India achieved a significant milestone in its renewable energy journey with the recent commissioning of 11 renewable energy management centres (REMCs). The REMCs allow centralised forecasting and monitoring of renewable energy generation which is crucial for its integration into the grid. The REMCs have been developed by Power Grid Corporation of India Limited (Powergrid) under the central government’s flagship Green Energy Corridors (GEC) I scheme.
The REMCs are equipped with artificial intelligence-based renewable energy forecasting and scheduling tools, which provide better visualisation and situational awareness to grid operators. REMCs coordinate with the respective state load despatchcentres (SLDCs) and are integrated with existing SCADA for the despatch of renewable generation. Currently, 55 GW of solar and wind power capacity is being monitored through these 11 REMCs. These 11 REMCs are co-located with the National Load Despatch Centre (NLDC), SLDCs in Tamil Nadu, Karnataka, Andhra Pradesh, Maharashtra, Madhya Pradesh, Gujarat and Rajasthan, and regional load despatchcentres (RLDCs) in Bengaluru, Mumbai and New Delhi.
As per an official statement released by the Ministry of Power (MoP), the development has placed India among a league of the few nations that have state-of-the-art management centres for renewable energy integration. “The planners of the GEC and REMCs are showing more vision than that shown by Europe and the US when they started renewable energy management,” stated R.K. Singh, minister of state (independent charge) power and new and renewable energy, at the inauguration of the Northern Region Renewable Energy Management Centre.
Need for renewable energy forecasting
Forecasting is necessary to deal with the challenges of variability and uncertainty in renewable energy generation given that the share of renewables in the energy mix will increase progressively. The share of installed renewable energy is expected to increase from 23.5 per cent at present to 32.7 per cent by 2022 and further to 39 per cent by 2030, if government targets are met. Therefore, there is an urgent need to equip power system operators at the national, regional and state levels with adequate state-of-the-art tools that facilitate real-time tracking of renewable energy generation.
The load despatch control centres (SLDCs/ RLDCs) lacked renewable energy forecasting systems till the recent commissioning of the REMCs. The decentralised method of forecasting/scheduling has been followed in India, in which each wind farm (over 10 MW) and each solar park (over 5 MW) has to submit its schedule individually. However, the static/ real-time SCADA information is not readily available to the system operator in this method. This creates limitations in the integration of renewable energy into the grid.
The REMCs were conceptualised in order to overcome this issue and aid renewable energy forecasting for long-term planning, operations and reserves management. The implementation of such state-of-the-art renewable forecasting and monitoring systems is also a global best practice. Such centres are operational in various countries like Spain, Germany, the US, Denmark, Belgium and Australia. In India, the REMCs were proposed to be set up in seven renewable-rich states, which will host about 70 per cent of the total envisaged wind and solar generation capacity (160 GW by 2022) – Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra, Madhya Pradesh, Gujarat and Rajasthan.
Technology
The REMCs have state-of-the-art SCADA systems, forecasting and scheduling tools, visualisation tools, display unit, and corresponding hardware and software, etc. The renewable energy forecasting tool gets inputs from multiple forecasting services providers (FSPs) as well as weather service providers (WSPs) to generate an optimal combinational forecast based on various algorithms. These FSPs or WSPs provide pooling station-wise input forecasting based on the outcomes of numerical weather prediction models. Sophisticated statistical models convert these parameters to generate the expected power output. Over a period of time, these statistical models have been improved based on actual production data.
The output from the forecasting tool will be available in day-ahead and intra-day time periods to support the SLDCs and RLDCs in generation scheduling, balancing need assessment, grid operation planning, load flow estimation, etc. Renewable generation forecasting will be done starting from the developer’s pooling station up to the state/region periphery aggregated level for each time block of 15 minutes. The scheduling tool will obtain the quantum of power to be injected by renewable generation sources in a particular area from developers so that integrated planning for supply-demand gap management can be done well in advance.
Overall, the REMCs will collect information from renewable energy generators, integrate with forecasting tools and accordingly prepare the final despatch schedule. Real-time monitoring of renewable energy generation will be facilitated through SCADA. The centralised mechanism of forecasting via REMCs ensures greater accuracy as compared to the decentralised method followed so far.
Financing
The REMCs have been set up under the GEC programme, which is financed via concessional loans of up to Euro 1 billion provided by KfW. As per the DPRs, the estimated total cost of the REMCs is Rs 4.09 billion financed from gross budgetary support of the MoP. The cost includes renewable energy forecasting tools, scheduling tools, SCADA, visualisation tools, display unit, corresponding hardware and software, annual maintenance charges (for six years after one year of warranty period), renewable forecasting and weather service charges (for four years), training as well as project management consultancy charges.
The REMC project was segregated into three packages – southern region (Tamil Nadu, Andhra Pradesh and Karnataka SLDCs and the Southern Regional Load Dispatch Centre), western region (Gujarat, Maharashtra and Madhya Pradesh SLDCs and the Western Regional Load Dispatch Centre), northern region (Rajasthan SLDC and Northern Regional Load Dispatch Centre), and the NLDC. The estimated cost of these packages is Rs 1.54 billion, Rs 1.53 billion and Rs 1.02 billion respectively. The REMCs are owned and operated by the respective load despatchcentres (LDCs).
The way forward
With the country aiming to achieve 175 GW of renewable capacity by 2022, the efforts to integrate this capacity need to be ramped up. As of March 2020, the installed renewable capacity stands at 87 GW, of which about 63 per cent is being monitored through the newly commissioned REMCs. Going forward, there is a need to set up more such centres as the use of advanced technology for forecasting and scheduling is imperative to enable the smooth integration of renewable energy into the grid.