Mature Technology: Digitalisation and efficient asset maintenance in hydropower plants

With 46,723 MW of installations as of May 2022, India’s hydropower seg­me­­nt is a significant contributor to the country’s energy mix. The total hy­­dropower ca­pacity has increased by ro­u­gh­ly 5 per cent

wh­en compared to 44,594 MW of installations in May 2017. Meanwhile, the fastest grow­ing rene­wable energy segment, solar has witne­s­s­ed an increase of 77 per cent in these fi­ve years. In fact, the country’s solar power ins­talla­tio­ns at 56,951 MW far outshine the hydro­power deployments. Factors such as long gestation periods, intensive capital re­quire­ments, long approval time­lines, as well as environmental and social conce­rns have led to a slowdown in hydro­po­wer development in India. However, rece­nt po­licy inter­ventions such as categorisation of hydro­po­wer as “renewable”, hydro­po­wer purchase obligations and budge­tary support for flood moderation and en­ab­ling infrastructure are expected to aid this segment’s further growth.

Moreover, as India moves towards 500 GW of non-fossil fuel-based energy by 2030, hydro­power is expected to play a key role in this energy transition journey. Apart from providing clean energy, it can help in balancing the intermittency of increasing volumes of renewable power in the grid. Mo­re­over, pumped hydro­po­wer storage can help in load levelling, peak load sharing and managing grid stability in times of erratic power demand and supply.

Thus, as the government irons out the kinks in this space through policy and regulatory interventions, there has been significant focus on improving the efficiency of existing hydropower projects through better operations and maintenance (O&M) pr­a­ctices. Further, advanced digital technologies are being deployed and there is adequate impetus to renovation and modernisation (R&M) of hydro­power plants. Mean­while, pumped storage projects are the talk of the town, with large assets be­ing plan­ned across the country to help in renew­able energy integration into the grid.

A brief look at the technology trends in the hydropower space…

R&M of hydropower assets

R&M, by definition, restores lost capacity through renovation of existing assets and im­proves their performan­ce, efficiency and reliability. Many hydro­power projects are already quite old with obsolete technology and thus, R&M helps deal with this technological obsolescence. Another benefit of R&M is that modernisation can be carried out with relatively fewer ap­pro­vals, land clearance requirements, and rehabilitation and resettlement issues, rather than setting up completely new projects. Owing to all these factors, R&M is highly cost effective when compared to se­tting up of new hydropower projects of the same capacity.

During 2017-22, renovation, modernisation, uprating and life extension works for 22 hydro­power projects have been plan­ned. This aggregate capacity of 4,847.8 MW includes R&M of 12 projects with 3,729.6 MW capacity, life extension of se­ven projects with 433.2 MW capacity and life extension and uprating of th­ree as­sets with 685 MW capacity. The revised aggregate ca­pacity of these 22 projects is ex­pec­ted to be 4,964 MW. Similarly, R&M works are planned at 57 projects during 2022-27. The present aggregate capacity of 9,016.3 MW will increase to 9,078.8 MW as a result of these activities.

Asset management and O&M

Asset management is a long-term app­roa­ch for O&M to ultimately improve the per­for­man­ce of a power plant. It helps op­timise power generation efficiency, output, risk manageme­nt and compliance with various statutory re­qui­re­ments. Inte­g­ra­ted asset management would require not only a proper O&M strategy but also correct documentation, repair and rehabilitation, and R&M, so as to properly utili­se the power plant to its full potential, be­sides extending its life.

O&M helps to ensure that all standard operation procedures are being followed. If required, further improvements can be made in operation procedures. Pre- and post-monsoon periodic dam safety ins­pe­ctions are an important O&M activity in hydropower plants. The Dam Safety Act, 2021 was formulated to ensure safe functioning of dams and to provide for the surveillance, inspection and O&M of specified dams. The guidelines for safety in­spection of dams include an overview of dam inspection, a dam safety inspection programme, inspection of em­bank­me­nt/co­ncrete­/masonry dams, ins­pe­c­tion of spillway outlets and mechanical eq­uip­me­nt, and inspection of gen­eral areas. Th­ey also inclu­de visual inspection and use of remo­tely operated vehicles and un­man­ned aerial vehicles, documentation and a comprehensive dam safety review by a panel of experts.

Digital technologies

Similar to other renewable power plants, digitalisation of hydropower plants can play a significant role in maximising the val­ue of current as­sets and help improve productivity. Further, O&M costs can be significantly reduced, and safety considerations can also be better managed. Many advan­ced tools are used nowadays to im­prove performance, including artificial inte­llige­nce, machine learning, big data, internet of things, computational fluid dynamics, un­man­ned aerial vehicles and robotics.

As a first step, constant data collection is important to help in analysis and identification of deviations and possible faults. Sm­art software can be integrated to help detect defects before they occur, and th­us save significant project downtime. Advanced real-time monitoring systems can be taught to identify normal parameters of plant functions, and can thus raise an alert in case of an anomaly.

Digital controllers with more accurate mea­surement of input and output parameters such as flow, pressure and power can help improve project efficiency of hydropower plants. Intelli­gent control systems are more useful to achie­ve precise adjustments in regulators. This regulation will be of vital importance when hy­dro­­po­­w­er plants are required to operate taking into consideration more and more integration of renewable energy into the grid. Digitalisation ma­kes O&M of power plants evolve from corrective to preventive and finally to predictive, so as to significantly reduce breakdo­wns, save costs and increase generation. When used in forecasting, digital technologies help improve prediction accuracy of renewable energy re­so­ur­ces. This helps hy­dropower plant operators to schedule their operations accordingly.

Pumped storage projects

Pumped storage plants, which are ideal for energy storage and load balancing, are becoming increasingly important in India’s energy landscape on account of the plans to integrate large volumes of renewable energy into the grid. As of May 2022, there are eight pumped storage projects install­ed in the country, with a total capacity of 4,746 MW. However, only six of these – of Ka­da­m­parai, Bhira, Sri­sai­lam, Ghat­gar, Pur­u­lia and Nagarjuna­sa­gar – with a total ca­pacity of 3,306 MW are working in pumping mode while the remaining two work only in generation mode.

According to the latest Central Electricity Au­­thority data, there are three pumped sto­rage projects with a total capacity of 2,700 MW un­der active construction. These are the 1,000 MW Tehri Stage II project in Uttarakhand, the 500 MW Kun­dah Sta­ges I, II, III and IV project in Tamil Nadu, and the 1,200 MW Pinna­puram project in An­dhra Pra­desh. Meanwhile, the 80 MW Koy­na Left Bank project in Maharashtra is held up at present and the detailed project re­port for the 1,000 MW Turga project in West Bengal has been approved. The im­portance of pumped storage projects for India’s clean energy transition can be gau­ged from the fact that survey and in­vestigation is in progress for 18 projects totalling 18,270 MW of capacity and a further 30 projects with 20,930 MW of capacity are at pre-feasibility stage.

Private parties, with massive clean energy deployment plans, have also shown a keen interest in this space. Thus there have been various announcements regar­ding development of pumped storage projects recently. The Greenko Group is a key player in this space and is constructing four pumped storage projects. In Feb­ruary 2022, it entered into an arrangement with Ayana Renewable Power to provide standalone storage capacity. The two companies plan to create despatchable renewable energy solutions for industrial and distribution companies in In­dia, including round-the-clock power supply of up to 1 GW. Greenko then entered into a strategic partnership with ArcelorMittal to construct a round-the-clock 975 MW nominal solar and wind project, which will be supported by the former’s pumped storage project. Further, in April 2022, the JSW Group announced its plans to develop a 900 MW pumped storage hydel pow­er project in West Bengal. The West Ben­gal government has agreed to construct a third pumped storage power plant at the Bandhunala project in Purulia.

Outlook

Hydropower is a key segment for India’s energy transition, and as such deserves the right focus. While growth in this segment has been slow over the past few ye­ars owing to sectoral challenges, policy in­terventions are being proposed in this sp­ace to help increase its uptake. In additi­on, efficient O&M practices, deployment of di­gital tools and R&M of existing assets can help utilise the capacity of existing hy­dro­power plants more effectively. Mean­w­h­ile, pumped storage projects are also ex­pec­ted to continue to gain traction as re­new­able energy integration is increasing. w