Hydrogen is a versatile energy currency that can be produced from fossil fuels or water and that also occurs naturally in rocks underground. Hydrogen has very low energy density by volume but is extremely energy dense by weight. Hydrogen shows promise as a clean fuel for heavy-duty transportation, steel-making, heating, and energy storage. Today, the vast majority of produced hydrogen is created from fossil fuels. Renewable hydrogen can be created through electrolysis, the process of using electricity to create hydrogen from water, but it is more expensive.

Hydropower, also known as hydroelectricity, is a semi-renewable resource that uses the flow of water to generate electricity. There are two major approaches to generating electricity from hydropower: storage hydroelectric systems and run-of-river systems. Hydro can also be used to store electricity in systems called pumped storage hydropower.

Industry, which includes large-scale manufacturing and production processes to make products such as steel, cement, and chemicals, is a significant source of greenhouse gas emissions. Reducing emissions from heavy industry, which often relies on fossil fuels to reach the high temperatures needed for many industrial processes, is challenging. Unlike the electricity sector, which already has economically viable solutions like wind and solar, the industry sector is still developing the technologies needed for cost-effective and scalable decarbonization. One solution is to use electrical technologies that can generate high temperatures, but this is often more expensive and has high upfront costs.

The three fossil fuels are oil, natural gas, and coal. Fossil fuels are hydrocarbons formed from deeply-buried, dead organic material subject to high temperature and pressure for hundreds of millions of years. They are a depletable, non-renewable energy resource.

Fossil fuel combustion (converting chemical energy into heat) powered the Industrial Revolution and is the largest contributor to climate change and air pollution. Significant infrastructure, economic value, geopolitical conflict, and legacy environmental issues are associated with fossil fuels.

Nuclear energy is a carbon-free and extremely energy dense resource that produces no air pollution. Nuclear reactions produce large amounts of energy in the form of heat. That heat can be used to power a steam turbine and generate electricity. There are 2 types of nuclear energy: nuclear fission (which is used today to produce electricity) and nuclear fusion (which is still in the research phase).

The term “renewable” encompasses a wide diversity of energy resources with varying economics, technologies, end uses, scales, environmental impacts, availability, and depletability. Key types of renewable energy resources include energy efficiency, solar, wind, hydropower, ocean, geothermal, and biomass. The use of renewable energy resources globally has been increasing rapidly. Most renewable energy resources have significantly lower environmental and climate impacts than their fossil fuel counterparts.

Natural gas (NG) is the most versatile and fastest-growing fossil fuel—used in all areas of the economy (industrial, residential, commercial, and transportation). It is a depletable, non-renewable resource composed primarily of methane gas (CH4), with smaller amounts of natural gas liquids, carbon dioxide (CO2), and water vapor. While natural gas is the cleanest-burning fossil fuel, it still produces CO2 when combusted. And because natural gas is primarily methane, it is itself a very potent greenhouse gas when it is emitted to the atmosphere uncombusted.

Nuclear fission is the process of splitting a large atom into two smaller atoms and releasing a LOT of heat. That heat is used to boil water, make steam, turn a turbine and generator, and produce electricity. Most nuclear power plants today are fueled by enriched uranium 235 to produce non-renewable, carbon-free, 24/7 electricity. The byproducts of nuclear fission are highly radioactive and must be secured away from people for hundreds of thousands of years.

Nuclear fusion has the potential to be an extremely energy dense and carbon-free energy resource that does not produce air pollution or radioactive waste. However, while nuclear fusion happens continuously in (and even powers) the sun, making nuclear fusion happen on earth is extremely challenging (think about putting the sun in a box). Currently, fusion is in the research phase and is not commercially viable. Nuclear fusion occurs when nuclei from two or more atoms are forced together and fuse to form a single larger nucleus, releasing lots of energy and heat. That heat would then be used to generate electricity.

Ocean energy, also known as marine energy or hydrokinetic energy, is an abundant renewable energy resource that uses ocean water to generate electricity. The form of energy takes advantage of ocean tides, waves, or the temperature difference between the surface and deep ocean. The majority of ocean energy technologies are still in research and development. While the potential of ocean energy is great, it faces significant technological, environmental, and financial challenges and has low levels of investment.

Oil is the most-used energy resource worldwide and provides more than 90% of global transportation energy. Because the majority of oil is produced by a limited number of countries, securing access to this resource has significant geopolitical consequences.

Prospecting is the very first stage of the oil and natural gas development process. It consists of Exploration, Permitting and Leasing.

Solar energy is radiant energy from the sun—a fully renewable energy resource. We use the solar resource to provide daylight, electricity, and heat. Solar PV is the fastest-growing electricity resource in the world. It is fully renewable with few environmental impacts, and the cheapest source of electricity in many countries.

Wind energy uses naturally flowing air in the Earth's atmosphere to generate mechanical power and electricity. It is a fully renewable resource and has few climate and environmental impacts. Wind energy is one of the lowest cost sources of electricity and is one of the largest and fastest growing electricity resources worldwide.