Estimating Energy Savings and Greenhouse Gas Emissions Reduction through Substitution of Penn State Harrisburg's Water Source

Project Drawdown highlighted the energy required to distribute water from a source to the people and noted that improvements to the water distribution system could reduce this energy. Rainwater and condensate harvesting, e.g., replacing non-potable use water from a distant treatment plant with locally harvested rainwater or condensate, has the potential the energy required for treating water and pumping it to the campus. This feasibility study assesses the potential of water capture and reuse at Penn State Harrisburg, based on potential end uses of the harvested rainwater and needed levels of treatment. Currently, the study of implementing water capture and reuse with buildings in Pennsylvania are few, especially in regard to Penn State Harrisburg’s campus. No studies to date have been conducted that determine the quantity of harvestable water that is produced on campus in comparison to water needs on campus, nor has the energy cost of transport been addressed. By analyzing different nonpotable water uses on campus, the feasibility analysis addresses the question of whether water capture and reuse can reduce carbon emissions on campus when compared to pumping potable water several miles for non-potable & potable campus uses. The feasibility analysis using estimated water usage suggest that the benefits of implementing rainwater harvesting and condensate harvesting do not justify the cost. For rainwater harvesting, it is estimated that 9,250 lbs. of carbon dioxide are saved through this process. Condensate harvesting may have a negative carbon cost of estimated 9,397.63 lbs. of carbon dioxide. However, while rainwater harvesting has a positive carbon return, the financial cost of a second piping system, plus the carbon cost of any required treatment may offset the savings. Based on these results, rainwater harvesting provides less benefit because it is not needed for landscape irrigation and the campus piping system is already in place. A better cost-benefit analysis may occur when implemented on new construction, such as with the new academic learning center being proposed. Also, it is important to note that higher-end uses require more treatment which results in more carbon emissions and less of a regional benefit. Future research will expand this study to find the feasibility of implementing a few above-ground tanks at specific locations around Penn State Harrisburg’s campus in areas where non-potable water is needed and currently being supplied by city water.

Monday Poster Session
Natalie Neptune
Related Conference Themes
Electricity Generation