Development of Solar Electricity Supply System in India: An Overview

1. Introduction

The changing lifestyle with rapid industrialization has made electricity an indispensable and essential commodity over the years. During the last few decades, increasing prices of electricity with increasing demand and decreasing fossil fuel reserves have raised many concerns for policy makers, investors, and customers. Moreover, existing supply chain also poses a challenge of carbon foot print due to its dependency on fossil fuels like coal and oil for electricity generation [1–3].

Initially used to supply electricity to satellites due to its high generation cost, solar technologies and its potential have improved enough to supply electricity not only to remote locations but also to supplement the national grid power at multimegawatt levels [7].

In India, wind- and solar-based systems have been getting good response under the conducive environment created through different policy measures. In this paper, our focus is only on the development of solar-based electricity supply systems. There are different kinds of support measures to promote grid connected and off-grid solar systems. We discuss these in detail in the subsequent sections.

2. India’s Potential for Solar Energy

India is located in the northern hemisphere, lying between latitudes 8°4′N and 37°6′N and longitudes 68°7′E and 97°25′E; the country is divided into almost two equal halves by the Tropic of Cancer (23°30′N). The southern half which coincides with peninsular India lies in the tropical zone, while the northern half belongs to the subtropical zone.

Due to its locational advantage, on average, the country experiences 250 to 300 sunny days per year and receives an average hourly radiation of 200 MW/km². The annual global radiation varies from 1600 to 2200 kWh/m² [6], which is typical of the tropical and subtropical regions. NREL recently released 10 km resolution solar resource maps for India based on the SUNY satellite. Figure 1 shows the annual average direct normal irradiance (DNI) across India, which illustrates that most areas of the country have greater than 5 kWh/m²/day of DNI. This image shows the areas of highest resource occurring in the state of Gujarat, Rajasthan, and the high-elevation Himalayan region. Figure 1 also shows large areas with annual average DNI greater than 5.5 kWh/m²/day in the state of Madhya Pradesh, Chhattisgarh, and Maharashtra and smaller land areas with similar resources in several other states. This area could be further increased by the use of building-integrated PV. Though large-scale CSP has not yet been deployed in India; one study has estimated that this technology alone could generate 11,000 TWh per year for India (Table 1). In addition, it also offers huge potential for decentralized distributed electricity supply system, which can address the problem of electricity to a remote location with less/lower transmission losses.

In spite of huge solar energy potential, the portfolio of RE has developed in a very unique way in India, though, lately introduced wind power technology has left behind all the traditional RE technologies such as biomass, solar power, and SHP as shown in Figure 2. It also demonstrates that solar power has the maximum untapped potential as 97.9% of estimated potential of 50000 MW. And the overall untapped potential of 81.3% seeks immediate attention of policy makers for exploiting this available RE resource in a very efficient and effective manner to overcome the problem of electricity shortage.

3. Development of Solar Electricity System under Different Policy Measures in India

Government of India has recognized the importance of solar energy as one of the sustainable sources of energy under National Action Plan for Climate Change (NAPCC). NAPCC aims to derive 15% of its energy requirements from RE sources by the year 2020 [10]. Various policy measures, such as preferential tariff or fixed tariff or feed-in tariff (FiT), RPO, excise duty exemption, and soft loan, have been implemented to achieve the above-mentioned target.

RPO is one of the tools which have been implemented by many countries to achieve their ambitious RE goals [11, 12]. In India, state electricity regulatory commissions (SERCs) determine the obligated entities, which generally include distribution companies, captive consumers, and any open-access users. Then these SERCs fix a certain proportion of electricity consumption as RPO targets for the above-mentioned obligated entities. Due to significant cost difference in solar and nonsolar RE technologies [13], most of the states have come up with their separate targets for solar electricity, as shown in Table 2. As per the National Tariff Policy, it is envisaged that the targets for solar RPO shall be 0.25% by 2012-2013 extending to 3% by 2022 [14], but only the state of Bihar has followed it in its solar policy the way it is expected.

A study conducted by MNRE shows that most of the states could not install capacity of solar system as per their RPO compliance requirement for the year 2012-2013 as on 12th of November 2012 (Table 3). The states like Uttar Pradesh (422.7 MW), Haryana (172.2 MW), Maharashtra (151.3 MW), and so forth, are far away from their RPO target. However, states of Gujarat (488.3 MW), Rajasthan (82.3 MW), and Karnataka (61.1 MW) have already surpassed their RPO requirement. Other states like Madhya Pradesh, Orissa, Punjab, and Uttarakhand may soon exceed their targets.

However, when annual solar capacity requirement for RPO compliance is analyzed (Table 4), it is found that India would need ~34,000 MW of solar capacity to achieve the target of 3% contribution from solar electricity till 2022. It means that set RPO targets are not sufficient to have a solar energy dominant RE development scenario [15]. The policy makers expect to fill this gap with states’ solar energy promotion policies and programmes. Most of the states have come up with their solar energy specific policies which are discussed in detail in subsequent sections.

As far as state-wise installation is concerned, Table 5 clearly demonstrates that states of Gujarat (65.83%) and Rajasthan (19.20%) have major share in total installed capacity (1047.87 MW). Other states like Andhra Pradesh (23.75 MW) and Maharashtra (21.00 MW) also have significant contribution. However, it is quite remarkable that out of 26 states 19 have shown their presence in the class of solar India in spite of relatively high generation cost (Table 5). It is expected that when cost will reduce with increasing capacity, states which have low or no capacity may contribute significantly.

Moreover, Table 6 shows that the installed capacity (1047.87 MW) under various policy measures is dominated by state policies (65.83%) which is in particular the success mantra of state of Gujarat (689.81 MW). The peculiarity of theses installation scenarios should be taken into account while devising the policy for future.

4. Conclusion

The study concludes that though JNNSM first phase could not perform up to the expectations, the state level policies have been doing well to fill the gap. The recently announced JNNSM Phase II target composition of 3600 MW for central and 5400 MW for states, changes in policies and schemes in light of the experience of Phase I, and development of 54 solar cities are likely to impact the National Solar Mission performance and enhance the overall visibility of solar-based electricity generation and utilization.