Solar energy is being increasingly seen as a strong value proposition by not only power producers but also a number of industrial, commercial and residential entities. These entities have been harnessing solar energy with the aim of reducing their power bills and improving the reliability of power their premises.
Taking a lead in this regard is Dayalbagh Educational Institute (DEI) in Agra, which has leveraged solar energy in a big way. All the institutional buildings including schools, colleges, the university and offices are powered by solar energy on clear days. All the hostels have solar cooking facilities and residents of Dayalbagh Colony are encouraged to install solar systems in their homes. To encourage users and make the proposition viable for them, net metering has been provided locally even though it is not yet available in Agra.
DEI, in particular, has taken initiatives to harness renewable energy through solar thermal and solar photovoltaic (PV) power plants. The entire university campus is powered by nine distributed rooftop solar PV power plants with a cumulative capacity of 558.2 kWp installed in 2010-11. In 2016, the institute added another 100 kWp of capacity and has well-laid plans to increase the capacity to 1.5 MWp by 2018. Apart from the Dayalbagh campus in Agra, a total of 40 kWp has been installed at the institute’s ICT distance education centres in various cities. In fact, the Dayalbagh town area has been declared a green campus by the Ministry of New and Renewable Energy.
The projects on the campus have been implemented in various phases by different contractors. Some of the prominent companies that were given turnkey projects are Bharat Heavy Electricals Limited (BHEL), Sunsure, Nanobright and Aarat Power. The modules used at the plant sites were procured from BHEL and Tata Power Solar. The solar power systems installed on the university campus were funded by infrastructure grants. The operations and maintenance is done in-house by developing local expertise through vocational courses in the university.
Microgrid to the rescue
The solar power plants at Dayalbagh supply power to the campus through a microgrid. This modern, small-scale electricity system comprises a group of distributed loads and distributed renewable energy resources that act as a single controllable entity in synergy with the grid. It has been designed to achieve specific local goals such as energy reliability, security, carbon emission reduction, diversification of energy sources and cost reduction.
The effectiveness of the renewable energy microgrid was evident during the major grid collapse on July 30, 2012 when over 600 million people across 22 states went without power for several hours. However, DEI remained unaffected as it had its own grid supplying power to the campus. According to Professor A.K. Saxena, Faculty of Engineering, “Even on normal sunny days, the institute is self-sufficient in power and is not affected by the frequent power outages. In cloudy conditions, careful battery management ensures uninterrupted power supply to the whole campus.”
Having commissioned the distributed solar-based microgrid, the institute is now exploring ways to make the system more efficient, reliable and economically viable in the face of dynamic loading conditions, weather vagaries and unreliable utility supply. To this end, the institute has undertaken multidimensional research and development activities to develop an indigenous decision support system based on remote site monitoring. This software would monitor the generation, load, weather conditions, grid supply conditions, etc. and suggest the optimal operation strategy to the operator.
Work is also in progress for finding ways for back-end optimisation. This is being done through the development of MATLAB-based simulation models, multi-objective evolutionary algorithms for optimisation, fuzzy criteria for identification of dynamic goals and multi-criteria decision support systems for selecting the optimal control strategy.
The institution has leveraged renewable energy in a number of other ways as well. It has installed three solar inverters with a capacity of 7.5 kVA each at the satsang hall in Dayalbagh. These inverters have been provided with an MPPT charge controller and power export facility, and have been instrumental in improving the quality and reliability of power. Moreover, a diesel van has been indigenously converted into a solar electric van by replacing the diesel engine with a 25 HP electric DC motor powered by a 96 V, 400 Ah battery bank. The batteries are charged by solar PV modules during the day and through electric charging at night. The van is being used to ferry residents and staff of DEI in Dayalbagh Colony.
DEI has also commissioned 20 kWp of solar power plants in Rajaborari, a remote village situated in the forest region of Madhya Pradesh, which receives only poor quality and unreliable grid power. The solar power projects were executed in collaboration with the Madhya Pradesh forest department with judicious design to take maximum advantage of solar power and ensure uninterrupted power for lighting and water pumping applications in schools, hostels, hospitals, etc. DEI also provided a solution for powering the Wi-Fi link between Rajaborari and Timarni. The intermediate radio tower of the Wi-Fi link was powered by solar panels. The panel capacity was not sufficient and resulted in frequent shutdowns due to deep discharge batteries. Moreover, as the tower was in a remote area, the panels were frequently stolen, resulting in the disruption of e-classes and monetary losses.
An alternative solution with revised solar capacity was proposed and implemented by DEI. The panels were mounted on the radio tower itself and an electric shock fencing and hooter alarm system were installed to prevent theft attempts. The system has been working properly since then, without any disruption or theft.
DEI has also leveraged solar thermal technology on the campus. Three solar thermal cooking systems have been installed in the three hostels of the institute. Each system comprises five dishes, each 16 square metres in diameter. The total average energy generated by the concentrators in one system is 200,000 kCal per day, which is equivalent to 19 kg of liquefied petroleum gas. The systems have helped in reducing cooking gas bills to a large extent.
The institute has also been working on other technologies such as solar-wind hybrid. An integrated solar-wind hybrid system with 3 kWp solar and 2 kWp wind capacity has been installed at the DEI ICT Distance Education Centre, at MTV Puram in Tirunelveli, Tamil Nadu. A remote monitoring system has been developed and deployed at the site for real-time remote monitoring and data logging of various solar and wind parameters.
The various initiatives taken by DEI demonstrate the increasing acceptance of solar energy as an effective source of power. Microgrids based on solar energy are being seen as a viable alternative to grid power. Apart from encouraging sustainable development and promoting self-sufficiency in energy generation, the microgrid at DEI is encouraging indigenous research and development among students. This would ensure quality research with relevance, and development of skilled manpower and intellectual property in the area.
Other universities can take a cue from DEI and implement a curriculum for vocational diploma and certificate courses in solar energy technologies, as well as design earn-while-you-learn schemes for students and encourage entrepreneurial start-ups through incubation cells. n
With inputs from Professor D. Bhagwan Das and Professor A.K. Saxena, Faculty of Engineering, DEI
By Mridula Pandey