Techno-economic Analysis of an Off-Grid Photovoltaic Natural Gas Power System for a University[edit | edit source]
This paper mainly focus on to determine the technical and economical feasibility of a PV-natural gas hybrid power system to supply electricity and energy for a university in Malaysia. Hybrid Optimization Model for Electric Renewable (HOMER) software was used to size, simulate and evaluate the hybrid power system in this analysis. The simulations provide some insights into the monthly electricity generated by the photovoltaic-natural gas system, net present cost (NPC) and cost of energy (COE) of the system, renewable fraction (RF) and greenhouse gas emissions of the system. With the inclusion of PV, the amount of natural gas burned in the hybrid system was reduced.
Overview[edit | edit source]
1)The objective of this study is to determine the technical and economical feasibility of a PV-natural gas hybrid power system to supply electricity and energy for a university. This analysis is conducted with the goal of reducing the natural gas consumption of the existing non-renewable energy source system with a keen eye on the cost effectiveness of a hybrid system. The reduced usage of natural gas is also set to be beneficial as it promises to reduce the greenhouse gas emissions by the system.For the purpose of this study, the hybrid system considered is a 2 MW PV generator and two 4.2 MW gas generators, and is used for electrifying the university as well as powering the air conditioning system for the campus. The solar irradiance data for the region is graphed. 2)Moreover, the Electric load graphs( hourly data and monthly data) depending on the average peak hours have been noted. This average peak hours also depends on office time, on season, off-season as university closes during vacation is also considered. 3)The economic feasibility analysis of the hybrid system is done by using HOMER software. The input data that is needed are as the following: solar resource data, electrical load data, economic constraints, technical specifications, cost constraints, types of components or equipment's, controls, emissions constraints etc. 4)Once the required data are available, the simulation can be run where calculations are performed to determine if the available renewable resources is able to meet the load demand. When the renewable resource is not sufficient to meet the load demand, the generator system or grid connection is considered. 5)The total costs of installing, operating and maintaining all the different configurations such as a hybrid system, stand alone renewable energy system, generator only system or grid integrated system is listed for the respective simulation inputs. 6)HOMER calculates the net present cost of the system/ life cycle cost of the system and even the LCOE. The COE gives an idea of the cost of electrical energy produced by the system.
System configuration in HOMER[edit | edit source]
1)The gas generators and load are connected directly to the AC bus whereas the PV generator is connected to the DC bus. Both these buses are then linked through a converter since this system only supplies AC load. 2)Determine the investment for gas generator it includes initial cost, operation and maintenance cost, price of natural gas. Even the life time of generator is to be considered. 3)PV generation the installing cost is considered. There is no maintenance cost involved as its life time is around 25 years. 4)The inverter cost and its replacement cost is considered which are same. The life time of the inverter is 15 years with 97% efficiency. 5)Economic constraints is interest rate with is considered to be 4%.
Simulation Results by HOMER[edit | edit source]
1)Electricity generated by the PV system as well as by the generator is presented given in monthly form. It even provides the contribution by the PV system and the generators. If excessive electrical energy is being generated then being utilized small storage units can be added to avoid wastage of electricity. 2)The simulation also provided categorized results that are also ranked according to the NPC but more specifically the lowest cost for each type of system.
Results[edit | edit source]
The result shows that the LCOE of the hybrid system is less as compared to only generators. 3)The hybrid system not only increases PV penetration but also reduces the cost of the total system compared to just the generators. 4)Importantly even if the initial cost of the solar PV system is more then the generator arrangement but if we consider the facts like maintenance, replacement, fuel cost. It show that the 97% of the total cost of the hybrid system is due to generator arrangement. 5)Emission also reduces by a considerable amount.
