A TECHNO-ECONOMIC ANALYSIS OF A LOW VOLTAGE ALTERNATING CURRENT SMART GRID

The report on a techno-economic analysis of a low voltage alternating current (LVAC) smart grid is for the purposes of providing reliable, efficient, and intelligent distribution of electricity to consumers in the Akwa Ibom State University (AKSU) main campus. The presented work assumes that recent advancements in power electronics, communication technologies and data analytics have been taken advantage of in order to enable real time monitoring, control and optimization of the LVAC grid performance. The analysis presented is for a grid designed to handle distributed energy resources (DERs) such as photovoltaic solar and battery-based energy storage systems. The extent of the present conventional LVAC grid serving AKSU main campus was determined with the aid of Google map and by physical inspection of the major blocks and by tracing of the low voltage lines serving the campus. Measurement of the total power consumption for the campus was obtained by taking hourly readings from the digital display of the 500kVA backup diesel generator serving the campus over a 4-day period. Mapping of the main campus and a top-level design of a smart fault protection scheme was carried out using the AutoCAD software. The campus was modelled into a seventeen bus system to represent all the departments in the main campus and possible power generation from solar-based DERs was simulated using Power World simulator software version 15.0. However, due to the high complexity of a seventeen bus system, the system was reduced to a four bus system, using four departments (Faculty of Education, Agricultural Engineering Department, Chemical Engineering Department and Electrical and Electronic Engineering Department) as a case study. A comparative cost analysis was performed using the cubic cost model (for diesel-based power generation) and a multi-year tariff order-based model (for PV and utility sourced power). The graphs of cost (N/kWh) against time in hours (hrs), were used to illustrate the total hourly cost incurred when the campus is served from public utility supply and graph of PV generation potential (kWh) against time (hrs) gives the total power generated when solar based DERs was used to serve the campus, results showed that integration of solar based DERs with other conventional sources of power supply in AKSU main campus is a viable choice. Therefore, it is recommended that the campus be served with solar based DERs and the excess PV generated energy used to feed other departments or stored in battery-based energy storage systems for future use.