New Delhi: As India pursues its ambitious solar energy plans, the national grid is girding up for a smooth transition to a low carbon economy. It’s a transition that is changing the face of the transmission business at every step, from the drawing board to costs and technology.
State-owned Power Grid Corp. of India Ltd, which is working to improve the capacity and efficiency of inter-state transmission networks, is setting up transmission corridors to supply power from solar parks to the national grid. It is also establishing 11 renewable energy management centres, each at a cost of around Rs40 crore, in clean energy-rich states such as Tamil Nadu, Karanataka and Andhra Pradesh.
“These centres will do the forecasting in the backdrop of concerns over grid stability, with solar being an intermittent electricity supply source,” said Subir Sen, chief operating officer, central transmission planning and smart grid at Power Grid.
Experts believe the technological breakthrough that the Indian solar energy sector awaits is commercially viable energy storage solutions which would also help grid stability. Lower capacity utilization of solar plants at about 18-24% compared with up to 80% in thermal projects means transmission cost per unit of power is higher for solar energy.
Also, the danger of a widespread grid breakdown due to the nature of electricity from clean energy sources such as solar and wind is real. In 2012, India’s saw its worst blackout which left nearly 620 million people without electricity for more than two days in a row. On 31 July that year, the northern grid collapsed, and on 1 August, the northern, eastern and north-eastern grids also broke down.
“Grid stability is important because of the intermittent nature of the infirm power. We are conscious of the event of 2012. The transmission part has been planned in a modular way to help renewable energy rich states transfer electricity. The grid parameters needs to be maintained in terms of transmission, dynamic compensation and forecasting,” said Sen, who is tasked with operationalizing the green corridors.
With 134,750 circuit kilometres and 217 substations, Power Grid caters to national grid’s interregional electricity transmission capacity of 75,000 megawatts (MW). India plans to generate 100 gigawatts of solar capacity by 2022. “We are prepared with work on in full swing on the green transmission corridors. We are absolutely confident,” said Indu Shekhar Jha, chairman and managing director (MD) of Power Grid.
But experts sound caution over the inadequate preparedness of the states and say while work is happening on the national grid level, a catastrophe may be brewing at the distribution grid level, which is the responsibility of the states.
“With 40,000MW of solar power targeted to come from 2 crore rooftops, there is a problem there. The distribution grid is not equipped to handle that. It will create utter chaos. I don’t see action happening on that by any of the states,” said Reji Kumar Pillai, president and chief executive officer (CEO) of India Smart Grid Forum, a public-private partnership formed by the power ministry.
The centre’s decision in February to double solar parks’ capacity to 40,000MW in three years has added to the challenge of integrating intermittent green energy into the grid. Of the remaining 60,000MW of solar power capacity to be put in place by 2022, two-thirds is to come from rooftops, which poses a challenge to distribution utilities.
Meanwhile, work on the national grid level is on with the green transmission corridors being set up in two phases with a total investment of Rs47,000 crore. The renewable energy management centres, which will play an important role in forecasting generation from clean energy sources, will depend on the weather monitoring system, weather forecasting service providers and a sophisticated algorithm to help maintain grid stability.
“The southern region bid has opened. Also training is on for state load dispatch centres and regional load dispatch centres (RLDCs). We are totally prepared for it,” added Sen of Power Grid. India’s national grid comprises five regional ones: northern, southern, eastern, north-eastern and western, which are interconnected.
RLDCs are responsible for maintaining grid discipline and supervising optimum scheduling and delivery of electricity in their regions, and function under Power System Operation Corp. Ltd. The country has 33 state load despatch centres, five RLDCs for the five regional grids, and one national load dispatch centre.
The industry is enthused by the opportunity. “The transmission sector, including for green energy corridors needs an investment of more than Rs1 trillion in next five years. We are excited about this opportunity, said a spokesperson for Sterlite Power Transmission Ltd. Grid integration of renewable energy also opens up opportunities for technology firms, which supports the government’s Make in India drive.
According to ABB India Ltd CEO and MD Sanjeev Sharma, solar energy presents a challenge to power grids as an intermittent, widely dispersed source of energy. A key game changer would be flexibility in the generation system—faster ramp-up to counter intermittency in renewable energy and scaling down to absorb excess in renewable energy.
