Coating India’s Rooftops with Solar Photovoltaics

It is a known fact that India is a rarest of the countries rich with sunlight radiation and offers the best hope to revolutionise solar energy in the world. It receives about 5,000 trillion kWh of radiation annually. For every square kilometre 50 MW of solar power can be commissioned that can yield average annually 42.5 GWh of electricity assuming present PV cell efficiency of 15%. - Jaideep N Malaviya

Renewable Energy, Green Power Electricity, Energy Conservation, Sustainable Energy, Environments, Solar power | Coating India’s Rooftops with Solar Photovoltaics - Electrical India Magazine on Power & Electrical products, Renewable Energy, Transformers, Switchgear & Cables
Coating India’s Rooftops with Solar Photovoltaics

India’s present electricity requirement is 1,102,900 GWh as per Central Electricity Authority. This means an area of 26,000 km2 is required to meet the country’s annual electricity demands using solar energy. Against India’s landmass area of 3,166,414 km2, it is a meagre 0.82% space required. Such is the gravity of sunlight that India receives. Presently the country has more than 2,500 MW of grid connected power plants besides additional nearly 200 MW off-grid systems. The National Solar Mission targets 20,000 MW of grid connected solar power and additional 2,000 MW off-grid solar by the year 2022. The challenge is in sight rather will grow much more.

The cost of solar PV modules (panel) has dropped by more than 60% in the past 5 years.Solar power generation broadly gets classified into grid type and off-grid type. The former feeds the generated power in the grid, traded under market mechanism. In the the off-grid system the energy generated is for captive consumption. Typical examples are lanterns, street lights, home lighting systems, pumping systems. Besides there decentralised systems in form of mini power packs & roof-top systems.

The rising cost of electricity and diesel is making solar power more attractive even at individual level. Particularly every dwelling be it industrial, commercial or household wants to explore how best a solar systems can be integrated.
Solar water heater (SWH) that works on thermal principle has reached a state of pinnacle and is a viable technology affordable to masses to consider on their rooftops. The country has presently more than 80 lakh m2 of solar collector (panel) area commissioned that is delivering daily 80 crore litres of hot water at 60OC on a normal sunny day. 80% of these installations are in the residential sector and is now considered as an amenity. Contrary to a decade ago when they were considered as disturbing the aesthetics of building these days the change in mindset has made it affable to any India as a mark of the individual’s commitment on use of a green technology. The last 3 years have seen markets more than double as per the source, Ministry of New and Renewable Energy, govt. of India. India is presently fourth global leader in SWH.

SWH is pre-dominantly a product of the urban masses and the rural rich. As per census of 2011 there are close to 10 crore residential houses in urban India. 95% of urban households are electrified. As a means of energy conservation drive in the critical case if the government plans to make solar water heaters mandatory to all electrified households, this potential translates to 19 crore m2 of collector area.

Electricity is equally an imperative commodity to a human being that provides quality of life and its minute absence makes life distressful. Hence the demand for individual solar power systems is also witnessing growth in India. The cost of solar PV modules is rapidly falling is converging to coal based electricity prices. The break-even may be achieved in the year 2015 (source A.T. Kearney). Thus the desire to use solar energy on micro level for individual needs is fast catching up.

The western countries have a popular concept of Building Integrated Photovoltaics (BIPV). A BIPV system consists of integrating PV modules into the building envelope, such as the roof or the façade. By simultaneously serving as building envelope material and power generator, BIPV systems can provide savings in materials and electricity costs and add architectural interest to the building. The cells are also made of colour that match the exterior walls. They resultant energy can be fed to the grid or also used for self consumption.

One of the essential criteria for any solar PV system to be successful in India is the south facing area should be shadow free so as to capture maximum sunlight. Many architects tend to overlook this requirement when drawing any building plan and thus deprive use of solar energy. Secondly urban buildings are densely populated hence getting shadow free south facing wall is a challenge. The only option is to make use of the open roof space. Hence Rooftop Solar systems are the way out.

If electricity is precedence and solar energy offers hopes then any open space must be welcome rather than emulating the western concepts. This puts a challenge to the architects and builders to create the best designs that favour any solar energy panel installation and can further be aesthetically appealing. What is vital is capturing the sun into energy for useful purpose. After all it is the generated power which can fulfil the needs. The modern mindset of masses has drastically changed and many take pride in displaying the panels on their rooftops to display their commitment to green technologies. A major advantage of rooftop systems is it prevents investment in land cost. Picture shows a rooftop solar PV installation in Raipur on the new building of Chattisgarh Renewable Energy Development Agency (CREDA). It is a classic example of building architecture that smartly incorporates the PV modules (panels) on the rooftop.

A basic economics of a 10 kW rooftop system is as shown below

As can be seen above solar power is not only feasible but costs less than grid supplied electricity. The Accelerated depreciation (AD) of (80%) resulting in 30% Tax credit in Income Tax under Section 80IA of the Income Tax Act, 1961 is a driver and all commercial and industrial rooftops should be the prime target. Recently Solar Energy Corporation of India (SECI), a government of India body had recently invited bid for 50 MW worth Rooftop projects and the response was overwhelming.

A major shortcoming for any solar energy project is the high capital cost. Banks and Financial Institutions are however now according priority to lending for renewable energy projects however to overcome this phobia companies can consider opting for RESCO (Renewable Energy Service COmpany) route. It is a business that develops, engineers, and installs projects designed to reduce the energy usage and maintenance costs for facilities, equipment, and infrastructure in a variety of end-user sectors. A RESCO often provides operations services, monitors savings, and assumes certain performance warranties and risks for its projects. It will enter into a formal understanding with a Financial Institution for financing the project under long term payment agreement. The beneficiary is thus relieved of the initial capital burden and is also assured of the returns from the project.

The present government has made its intentions clear to bring aggression in solar power generation. Right from Railways to ultra mega solar power projects of several hundreds of MW to the annual budget presented in June 2014 by the new government there were a surfeit of announcements encouraging solar energy projects by allocating 1,500 crore of funds, albeit largely for ultra mega solar power projects. But if one reads through the fine print then there will be 100 smart cities developed besides 60 ‘Solar Cities’ already in place. There is also Solar Purchase Obligation (SPO) in place which requires the electric utilities company to generate or purchase solar power. It is 0.25% of the total traded power with 2012-13 as the base year and increases to 3% by the year 2022-23. SPO mechanism will help develop rooftop solar energy markets by bundling several small developers where open roof space is available to generate solar energy. The ground is already set for solar energy projects to take-off and it is up to the buildings to take up the challenges by offering their roofs.

In the benefit of masses a National toll free Solar Energy Helpline (To reach it call 1800 2334477) is also operative since August 2011, which is perhaps the first of its kind by any country. Urban cities in India are growing and shall continue to expand vertically together with increasing electricity requirements and greenhouse gas emissions. Rooftop solar PV facilities offers potential benefits including reducing dependence on fossil fuel based generation, savings on investment in transmission and distribution infrastructure, savings on reducing the network losses, reduced cost for managing the scheduling of electricity and can eliminate purchase of expensive energy from the market. It will not be a surprise to see PV modules on rooftops just the way we witness the multiple dish antennas on all the roofs or walls facing the sky. One who sets his sight on integrating solar PV in buildings will emerge the winner keeping in mind the long term business returns it will offer.


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