- Researchers analysed India’s historical weather patterns to predict renewable energy “drought” events, which are periods of low wind and solar energy availability.
- Results show links between energy drought events and weather patterns such as the western disturbances and monsoon withdrawals.
- Climate change and shifts in renewable energy investments could change these outcomes in the future.
India’s renewable energy boom may not be immune to weather shocks. A study reveals that combined solar and wind generation can plunge during certain weather conditions, creating ‘renewable energy droughts’ that last up to nine days, especially in the winter season in India.
The study by meteorologists in the U.K. attempted to identify periods of low wind and solar energy availability based on historical weather patterns across India, potentially affecting energy production and demand. Days when the combined production of solar, and wind energy was below a cutoff threshold were classified as ‘renewable energy drought’ events.
To understand how historical weather patterns might affect a solar and wind-energy-based grid, the study looked at a 42-year study period from 1979 to 2022. The researchers assumed India’s 2022 renewable energy capacity to be applicable throughout the study period. Using historical weather data, they modelled the weather conditions likely to cause days of low solar and wind energy production.
Results show that renewable energy droughts are most commonly expected in India from November to February, and are typically multi-day events. The longest predicted event was 9 days long, and occurred twice during the 42-year study period. Specific weather patterns such as the western disturbances, or the winter dry period were more frequently associated with drought occurrence and can currently be predicted 10–15 days in advance, which makes mapping and following them useful in predicting energy droughts.
Hannah Bloomfield, an Academic Track Fellow at Newcastle University and one of the authors of this study, highlights the need for such research in the Indian context. “India has a ridiculously large proportion of the world’s solar and wind power,” she says. “There exists a huge amount of renewables, and equally huge demand. Yet, there is a surprising lack of studies on blackouts and power grids in the Global South compared to Europe or America, where it’s actually much less of a problem.”
Currently, wind and solar energy comprise the majority of the renewable energy infrastructure in India, with a total of 106 GW capacity for solar energy and 50 GW capacity for wind energy as of 2025. The study finds very little overlap between solar and wind energy “drought” days, implying that when wind production is low, solar production is often sufficient and vice versa. Only rarely do they both fall short at the same time.
“So you can build your grid in a very clever way,” explains Bloomfield. “If you already have a lot of wind energy capacity, investing in solar energy capacity means you can have more stable energy generation throughout the year. That’s why we looked at them together.”
India’s climate landscape
As of April 10, India is reported to have the infrastructural capacity to produce 220 gigawatts of renewable energy, primarily in the solar and wind energy sector. This is in line with the country’s larger goal of achieving 500 gigawatts of installed renewable energy capacity by 2030.
While this shift in energy capacity holds promise for a greener energy grid, it also results in the system becoming more sensitive to weather conditions. Renewable energy production depends heavily on meteorological variables such as wind speed, seasonal weather patterns, and cloud coverage. To ensure a long-term stable and resilient energy grid, it is important to anticipate how certain weather patterns might affect wind and solar energy production.
Prasanth A. Pillai, a senior scientist at the Indian Institute of Tropical Meteorology explains how India’s diverse climatology would influence the way we set up our renewable energy grids. “India has a wind-reversing system. In the summer time, the wind blows southwest and in the winter, the wind blows northeast. These kinds of changes produce different types of climatology for the country,” says Pillai. “So, for example, if you’re interested in setting up windmills, you need to understand that such wind changes exist in nature, and are unavoidable”
This variability is rooted in India’s diverse climatic zones. According to the World Bank’s climate profile, the northern states in India experience a more continental climate, coastal regions experience stable warm temperatures throughout the year and frequent rainfall, the western part is largely arid and semi-arid, whereas the southwest experiences a wet tropical climate.
As a result, weather patterns in India are very dependent on both the region, and the time of the year. “If weather forecasters want to anticipate weather patterns that can cause such renewable energy drought events in the future, it’ll be very dependent on the location and what time of the year it is,” adds Bloomfield.
The study analysed thirty different weather patterns across India, mainly driven by rainfall variability, to understand their relationship with renewable energy drought events. Events such as the winter dry period (low winds over the western coast), retreating monsoon (low winds over North-West), and western disturbances (high precipitation in the North) were most commonly associated with renewable energy drought events.
The study notes that the presence of these weather patterns do not always indicate the start of an energy drought event, but are still useful potential indicators to predict renewable energy drought events since their predictions are more reliable than specific meteorological variables.
Since there was no clear linkage between the thirty different weather patterns and drought events, the study also conducted impact-based forecasting to group patterns of weather conditions present during energy drought days.
The impact-based forecasting revealed that on the days that renewable energy drought events occurred, there were three distinct anomalous weather patterns associated with them: a weak northeast monsoon, summer monsoon withdrawal, and southern western disturbance.
Each of these affected renewable energy production in different ways. The northeast monsoon affected wind energy production, and worsened already low solar production due to winter. The summer monsoon withdrawals resulted in low wind production due to weak transition winds and low solar production especially over northwestern India, where most solar installations are placed. The southern western disturbance also primarily reduced solar production due to cloud coverage over western India.
Pillai expands on the challenge during monsoon withdrawals. “When you’re transitioning from the summer monsoon which is from June to September, to the winter monsoon which begins from November, you have a period of calm between September to November. You’ll have weak winds during this period, and you may rely on solar radiation for energy production instead. But if cloudiness persists, you won’t have good solar production either,” he says.
Climate modelling and weather prediction
To reconstruct the past weather conditions of India, the study utilised the ERA5 re-analysis dataset, produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). Re-analysis data is a mix of both past observational climate data, and current climate models, that produce a close-reconstruction of past weather conditions.
“ERA5 is a high resolution global dataset. It makes use of weather observations made in the near past and climate modelling to predict what the weather would’ve looked like historically,” explains Pillai. “It has its own limitations, though. At the end of the day, it is not entirely made up of past observations, and it uses climate modelling outputs to fill in the gaps in observational data. Not all parts of the world may have historical weather observations available for the model’s input.”
Yet, even with high quality weather data sets, climate change is expected to have an impact on future studies linking weather forecasting and energy grids. “From a policy perspective, one big gap in this research area is climate change,” explains Bloomfield. “Many climate models do not represent weather conditions like the monsoon very well. We have to find some other good models that have high resolution data for this kind of energy work. We need to do similar studies but with future climate projections. Because, say, if climate change leads to longer or more intense monsoon periods, then that’s going to be an added layer of challenge.”
“In recent times, we’ve seen a delay in monsoon withdrawals, happening in October rather than its usual time. If you’re investing in solar energy expecting clear skies and good heating, but your climate changes in such a way that the monsoon starts earlier and ends later, it can be quite challenging. Accurate predictions can make it easier to overcome some of this unpredictability” adds Pillai, giving an example of such changes.
Earlier this year, in an attempt to improve weather forecasting for renewable energy grids in India, the Central Electricity Authority issued new guidelines to install Automatic Weather Stations in wind and solar plants across the country.
Apart from just uncertainties with climate change, the study also notes that investments in renewable energy in India are still largely skewed towards solar energy. If the balance between solar and wind capacity changes in the future, then some of the weather patterns associated with drought events may no longer have the same impact.
Despite these uncertainties, Bloomfield sees promise for renewable energy production in India. “I think these results are actually really promising for routes to net zero. We were looking for the worst-case-scenarios, days where there would be potential regional blackouts, because there wouldn’t be enough energy. And there weren’t many. The magnitudes weren’t that big,” she says.
Banner image: Solar plant in Uttar Pradesh. Currently, wind and solar energy comprise the majority of the renewable energy infrastructure in India. Image by Citizenmj via Wikimedia Commons (CC BY-SA 3.0).
