to produce biopower. However, the impact of biopower on climate change is complex. Despite being initially perceived as carbon neutral, the use of fossil fuels in bioenergy systems and the land requirements for biomass production can have significant environmental consequences.

While energy use is connected to prosperity, the relationship is not linear. Different countries achieve varying levels of prosperity at the same energy use per capita, and there are diminishing returns where increased energy use results in smaller improvements in prosperity. High levels of prosperity can be achieved with lower energy consumption.

Access to safe water is vital for human well-being. While progress has been made, millions still lack basic water services. Energy plays a key role in expanding water access, powering machinery, pumps, and purification systems. Increasing energy use per capita improves access to clean water, but the impact diminishes at higher energy levels.

Energy use and economic output are interconnected. Wealthier countries typically have higher energy consumption per person, contributing to their higher GDP per capita. However, various factors such as economic structure, geography, lifestyle, and public policy also influence energy consumption.

Energy is essential for education, enabling longer study hours, technological advancements, and improved outcomes. While access to education has improved globally, certain regions still face challenges. Increasing energy access, particularly electricity, positively impacts education.

Women represent 40% of the global solar photovoltaic (PV) workforce, double the share in the wind industry and oil and gas sector. However, they are mainly in administrative and non-STEM technical positions, with underrepresentation in STEM and senior management roles. Gender bias and barriers to recruitment, advancement, and work-life balance exist in the industry, with women reporting higher perception of pay gaps and barriers.

The global wind energy industry has seen substantial growth, but women make up only 21% of its workforce, lagging behind other renewable energy sectors. Barriers to gender equity include cultural norms, limited awareness of opportunities, and lack of support policies. Companies can promote change by prioritizing fairness, transparency, and work-life balance.

Prime movers are devices that convert natural sources of energy into mechanical energy to generate electricity. Historically, hydropower from water turbines and steam turbines played major roles. Gas turbines emerged as a more efficient and cost-effective option. In recent years, solar cells and wind turbines have made significant advancements, providing competitive and environmentally friendly alternatives to traditional energy sources.

Boston relies on fossil fuels for over 70% of its energy needs, with natural gas and refined oil being the dominant sources. To achieve carbon neutrality by 2050, Boston is increasingly focusing on low-carbon energy sources such as nuclear power, hydropower, wind, and solar energy.

Biopower is the production of electricity from biomass-derived fuels, with significant growth in Brazil due to sugarcane-based ethanol byproducts, while in certain regions like the United States, Germany, and the United Kingdom, waste-to-energy facilities are used due to land constraints and landfill opposition.

Hydropower's history traces back to 1882 when the first facility began supplying electricity in Wisconsin. Its adoption surged across North America, Europe, and beyond, with China notably driving expansion in recent decades. Hydropower now contributes 17% of global electricity, surpassing nuclear, wind, solar, bioenergy, and geothermal combined.

Millions of people die each year due to indoor air pollution caused by the combustion of solid fuels and kerosene in inefficient stoves. Heart disease, stroke, COPD, lung cancer, and other illnesses are major contributors to these deaths. Access to clean cooking fuels is closely linked to lower death rates, with countries having universal access showing the lowest rates.

In Europe, energy insecurity affects 8% of the population, with some countries facing higher rates of thermal discomfort. Milder winters due to climate change have improved overall energy security, but about 35 million people still struggle to stay warm. Germany, Spain, Italy, and France have a significant number of individuals affected.

Direct Air Capture and Storage (DACCS) systems, which remove CO2 from the atmosphere, offer a significant carbon benefit depending on the energy mix of the regional grid. The greatest carbon benefit is achieved when DAC processes utilize zero-carbon sources like renewables and nuclear power. The ongoing decarbonization of the grid in most regions of the United States supports the effectiveness of DAC and electrification technologies.

Geothermal power has a long history, with Native Americans and ancient civilizations like the Greeks and Romans utilizing its benefits. Today, countries such as the United States, Indonesia, the Philippines, Turkey, and New Zealand are leading the way in building new geothermal power projects to harness clean and sustainable energy from the Earth's heat.