In 2016, almost no household in Surat had rooftop solar plants. Two years later, there were 6,000
By Ashvini Kumar & Paul Faeth
About 70% of India’s electricity is produced using coal, requiring significant amounts of water to expel waste heat during the generation process. This is besides the water required for ash handling and other in-house needs. Energy security thereby gets inextricably linked with water availability.
Based on field data from a number of thermal power plants in India, it has been estimated that, depending on the kind of power plant, its specific water requirement could range from 1.67 to 5.27 cubic metres per MWh. Considering an installed thermal power capacity of 226 GW with an average all-India plant load factor (PLF) of 61%, the water lost annually to cooling thermal power plants, based on a water requirement of two cubic metres per MWh of power generated, comes to over 2.4 billion cubic metres. Going by the central government’s per capita norms of water use, this quantity would be adequate to serve the annual water needs of around 164 million people in rural areas or 48.7 million people in cities with sewer lines.
With India’s current economic growth and dependence on coal for the next 20 years, water consumption in the power sector would increase manifold even with enhanced water use efficiency. Given water’s centrality in other key sectors—such as agriculture, domestic, and industry—and the drying effects of climate change, saving water wherever possible is critical for India.
If the government’s plans to reduce India’s dependence on coal are realised, a substantial amount of water could be saved, since, unlike coal, electricity produced by solar photovoltaics (PVs) does not generate waste heat, requiring only 0.1 cubic metre of water per MWh generated for occasional washing. India has committed to produce 40% of its power supply from non-fossil fuel sources, with a focus on solar power. If this happens, and that growth continues for another 10 years, the annual water consumption for power generation would be 30% less by 2040.
In addition to saving water, renewable energy also reduces air pollution, which has reached alarming levels in many parts of the country. While coal-fired power generation results in the emission of harmful soot, sulphur dioxide, nitrous oxide, and mercury, power generated from renewables produces no such emissions.
Given this background, the government’s target to achieve 100 GW of solar power capacity by 2022 merits special appreciation. Utility-scale solar power projects have achieved tremendous success, with tariffs breaching coal tariffs from new plants and an ecosystem for large capacity project development being created. However, capacity addition through installation of rooftop solar plants in domestic, institutional and commercial segments has been slower. To accelerate their adoption, demand aggregation initiatives—focusing on reaching out to consumers, creating visibility for policies, and vendor base for rooftop solar PV plants—are being implemented in cooperation with state nodal agencies, electricity distribution companies, developers, and a large number of student volunteers. For example, the Ministry of New and Renewable Energy (MNRE) has recently launched a big campaign for solar market aggregation for rooftops in Gujarat, Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Daman and Diu, and Dadra and Nagar Haveli.
So, what’s in it for consumers and businesses? For consumers, rooftop solar can substantially reduce electricity bills since the electricity generated by rooftop solar panels directly meets the consumer’s load requirement, leading to less power drawn from the grid.
In 2016, almost no household in Surat had rooftop solar plants. Two years later, there were 6,000 due to subsidies offered by MNRE, extensive outreach by the Surat Municipal Corporation with the help of youth volunteers, and affordable solar PV loans offered by the Sarvodaya Sahakari Bank. With the subsidies, the payback time for rooftop PV is six years, which means a consumer installing a rooftop solar plant gets free electricity after that period.
The system can be cost-effective for businesses too, depending upon the local tariff. Solar power has the benefit of providing long-term price stability at a time when electricity prices are going up by 3-4% annually. In contrast, the cost of solar has come down by 80% in the last five years. Solar also enhances brand reputation for consumer-facing businesses looking to promote their corporate sustainability practices.
The evidence from Surat and other places points to an imminent explosion in the solar market in India that will bring a revolution in the power sector. In times of looming water crisis, it is indeed good news for India that the growing share of renewables in the power mix allows India to meet its development needs while reducing its water usage.
(Kumar is senior director, Renewable Energy Technology Applications, TERI & Faeth is Principal at the Cadmus Group. Views are personal.)