Design and Optimization of Hydro/Solar/Wind/DG System using HOMER Pro for Gilgit Baltistan, Pakistan /

Abstract

In the past few decades, global warming has been major concern of developed and underdeveloped countries. Pakistan is also among the countries which are facing severe climate change problems. The current energy mix of Pakistan is such that conventional fossil fuel contributes around 70 %. Many rural areas of the country are still without electricity. One of the main reasons for un-electrified rural areas is the high cost of transmission and distribution systems due to a dispersed population. For the past few years, Pakistan has started exploring its green energy resources. The Gilgit-Baltistan (GB) region of Pakistan is famous for its scenic beauty, tourism and hydro resources. The local trade activities will flourish in future due to the passage of main CPEC route through this region. The electricity demand of this geographically scattered area is fulfilled by various independent mini/micro hydroelectric power plants. The current energy mix of Gilgit-Baltistan states that Hydro, Wood, LPG and Kerosene have shares of 24%, 30%, 40% and 06% respectively, in meeting the total energy demand of this area. The situation becomes nasty in winter due to harsh weather below freezing point and low water flow in streams/rivers. This results in very low hydroelectric power generation, thus for daily life activities, most of the population have to rely on fire-woods, biomass and diesel generators. Deforestation and environmental complications emerge due to extensive use of woods for domestic and commercial purposes. Apart from hydro, Gilgit Baltistan has good potential for wind and solar energy, thus utilization of these resources can cater the severe situation in winters. While in summer, future regional grid project will enable excess electricity form these renewables to be added to the national power system. This study focuses on the resource estimation of hydro, wind and solar energy in 20 remote sites of Gilgit Baltistan and presents a hybrid power system model at the respective sites. The wind speeds and solar irradiances required for our study are accessed from the NASA site by using HOMER Pro software. The other required data (load and water flow rate) for hybrid system modeling are provided by the government and non-government organizations of area under study. The techno-economic analysis shows that wind/hydro hybrid renewable energy system (HRES) gives the most favorable solution at all the sites with no capacity shortages. The optimized results give the cost of energy (COE) up to 0.043-0.084 $/kWh for wind and hydro combinations. PV/wind/hydro also demonstrate 2nd favorable result with COE ranges 0.046-0.092 $/kWh, but it accounts for some initial capital in the net present value. Moreover, study of these 20 sites reveals the fact that if current energy mix of GB is replaced for these sites by the proposed hybrid model, this can save 89263 tons of CO2 per year. Thus 8210 hectors of forest can be preserved from absorbing GHGs, while 0.0384 km3 volume of glaciers in GB can be protected from melting. Thus, glaciers of GB can be preserved by adopting suggested green hybrid systems for energy demand.