With the energy consumption of buildings trending upwards and energy prices rising, several commercial establishments are finding that their energy bills are fast becoming a significant part of their operational budget. In this paper, we describe the practical lessons learnt when the facility manager of a large office building in Australia was considering the of use of renewables to reduce the building's peak demand. We first illustrate how analytics can use used on data gathered by a building management system (BMS) to yield rich insights into the factors affecting the building's peak demand. We then describe the efficacy of solar PV and battery storage systems in alleviating the peak demand. We believe that the lessons learnt from our experience: (i) are generic as it informs facility managers of key factors to consider when incorporating renewables, and (ii) provides holistic guidelines when integrating solar PV and battery storage for reducing a building's peak demand and operating energy costs.