Achieving Higher Prosumption by Sharing the Renewable Energy Investment with Energy Demand Management: the Case of an Office Building

This paper highlights the efforts made by an office building to minimize its dependence on fossil-fuel based electricity by allocating a fixed capital for the purpose. The primary intent was to install a grid-interactive solar power plant that would help offset the electricity imported from the power grid. Consultations were held with the building owners to propose an alternative which would allow them to achieve higher energy prosumption by prioritizing energy demand management over renewable energy investment. The logic presented to assist in the decision making in favor of this suggestion was based upon the following facts. First, a quick calculation showed that the office building did not have sufficient rooftop space for installing a solar power plant that could offset half of the purchased electricity. Next, many of the electrical appliances in the building were old and inefficient and it made perfect sense to replace the "low-hanging fruits"; the investment made on these retrofits would be recovered in a shorter time span as compared to the investment made on renewable energy generation. Finally, the capital remaining after the investment made on energy-efficiency retrofits would be used for installing a solar power plant that can be accommodated on the roof of the building. A full year of monitoring of the energy performance of the building after the adoption of the energy efficiency and solar power plant shows that thanks to sequencing of energy demand management followed by renewable energy generation, the building has been able to achieve a higher energy prosumption within the allocated budget. Moreover, the payback period on the investments would be faster than if all the capital was mobilized for renewable energy generation.