The limitations of c-Si have led to research into thin-film PVM alternatives. Commercial thin-film PVM technologies, primarily cadmium telluride (CdTe) and copper-indium gallium-selenide (CIGS) solar cells, constitute roughly 10 per cent of the PVM market today and are already cost-competitive with silicon. Unfortunately, some commercial thin-film technologies are based on scarce elements, which makes it unlikely that they will be able to achieve terawatt-scale deployment at reasonable cost. The abundance of tellurium in the earth’s crust, for example, is estimated to be only one-quarter that of gold.
Emerging thin-film technologies, which are in the research stage, use neo-age material systems and device structures and have the potential to provide superior performance with lower manufacturing complexity and cost. Several of these technologies use materials abundant on the earth-even silicon in some cases. Other properties of some new thin-film technologies, such as low weight and compatibility with installation in flexible formats, promise reductions in BOS costs along with lower module costs.
Though these emerging technologies are not nearly competitive with c-Si today, they have the potential to significantly reduce the cost of PVM-generated electricity in the future. And while the private sector is likely to view R&D investments in these technologies as risky, the payoff could be enormous. Therefore, to increase the contribution of solar energy for long-term climate change mitigation, I strongly recommend that a large fraction of government resources for solar research and development focuses on environmentally benign, emerging thin-film technologies that are based on Earth-abundant materials. Technically, that would be the ideal way forward, catapulting India into a new realm of growth by making it energy powered!
Need for solar powered cities
With the changing urban landscapes and rapid economic development, we are seeing a spurt in energy demand of urban centres, leading to enhanced greenhouse gas (GHG) emissions. Mega cities across the world have set up stiff goals to be renewable-energised and reduce GHG, and countries like USA, China and Australia have already started setting up Solar Cities. So is the time ripe for India to follow the same?
Indian cities and towns are experiencing rapid growth in their peak electricity demand. The local governments and the electricity utilities are finding it difficult to cope with this rapid rise in demand. As a result, most of the cities/towns are facing electricity shortages.
In this context, the ‘Development of Solar Cities’ programme is designed to support/encourage urban local bodies to prepare a roadmap to guide their cities in becoming ‘renewable energy cities’ or ‘solar cities.’ The government has already initiated various programmes in the urban sector for promoting solar water heating systems in homes, hotels, hostels, hospitals and industry; deployment of SPV systems/devices in urban areas for demonstration and awareness creation; establishment of ‘Akshya Urja Shops’; design of solar buildings; and urban and industrial waste-/ biomass-to-energy projects. The solar city programme aims to consolidate all the efforts of the Ministry in the Urban Sector and address the energy problem of urban areas in a holistic manner.
Solar Cities, by nomenclature, are those which have renewable-based electrification programmes in place. The basic aim is to achieve a systemic reduction in conventional energy use by 10 per cent over a period of 5-3-1-year. The alternate categorisation would be to motivate local governments in adoption and implementation of new renewable energy technologies. The civil administration identifies cities based on their population, potential and commitment for adoption of renewable energy and energy conversation modalities in the city activities, regulatory compliances for deployment of renewable energy initiatives, resources availability and sustenance activities that have been initiated already in the city.
There may be cities which don’t fall under the 0.5-5 million population bracket but can be given the Solar City status under a special category notification. Ideally, these are places in the north-eastern states, islands, union territories and hilly regions. Initial plan for the programme was to flourish a total of 60 cities, with a minimum standard base of one city per state and the maximum count going up to five. The plan is to have a centre-state partnership model in terms of development.
The key objectives of the plan are to:
- Enable and empower urban local governments to address energy challenges at city level
- Provide a framework and support to prepare a Master Plan including assessment of current energy situation, future demand and action plans
- Build capacities in the urban local bodies and create awareness among all sections of civil society
- Involve stakeholders in the planning process
- Oversee the implementation of sustainable energy options through public-private partnerships.
With these objectives in mind, the government is providing administrative and financial support. Demarcations in this case are the assistance in preparation of the master plan for increasing renewable energy supply and energy-efficiency measures for a city, setting up of knowledge groups and system integrator panel for implementation of the master plan, awareness generation and capacity building activities, and above all financial incentives for project implementation as per the MNRE code.