I need what are the disadvantages that are found in generating the power from solar panels.
development of a sun tracking mechanism (servo motor or DC motor control system) to get the maximum power from the photovoltaic power plant
Designing a low cost MPPT for a Small roof top Solar PV system to improve performance when there is mismatch in the PV modules used or there is partial shading.
Solar PV gives out put only when Sun shines. This may on average 5 to 7 hours/day. The Solar PV has a maximum plant factor of about 30% compared to a fissile fueled plant with almost 80 to 90% plant factor. To get best out of solar some storage will be required. Now large scale generation with 24/7 Generation with CPV 20MW is available with Molten salt storage. The costs are now little higher but is coming down. We need a SMART grid to absorb this type of intermittent .Solar PV power. But future is going to be with SMART grids and interstate inter country connected Transmission line. Then the problem of generation when sun is not there doesn't arise as there will be sunshine somewhere in the world. Distributed Generation reduces all the Tran.& Dist. losses in the system. http://www.energycentral.com/generationstorage/solar/news/en/21645224/PNM-Solar-Storage-System-a-First-
When Solar PV Generation is Grid connected for the safety of personals who had to work on the failed line There should be connectors to isolate the Solar PV supply from the grid line. This is a major disadvantage and adds to the costs of the system. Presently the inverters are only guaranteed to a maximum of 20 years so for LCoE calculations people take this 20 years as life of the system and end up with very high figure and compares high with cost of subsidized Coal power generation. Designing good quality inverters of life higher than that of the present solar PV will reduce LCoE figures and will score better. Please go through-- http://www.appropedia.org/Levelised_Cost_of_Electricity_Literature_Review -.- and in particular Should solar photovoltaics be deployed sooner because of long operating life at low, predictable cost?-- http://www.pelagicos.net/ENVS4100_fall2010/readings/Zweibel_2010.pd - http://www.asrc.cestm.albany.edu/perez/2011/solval.pdf Please forward your views on these
Dear Kanaga Gnana,
you can go with the designing , modelling and performance study on solar concentrators.
Prashant Sandhi When you have distributed Generation by rooftop solar PV it could feed back into the mains when the LT distribution line trips due to some fault either in the LT system or on a HV failure in the system. The LT and HV line has to rendered safe to work for maintenance people who want to repair the fault on the circuit. So back feed has to be prevented for the safety of the personals working on the defective line which should not have any voltage fed in. Proper earthing at the place of work is normally done this will trip the solar PV. But on safety regulations the solar PV power should be interrupted to prevent back feed. The house can continue to get the PV supply for its own use. Hope this is clear now.
The line can fail in many ways. Snapped line may be due to a tree falling, It could be due to a failure of an insulator, On an over load the conductor joints could fail, a lightning could strike the line and causing the line to trip, Two conductors touching each other by accident, A hoist or crane hitting the wires, The transformer getting burnt or gets failed. There can be many such cases.of the tripping of a line. You point is taken but if the line has tripped people will have to work on the line it must be safe for them to work.
Please note even on HT HV lines insulators can be changed by working HOT on the line. Proper insulated tools are required and will take more time. Islanding
One of the most important safety issues for small customer-sited PV systems is a condition
called islanding. Islanding is where a portion of the utility system that contains both loads
and a generation source is isolated from the remainder of the utility system but remains
energized. When this happens with a PV system, it is referred to as PV-supported
islanding.
The safety concern is that utility power goes down (perhaps in the event of a major storm)
and a PV system continues to supply power to a local area. While a utility can be sure that
all of its own generation sources are either shut down or isolated from the area that needs
work, an island created by a residential PV system is out of their control. There are a
number of potentially undesirable results of islanding. The
principal concern is that a utility line workers will come into
contact with a line that is unexpectedly energized. Although
line workers are trained to test all lines before working on
them, and to either treat lines as live or ground them on both
sides of the section on which they are working, this does not
remove all safety concerns because there is a risk when these
practices are not universally followed.
Fortunately, although islanding is a very real condition,
inverter technology is such that there is no chance of a PVsupported
island stemming from a interconnected residential or small commercial systems
with inverters with built-in anti-islanding safety features. Grid-tied inverters monitor the
utility line and can shut themselves off as quickly as necessary (in 2 seconds or less) in the
event that abnormalities occur on the utility system. At Sandia National Laboratories and
Ascension Technology, extensive testing of inverters under a variety of laboratorycontrolled
worst-case conditions led to the development of the definition of a “nonislanding
inverter.” A good discussion of islanding and anti-islanding inverters is contained
in the annexes to IEEE Std 929-2000 and in Greg Kern, et al., “Results of Sandia National
Laboratories Grid-Tied Inverter Testing.” from http://www.abcsolar.com/pdf/connectingtogridmanual.pdf
http://wenku.baidu.com/view/95c89cfbfab069dc502201a2.html
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