Solar panels or green roofs? Why pick one when you can use both?

Modern-day cityscapes and cramped urban layouts make it difficult for people to adopt most of the commonly recommended 'green' measures, such as switching to renewable forms of energy and lowering their carbon footprint with the help of green cover. Realistically, very few of us can boast of expansive gardens, lush lawns, or even free land to devote to renewable energy-generation units, such as windmills or solar panels.

To counter this, experts literally approached the solution from the top-by way of green roofs. Also known as roof gardens, green roofs comprise flower beds, lawns, shrubs and even trees, and are very useful in improving the 'green quotient' of the habitats they top.

Greener roofs, cleaner environments

Green roofs do not just add to the aesthetics of the edifice, but also bring with them numerous 'green' benefits, such as managing and controlling run-offs after heavy rains, bringing down the internal temperature within the structure and even extending the life of the roofing materials underneath the roof gardens by protecting them against the direct impact of the elements.

Further, green roofs are also useful in reducing the urban heat island effect, which occurs when hard surfaces in the urban landscape trap heat during the day, and release it back into the atmosphere at night. The urban heat island effect is very harmful to the environment, as it increases the need for air-conditioning and other energy-intensive cooling mechanisms.

The constant cycle of evaporation and transpiration that occurs in a roof garden helps to regulate and lower the air temperature, while the relatively cooler surface of the roof minimises the amount of daytime heat that is absorbed.

Merging solar gains

The benefits of solar energy are many, and have been extensively documented, time and again. Most people, however, believe that solar installations and green roofs must be mutually exclusive, since, with such limited space, it seems inconceivable that the functioning of one of these two does not interfere with that of the other.

And yet, the truth is that green roofs go much beyond simply 'not interfering' with solar panels-in fact, they even go on to enhance the efficiency of these panels by up to 16 percent, by cooling the ambient temperature around them. Further, by reducing the energy required for heating and cooling, these roofs reduce the workload on the solar energy system.

Several rooftop garden-solar array formats have been launched by manufacturers in recent times, which strategically position the arrays and green cover so as to allow the plants ample sunlight and also boost the performance of the solar panels. These are catching on as a popular, relatively inexpensive and aesthetic way of adding that 'touch of green' to modern, urban lives.