India is in the process of developing its renewable energy technologies in a bid to ensure a sustainable power system. The evolution of existing renewable energy technologies to smart renewables will help power economic growth. As such, the focus currently is on developing a roadmap for the integration of renewable energy with the smart initiatives being taken by the government.
At the recently held World Renewable Energy Technology Congress, 2017, industry stakeholders including developers, policymakers, manufacturers and academics discussed the future intersection of smart cities, smart rooftop and smart grids…
India is developing 100 smart cities, of which work is currently in progress for 20 cities. These cities will have planned infrastructure and land use, smart accommodation, and smart transport and governance, besides being equipped with smart grids that will not only monitor but also empower citizens to regulate their power consumption. At the cusp of this union lies the proposal to partly power the smart cities through renewable energy sources, with a minimum of 10 per cent power being generated through solar.
Smart rooftop solar
Rooftop solar forms an essential part of the smart cities development programme, with a mandatory 10 per cent of power to be procured from this source. This is primarily aimed at addressing various issues that exist in the sector, such as voltage instability and intermittent power supply. According to Kanika Khanna, chief technical officer and director, Sunkalp Energy, rooftop solar can be used to solve the problem of voltage instability arising from solar power being fed into the grid. Moreover, given the issues regarding payments from utilities, rooftop solar could prove to be a way out. Inverters used for rooftop solar power generation can feed reactive power into the grid. However, standardised communication among devices will have to be enabled, making them smarter for smooth grid integration. This would further enable the use of smart technologies for peak power management, thereby flattening sudden spurts in the demand curve. The Solar Energy Corporation of India (SECI) is playing a key role in developing policies for rooftop solar. According to R.K. Jain, additional general manager, SECI, the corporation has commissioned 100 MW worth of rooftop solar projects and has about 1,000 MW of projects in the pipeline. SECI is bringing out two schemes for the promotion of smart rooftop technology – a 500 MW tender for residential, institutional and non-governmental organisation-owned buildings and customers, and a 1,000 MW programme for government buildings.
Rooftop solar power systems not only help overcome the usual challenges associated with grid-based power but also lead to considerable savings over the lifetime of the system. Pratyush Kumar Thakur, chief operating officer, Statkraft BLP Solar, estimates the savings to be around Rs 13.8 million over a 25-year period for a 100 kW power system installed in opex mode. However, the smartness in rooftop systems comes into play at the design stage. There should be minimum deviation in the design of the final on-site system from the planned design, to which end a proper assessment of the rooftop site is necessary. Often, structures present on industrial rooftops act as obstructions, which must be cleared before taking up a project. Load consumption should be matched with the capacity of the installation and excess generation must be managed either through net metering and/or energy storage systems.
Power outages, planned or unplanned, are a major issue for a developing urban society and can be especially detrimental to the quality of life expected in a smart city. G. Ganesh Das, head, strategy, business excellence and collaborations, digital and business intelligence, Tata Power Delhi Distribution Limited, believes that smart rooftop solar can be a solution for integrated outage management. Advanced integrated management systems such as supervisory control and data acquisition, advanced metering infrastructure and operational management systems have a significant role to play in the development of smart solar systems. The company has pledged to install 400 MW of rooftop solar projects by 2025. Das believes that grid infrastructure is changing for the better on the back of the government’s green energy corridors and smart grid initiatives. However, the integration of smart grids into the existing grid infrastructure is necessary to enable a better grid. Self-healing networks are being introduced in the country to minimise downtime and maximise grid efficiency. In addition, it is becoming increasingly important to develop the ability to manage overall power instead of only peak power, which occurs for a short duration.
Moving to a smart grid-based power distribution and transmission infrastructure is becoming even more essential as the country grapples with ageing components and the resultant power losses in lines. This, in addition to the inability of the government to provide good quality power to end consumers despite being power surplus, further illustrates the need for a complete system overhaul. Tarlochan Kaur, head, Department of Electrical Engineering, PEC University of Technology, Chandigarh, believes that these challenges are often drivers of distributed systems. Given the emerging cost trends for solar power plants, decentralised systems prove to be beneficial, especially in the wake of new loads such as electric vehicles.
Also, the use of storage solutions along with distributed generation provides the smart factor required for future development of the segment. Storage helps decouple the supply and demand parameters while answering questions of when to charge or source power and when and how much load should be discharged. The inclusion of energy storage systems in solar systems can greatly enhance the function of solar power in smart grids and microgrids, which are an essential part of distributed power systems.
With power generation, transmission and distribution on the path to becoming smart, energy management at the consumer end assumes significant importance in a smart city set-up. Energy management would require a self-healing power network that has the capability to not only prevent faults, but also detect and rectify them. According to Anil Poluru, head, utility, India, Trinasolar, grid infrastructure must take a step further by being able to communicate with devices to analyse consumption patterns and predict load based on the information. Upgrading the existing infrastructure to a smart grid network will help resist attacks, optimise assets and efficiently maximise the use of power fed into the system.
By bringing together elements such as smart rooftop power generation and smart grids, smart cities are expected to solve key urban challenges. According to Arun K. Tripathi, director general, National Institute of Solar Energy, the scope of smart cities extends beyond energy, utilities, waste management and infrastructure and goes deep into making smart citizens. However, successful implementation of the programme inevitably comes down to the use of smart energy. The issue of traffic management and pollution prevalent in major cities in the country can be handled through the increased use of electric smart vehicles. Also, the multiple wire-nets hanging in urban skies need to be managed to provide better quality power and prevent line losses in smart cities. Waste management including collection, transportation and storage can be done by employing smart waste-to-energy technologies such as plasma gasification that do not even require waste segregation. In addition, the use of building codes and building-integrated photovoltaics can help in demand-side management of smart cities.
In addition to the incorporation of smart renewables into urban infrastructure, the experts stressed on smart policy implementation. Randeep Bora, head, government business, Cleanmax Solar, cited Bhubaneswar as an example of one of the smart cities under development. He said that as per the smart cities mandate, Bhubaneswar requires 110 MW of power to be sourced from rooftop solar. However, the total rooftop solar potential of the city currently stands at only 40 MW. Therefore, the policies and targets for smart cities need to be set accordingly. Further, he believes that the uptake of rooftop solar will have to grow across the industrial and residential segments alike for the smart cities programme to succeed.
The market for smart renewables is driven by the need to solve urban infrastructural bottlenecks that include inefficient power system utilities. With the growing share of renewables, grid networks will increasingly need to become smarter to allow smooth integration of the power thus generated. The development of smart cities is a step in the right direction where smart technologies come together with new and smart renewables to provide a better quality of life.