Power Generation, Transmission, and Use

Markets, Regulation, and Oversight

Impacts of Power Generation and Transmission

Looking Ahead


CEIR Report Map


Maryland Power Plants and the Environment (CEIR-18)

2.5.2 Generation: Comparison with Consumption

The provision of adequate levels of electric power generation for Maryland consumers does not require that the level of power generation within the State’s geographic border match or exceed the State’s consumption. Historically, Maryland’s consumption of electricity has exceeded the amount of energy generated within the state, necessitating imports from out-of-state resources. Although there is sufficient generating capacity in Maryland to meet the State’s electricity consumption needs, Maryland, as part of PJM, often relies on lower-cost generating resources from within PJM as a whole, as well as electric power that can be imported into the PJM footprint. Consequently, imbalances between Maryland consumption and generation should not be viewed as adversely affecting reliability or availability of electricity in Maryland.

With high import requirements, interregional transmission plays a much more critical role in sustaining reliable service. In addition, Maryland’s high electric demand relative to in-state generation supply can produce high electricity prices when transmission limits and congestion require the use of higher-cost electricity resources located closer to load centers.

Click to OpenGeneration Fuel Mix Since 1990Electricity consumption in Maryland during 2015 exceeded electricity generation in the state by approximately 44 percent. Table 2-10 compares electricity consumption and generation in Maryland over the past ten years. The largest reduction in in-state generation was from coal-fired power plants. In 2015, coal-fired power plants generated 13,923 MWh as compared to 23,668 MWh in 2010.

PJM’s 2015 Regional Transmission Expansion Plan (RTEP) report notes that power plant deactivation requests significantly decreased in 2015 when compared to the prior three years. In 2015, PJM received deactivation requests totaling 1,626 MW, compared to the 2012-2014 deactivation requests which collectively equaled 26,480 MW. PJM noted that the 2012-2014 deactivation requests were the result of environmental regulations, competition from new generating plants fueled by Marcellus Shale natural gas, new renewable units, and market impacts from demand response and energy efficiency programs. PJM also noted that the market indicates that gas-fired generation may exceed coal-fired generation within the next several years. This is the result of an array of factors including the low price of natural gas, environmental regulations which have served to increase the cost of generation by coal plants more than generation by natural gas plants (for example, the Regional Greenhouse Gas Initiative (RGGI)), and the retirement of coal-fired generating resources in PJM over the past several years.

Table 2-10 Total Maryland Electric Energy Consumption and Generation (thousands of MWh), 2006-2015

  Retail Sales (Consumption) Sales + T&D Losses* Generation Net Imports Percentage of Sales Imported
2006 63,173 66,964 48,957 18,007 27%
2007 65,391 69,314 50,198 19,116 28%
2008 63,326 67,125 47,361 19,764 29%
2009 62,589 66,344 43,775 22,570 34%
2010 65,335 69,256 43,607 25,648 37%
2011 63,600 67,416 41,818 25,598 38%
2012 61,814 65,522 37.810 27,713 42%
2013 61,899 65,613 35.851 29,763 45%
2014 61,684 65,385 37.834 27,551 42%
2015 61,709 65,412 36.390 29,022 44%

* Assumes Transmission and Distribution (T&D) losses of 6 percent.

Source: U.S. Energy Information Administration, “Retail Sales of Electricity, Annual.


U.S. Energy Information Administration, “Retail Sales of Electricity, Annual.”
U.S. Energy Information Administration, “Net Generation by State by Type of Producer by Energy Source, EIA-906, EIA-920, and EIA-923.”

Generation Fuel Mix Since 1990

Over the last several decades, the generation fuel mix in Maryland has shifted. The shifts in fuel mix are the results of various factors, including plant closures, economics, technology advancements, and environmental requirements. Since 1990, coal, the predominant generating fuel in Maryland, has seen its share of total generation decline relative to that of natural gas. In addition, the amount of electricity generated in Maryland has significantly declined since it peaked in 2005 with 52.6 million MWh.  In 2014, Maryland generated 37.8 million MWh, a decline of approximately 28 percent compared to 2005 generation.

Maryland Generation Fuel Mix (Thousands of MWh)

Demand Load vs. Typical Winter Demand Load

Source: U.S. Energy Information Administration