Power Generation, Transmission, and Use

Markets, Regulation, and Oversight

Impacts of Power Generation and Transmission

Looking Ahead


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Maryland Power Plants and the Environment (CEIR-18)

4.3.1 Generating Facilities

Effects on Wetlands

Wetlands are important components of the environment, forming the interface between terrestrial and aquatic ecosystems. Wetland communities often consist of a diversity of plant species, a number of which may be species of concern. Wetlands also provide numerous values to society, including fish and wildlife habitat, flood protection, erosion control, and water quality maintenance. At the end of the 18th century, Maryland had nearly 1,650,000 acres of nontidal wetlands (24.4 percent of the surface area); 220 years later, in 2009, Maryland had only about 345,000 acres of nontidal wetlands (4.8 percent of its surface area), a reduction of approximately 80 percent. To address such losses, the State developed regulations under Maryland’s 1991 Nontidal Wetlands Protection Act, with the goal of no net loss of nontidal wetlands. Under nontidal wetlands regulations, permanent impacts to nontidal wetlands must be mitigated at various ratios depending on the type of wetlands affected. For example, a ratio of 3:1 is applied to scrub/shrub and forested Wetlands of Special State Concern; a ratio of 2:1 is applied to other scrub/shrub and forested wetlands, and to herbaceous wetlands of special State concern; and a ratio of 1:1 is applied for emergent wetlands. Analogous to this, the 1994 Tidal Wetlands Regulations were developed to regulate activities in tidal wetlands, and mitigation ratio requirements are similar for State tidal wetlands. Temporary impacts and impacts to wetlands buffers do not usually have replacement mitigation requirements but may require compensatory or enhancement measures.

The CPCN process includes assessing potential wetlands impacts and developing appropriate mitigation equal to or greater than those required by these regulations. While wetlands are present at nearly all Maryland’s power facilities, impacts to these wetlands can usually be avoided. Where especially valuable wetlands are present, the CPCN process can identify special conditions to ensure their protection. For example, the CPCN to construct the Competitive Power Ventures (CPV) generation facility in Charles County included the following conditions to protect the Zekiah Swamp Natural Environmental Area, a Nontidal Wetland of Special State Concern:

Generation facilities such as the KEC and Mattawoman projects will require associated linear facilities including gas and water pipelines and transmission lead lines. Construction of gas and water linear facilities has the potential to affect streams and wetlands through vegetation removal or ground disturbance. Impacts to wetlands may be minimized through advanced construction techniques such as horizontal directional drilling (HDD). For example, PPRP has recommended CPCN license conditions for both KEC and Mattawoman that require HDD along natural gas pipeline corridors to avoid impacts to Wetlands of Special State Concern.

Impacts on Forests and Maryland’s Green Infrastructure

The importance of forest resources is manifold. Forests provide habitat for wildlife including important game species such as white-tailed deer and wild turkey. On the ground, forests filter stormwater of nutrients and other pollutants, and prevent the erosion of the landscape; while in the air, they filter out air pollutants and perform the vital function of producing oxygen. As a forest grows to maturity, it sequesters carbon both as plant tissue and soil-forming materials from dropped leaves and branches. Forests are also important as commercial resources for providing construction materials and as a renewable fuel source. Nevertheless the historic losses of Maryland’s forest resources have been compelling, which prompted enactment of the Forest Conservation Act (FCA) in 1991. With the exception of projects located in heavily forested Allegany and Garrett Counties, all construction developments of greater than 40,000 square feet must comply with the FCA.

Under the FCA, existing forest condition and character are integral parts of the development planning process, including power plant and transmission line siting, across the state. The FCA requires the applicant to submit both a Forest Stand Delineation defining the nature and character of the existing forest and a Forest Conservation Plan for protecting the most ecologically valuable areas of forest. Under the FCA, tree conservation, replanting, and other environmental parameters must be considered before any development disturbs forest resources. The Maryland Forest Preservation Act of 2013 amended the State’s forest conservation policy to maintain a 40 percent tree canopy state-wide, in essence, a no-net-loss requirement. This legislation will help maintain and protect the state’s forests, which is crucial to the health of local rivers, streams and the Chesapeake Bay. In addition to the no-net-loss requirements, this legislation adds a dual sustainability certification requirement for State Forests, and extends tax benefits to more Marylanders who work to increase tree cover on their property.

DNR has established land conservation strategies to preserve and restore the state’s ecological health. One of DNR’s programs, the Green Infrastructure (GI) Assessment, is designed to identify and map large areas of contiguous forest habitat hubs and narrower natural corridors that connect the hubs and allow movement among faunal and floral populations. The GI Network is important to the State because the size of forest patches correlates directly with the species of plants and animals that inhabit them and the diversity that the patch of forest can support.

Maryland's forest policies include a "no net loss of trees" standard as well as an overall percent cover goal.  The Forest Conservation Act (1991), the Sustainable Forestry Act (2009), and the Forest Preservation Act (2013) all bear on actions that remove forests or develop nonforested land. Consistent with these Acts, the PSC has certain responsibilities with respect to forest conservation during the CPCN review, as specified in the Natural Resources Article, 5-1603 (f):

"After December 31, 1992, the Public Service Commission shall give due consideration to the need to minimize the loss of forest and the provisions for afforestation and reforestation set forth in this subtitle together with all applicable electrical safety codes, when reviewing applications for a certificate of public convenience and necessity issued pursuant to § 7-204, § 7-205, § 7-207, or § 7-208 of the Public Utilities Article."

Click to OpenMaryland's Forest Conservation Act (FCA) and Solar GenerationCompliance with FCA mitigation standards for tree removal or for development of agricultural land generally meets the requirements of the PSC review. FCA provides a set of minimum standards that developers must follow when designing a new project. County and municipal governments are responsible for making sure these standards are met, but may choose to implement even more stringent criteria.  New CPCNs issued for the construction of electric generating facilities require compliance with these requirements. Once a CPCN has been issued, certain FCA exemptions are available to utilities for subsequent maintenance activities. Generation project developers are required to consult with their respective counties and comply with the county’s requirements for any afforestation, reforestation or mitigation that may apply to the project. PPRP also recently initiated its promotion of native Maryland pollinators and their habitats (see sidebar).

Click to OpenPromotion of Native PollinatorsThe CPCN process also considers the quality of the natural resources lost as the license conditions are developed. For example, the CPCN to construct the Rock Springs generating facility in Cecil County included restoration conditions to compensate for values of mature forest lost and some of the nitrogen deposition caused by the facility’s emissions. Specifically, the applicant was required to plant 50 acres of young trees to replace 20 acres of mature forest. The reforestation was directed to riparian areas to increase the likelihood that deposited nitrogen would be intercepted before reaching Chesapeake Bay tributaries. At one reforestation site, 18 acres in size, 80 percent of the planted trees died by the summer of 2013. PPRP is re-evaluating the efficiency of such restoration projects.

Impacts on Biological Resources


New generation facilities primarily affect wildlife by removing habitat during construction of the project. For example, the Cove Point LNG expansion project, once operational, will allow the facility to produce liquefied natural gas for exportation; however, it requires that 97 acres of forested area be cleared for construction laydown and staging areas. The loss of habitat from this area will affect forest interior dwelling species (FIDS) of birds, including the scarlet tanager, barred owl, pileated woodpecker, and eastern whip-poor-will. The loss of FIDS habitat will also affect properties adjacent to the area to be cleared. Wildlife will be affected by loss of habitat, and addition of light, noise, and activity during the construction period.

Wind energy projects can also have a substantial impact on wildlife during operations, especially to birds and bats. Depending on the number of wind turbines, usually installed in linear arrays, facilities can occupy large areas on the landscape when the turbines, service roads, and operations buildings are considered as a whole. A much greater area is often needed during the project construction phase as the large towers and turbine blades require broad lay-down areas during assembly. The loss of habitat can lead to the eradication or displacement of species in these areas.

All of the wind power facilities proposed for construction in Maryland have been in the predominantly forested habitats of Garrett and Allegany counties. The forests of western Maryland are considered to be a southern extension of the northern hardwood forests that extend more broadly to the north, and historically included pure stands of white pine, eastern hemlock, and red spruce. At present, however, logging, coal mining, and home construction have fragmented much of these forests. Where contiguous forest exists, wind power development within these forests could increase fragmentation. Fragmentation affects birds and bats as well as other terrestrial species through direct loss of forested habitat, the encroachment of species that can have direct (e.g., brown-headed cowbirds that parasitize songbird nests) or indirect (e.g., raccoons that can be disease vectors for rare mammals) detrimental effects, the potential disruption of corridors for daily movement or seasonal migration, and the failure of the resident species to adapt to the wind power facility.

PPRP and DNR’s Wildlife & Heritage Service routinely review and comment on Bird and Bat Conservation Strategies (BBCSs) for wind power projects. BBCS (formerly known as Avian Protection Plans) are project-specific documents that outline a program to reduce the potential risks of bat and avian mortality that may result from the construction and/or operation of a project.  The ultimate goal of a BBCS is to avoid impacts to avian and bat species to the greatest extent possible, including species protected under the Migratory Bird Treaty Act, the Bald and Golden Eagle Protection Act, and the Endangered Species Act, as well as the State Maryland Nongame and Endangered Species Conservation Act, and applicable County regulations. 

A BBCS must be structured around careful project planning, siting, and construction, allowing power project developers to avoid impacts to birds and bats that could result from construction, operation, and decommissioning of projects.  Appropriate power project design and construction measures must be implemented to avoid and minimize avian and bat impacts to the greatest extent practicable. The goal of avoidance and minimization measures for birds and bats is to eliminate aspects of a project that pose risks to these species.

Although raptor mortality rates at wind power projects in the Appalachian Mountains have been minimal to date, they have been elevated in some western states. Conversely, bat mortality rates at some wind power projects along the Appalachian Mountains have been among the highest reported. Birds and bats are typically treated separately in a BBCS document, therefore, with unique avoidance and minimization measures applied as appropriate. If monitoring indicates that avoidance and minimization measures are not effective, adaptive management measures have been implemented, including additional conservation measures, as needed.

In Maryland, land-based wind power facilities less than 70 MW can apply to the PSC for an exemption from having to obtain a CPCN. Although this exempts developers from the coordinated PPRP environmental review, they must still comply with federal and State regulations protecting threatened and endangered species.

Rare, Threatened and Endangered Species

Rare, threatened and endangered (RTE) species, whether federal-listed under the Endangered Species Act or State-listed under Maryland’s Threatened and Endangered Species regulations, are distributed throughout the state; however for the most part, these species are restricted to highly specific habitats. Generation projects proposed in Maryland must undergo environmental review by the DNR’s Wildlife & Heritage Service (WHS) to identify any RTE species known to occur in the vicinity of the affected area. Any recommendations made by the WHS during the environmental review usually form the basis for conditions in the CPCN. Regardless of the kinds of habitat involved, State-listed threatened and endangered plants and wildlife are protected under State law. Table 4-5 lists the number of protected species by category that the CPCN process considers when evaluating potential adverse effects and developing protective recommended license conditions.

Table 4-5 Number of State-Listed Rare, Threatened, and Endangered Species by Category

Summary of State Listed Species*
Category Plants Animals
Endangered 271 91
Threatened 74 19
In Need of Conservation n/a 29
Endangered Extirpated 100 28
Total 445 167

* Summary of State Listed Species only includes species listed in COMAR 08.03.08
Source:  Maryland DNR:

Although few applications for power generating facilities affect listed threatened and endangered and rare species, a number of individual cases have considered potential impacts to Northern Long Eared Bat, Eastern Small-footed Bat, Bald Eagle, tiger beetles, Delmarva Fox Squirrel, Carpenter Frog, timber rattlesnake, and plant species such as Purple Pitcher Plant, New Jersey Rush, and Winterberry. During a recent visit to the proposed Dan’s Mountain Solar site in Alleghany County, WHS personnel determined that four specific points along the eastern part of the site and directly bordering it likely provide habitats for two listed RTE species and one rare species in Maryland; these species include Allegheny Woodrat (Neotoma magister; State Endangered); Eastern Small-footed Bat (Myotis leibii; State Endangered); and Timber Rattlesnake (Crotalus horridus; not listed, but rare). In addition, Northern Long-eared Bat (Myotis septentrionalis) has been documented recently in the vicinity of the Dan's Mountain Solar project site. The Northern Long-eared Bat was recently listed as Threatened under both federal and Maryland Endangered Species Acts. These four species of concern could be affected by the development of the proposed solar facilities at this site. PPRP has drafted CPCN license conditions requiring the project developer to produce a binding Habitat Conservation Plan that will protect these four species. Further, given that forest clearing will be required to complete this solar project, PPRP recommended that Dan’s Mountain Solar coordinate with the U.S. Fish and Wildlife Service regarding Northern Long Eared Bat.

Wind turbines can kill birds and bats that collide with them, or as recent research has shown, cause the death of bats through barotrauma, a fatal hemorrhaging of the lungs of bats from the rapid change in air pressure near the spinning turbine blade. After two decades of study at a number of wind power facilities in the U.S. and abroad, there is evidence that the numbers of bird fatalities are small at most locations. Two to three birds are killed annually per wind turbine on average. Studies at facilities constructed on eastern Appalachian ridges in West Virginia and Pennsylvania report similar rates of bird fatality. In contrast, the numbers of bats killed at these regional facilities are among the highest ever reported, and annual estimates range into the thousands for each project. It is currently believed that most of the bat fatalities occur during the late summer to fall migration period as bats move to their over-wintering habitat.

Until recently, wind turbines were not known to have killed any threatened or endangered species of bats. It has now been documented, however, that an Indiana bat was killed at a wind energy facility in Indiana. Western Maryland provides year-round habitat to the federally Endangered Indiana Bat, and the State-listed Endangered Eastern Small-footed Bat. Most records of these two species come from winter cave surveys when the bats are hibernating. Much less is known of their habits during the flying season as they disperse throughout the landscape; however, a recent radio-tracking study followed a single female Indiana bat from a Pennsylvania cave to Carroll County, Maryland. The seasonal and daily activity patterns of these rare species must be investigated further before concerns about the risks posed by proposed wind turbines can be adequately addressed and mitigation activities defined.

An even greater concern for populations of cave-hibernating bats, such as the Indiana Bat, the Northern Long Eared Bat, and the more common Little Brown Bat, has developed since White Nose Syndrome was found to be severely affecting bats in caves of the northeast. This fungal disease, first noted in 2006, has spread rapidly throughout eastern North America, causing up to 90 percent bat mortality in some caves. Bats succumb to White Nose Syndrome during winter hibernation periods after becoming sick and either dying within the cave or departing prematurely and perishing outside the cave during winter. The fate of these bat species, when considering the cumulative impacts of White Nose Syndrome and the growing wind energy industry, has yet to be determined. The U.S. Fish and Wildlife Service has recently published a 4(d) Rule for the Northern Long Eared Bat that identifies protections provided under the federal Endangered Species Act related to certain practices, and has designated a White Nose Syndrome Zone within which certain actions are considered, such as tree removal. Within the White Nose Syndrome Zone, Allegany County is designated as a county with known White Nose Syndrome infected hibernacula (Download Adobe Acrobat Reader).

Listed species potentially affected by the proposed Dan’s Mountain Wind project include Allegheny Woodrat (Neotoma magister; State Endangered); Eastern Small-footed Bat (Myotis leibii; State Endangered); and Timber Rattlesnake (Crotalus horridus; not listed, but rare). PPRP is developing CPCN licensing conditions in conjunction with WHS that will require mitigation elements for each of these species. Some elements of these conditions include:

Planting of mast-producing trees as food source for Allegheny woodrats.

Cumulative Effects

Potential cumulative effects of generation facilities are dependent on their location, size and the amount of habitat disturbed. The most noticeable impacts are associated with wind turbines, which can kill birds and bats through collisions. The cumulative impact of bird fatalities, at present, is not considered to be severe for any one species, as no single species appears to be disproportionately affected. In addition, operational (e.g., lighting that can attract birds) and design (e.g., guyed structures) circumstances that can contribute to higher fatalities are better understood and new wind power facilities are constructed with reduced lighting and no guy wires to minimize impacts. Birds considered most at risk are songbirds that migrate nocturnally. High fatality events for these species often coincide with nights that have a low cloud cover resulting in birds flying closer to ground level. Although the Migratory Bird Treaty Act prohibits the “take” of any birds, the U.S. Fish and Wildlife Service, in practice, only requires that good faith efforts be employed to avoid fatalities.

The cumulative impact to bat species is of greater concern. The high level of recorded bat fatalities has been distributed among only a few species, predominantly red and hoary bats. These two species undertake long distance seasonal migrations and typically roost in trees, whereas most other species have shorter seasonal movements to and from caves in which they over-winter. While the specific population characteristics of these species are uncertain, they are relatively long-lived and they produce few offspring annually, both characteristics that make them less able to sustain a high level of fatalities. Recent PPRP-funded studies of bat activity in western Maryland have recorded high numbers of these two species during spring monitoring. Another study examined population genetics indicated red bats appear to have a larger overall population size than hoary bats, and may be better able to absorb losses from wind energy facilities.

Maryland's Forest Conservation Act (FCA) and Solar Generation

Solar Panels in the sun.Maryland’s agricultural land is an attractive option for siting solar generation facilities. There are more than 10 proposed solar generation facilities currently under review by PPRP. The availability of large tracts of open land in rural communities, which generally does not require extensive site work (e.g., grading, or clearing), is ideal for solar generation development, particularly if located within close proximity to a power substation. 

Maryland’s Forest Conservation Act (FCA), specifically Maryland Code, Sections 5-1602(b)(5) and 5-1603 of the Natural Resources Article, establishes standards for land development that make the identification and protection of forests and other sensitive resources an integral part of the site planning process. The conversion of agricultural land for power generation, irrespective of the need for tree clearing, requires mitigation if a CPCN has not been issued. Generation projects must be permitted through the CPCN licensing process, and must minimize forest loss during site development. As such, PPRP recommends project-specific CPCN license conditions requiring generation project developers to consult with their respective counties to determine that county’s requirements for any afforestation, reforestation or mitigation that may apply to the project.

Promotion of Native Pollinators

Image of butterfly at flowerPlants must rely on pollen vectors, from wind to insects to birds, to transport their pollen to another individual and attract the same species repeatedly to bring about successful pollination. Visitors must cause pollen transfer for plants to ultimately set seed and be successful. Pollinators contribute substantially to the success of our fruit, nut, and vegetables crops; however there has been a significant loss of pollinators, including honey bees, native bees, birds, bats, and butterflies, from the environment over the last few decades.

Image of a honey bee on flowers
Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators was proclaimed by the President in a memorandum issued on June 20, 2014. Migrating Monarch butterflies dropped to the lowest recorded population level in 2013-14. The loss of native bees, which also play a key role in pollination of crops, is much less studied, but many native bee species are believed to be in decline. Scientists believe that bee losses are likely caused by a combination of stressors, including poor bee nutrition, loss of forage lands, parasites, pathogens, lack of genetic diversity, and exposure to pesticides.


Image of a hummingbird at a flower
PPRP recently initiated its promotion of native Maryland pollinators and their habitats. The promotion of pollinators is done through a cooperative agreement with applicants of new generation projects to investigate the feasibility of providing onsite ecologically-friendly, self-sustaining habitats for honeybees, bumblebees, other important insects, and other pollinators. These habitats would take the place of frequently mowed or crop areas (but never replace forested habitats) on a project site. The pollinator habitats consist of native herbaceous plants that are known to attract a variety of pollinator species (e.g., Bee Balm, Butterfly Milkweed, Black-eyed Susan, Joe-Pye Weed, etc.). Image of a monarch butterfly at flower
These habitats are relatively maintenance-free, and once established, often only require an annual or semi-annual mowing. They generally require no application of herbicides or fertilizers, and are friendly to native birds and other wildlife. Pollinator habitat also can be managed in electric transmission rights-of-way with integrated vegetation management (IVM) as two distinct plant communities; grass and herbaceous plants within the wire zone (under and 20-feet outside conductors), and a shrub/scrub border zone from the wire zone to the ROW edge to develop meadow habitat and shrub habitat along the ROW border and in ravines.