As used in this chapter, “gross revenue” means revenues received by an electric public utility from the sale of electric energy within the city. “Gross revenues” includes revenues from the use, rental or lease of operating facilities of an electric public utility other than residential-type space and water heating equipment. Gross revenues do not include proceeds from the sale of bonds, mortgage or other evidence of indebtedness, securities or stock, or sales at wholesale prices by one public utility to another when the utility purchasing the service is not the ultimate consumer, and revenue from joint pole use.