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C-WET/MNRE select 3TIER to develop national 'Solar Atlas of India'

Publicly available solar information from the Indian government will guide development, attract investment, and accelerate the growth of solar energy.

3TIER India Private Ltd 1 has been selected through a global tender for satellite data to create a Solar Atlas of India. The signed agreement is with the Centre for Wind Energy Technology (C-WET), an autonomous research and development institution that forms a part of the Indian Ministry of New and Renewable Energy (MNRE).

Under the terms of agreement, 3TIER will work directly with C-WET2 to develop and disseminate critical investor-grade information that will enable India to meet its ambitious solar energy capacity targets. 

"The collaboration between 3TIER and C-WET will greatly help in evaluating and prioritizing required infrastructure, such as solar generation facilities, storage technology, and transmission lines -- in essence, answering where and how to invest in order to harness India's considerable solar energy potential," said Dr. S. Gomathinayagam, executive director, C-WET. "The resulting nationwide solar study will help investors and market players clear the first hurdle in the process by filling a critical information gap." 

Under the Jawaharlal Nehru National Solar Mission (JNNSM), India aims to reach 20 GW of grid-tied solar power, 2 GW of off grid solar power, and 20 million square meters of solar thermal collector area by 2022. Meeting these targets will require long-term market certainty in order to attract the necessary inward investment of capital. 

"Long-term certainty is not solely generated by strong, stable government policy," said Mr. Nikhilesh Singh, managing director of 3TIER India. "It also requires long-term certainty in the resource."
According to Nikhilesh, prospective developers and investors need information to quickly assess whether solar projects will be commercially viable and able to meet energy production expectations. A large part of ensuring project feasibility is optimal siting. 

"This involves appropriately sizing the system to match the available energy resource, evaluating proximity to transmission and major centers for energy demand, as well as ensuring that the infrastructure is equipped to manage the influx of energy from a variable source," Nikhilesh explained. "The forthcoming Solar Atlas will provide a detailed view of India's solar power resources, which -- while vast -- vary significantly both across geography and over time." 

Importance of accurate forecasting

Having a clear understanding of resource variability prior to investment is crucial, since falling short of energy estimates has a direct impact on project production and profitability. 3TIER pioneered the use of satellite technologies in calculating pre-construction solar energy estimates and has set the global best practices for project planning. To date, this has enabled global project developers to secure investments worth over €4 billion. 

This state-of-the-art satellite methodology analyses the range of factors that impact surface irradiance conditions, such as cloud movement, air quality, and cyclical events like cyclone seasons and monsoons. In a previous study by 3TIER, India's monsoon was shown to cause resource reductions of as much as 30-40% in some parts of the country from pre-onset solar production. The timing and impact of the monsoon vary significantly from year to year and can be strongly felt -- even in typically sunny regions like Rajasthan. 

The Solar Atlas will provide a clearer understanding of this weather anomaly along with spatial and hourly solar irradiation variability. It will include a series of monthly solar resource maps covering the entire country and long-term solar resource and meteorological datasets at 115 locations. 

"All information will be regularly updated to include the most recent months and will be validated by C-WET's Solar Radiation Resource Assessment (SRRA) stations spread across the country," said Dr. G. Giridhar, director of the SRRA Mission Mode Project at C-WET. The data quality checks and accuracy levels are facilitated through an active collaboration between C-WET Chennai and Deutsche Gessellschaft für Internationale Zusammenarbeit (GIZ) GmbH.


1. 3TIER is a wholly owned subsidiary of Vaisala and a leading source for global renewable energy assessment and forecasting information.
2. C-WET is entrusted by the Indian government through a mission mode project to create and share commercially relevant weather resource information with prospective future financiers and the wider investor community. This ambition forms part of a wider strategy to ensure adequate solar radiation data is available to the domestic and international business community, with a particular emphasis on those that have already identified the Indian market to be of strong solar investment interest.


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Energy efficiency  •  Energy infrastructure  •  Photovoltaics (PV)  •  Policy, investment and markets  •  Solar electricity