DELMARVA POWER & LIGHT COMPANY TO THE BANK OF NEW YORK MELLON, Trustee. ONE HUNDRED ANDSIXTH SUPPLEMENTAL INDENTURE Dated as ofJanuary 1, 2010 (but executed on the dates shown on the execution page)

Exhibit 4.4

CONFORMED COPY

DELMARVA POWER & LIGHT COMPANY

TO

THE BANK OF NEW YORK MELLON,

Trustee.

ONE HUNDRED AND SIXTH SUPPLEMENTAL

INDENTURE

Dated as of January 1, 2010

(but executed on the dates shown on the execution page)

This ONE HUNDRED AND SIXTH SUPPLEMENTAL INDENTURE, dated as of the first day of January, 2010 (but executed on the dates hereinafter shown), made and entered into by and between DELMARVA POWER & LIGHT COMPANY, a corporation of the State of Delaware and the Commonwealth of Virginia, hereinafter called the Company and THE BANK OF NEW YORK MELLON, a national banking association, hereinafter called the Trustee;

WITNESSETH:

WHEREAS, the Company heretofore executed and delivered its Indenture of Mortgage and Deed of Trust (hereinafter in this One Hundred and Sixth Supplemental Indenture called the “Original Indenture”), dated as of October 1, 1943, to the New York Trust Company, a corporation of the State of New York, as Trustee, to which The Bank of New York Mellon is successor Trustee, to secure the First Mortgage Bonds of the Company, unlimited in aggregate principal amount and issuable in series, from time to time, in the manner and subject to the conditions set forth in the Original Indenture granted and conveyed unto the Trustee, upon the trusts, uses and purposes specifically therein set forth, certain real estate, franchises and other property therein described, including property acquired after the date thereof, except as therein otherwise provided; and

WHEREAS, by one hundred and five indentures supplemental to said Original Indenture dated as of October 1, 1943, of which one hundred and five supplemental indentures the One Hundred and Fifth Supplemental Indenture is dated as of September 22, 2009, the Original Indenture has been modified and supplemented (hereinafter, as so supplemented and amended, called the “Indenture”); and

WHEREAS, the execution and delivery of this One Hundred and Sixth Supplemental Indenture has been duly authorized by Unanimous Written Consent of the Board of Directors of the Company, and all conditions and requirements necessary to make this One Hundred and Sixth Supplemental Indenture a valid, binding and legal instrument in accordance with its terms, for the purposes herein expressed, and the execution and delivery hereof, have been in all respects duly authorized; and

WHEREAS, it is provided in and by the Original Indenture, inter alia, as follows:

“IT IS HEREBY AGREED by the Company that all the property, rights and franchises acquired by the Company after the date hereof (except any hereinbefore or hereinafter expressly excepted) shall (subject to the provisions of Section 9.01 hereof and to the extent permitted by law) be as fully embraced within the lien hereof as if such property, rights and franchises were now owned by the Company and/or specifically described herein and conveyed hereby;”

and

WHEREAS, the Company has acquired certain other property, real, personal and mixed, which heretofore has not been specifically conveyed to the Trustee;

NOW, THEREFORE, this ONE HUNDRED AND SIXTH SUPPLEMENTAL INDENTURE WITNESSETH that for and in consideration of the premises and in pursuance of the provisions of the Indenture:

The Company has granted, bargained, sold, released, conveyed, assigned, transferred, mortgaged, pledged, set over and confirmed, and by these presents does grant, bargain, sell, release, convey, assign, transfer, mortgage, pledge, set over and confirm unto the Trustee and to its successors in the trust in the Indenture created, to its and their assigns forever, all the following described properties of the Company, and does confirm that the Company will not cause or consent to a partition, either voluntary or through legal proceedings, of property, whether herein described or heretofore or hereafter acquired, in which its ownership shall be as tenant in common, except as permitted by, and in conformity with, the provisions of the Indenture and particularly of Article IX thereof:

2

No. 1 — All that certain lot, piece or parcel of land, situated in the South Murderkill Hundred, Kent County, State of Delaware lying on the south side of Bowers Beach Road (Co. Rd. 18) across from the intersection of Bowers Beach Road and Old Bowers Road being bounded on the north by said Bower Beach Road, on the east and south by residue lands now or formerly of North Bowers Farm, LLC and on the west by lands now or formerly of Francis J. Webb, Trustee, being all of Lot 1, including the 5 foot right of way dedication as shown on a survey entitled “Minor Subdivision Plat – lands of North Bowers Farm, LLC” as prepared by Becker Morgan Group, Inc. and recorded in the Kent County, Maryland Recorder of Deeds Office, Vol. 5255, Page 111 on December 23, 2009, and being more particularly described as follows to wit:

Beginning at a point along the southerly right of way of Bowers Beach Road at a corner for this parcel and lands of Francis J. Webb, Trustee, said point of beginning being southeast of the centerline intersection of Bowers Beach Road and Old Bowers Road, thence from said point of beginning and running with the southerly right of way line of Bowers Beach Road the following four courses and distances 1) South 85º29’23” East a distance of 498.33 feet to a point; thence 2) curving to the left on an arc of a circle of a radius of 2,899.79 feet and an arc length of 344.88 feet, chord bearing of said arc being South 88º53’49” East a distance of 344.68 feet to a point; thence 3) South 02º18’15” East a distance of 5.00 feet to a point; thence 4) curving to the left on an arc of a circle of a radius of 2,904.79 feet and an arc length of 3.96 feet, chord bearing of said arc being South 87º39’24” East a distance of 3.96 feet to a point at a corner for this parcel and residue lands of North Bowers Farm, LLC; thence turning and running with said residue lands of North Bowers Farm the following five courses and distances 3) South 07º01’00” West a distance of 645.15 feet to a set iron rod with cap; thence 4) North 82º59’00” West a distance of 177.74 feet to a set iron rod with cap; thence 5) North 75º45’11” West a distance of 212.10 feet to a set iron rod with cap; thence 6) South 77º05’29” West a distance of 176.17 feet to a set iron rod with cap; thence 7) North 80º18’22” West a distance of 223.27 feet to a set iron rod with cap at a corner for this parcel and in line with lands of Francis J. Webb, Trustee; thence turning and running with said lands of Webb 8) North 00º39’04” East a distance of 618.86 feet to the point and place of beginning and containing 11.551 acres of land, be the same more or less.

AND the aforesaid Lot 1 being described separate and apart from the Dedication above, as follows:

All that certain lot, piece or parcel of land, situated in the South Murderkill Hundred, Kent County, State of Delaware lying on the south side of Bowers Beach Road (Co. Rd. 18) across from the intersection of Bowers Beach Road and Old Bowers Road being bounded on the north by said Bower Beach Road, on the east and south by residue lands now or formerly of North Bowers Farm, LLC and on the west by lands now or formerly of Francis J. Webb, Trustee, being all of Lot 1 as shown on a survey entitled “Minor Subdivision Plat – lands of North Bowers Farm, LLC” as prepared by Becker Morgan Group, Inc. and recorded in the Kent County Recorder of Deeds Office (P.B. xx/xx) on December xx, 2009 and being more particularly described as follows to wit:

Beginning at a set iron with cap along the southerly right of way of Bowers Beach Road at a corner for this parcel and lands of Francis J. Webb, Trustee, said point of beginning being southeast of the centerline intersection of Bowers Beach Road and Old Bowers Road, thence from said point of beginning and running with the southerly right of way line of Bowers Beach Road the following two courses and distances 1) South 85º29’23” East a distance of 497.99 feet to a set iron rod with cap; thence 2) curving to the left on an arc of a circle of a radius of 2,904.79 feet and an arc length of 349.44 feet, chord bearing of said arc being South 88º56’10” East a distance of 349.23 feet to set iron with cap at a corner for this parcel and residue lands of North Bowers Farm, LLC; thence turning and running with said residue lands of North Bowers Farm the following five courses and distances 3) South 07º01’00” West a distance of 645.15 feet to a set iron rod with cap; thence 4) North 82º59’00” West a distance of 177.74 feet to a set iron rod with cap; thence 5) North 75º45’11” West a distance of 212.10 feet to a set iron rod with cap; thence 6) South 77º05’29” West a distance of 176.17 feet to a set iron rod with cap; thence 7) North 80º18’22” West a distance of 223.27 feet to a set iron rod with cap at a

3

corner for this parcel and in line with lands of Francis J. Webb, Trustee; thence turning and running with said lands of Webb 8) North 00º39’04” East a distance of 613.85 feet to the point and place of beginning and containing 11.454 acres of land, be the same more or less.

No. 2 — All that lot or parcel of land located in the Seventh Election District, Town of Port Deposit, Cecil County, Maryland, as recorded in the Cecil County, Maryland Recorder of Deeds Office, Book 2726, Page 229 on September 25, 2009, and more particularly described as follows:

Beginning for the same at an iron pin with cap set on the northern right-of-way line of Maryland route 276 (see S.R.C. plat 20876). Said beginning point further being located on the division line between the lands now, or formerly of, Richard H. Mason Sr. (see W.L.B. 697/533) and the herein described Phillip Ohler lands (see W.L.B. 2518/623).

THENCE, leaving said beginning point so fixed and binding on the aforesaid division line,

1. North 39 º 44’ 44” West 100.00 feet to a point on the southern line of lands now or formerly of The Arundel Corporation lands,

2. North 53 º 52’ 24” East 40.08 feet to a point on the western line of lands now or formerly of Christopher D. and Catherine A Sigmon (see W.L.B. 2224/405)

THENCE, leaving the Arundel Corporation lands and binding on the Sigmon lands,

3. South 39 º 44’44” East 100.00 feet, to an iron pin with cap set on the northern right-of-way of the aforementioned Maryland Route 276.

THENCE, leaving the Sigmon lands and binding on the said right-of-way, wih the arc of a curve to the left, 40.08 feet, said curve having a radius of 850.00 feet and being scribed by a chord of;

4. South 53 º 52’ 24” West 40.08 feet to the place of beginning.

CONTAINING in all 0.092 acres (3,993 square feet) of land, be the same more or less.

BEING THE SAME lot or parcel of land which was conveyed to Philip Ohler, by Wildwood Enterprises, Inc., by its deed dated June 11, 3008 and recorded among the Land Records of Cecil County in Book 2518, page 623.

TOGETHER WITH the buildings and improvements thereupon erected made or being, and all and every the rights, alleys, ways, waters, privileges, appurtenances, and advantages pertaining or belonging thereto.

No. 3 — The following additional real properties:

State and County

MARYLAND

Dorchester

4

State and County

MARYLAND

Somerset

State and County

MARYLAND

Wicomico

Together with all other property, real, personal and mixed, tangible and intangible (except such property as in said Indenture expressly excepted from the lien and operation thereof), acquired by the Company on or prior to December 31, 2009, and not heretofore specifically subjected to the lien of the Indenture.

Also without limitation of the generality of the foregoing, the easements and rights-of-way and other rights in or not used in connection with the Company’s operations, which are conveyed to the Company and recorded in the following Real Property Deed Records to which reference is made for a more particular description, to wit:

State and County

DELAWARE

New Castle

5

6

State and County

DELAWARE

Kent

State and County

DELAWARE

Sussex

7

State and County

MARYLAND

Caroline

State and County

MARYLAND

Cecil

8

State and County

MARYLAND

Dorchester

State and County

MARYLAND

Harford

State and County

MARYLAND

Kent

9

State and County

MARYLAND

Queen Anne’s

State and County

MARYLAND

Somerset

10

State and County

MARYLAND

Talbot

State and County

MARYLAND

Wicomico

State and County

MARYLAND

Worcester

11

State and County

VIRGINIA

Accomack

The following is a schedule of bonds issued under the Eighty-Eighth Supplemental Indenture and Credit Line Deed of Trust, effective as of October 1, 1994, that can be designated as First Mortgage Bonds, Series I, which may also be designated as Secured Medium Term Notes, Series I; and First Mortgage Bonds, Pledged Series I.

First Mortgage Bonds, Series I/Secured Medium Term Notes, Series I

First Mortgage Bonds, Pledged Series I

As supplemented and amended by this One Hundred and Sixth Supplemental Indenture, the Original Indenture and all indentures supplemental thereto are in all respects ratified and confirmed and the Original Indenture and the aforesaid supplemental indentures and this One Hundred and Sixth Supplemental Indenture shall be read, taken and construed as one and the same instrument.

This One Hundred and Sixth Supplemental Indenture shall be simultaneously executed in several counterparts, and all such counterparts executed and delivered, each as an original, shall constitute but one and the same instrument.

The recitals of fact contained herein shall be taken as the statements of the Company, and the Trustee assumes no responsibility for the correctness of the same.

The debtor and its mailing address are Delmarva Power & Light Company, 800 King Street, P.O. Box 231, Wilmington, Delaware 19899. The secured party and its address, from which information concerning the security interest hereunder may be obtained, is The Bank of New York Mellon, 525 William Penn Place — 38^th Floor, Pittsburgh, Pennsylvania 15259, Attn.: Corporate Finance.

12

The Company acknowledges that it received a true and correct copy of this One Hundred and Sixth Supplemental Indenture.

This One Hundred and Sixth Supplemental Indenture is executed and delivered pursuant to the provisions of Section 5.11 and paragraph (a) of Section 17.01 of the Indenture for the purpose of conveying, transferring and assigning to the Trustee and of subjecting to the lien of the Indenture with the same force and effect as though included in the granting clause thereof the above described property so acquired by the Company on or prior to the date of execution, and not heretofore specifically subject to the lien of the Indenture; but nothing contained in this One Hundred and Sixth Supplemental Indenture shall be deemed in any manner to affect (except for such purposes) or to impair the provisions, terms and conditions of the Original Indenture, or of any indenture supplemental thereto and the provisions, terms and conditions thereof are hereby expressly confirmed.

The recitals hereinabove set forth are made solely by the Company and the Trustee shall have no responsibility therefor.

(SIGNATURE PAGE FOLLOWS)

13

IN WITNESS WHEREOF, the Company has caused this instrument to be signed in its name and behalf by its President, and its corporate seal to be hereunto affixed and attested by its Assistant Secretary and the Trustee has caused this instrument to be signed in its name and behalf by a Vice President and its corporate seal to be hereunto affixed and attested by an authorized officer, effective as of the 1st day of January, 2010.

14

DISTRICT OF COLUMBIA: SS.

BE IT REMEMBERED that on this 8^th day of April, 2010, personally came before me, a notary public for the District of Columbia, David M. Velazquez, President of DELMARVA POWER & LIGHT COMPANY, a corporation of the State of Delaware and the Commonwealth of Virginia (the “Company”), party to the foregoing instrument, known to me personally to be such, and acknowledged the instrument to be his own act and deed and the act and deed of the Company; that his signature is in his own proper handwriting; that the seal affixed is the common or corporate seal of the Company; and that his act of signing, sealing, executing and delivering such instrument was duly authorized by resolution of the Board of Directors of the Company.

GIVEN under my hand and official seal the day and year aforesaid.

Certification

This document was prepared under the supervision of an attorney admitted to practice before the Court of Appeals of Maryland, or by or on behalf of one of the parties named in the within instrument.

15

BE IT REMEMBERED that on this _13 day of April, 2010, personally came before me, a Notary Public for the State of New York, Thomas J. Provenzano, Vice President of THE BANK OF NEW YORK MELLON, a national banking association (the “Trustee”), party to the foregoing instrument, known to me personally to be such, and acknowledged the instrument to be her own act and deed and the act and deed of the Trustee; that her signature is her own proper handwriting; that the seal affixed is the common or corporate seal of the Trustee; and that her act of signing, sealing, executing and delivering said instrument was duly authorized by resolution of the Board of Directors of the Trustee.

GIVEN under my hand and official seal the day and year aforesaid.

[Seal]

16

CERTIFICATE OF RESIDENCE

THE BANK OF NEW YORK MELLON, successor Trustee to the Trustee within named, hereby certifies that it has a residence at 525 William Penn Place — 38^th Floor, Pittsburgh, Pennsylvania 15259.

17