The City of LaGrange and Georgia Power Company filed a joint petition for a declaratory order with the Georgia Public Service Commission (PSC), to determine which had the right under the Georgia Territorial Electric Service Act, OCGA § 46-3-1 et seq., to provide electric service to a new industrial customer. Upon stipulated facts, the PSC determined that the City did not have the exclusive right to provide such service, but that the customer should have the right to *61choose from among the authorized suppliers. The superior court affirmed the PSC’s order, and the City appeals.
The record reveals that in an effort to attract new industry to the City, the Development Authority of LaGrange constructed a building in an industrial park on speculation. Temporary electric service to the site during construction was provided by the City on application of the contractor, and service was transferred to the Authority after completion of the shell. The building was purchased by a manufacturer of plastic bags, and electric service was again transferred, this time to the contractor hired by the purchaser to complete construction of the facility. When operational, the premises, located within an area annexed to the City after March 29, 1973, will have single-metered service and a connected load in excess of 900 kilowatts. Both appellant and appellee own lines and are authorized to provide service to the location.
The Georgia Territorial Electric Service Act generally provides for assignment of electric suppliers by geographical location. However, OCGA § 46-3-8 (a) (4) provides in pertinent part that “[notwithstanding any other provision of this part, but subject to subsections (b) and (c) of this Code section, . . . service to one or more new premises ... , if utilized by one consumer and having single-metered service and a connected load which, at the time of initial full operation of the premises, is 900 kilowatts or greater . . . , may be extended and furnished, if chosen by the consumer . . . [b]y any electric supplier owning lines in a municipality if the premises are located in a geographic area annexed in any manner to such municipality after March 29, 1973.” Thus, subsection (a) of the statute gives “large load” consumers (such as the one in this case) the right to choose among the authorized suppliers of electric service. Subsection (b) of the statute, the “grandfather clause,” provides, however, that, notwithstanding the customer choice provision, “every electric supplier shall have the exclusive right to continue serving any premises lawfully served by it on March 29, 1973, or thereafter lawfully served by it pursuant to this part . . . ,” thereby providing for an exception to the customer-choice provision when the customer’s premises has been lawfully served previously by a provider pursuant to the Act.
The City contends the trial court erred by affirming the PSC’s order because, having lawfully provided service to the premises during construction, OCGA § 46-3-8 (b) granted to it the exclusive right to continue serving the premises. We do not agree. The City provided electric service to the temporary construction site in question here, a construction site which at that time did not qualify as a large load consumer; thus, no choice was involved in the selection of the provider of electric service to that site. The City now seeks to extend that temporary provision of electric service to the permanent prem*62ises on the basis that it has been “grandfathered” into the exclusive right to provide such service by subsection (b). We are not persuaded by the City’s interpretation of the statute, which would deprive certain large load consumers in situations such as the one here of their statutory right to choose a provider of electric service under subsection (a), thus eviscerating that entire subsection and the intention of the legislature in enacting it. Under the City’s interpretation, customer choice would be eliminated whenever temporary service is provided to construction sites under other parts of the Act. The new large load customer here would be “locked in” to the choice made by the City — a party not totally without self-interest in that it is also the beneficiary of this choice, since it is the supplier chosen. Thus, the evident purpose, and indeed the plain words of subsection (a) of OCGA § 46-3-8, would be rendered meaningless: there would be no customer choice.
Our rejection of the City’s interpretation of subsection (b) is further supported by an examination of subsection (f) of the statute, which, while not addressing itself at all to large load consumers,, specifically provides that a supplier may furnish temporary or construction service to premises in some instances and yet not acquire the exclusive right to provide permanent service to the premises. Since subsection (f) is nowhere qualified as an exception to subsection (b), the interpretation urged by the City places the plain language of subsection (f) in conflict with subsection (b).
Such a result is not only anomalous, it is unnecessary. The PSC interpreted subsection (b) so as to harmonize all three subsections of the statute to provide a reasonable and sensible construction. Under the PSC’s interpretation, the providing of temporary service to a construction site by one supplier of electric service does not foreclose the large load consumer from choosing another authorized supplier for the permanent service to the completed site. In this manner subsection (a) is given its plain and unambiguous meaning that large load customers may choose among the authorized electric suppliers; subsection (b) continues to authorize every supplier who once furnishes permanent service to premises in accordance with the Act to have, notwithstanding any other provision, the exclusive right to continue serving those premises; and subsection (f), which simply has no bearing on this issue, remains viable according to its plain language in the situations in which it was intended to apply without any conflict with subsection (b).
In interpreting OCGA § 46-3-8, it is our duty to consider the subsections in pari materia, and to reconcile them, if possible, so that they may be read as consistent and harmonious with one another. Board of Trustees v. Christy, 246 Ga. 553 (272 SE2d 288) (1980). The construction given the statute by the PSC is consistent with these *63established principles of statutory construction. Moreover, the PSC, as the agency charged with oversight and supervision of electric power companies in this State, OCGA § 46-2-20 (a), including the enforcement and administration of the Georgia Territorial Electric Service Act, is entitled to great deference in its interpretation of the Act. “The administrative interpretation of a statute by an administrative agency which has the duty of enforcing or administering it is to be given great weight. [Cits.]” Mason v. Svc. Loan &c. Co., 128 Ga. App. 828, 831 (198 SE2d 391) (1973).
We find no merit in any argument that the Supreme Court’s holding in City of Calhoun v. North Ga. Elec. &c. Corp., 233 Ga. 759 (213 SE2d 596) (1975) requires a different result. Although both City of Calhoun and the case sub judice involve the Georgia Territorial Electric Service Act, that is the only point of reference these cases have in common since City of Calhoun was concerned solely with a constitutional challenge to the Act, and does not suggest or intimate the validity of a different interpretation.
Since we find that the PSC correctly interpreted the statute, the superior court did not err by affirming the PSC’s order.
Judgment affirmed.
Birdsong, C. J., Deen, P. J., Carley, Pope and Benham, JJ., concur. McMurray, P. J., Banke, P. J., and Beasley, J., dissent.