This is an exciting time for the energy industry—energy revolutions are underway and things are changing quickly. Fossil fuels (coal, oil, and natural gas) and biomass have dominated the energy landscape for centuries and are the leading contributors to global climate change, hazardous environmental impacts, and human health issues. However, global energy production is now shifting to clean sources, like energy efficiency and renewables, that release little to no greenhouse gases and have fewer environmental impacts. This shift is critical to reaching net zero* goals and limiting the increase in global average temperatures, as well as improving air quality and reducing the human health effects of energy.

Biofuels are an energy currency derived from renewable biological sources, such as plants, algae, and organic waste materials. They can replace fossil fuels like gasoline and diesel. However, current feedstock use and production methods raise debates and concerns related to their environmental impact, land use, and competition with food production. Biofuels are mainly used for transportation, but they are a very small contributor to transportation energy. Demand for biofuels is expected to grow in the next five years due to climate goals and policy mandates.

Biomass is a semi-renewable energy resource that comes from plants and animals. Biomass can be burned directly for heat or converted to liquid and gaseous fuels for transportation and electricity generation. Humans have been using biomass for heating, cooking, and lighting for thousands of years and 2.4 billion people still use this form of “traditional” biomass. Today, biomass is also used at commercial scale for heating and electricity generation as well as in liquid form for transportation. Advocates for biomass argue it is carbon neutral, but some types of bioenergy actually increase greenhouse gas emissions.

Carbon management includes natural and technological solutions for removing ambient CO2 from the air or capturing CO2 emissions from industrial processes, and then using the CO2 or sequestering it so that it doesn't contribute to climate change. CO2 is naturally removed from the air through our environment by plants, soils, oceans, and wetlands. Carbon dioxide removal (CDR) enhances these biological processes or uses technology to remove CO2 from the atmosphere. Carbon capture and storage (CCS) uses technology to capture and store CO2 before it is released into the atmosphere. CDR and CCS are still in the early stages of commercialization and remain expensive forms of reducing CO2 in the atmosphere.

Coal is the most carbon-intensive fossil fuel and a huge contributor to climate change, air pollution, and land disruption. It is a chemically complex, rock-like hydrocarbon that contains heavy metals (e.g., mercury and lead), sulfur, and radioactive material. Coal is mined from the Earth and burned to convert chemical energy to heat. Coal is primarily used to generate electricity and for heating.

Electricity generation is responsible for 32% of global greenhouse gas (GHG) emissions, and electricity demand is growing. Decarbonizing the electric power sector is critical to meeting the growing demand while simultaneously reducing overall carbon emissions.

Integrating more renewable resources is a key component for decarbonizing the electric power sector, however this poses challenges due to the intermittency of renewable resources like wind and solar. Some tools available to integrate renewables into the grid include storage, flexible loads, overbuilding, and regional integration.

Once a suitable well location has been identified, permitted, and leased, the next steps for oil and natural gas development are drilling, completion, and production:

Drilling typically takes about 50-60 days. It starts with preparing the site (clearing and leveling) and setting up a drilling rig to drill a borehole and feed steel pipe into the well. Drilling mud is used to manage downhole pressures, provide information about the rock layers being drilled through, and keep the drill bit cool. Safety equipment, such as a blowout preventer, is installed to prevent oil and natural gas from being released in rare unexpected overpressure situations.
Completion is a 1-5 week process where the steel pipe in the well is perforated to connect the well bore to the oil or gas reservoir. As needed, additional recovery techniques such as hydraulic fracturing (for low permeability reservoirs) or steam flooding (for thick oil) are applied. A Christmas Tree (series of valves) is installed at the top of the well. As reservoir pressure declines, a pumpjack is installed.
Production from a completed well can last 50+ years. During the production step, the well is monitored, maintained, and managed. In the U.S. the mineral rights owners (individuals) typically receive royalty interest payments on the oil and natural gas produced. In most other countries, the federal government owns the mineral rights.

Electricity is a high-quality, extremely flexible, efficient energy currency that can be used for delivering all types of energy services, including powering mobile phones and computers, lights, motors, and refrigeration. Two-thirds of electricity globally is generated from fossil fuels in thermal power plants, where an average of 55% to 70% of resource energy is lost as waste heat. Electricity generation from cleaner renewable energy sources, particularly wind and solar PV, is rapidly increasing.

An energy system converts primary energy resources like fossil fuels or wind into energy services. Energy services are what humans care about, like hot showers and cold beverages. There are energy losses each time we convert energy from one form to another. Energy systems are most efficient when we can closely match the resource with the service (e.g., using sunlight for illumination). The earth is an open energy system that is always getting new energy from the sun.

Energy efficiency is providing the same or better service (lighting, thermal comfort, cooking, transport) using less energy. Energy efficiency is the most cost effective way to meet demand for energy services while reducing energy consumption and the associated climate and environmental impacts. While it may be difficult to imagine energy that is not consumed, energy efficiency is a significant global energy resource that plays an essential role in the path to decarbonization.

Policies shape decisions about energy production and use. Institutions ranging from local governments to international trade organizations use different types of policy instruments, such as building energy codes, tax credits, and air quality standards, to influence energy-related behaviors. Energy policies are forged by pressure from stakeholders with a host of interests including economic development, geopolitical security, climate action, and rapid deployment of new technology.

Energy storage allows energy to be saved for use at a later time. Energy can be stored in many forms, including chemical (piles of coal or biomass), potential (pumped hydropower), and electrochemical (battery). Energy storage is a valuable tool for balancing the grid and integrating more renewable energy. When energy demand is low and production of renewables is high, the excess energy can be stored for later use. When demand for energy or power is high and supply is low, the stored energy can be discharged. Due to the hourly, seasonal, and locational variability of renewable production, energy storage is critical to facilitating the clean energy transition.

Rising greenhouse gas (CO2, methane) levels due to carbon-intensive human activities since pre-industrial times have resulted in an increase in the Earth’s surface temperature, which is known as global warming. Global warming is causing climate change and resulting in harmful impacts on humans and our environment. Climate change is an urgent problem. We have the tools and solutions to tackle climate change, but implementation remains a huge challenge.

Residential and commercial buildings are the largest contributors to global greenhouse gas (GHG) emissions. GHG emissions in buildings come mainly from the consumption of energy for heating, cooling, lighting, and operating various appliances, as well as from construction, materials, and maintenance.

Decarbonizing buildings is crucial in the efforts to mitigate climate change and achieve sustainable development. Building decarbonization involves energy efficiency, electrification, increased use of renewable energy sources, adoption of sustainable building practices, and supportive policies and regulations.

Over 90% of transportation is fueled by oil, and transportation accounts for almost two thirds of the oil used worldwide. Transportation is responsible for 15% of global Greenhouse Gas (GHG) emissions and is a major contributor to other air pollutants that affect human health. One of the most effective ways to decarbonize transportation is to replace gasoline powered personal vehicles (which account for 60% of the energy used in transportation) with electric vehicles (EVs). Long-distance travel via air, maritime, and long-haul road, on the other hand, is harder to decarbonize.

Energy and the environment are inextricably linked. Delivery of energy services (what humans want) is the leading source of greenhouse gas emissions, and our energy resource use affects water, land, and wildlife as well. All energy resources have environmental impacts, but some, namely fossil fuels, have more impacts than others.

The negative impacts of energy resource use disproportionately affect low income communities and communities of color in the US and globally. As our population grows and energy access increases, it is important to figure out how we will deliver energy services sustainably and in a way that addresses inequities in environmental impacts.

Petroleum-based fuels like gasoline, diesel, jet fuel, and shipping fuel are all made from crude oil through the process of refining and make up almost 90% of the world’s transportation energy. These fuels contribute significantly to air pollution and climate change.

Petroleum-based fuels are high energy density fuels, both by weight and by volume, which makes them valuable for transportation (where you are carrying your fuel around with you).

Geothermal energy makes use of abundant natural heat deep below the Earth’s surface. Geothermal resources are accessible where the Earth’s crust is thin or faulted or near volcanic activity, which often occurs near tectonic plate boundaries. Geothermal energy is used for heating and electricity generation. Geothermal power plants are a source of 24/7 renewable electricity, unlike wind and solar which are variable and dependent on weather conditions.

Access to sustainable modern energy services is fundamental for economic growth and human development. It is one of the Sustainable Development Goals laid out in 2015 by the United Nations (SDG 7). Access considers two dimensions:

Electricity: Access advances education, health, productivity, security, comfort, and entertainment. It also facilitates higher-value economic opportunities.
Clean cooking fuels: Access improves the lives of women and children by dramatically reducing health impacts related to indoor air pollution, decreasing the exposure to risks associated with collecting traditional biomass, and increasing available time that can be devoted to other economic activities.
Energy access and consumption are highly related to the Human Development Index (HDI) that takes into account life expectancy, education, and health to measure a country’s well-being. A country’s fuel mix is also related to its level of development: less developed countries use a higher share of traditional biomass, while more developed countries use more electricity.

Nevertheless, a significant portion of the world population still does not have access to reliable electricity or clean cooking fuels, creating a challenge for equity in development opportunities.

The grid delivers electricity from generation points to demand centers. Supply and demand of electricity must be balanced in real-time to ensure system stability and reliability. The electric grid is a natural monopoly because it is most efficient for one operator to provide the service. To ensure consumers are not overcharged, grid operators are overseen by a regulator.