Wind Variability in Renewable Energy Production

A Closer Look at Energy Forecasting Challenges in India

In the realm of renewable energy, wind and solar power stand out for their potential to reduce carbon emissions at scale. However, the journey from potential to power isn't without its hurdles, with renewable energy variability posing a significant challenge to grid operators and asset owners. The level of variability, and hence the challenges, depends on local climates and the locations of renewable assets.  Let’s compare the variability in two regions where we have worked. 

Why does this matter? 

It is essential to match the supply of electricity with the system demand at every point in time. Higher variability necessitates grid operators to ramp up and down other generation sources rapidly. If 1000 MW of wind generation disappears in an hour, that will require new generation to be turned on to avoid a blackout. Grid management becomes much more challenging as variability increases. For wind farm operators, new rules in India stipulate strong penalties for getting forecasts incorrect. Operators lose 100% of wind revenues if forecasts deviate by more than 15%. So large variability is not their friend!

What did we examine?

In this exploration, we have analysed the variability of wind power generation across two distinct regions: the UK (split into onshore and offshore) and North West India, across a portfolio of on-shore wind farms. 

Figure 1: A month of wind generation data for UK onshore and NW india, showing the daily volatile nature of wind power generation.

Data cleaning and resampling was applied to compare the data on an hour-to-hour basis. Variability was then calculated using the mean absolute change in hourly generation, normalised by the average generation to enable comparisons. .

Variability Results

Figure 2: Hourly variability of wind generation in North West India and the UK.

The analysis reveals striking differences in the hourly variability for wind power generation across North West India (15%) being more than double that of the UK onshore (7%). These figures highlight the greater variability in wind generation in India compared to the UK, making forecasting and grid management a much more complex task.

What could be causing this?

There are a number of factors which could be behind the difference in variability: 

• Better “quality” wind resource. The UK is sometimes called the Saudi Arabia of wind. It has relatively reliable and high wind speeds with many wind sites either offshore or not too far from the coast, making them free of hills which disrupt wind. 
• The wind generation fleet in the UK is reasonably geographically dispersed: on-shore and off-shore locations from Scotland to the South East coastal regions to the South West. In North West India, the bulk of the wind farms are located close to the Pakistan border where land is cheap. The greater the geographic diversification, the smoother the generation profile.

What does this mean for wind energy in such regions? 

In regions like North West India, it's crucial to develop strategies for real-time grid management. This involves acquiring advanced knowledge and implementing sophisticated forecasting tools designed to navigate complex local wind patterns effectively. Such measures can lead to cost savings and reduced carbon emissions for both grid and wind farm operators

As India continues to harness wind energy, addressing the challenges posed by resource variability is paramount. By embracing innovative technologies and smart solutions, we can significantly improve forecasting precision and grid operation, setting the stage for a more sustainable and dependable energy future.