India has the potential to set up 300 Gigawatt of power generation capacity by tapping into floating solar technology, Mitesh Patel, Director of Renewables, Asia and EMEIA at Engineering, Procurement and Construction (EPC) giant Black & Veatch tells ETEnergyworld in an interview. Edited excerpts..
What is the business case for floating solar as a renewable energy technology? Globally, what has been the experience of different regions in adopting floating solar? Which are the biggest floating solar projects operating globally?
Often floating solar projects are driven by land acquisition issues. Solar farms often need four to five times more land than traditional power generation facilities. In Asia, a piece of land can have several land titles. With fragmented land ownership, resolving cost and compensation issues could take a long time. On the other hand, most water bodies are owned by utilities and governments. In such cases, acquiring land would be more straight-forward. Asian utilities have started building floating solar farms. There are examples in Hong Kong, Thailand and India. The world’s largest floating solar power plant is in China’s Anhui province, on a lake formed on top of a disused coal mine. Asia’s tropical climate offers good opportunities for renewable energy. Wind energy is generally associated with more arid areas. Floating solar systems open new opportunities.
What are the main benefits and issues or challenges with floating solar as against ground-mounted systems?
In terms of benefits, floating solar farms help reduce evaporation from water bodies. There is less algae production as there is less sunlight going into the water bodies. If the floating solar farm are built near hydropower plants, developers can leverage on existing power facilities, such as transmission lines. Developers may need to upgrade the transmission lines, however they would already have the right of way. Cost of EPC is higher for floating solar farms, compared to ground mounted solar farms. However, with floating solar farms achieving additional generation due to the cooling effects of water, the levelized cost from both forms of solar farm is comparable.
As far as challenges are concerned, one of the issues is that floats are made from high-density polyethylene (HDPE) materials that are UV resistant. Floating structures, as they are injection moldings, are very bulky. Transporting such floats to site could be challenging. Black & Veatch is working with float manufacturers to find a solution for this. Another issue would be securely anchoring and mooring the floating solar farms. For example, they need to be anchored in a way that can withstand weather extremities. In cases where water level is deep, the team will need to figure out how to anchor the floats safely. If the water body is too large, mooring it on shore may not be an optimum solution. We are looking into increasing the efficiency of floating solar panels. One option is to use bifacial modules, where the bottom side of panels is also able to increase energy production. However, water has one of the lowest gains of reflection. We are investigating how floats can be used to enhance bifacial technology.
What has been India’s experience in setting up floating solar? Can you name a few companies or projects that are under operation in India?
Floating solar projects in India include a 10 kW plant in Kolkata, a 100 kW by NTPC in Kerala and a 2 MW project by Greater Visakhapatnam Smart City Corporation Limited (GVSCCL) in Vishakhapatnam. Indian state-run power giant NTPC has issued a tender for 70 MW of grid-connected floating solar at its Rajiv Gandhi Combined Cycle Power Plant (RGCCPP) in Kayamkulam, in Kerala.
Can you share the details of the overall estimated resource potential of floating solar both globally and in India?
The government of India has recently announced its plan to develop 10 GW of floating solar capacity in the country over the next three years till 2020-21. In India, it is estimated that as much as 300 gigawatt (GW) of floating PV power plants can be set up by utilizing just 10 per cent to 15 per cent of water bodies in states such as Kerala, Assam, Odisha, and West Bengal.
What is the typical size of investment required for setting up floating solar projects? How does that compare with ground mounted systems? What needs to be done to bring down the cost differential between the two systems?
The EPC cost of ground-mounted solar plant is US$600-650 per KW. For floating solar plants, the EPC cost is US$800-1200 per KW. Floating solar systems cost 25-45% higher. Where the land cost is high, the business case for floating solar would be stronger.
Can you share the highlights of the work being done by Black and Veatch in floating solar?
In Taiwan, a recent example is our Asian project for a technology major, via Black & Veatch’s wholly-owned subsidiary Diode Ventures, to develop a solar farm of up to 100 megawatt (MW) which will have a certain portion above the surface of local fish farm ponds. This project, in Tainan City, builds upon our floating solar project experience in other Asian cities. In Hong Kong, Black & Veatch recently began exploring the feasibility of large-scale implementation of floating solar farms at Hong Kong’s 17 impounding reservoirs under a feasibility study being carried out for the Water Supplies Department of the Hong Kong SAR. In addition to generating power from renewable resources, engineers are studying whether large-scale floating solar farms could help Hong Kong reduce water loss and improve water quality by suppressing algae growth. Preliminary results indicate water loss through evaporation from the surface area covered by floating solar farms can be reduced by as much as 70%, a critical benefit in water scarce regions relying on surface water reservoirs. In Indonesia, one of our clients is planning to develop a total of 500 MW Floating Solar Power Plant – Utility Scale under three different projects. We have been engaged for a pre-feasibility study.
ET Energy World