Types of Energy

Coal is a fossil fuel formed from the remains of ancient plants that were buried and transformed by heat and pressure over millions of years. It generates electricity by being burned to produce heat, which creates steam that turns turbines connected to generators. Although coal has historically been a major part of Maryland’s electricity mix, its role continues to decline as older power plants retire and cleaner energy technologies continue to grow. Baltimore remains one of the nation’s largest coal export ports.

Petroleum, commonly known as crude oil, is a naturally occurring fossil fuel formed from the remains of ancient marine plants and animals over millions of years. After being extracted from underground reservoirs, it is refined into products such as gasoline, diesel fuel, jet fuel, heating oil, and other petroleum-based products. In Maryland, petroleum plays only a small role in electricity generation but remains the state’s primary transportation fuel. Like other fossil fuels, burning petroleum releases carbon dioxide and other air pollutants.

Wind energy generates electricity by using moving air to spin turbine blades connected to a generator. Wind power produces electricity without combustion or emissions and has been a proven technology for decades. Maryland has both land-based wind resources in Western Maryland and continues to pursue offshore wind development off the Atlantic coast.

Hydropower generates electricity by harnessing the energy of falling or flowing water to spin turbines connected to generators. It is one of Maryland’s largest renewable sources of electricity. The Conowingo Hydroelectric Generating Station on the Susquehanna River is the state’s largest hydroelectric facility and supplies renewable electricity to the regional power grid.

Biomass is renewable organic material derived from plants and animals, including wood waste, agricultural materials, and other biological resources. Advanced wood heating systems convert sustainably sourced biomass into heat while supporting sustainable forest management and rural economies. Maryland continues to invest in advanced biomass technologies and wood energy initiatives.

Geothermal energy uses the Earth’s constant underground temperature or naturally occurring heat for heating, cooling, and energy generation. While Maryland’s geology is not suitable for utility-scale geothermal power production, geothermal heat pumps are increasingly used in homes and commercial buildings to improve energy efficiency.

Wave energy captures the motion of ocean waves to generate electricity. Although the technology is still emerging and has not been widely deployed at a commercial scale, it has significant long-term potential as a renewable energy resource.

Nuclear energy generates electricity through the fission of uranium atoms, producing heat that powers steam turbines. Because it does not produce direct carbon emissions during electricity generation, nuclear power is considered a zero-carbon energy source. Maryland’s largest source of in-state electricity is the Calvert Cliffs Nuclear Power Plant, whose two reactors can produce approximately 1,790 MW of electricity. Across its full life cycle, nuclear energy has among the lowest greenhouse gas emissions of any electricity-generating technology.