19-10-2012, 01:18 PM
GRID INTERACTIVE ROOF TOP SOLAR PHOTOVOLTAIC POWER PLANT AT SEWA BHAWAN
GRID INTERACTIVE ROOF.pdf (Size: 1.35 MB / Downloads: 303)
Executive summary
The proposed Roof Top Solar Photovoltaic Power Plant at Sewa Bhawan would
utilize vacant area of about 375 sq. m. available on the terrace of the north wing of
the building. The SPV power plant with proposed capacity of 25 kWp would be
connected to grid. No battery storage has been provided. It would meet partial load
of the building during working days and feed the surplus power available to the grid
during week end and holidays. The grid connected SPV project would be a
demonstration plant to harness renewable energy and the data on generation would
be utilized for analysis of the various aspects of operation as also that of availability
of power.
The 25 kWp SPV power plant is estimated to afford annual energy feed of 42 MWh
considering efficiency of the solar module as 16%, Inverter/ Power Conditioning Unit
(PCU) as 94% and losses as 3% in the DC and AC system. The Plant would
operate at an annual capacity utilization factor of 19%. The energy available from
the Plant would vary from a minimum of 3.33 MWh during the month of January to a
maximum of 4.13 MWh during the month of March.
INTRODUCTION:
Harnessing of non polluting renewable energy resources to control green
house gases is receiving impetus from the government of India. The solar
mission, which is part of the National Action Plan on Climate Change has been
set up to promote the development and use of solar energy in for power
generation and other uses with the ultimate objective of making solar energy
competitive with fossil-based energy options. The solar photovoltaic device
systems for power generation had been deployed in the various parts in the
country for electrification where the grid connectivity is either not feasible or not
cost effective as also some times in conjunction with diesel based generating
stations in isolated places and communication transmitters at remote locations.
With the downward trend in the cost of solar energy and appreciation for the
need for development of solar power, solar power projects have recently been
implemented. A significant part of the large potential of solar energy in the
country could be developed by promoting grid connected solar photovoltaic
power systems of varying sizes as per the need and affordability coupled with
ensuring adequate return on investment. It has been proposed to set up a 25
kWp grid connected solar photovoltaic power plant on the roof top terrace of
the north wing of Sewa Bhawn as a pilot project.
SITE DESCRIPTION:
The Sewa Bhawan has two wings known as north wing and south wing. The
lay out of the rooftop terrace is shown in the Exhibit – II. The terrace on the
north block has communication antennas and an area of about 375 sq meters
is vacant which could be used for SPV installation of 25 kWp. The terrace of
the south wing having an area of about 1000 sq. meters is vacant and could
also be used for larger size SPV installation. It is proposed to utilize the vacant
area available on the north wing for installation of 25 kWp which could serve as
a grid connected demonstration system and could be used for collection of
data for analysis on the of availability of solar power. The development on the
south wing terrace could be taken up later.
BRPL Supply
Electrical Power requirement for Sewa Bhawan is met from two sources of
BRPL viz Main supply from sub-station Sector-1 and sub-station Sector-9, R.
K. Puram. The power received at 11 kV level is stepped down to .4 kV by 4
Nos. dry type 11/ 0.4 kV, 4x1600 kVA distribution transformers located at the
S/S in the ground floor of the Sewa Bhawan building. The load of north wing
where the office of CEA is located is fed from transformers (TR-3 & TR-4).
The maximum load for CEA is to be around 1-1.2 MW (1600 -1800 Amp). A
4x600 kVAr capacitor bank has also been provided to improve the power
factor.
The Sub-station at Sewa Bhawan is operated and maintained by officers and
operators of CPWD. The changeover of power supply from main to alternate
is, however, under the control of BRPL.
ANNUAL ENERGY GENERATION:
The annual energy generation from the SPV power plant has been worked out
based on the data on mean global solar radiant exposure over Delhi at
Safdarjung. The mean global solar radiant exposure varies from 3.72 kWh/m2
/day in the month of December to 7.08 kWh/m2 /day in the month of May. The
month-wise mean global solar radiant exposure is given at Annex-I.
Considering the efficiency of PV module at 16% and temperature coefficient of
4.4 % per oC, the annual energy generation feed into the grid is estimated as
42 MWh. This takes into consideration an efficiency of the Power Conditioning
Unit (PCU) as 94% and losses in the DC and AC system as 3% each up to the
point of interconnection. The month wise energy generation during the year is
given at Annex-II and shown below.
COST OF ENERGY GENERATION & TARIFF:
The Tariff for the sale of energy from the SVP Power Plant at Sewa Bhawan
has been worked out considering that equity ratio of 70:30. The interest rate
on the loan has been adopted as 12.79 % based on the prime landing rate
(PLR) as per CERC. The salvage value of the project has been considered at
10% and the depreciation has been based on the differential depreciation
approach as per the CERC Notification dated 16th September, 2009. The
depreciation of 7% has been adopted during the 1st 10 years and based on
straight-line method for remaining useful life. The interest rate on the working
capital has been adopted as 13.79 % based on the prime lending rate of
CERC. The working capital has been worked out based on the CERC norms.
The O & M expenses have been adopted at the rate of Rs.9 lakh / MW for the
first year operation and escalated @ 5.72% / annum. The data sheet
indicating the various parameters adopted in the computation of the Tariff as
per CERC norms is enclosed as Annex-.IV.