A ten-year analysis of solar irradiance by Solargis (which describes itself as “a data and software architect for bankable solar investments”) has illustrated the impacts of significant resource variability on several key global solar markets including India, Australia and North America.

As margins tighten for solar asset owners and investors, investment in high-quality data is crucial to understanding – and managing – the impacts of this variability on performance and profitability.

Solargis’ 10-year solar performance maps illustrate how solar irradiance levels have deviated from the long-term averages that are often used to underpin production estimates and financial models. Significant variation both above and below these averages has been witnessed across North America, India and Australia, highlighting the variability challenge presented by solar, a promising yet intermittent renewable energy source.

With a solar performance coming under increased scrutiny because of changing global energy market conditions, investment in robust resource data throughout the lifetime of solar projects has become a prerequisite for asset owners and operators seeking to manage the financial impacts of this variability.

“We are seeing margins tighten on global solar projects, due to multiple factors like the phase-out of tax credits and subsidies, price volatility and rising supply chain costs. High-quality solar data will help to better understand and address deviations from expected production, forecast short-term performance and ultimately support effective integration into modern digitalised grids,” says Solargis CEO Marcel Suri.

“Through our work, we hope to highlight the variability challenge in key markets to best support policymakers, planners and consultants and encourage the adoption of high-quality, long-term data into renewable energy decision-making.”

Key observations from the Solargis maps include:

Global horizontal irradiation, yearly to long-term average difference, for India

India: The Solargis irradiance maps indicate up to seven per cent below average solar irradiation for the sub-continent over the last four years – reflecting the concerns of local asset managers about a decline in irradiance levels. This is particularly notable around highly developed areas where aerosols and cloud cover can impact resource availability. If this data isn’t considered by developers, it could result in solar farms underperforming, with wider implications for investor confidence in one of the world’s fastest-growing solar markets.

Global horizontal irradiation, yearly to long-term average difference, for North America

North America: The Solargis maps indicate below-par irradiation in the north and southeast when comparing the last ten years of averages vs long-term trends. The above average levels in the northwest, particularly last year, reflect anomalies such as the recent heat dome, which saw temperatures reach record highs of 49.6°C.

By harnessing a long-term, data-driven approach to solar power generation that can flag anomalies with high accuracy, developers and asset owners in North America can better prepare their projects for variable weather conditions. This will be critical as the Investment Tax Credit (ITC) phases out, impacting long-term revenue security.

Global horizontal irradiation, yearly to long-term average difference, for Australia

Australia: As a country with great potential for solar power, the last five years of maps indicate significant irradiance variability across the continent when compared to long-term averages, reflecting extreme weather conditions such as those that contributed to notable events like the “Black Summer” bushfire season of 2019-2020.

With the Solargis team seeking to understand phenomena such as El Niño and La Niña through their long-term data analysis, the future of solar integration on the continent depends on expert, reliable understanding of how investors and asset managers can prepare for and manage extreme weather events while integrating these future technologies into the grid as the nation transitions from fossil fuels.

Suri concludes: “Controlling the weather is outside of our capabilities, but what solar developers, owners and operators can control is their knowledge. Vital, trusted intelligence on the solar resource, albedo, and specific geographical conditions at project sites can be the difference between an asset which retains its value throughout its lifecycle, and one which fails to live up to its potential.”

This article first appeared in Modern Power Systems magazine.