Need for paradigm shift in design philosophy for tasks involving water - energy nexus

Abstract

Since both water and energy are highly vital and scarce resources, for the sustainability of any economic development plan (either at macro level or micro level), it is necessary to consider the interconnection between water and energy. Alternative strategies should be explored which considers this interconnection. This necessitates a paradigm shift in the design procedure/philosophy itself, the initiatives towards which are still in inception. This work proposes a typical design philosophy concerning water energy nexus and demonstrates its application at a university level scenario for augmentation of drinking water requirement. Three alternative strategies are considered for augmentation namely locating additional bore wells within the campus, reuse of treated sewage water for toilet flushing and utilizing wasted runoff from the upstream during rainy seasons. The alternatives are analysed to evaluate their merit in savings in energy utilization and water generation. The third alternative consisting of constructing a retention pond to collect the runoff water is found to be most viable which contributes most optimally towards savings in energy requirement as well as meeting the needs of water requirement. While reuse of treated wastewater contributes to 45000 l/day of water, it comes at the cost of 490 kWh/day. The construction of detention pond generates 200000 l/day of water during monsoon seasons which can used to meet water requirement as well as recharge of the groundwater. The energy requirement can be made almost nil by transporting the water under gravity flow.