Provided herein are methods for manufacturing T cells. In certain embodiments, methods for manufacturing T cells which express a cell surface receptor that recognizes a specific antigenic moiety on the surface of a target cell are provided. Such methods may include, but are not limited to, steps of (1 ) enriching a population of lymphocytes obtained from a donor subject; (2) stimulating the population of lymphocytes with one or more T-cell stimulating agents to produce a population of activated T cells, wherein the stimulation is performed in a closed system using serum-free culture medium; (3) transducing the population of activated T cells with a viral vector comprising a nucleic acid molecule which encodes the cell surface receptor, using a single cycle transduction to produce a population of transduced T cells, wherein the transduction is performed in a closed system using serum-free culture medium; and (4) expanding the population of transduced T cells for a predetermined time to produce a population of engineered T cells, wherein the expansion is performed in a closed system using serum-free culture medium. Also provided herein are populations of engineered T cells produced by the methods described herein and pharmaceutical compositions thereof. Provided herein are methods for manufacturing T cells. In certain embodiments, methods for manufacturing T cells which express a cell surface receptor that recognizes a specific antigenic moiety on the surface of a target cell are provided. Such methods may include, but are not limited to, steps of (1 ) enriching a population of lymphocytes obtained from a donor subject; (2) stimulating the population of lymphocytes with one or more T-cell stimulating agents to produce a population of activated T cells, wherein the stimulation is performed in a closed system using serum-free culture medium; (3) transducing the population of activated T cells with a viral vector comprising a nucleic acid molecule which encodes the cell surface receptor, using a single cycle transduction to produce a population of transduced T cells, wherein the transduction is performed in a closed system using serum-free culture medium; and (4) expanding the population of transduced T cells for a predetermined time to produce a population of engineered T cells, wherein the expansion is performed in a closed system using serum-free culture medium. Also provided herein are populations of engineered T cells produced by the methods described herein and pharmaceutical compositions thereof. A power system for an electrical system with highly fluctuating loads is powered by one or more power sources that are slow to react to load changes. The power sources are connected to electrical equipment used on the drill rig which provide active load to the generators. One or more load banks may be positioned to provide passive load to the generators to maintain generally constant generator load, while allowing for instant access to power as active load increases. Generators may be run at 100% capacity, a maximum efficient capacity, or at a high enough level to allow for a sufficiently rapid increase in power output. At least one parameter of a drilling operation may be utilized to anticipate load demand changes.