Double the value of your solar panels

 

The ideal space for locating solar panels is a small part of a residential colony: the terrace of buildings, which should be out of bounds to residents and free from shadows. Such isolated areas are valuable not only for collecting solar energy but also for collecting rainwater.

How much rain does India get in a year? 1083 mm, according to World Bank data. If you set apart 1 Sq M of collecting area, you can get the volume of water calculated as

Area in Sq M X Rainfall in Meters/year X Efficiency

The efficiency question arises because of evaporation, leakage, etc. Getting an efficiency of 60% seems reasonable. Using the data and the formula given above, we arrive at a figure of

1 X 1.083 X 0.6, or roughly 0.65 Cubic Meters of water. If you set apart 30 Sq M of collection area per resident in an apartment building, you can collect 19.4 Cubic Meters of water per year, approximately 53 Liters/day per resident. It's not luxurious, but we can survive on that.

In a world in which climate change threatens our water resources, we cannot afford to ignore rainfall water collected on building roofs and terraces. Plans for future buildings must provide for collection and filtering. Designing and manufacturing solar panels to enable this will be essential for overall efficiency.

The double-duty solar panels should be able to withstand rain and let it run into the water collection system. They should not contaminate the water. They should also function efficiently as solar energy collectors soon after the rain stops.

Given the importance of solar panels for sustainable living, researchers must focus on cost-effective and reliable ways of turning solar panels to face the Sun. This will be near impossible on sloping tiled roofs but should be possible on the terraces of multi-story apartment blocks. The designs should consider at least the sun's daily movement. However, it is worth noting that the Sun also moves annually. A quarterly manual turning could take care of this.

Srinivasan Ramani