Rooftop Solar plants are precisely what they are: Solar plants that are installed on the roofs of offices, factories, universities and other buildings to generate clean and efficient solar power.
While there has been enormous interest and investment in the utility-scale solar power plants in India, there is also a growing interest in the untapped and unexplored rooftop solar sector. This change in direction throws up quite a few challenges and surprises.
The first challenge is that rooftops in India or in other parts of the world hold utilities such as water tank, AC chillers, ducts, heat vents etc. Thus, space available is limited. Adding to this challenge is another one: roofs can be RCC, sloping RCC, slanting metal or curved metal.
An example of this challenge is the Carlsberg factory where the roof was dome-shaped and highly curved. Engineers from CleanMax Solar established access to the rooftop by setting up a ladder through which a safety line with harnesses and ropes was established around the dome. Wires with anchor points were designed to hold the workers and a walkaway was created to enable easy movement across the roof. Workers were also given special training every day.
The 471 kWp plant was completed in a record 60 days and is the first solar-powered brewery in the country.
Read the full case study here.
The second challenge is that rooftop solar plants in India are usually in cities. This means that the pollution in urban zones can lead to high temperature and low irradiation on the solar panels. On the other hand, utility-scale solar projects are far away from densely populated areas and enjoy clear and open skies. But in urban zones, commercial buildings have high electricity charges. Thus, rooftop solar plants can be put up as, on an average, they 25-40% cheaper than prevailing grid electricity. CleanMax Solar with its OPEX model has 60% of its rooftop projects in urban areas wherein corporates or institutional clients save money on their electricity bills without any investment.
The third challenge is the direction and angle of inclination of the roofs. The ideal direction for solar project installation is South. But rooftops may not always allow that. This challenge was faced and successfully overcome by CleanMax Solar in the case of NBC Bearings facility in Rajasthan. We chose to install on the ground, thus allowing higher generation than a north lit roof. CleanMax Solar installed a tracker-based system after flattening a 40-year old scrapyard. A tracker-based system ‘tracks’ the movement of the sun through the day – it is an axle based on a shaft that rotates to maximize the solar irradiation that falls on the modules. The shaft starts at 45 degrees east in the morning and goes up to 45 degrees west in the evening.
Other challenges faced by the rooftop industry include the availability of load at the client’s site and net-metering regulations – both of which play a critical role in the financial viability of rooftop solar plants in India.
What the rooftop solar industry in India needs today, are policies that favor the growth of this segment. This market primarily runs on the CAPEX model, but the Build-Own-Operate (I.e. BOO) OPEX Model (model without investment) has been single biggest factor in rapid growth and adoption of rooftop solar category in last couple of years . India’s ambition of 40 GW of rooftop power plants by 2022 seems difficult but attainable.
CleanMax Solar set up Konecranes’ first ever global solar plant near Pune in Maharashtra. The company set up a solar plant under the BOO Model and took upon itself the responsibility to maintain the plant and ensure uninterrupted power generation. The plant has a net-metering facility where surplus power is sent to the grid on weekly holidays for which Konecranes gets the credit. This facility is estimated to save the company 17% in electricity bills.
Read case study here.
Another illustration of CleanMax Solar’s capability is the setting up of the 1MW plant in NIT, Karnataka.
Read case study here.
This was set up on 11 academic, administrative and hostel buildings to handle 15% of the campus’ power requirements. This plant will be maintained by CleanMax Solar for the next 25 years.