The City of Nelson retained Associated Engineering to complete a feasibility study for a District Energy System. Two potential areas had been identified for assessment, the downtown Lakefront area and the Selkirk college campus. For each of the study areas, a building inventory and the estimated energy loads were summarized. Since all of the potential customer buildings were existing buildings, a high level assessment of the likely current heating system and the level of effort required to retrofit to a District Energy System was made.
Associated Engineering developed a model to analyze various combinations of connected buildings. The model compared the capital costs necessary to provide a central energy plant and to connect all the buildings with District Energy distribution piping against projected revenue from energy sales from those buildings. By repeating this analysis on various “nodes” of the system, the optimum first phase and subsequent phasing of the District Energy System could be determined.
Three energy sources were considered for providing the base energy load to the District Energy System. These consisted of biomass boilers, lake sourced heat pumps and geoexchange sourced heat pumps. A delivered cost of energy analysis determined that biomass boilers provided the most cost-effective energy source. Associated Engineering provided a concept design for the first phase of District Energy System, supported by a cost estimate and business case analysis.
O&M costs, debt servicing, grant funding and energy sales revenues were projected over the project lifecycle in order to identify potential energy rate pricing and structure. This information together with greenhouse gas emissions reduction analysis allowed the City of Nelson to proceed to the next steps in their District Energy System implementation strategy.