A lot has changed since the 1960s when solar technologies first made their debut, and solar photovoltaics (PV) were seen as a thing of the future. Today India is spearheading the technology evolution. Since 2011, technology advancement leading to attractive pricing, reliability and scalability has made solar energy the preferred choice for clean energy adoption, spurring the exponential growth of the sector.
Photovoltaic modules are at the center of all technology advancements in solar power. Today, polycrystalline solar panels have an efficiency range of 16 to 18%, increasing up to 24% with the help of monocrystalline, along with the PERC technique. With increase in efficiency, power ratings of modules have improved to 350 Wp and higher, allowing the module to harvest more energy from the same size module. PV modules are also seeing a technology shift in other components such as backsheets, EVA and frames. With options like PET (Polyethylene terephalate) and PVDF (polyvinylidene fluoride) technologies in back sheet production, Tedlar type backsheets are becoming obsolete.
Inverter technologies are also continuously maturing, with increased power ratings from 500 kW to 5 MW helping to accelerate the construction timeline. Inverters are subject to intensive ongoing innovation to meet the evolving roles in a PV power plant. As a key element of a photovoltaic system, irrespective of the power range, the efficiency and reliability of solar power generation from a project are essentially determined by the properties of the PV inverters. Today, invertors come with inbuilt monitoring, with all possible communication protocols. PV inverters can now supply reactive power during the night, to supply highly inductive loads in the plant, like transformers. New generation inverters are more reliable and play a central role in the cost optimization and machine intelligence of a solar plant.
Transformer designs have evolved to meet inverter requirements in terms of dv/dt withstand, impedances, and galvanic isolation. Nowadays two Core Coil Assembly (CCA) transformers are popular, and being used extensively to reduce the Balance of System (BOS) cost without compromising impendence and galvanic isolation. The introduction of 1500V DC system has really helped developers to construct and operate plants efficiently. Inverters are now capable of handling up to 60% DC overloading to flatten the generation curve.
Self-adjusting tracker control systems can boost PV power plant energy output by 15-20% per cent. These intelligent systems not only continuously analyse and optimize the tracking algorithms of each individual row, but also monitor and predict weather conditions. These systems combine weather forecasting, advanced sensors and machine learning technologies to maximize the energy yield. It has been proven that the increase in power production is correlated to better performance of the plant and lower operating costs.
Remote monitoring has been found to be essential in analyzing the health of the solar PV system. As most solar plants are installed in locations such as industrial zones and hinterlands, it becomes imperative for the provider to have access to information concerning its functioning on a daily basis. Operations and maintenance (O&M) providers will have limited knowledge about local weather conditions and the effect of the terrain on the performance of the plant. This is where remote monitoring comes into play. Since clients are also provided with access to remote monitoring systems, it has helped to bridge the information gap with access to seamless updates about the plant. It helps to optimize plant performance and maximize client’s sustainability mission. At a time when data privacy and protection are of utmost importance, usage of the best privacy tools in the market is necessary to protect sensitive data, including preventing security breaches.
Advanced data analytics tools are also playing a crucial role in operation and maintenance. We are monitoring plants and identifying possible failures much earlier, with the help of specialized SCADA systems. Almost all equipments communicate to SCADA, and condition monitoring reduces down time.
Drones have also emerged as a viable solution for monitoring solar farms, especially in remote locations covering a wide area. Drones today are used extensively to survey land while developing large scale solar farms. Using such technology, drones with thermal sensing can identify PV modules or parts of the solar plant which are not performing or experiencing breakdown, thereby enabling speedy repairs for optimum performance in large scale solar farms.
Today, solar developers are using best in class technology for water conservation during operations and maintenance, with the use of highly specialized cleaning methods. These include increased pressure cleaning tools, which reduce the amount of water used, and also dry cleaning methods. Robotic cleaning systems are also being used extensively in module cleaning, as they reduce water consumption by increasing precision.
Going forward, corporates looking to adopt solar power have a lot to be excited about, as technology evolves further. Given the advent and rapid development of artificial intelligence (AI), machines will become more efficient and intelligent and will help in accelerating the growth of the solar industry. AI will be increasingly used in frequency regulation, weather forecasting, optimizing project performance and predictive maintenance.
Distributed generation, wherein private users generate and use their own electricity from renewable sources, is receiving greater attention as a cost effective form of solar power generation. The current grid infrastructure will not accommodate this diversification in energy sources without changes. So Government of India will quickly need to move towards a ‘smart grid’, which entails a fully automated power delivery network that monitors and controls every consumer and node, ensuring a two-way flow of electricity and information. AI will be the brain of this future smart grid. As a result, large regional grids will be replaced by specialized microgrids that manage local energy needs with finer resolution.
To improve the capacity utilization factor (CUF), solar developers are now moving towards energy storage and wind-solar hybrid plants, to supply energy during non-solar hours as well. Various battery technologies are being developed to make solar + storage a viable and scalable solution. With increased focus on Electric Vehicle (EV) Infrastructure, solar carports are getting more attention, as one obvious way to ensure that EVs are powered by renewable energy.
By Mr Pravin Narkhede, Head Engineering, CleanMax Solar