Plant solar trees, solve space problem

A few months after it began operations at two sites in New Delhi, the Solar Power Tree, a space-saving power generating intervention using solar energy, is performing steadily at both locations. Shibnath Maity and his team developed the solar tree at Durgapur, West Bengal-based Central Mechanical Engineering Research Institute (CMERI), which is affiliated to the Council of Scientific and Industrial Research (CSIR).

The tree generating 5 kW of electricity was installed at the residence of Science and Technology Minister Harsh Vardhan at Tees January Marg; the other tree, generating 3 kW, was put up at the head office of CSIR at Anusandhan Bhavan at Rafi Marg. According to CMERI’s internal estimates, 25 units of electricity is being saved per day by operating the bigger tree while 15 units is being saved per day at the CSIR headquarters. At a unit cost of Rs 8, the savings per day per tree comes to INR 6,000 (USD 90) and INR 3,600, respectively.

The standard solar power tree, for which CMERI has a patent, takes up only four square feet of space and produces about three kilowatts (kW) of power, enough for about five households. The biggest boon of using this solar power tree is that it saves space.

Land benefit

In general, it requires about 3.5 acres of land to produce 1 MW of solar power. For any state in the country to survive on green energy, there will be requirement of thousands of acres of land. This is a contentious issue for a land-scarce, highly populated country like India whose abundant incident sunshine is not that easily utilised. This invention goes a long way to remove the barrier of land requirement.

The solar tree has several advantages. Apart from using four square feet instead of 400 to generate 5 kW, it holds the panels higher so they get 10-15% more sunlight in a day.

The placing of poled panels also make it possible to produce green power in rooftops, gardens, road verges and farms without altering the nature of the landscape. Placing a water sprinkler on top enables automatic cleaning of the panels.

Maity and his team are now looking to add additional features. For instance, it is possible to harness 10% more power by rotating the panel direction twice a day by using a module that aligns itself with the movement of the earth. They are thinking of aesthetic aspects as well.

The 5 KW solar power tree has a full load capacity of 60% of the peak and a battery backup of two hours. The experimental cost is right now INR 500,000, which is expected to reduce significantly once the product is commercialised.

So far, the institute has transferred the technology to three firms. Two of them are Kolkata-based Vibes Solar Solutions LLP and Mineworth Engineering Products Pvt Ltd. The third is Andaman-based Prasur Electricals and Engineering Company. Under the terms of technology transfer, the licence is for seven years and royalty is to be paid on annually on the basis of sales.

Speaking of popularising the technology, Mineworth Engineering’s Sunil Maheshwari told, “We are getting enquiries both for rooftop and ground-mounted solar power plants. We have business connections with PSUs (public sector units) and are providing them with the option of installing the solar power tree for their energy requirements.” Mineworth is an empanelled channel partner of the Ministry of New and Renewable Energy (MNRE) under the Grid Connected Rooftop and Small Solar Power Plants Programme.

The Indian government has set an ambitious target of investing USD 100 billion in generating solar energy by 2032, and a target to achieve five-fold increase in use of solar power by 2022. India has set a target of 100 GW by 2022, which is divided as 60 GW of land-mounted grid connected solar power and 40 GW of rooftop grid interactive solar power.

Right now, solar’s share in India’s renewable energy capacity of 42.85 GW is only 15.78%, according to a recent report. The country’s solar potential is far higher, 748 GW. Interesting experiments like Kochi international airport, the world’s only fully solar-powered airport and solar panels atop canals in Mehsana and Vadodara in Gujarat (the first state in India to have a solar power policy) are important pointers in the direction of the possibilities that lie in generating clean energy but also the challenges in the form of land requirements.

CMERI’s solar tree breaks this barrier and has a large potential in meeting India’s clean energy and climate-friendly targets.

(This article first appeared at the India Climate Dialogue)