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Insights into Editorial: Rooftop energy

Insights into Editorial: Rooftop energy

In Bengaluru, the Laser Mapping Technology — light detection and ranging (LiDAR) — is being used for mapping its potential to generate rooftop solar energy.

Over the fortnight, a helicopter armed with LiDAR system will fly across the city. It will cover an approximate area of 1,100 sq. km, generating high resolution images of rooftops of buildings in the city.

How does LiDAR works?

The LiDAR technology will send pulsed laser light on to the rooftop of a building and translate the reflected light into data points.

Based on objects such as trees surrounding the rooftop, shadow-free area available for solar power generation will be calculated and an estimate will be arrived at as to the capacity of solar generation of each building in the city.

Once the data is collated and presented to the Energy Department, residents of the city will be able to check the capacity of solar power generation of the rooftops of their respective buildings.

This looks similar to Google’s Project Sunroof, which is currently available only in America.

What is the objective and targets of National Solar Mission?

The Jawaharlal Nehru National Solar Mission, also known as National Solar Mission, is one of the eight key National Missions of India’s National Action Plan on Climate Change (NAPCC).

The objective of the National Solar Mission is to establish India as a global leader in solar energy, by creating the policy conditions for its development across the country.

The Mission has set the ambitious target of deploying 1, 00,000 MW of grid connected solar power by 2022.

The target will comprise of 40 GW Rooftop and 60 GW through Large and Medium Scale Grid Connected Solar Power Projects.

The mission is aimed at reducing the cost of solar power generation in the country through long term policy; large scale deployment goals and aggressive R&D.

What is the significance of Rooftop Solar?

Rooftop solar installations are needed if the target of creating 40 GW of capacity connected to the grid by 2022 is to be realised.

Major solar projects that connect to the grid often face the challenge of land acquisition and transmission connectivity.

This has led to a delay in planned capacity coming on stream during 2017: nearly 3,600 MW did not get commissioned during the last quarter, out of a scheduled 5,100 MW.

Rooftop solar represents only about 11% of the country’s 19,516 MW of total installed capacity at the start of 2018. Rooftop solar can be exploited to achieve this target.

How does Bengaluru’s mission help in exploiting solar power potential?

Bengaluru’s aerial mission to produce a three dimensional map of rooftop solar power potential using Light Detection and Ranging (LIDAR) data can give this key source of power a big boost.

A survey helps determine usable rooftops, separating them from green spaces, and analyses the quality of the solar resource.

With steady urbanisation, solar maps of this kind will help electricity utilities come up with good business cases and investment vehicles and give residents an opportunity to become partners in the effort.

As part of Bengaluru’s mission, residents will be able to check their solar power production potential online from the same portal where electricity bills are paid.

What is to be done to improve growth of rooftop solar power?

Rooftop solar power growth has demonstrated an overall positive trend in the recent quarters. But this will need to be scaled up massively to achieve the national target.

Domestic policy has to evaluate the impact of factors such as imposition of safeguard duty and anti-dumping duty on imports, and levy of the goods and services tax on photovoltaic modules.

The policy should be attuned to the overall objective of augmenting capacity.

The Centre should come up with incentives, given the enormous investment potential waiting to be tapped and the real estate that can be rented.

The southern States and Rajasthan together host the bulk of national solar infrastructure on a large scale. With some forward-looking policymaking, they can continue to lead by adding rooftop capacity.


India, which is a founder-member of the International Solar Alliance launched in Paris during the climate change conference more than two years ago, must strive to be a global leader.

Initiatives such as the Bengaluru mapping project can contribute to assessments of both real potential and risk. The same kind of project can be implemented in other major cities as well to assess the rooftop solar power potential.

This is crucial for projects on a large scale involving significant exposure for financial institutions, including banks.

With on-going improvements to solar cell efficiency and battery technology, rooftops will only get more attractive in the future.