The phrase "additional source of energy" is correct and usable in written English.
It can be used when discussing various forms of energy, especially in contexts related to renewable energy, sustainability, or energy production.
Example: "Solar panels provide an additional source of energy that can help reduce our reliance on fossil fuels."
Alternatives: "extra energy source" or "supplementary energy source".
A possible limitation of the present study was that the FAT-M was administered in addition to the rats' normal diet (i.e., purine), possibly providing an additional source of energy that may impact spontaneous behavior.
Oil shale is on the rise as an additional source of energy.
This material could potentially serve as an additional source of energy for volatile release.
The diets also contained soya bean meal and/or urea as additional sources of nitrogen, sugar beet pulp and barley in a 1 1 ratio as additional source of energy, extruded linseed as supplemental 18 3 n − 3, a mineral and vitamin mix and a vitamin E preparation.
Sophisticated models require an additional source of energy (Barbosa et al. 1985; Shemansky 1988; Delamere and Bagenal 2003; Delamere et al. 2005; Steffl et al. 2006).
Ever since, astronomers have detected subtle brightness and color changes of the slowly fading afterglows of some GRBs that hint at an additional source of energy in the region, but firm evidence was lacking.
The White House's trumpeting of the energy crisis helped to feed the myth that America desperately needs additional sources of energy, clean or no.
In the first place, the scenarios measure only the "fire load," or amount of combustible material, already in the building; the tests don't anticipate additional sources of energy that might be introduced into the building.
Asked what they were doing to increase domestic oil refining capacity and bring on additional sources of energy, the executives said investments in their industry can take decades to come to fruition.
But state and local officials, including the Department of Public Utility Control, as well as energy company engineers insist the pipeline is necessary to provide energy to customers this summer and to avoid power outages because of the rapidly growing need for additional sources of energy.
