Firstgreen has analyzed the performance of an upcoming grind connected 1 MW solar power project. The project has selected a location in Rajasthan near Baap Substation which has a very good solar insolation. The modules selected are Mono Crystaline Silocon by Candana SP 230 Wp each. The inverters selected for the plant are by Hefai 450V-800V output voltage and 50 kW each. The system design considers 12 modules in each string and there are 362 strings. Total number of modules used are 4344 modules with a total capacity of 999 kW capacity. This report analyses the following parameters.
- What is the global radiation energy of the sun at the selected location.
- What is the maximum electrical power which generates the selected PV system
- What is the amount of electrical energy that the selected PV system produces in a year
- What is the specific production of electricity in terms of kWh/kW
- How much are the losses during the conversion in PV modules (thermal degradation, the Discrepancy).
- How much are the values of loss factors and the normalized output
- What is the value of the Performance Ratio (PR)
- How much are the losses in the system (inverter, conductor, etc…)
What is the value of energy produced per unit area throughout the year
The area required for this plant is about 5000 sq.mts area, and it has no objects that could cause shadows.
The first thing we need to analyze is the solar path diagram for the site and understand the albedo effect. The value of Albedo effect for Rajasthan locations sites is 0.14 to 0.22; we will take average 0.2
The number of modules in series are selected in order to achieve a MPP voltage compatible with the inverter voltage levels window.
PV system is comprised of a 2622 Canadian Solar CS6P-230M The PV system is mounted on a stainless steel support structure facing south east and tilted at 15°. Such a tilt angle was chosen to maximize yearly energy production.
U-I characteristics for irradiation h = 1245 W/m2and working temperature 60°C.Output power P = f(U).
The simulation was conducted through PVSYST software and analyzed the different configurations and operating parameters of the site.
Global horizontal irradiation energy of the sun for a year in the territory of Rajasthan, according to results from PVsyst program is h=1000 kWh/m2year.At the panel surface the level of radiation is 7.9% higher because the panels are tilted. This value is reduced for 3.3% because of the effect of Incidence Angle Modifier (IAM) and the final value is: h = 1245 kWh/m2year.
Horizontal global irradiation sum =3.6 kWh/m2.
- Horizontal diffuse irradiation sum =1.3 kWh/m2.
- Horizontal global – clear sky =4.40 kWh/m2.
- Horizontal diffuse – clear sky =0.84 kWh/m2.
- Maximum electric power that PV system generates in output of inverter is pnom =603kWp.
- Annual produced electric energy in output of inverter is: 1489MWh
Losses of power during PV conversion in modules are:
- FV losses due to irradiation level = 2.4%
- FV losses due to the temperature scale = 11.2%
- Losses due to quality of modules = 2.6%
- Losses due to mis match of modules = 1.1%
- Losses due to conduction resistance = 1.0%.
Loss factors and Normalized production are:
- Lc – Panel losses (losses in PV array) = 19.4%
- Ls – System losses (inverter) = 3.3%
- Loss factors and Normalized production (per installed kWp) are:
- Lc – Panel losses (losses in PV array) per maximum power = 0.55 kWh/kWp/day
- Ls – Losses in the system (inverter) for maximum power = 0.20 kWh/kWp/day
- Yf – Useful produced energy (the output of inverter) for maximum power = 2.77 kWh/kWp/day
Performance ratio (PR) is the ration between actual yield (output of inverter) and target yield.
- System losses are losses in the inverter and conduction. They are Ls = – 3.2 %.
- System Efficiency (of inverters) is: 1– 0.032 = 0.968, or _sys = 96.8 %.
- Overall losses in PV array (temp, module, quality, mismatch, resistant) are: Lc = – 21.6%.
- PV array efficiency is: Lc = 1– 0.216 = 0.784, or nrel = 78.4 %.
The design, the optimization and the simulation of the PV systems for use in Rajasthan have been analyzed and discussed, and the following conclusions are drawn: average annual PV system energy output is 1012 kWh/kWp and average annual performance ratio of the PV system is 78.4 %.
The performance ratio shows the quality of a PV system and the value of 78.4% is indicative of good quality Usually the value of performance ratio ranges from 60-80% This shows that about 21.6% of solar energy falling in the analyzed period is not converted in to usable energy due to factors such as losses in conduction, contact losses, thermal losses, the module and inverter efficiency factor, defects in components, etc.
It is important that we have matching between the voltage of inverter and that of the PV array, during all operating conditions. Some inverters have a higher efficiency in certain voltage, so that the PV array must adapt to this voltage of maximum efficiency. Use of several inverters cost more than using a single inverter with higher power.
In Normalized production and Loss factors figure is presented the histogram of the waited power production of the array, compared to the inverter’s
nominal power. Estimation of the overload losses (and visualization of their effect on the histogram). This tool allows to determine precisely the ratio between array and inverter Pnom, and evaluates the associated losses.
Utility-interactive PV power systems mounted on residences and commercial buildings are likely to become a small, but important source of electric generation in the next century. As most of the electric power supply in developed countries is via centralized electric grid, it is certain that widespread use of photovoltaic will be as distributed power generation inter-connected with these grids.
This is a new concept in utility power production, a change from large-scale central examination of many existing standards and practices to enable the technology to develop and emerge into the marketplace. As prices drop, on-grid applications will become increasingly feasible. For the currently developed world, the future is grid-connected renewables. In the next 20 years, we can expect only a slight improvement in the efficiency of first generation (G-1) silicon technology. Will we witness a change of the dominant technology of the G-1 in an era of market share with second generation technology (G-2), based mainly on thin-film technology (with 30% cost reduction). While these two branches will largely dominate the commercial sector of PV systems, within the next 20 years will have increased use of third generation technology (G-3) and other new technologies, which will bring to enlarge the performance or cost reduction of solar cells. During this project, the overall results of the simulation system to connect to the network PV is bringing in the best conditions possible, by using the software package PVsyst. Overall, the project gives them understand the principle of operation, the factors affecting positively and negatively, losses incurred before the conversion, conversion losses and losses in the cells after conversion. All this helps us to make optimizing FV systems under conditions of Rajasthan.