consultation services in the field of energy distribution, conservation, management, energy use, energy purchasing, energy efficiency and assessment of existing energy systems; power plant consultation services; management of energy facilities; power marketing and brokering; and services in the field of natural gas and/or electric power, namely, sale of gas and/or electric power purchased from other gas or electric power producers, suppliers or sources to other buyers; power quality monitoring, analysis and reporting services; energy services in the field of energy and lighting analysis, audits, recommendations and retrofits