The paradox of renewable energy is that the more sources there are, the more unstable the grid becomes.

The grid is responsible for transporting electrons from where they are produced to where they are consumed.

Energy is produced and distributed close to instantly to where it’s needed. Due to the lack of large-scale storage solutions, it is produced in a continuously adjusting flow based on projected supply and demand. This process of adjusting supply to demand is what people mean by balancing the load.

This leads to two important grid properties:

1) It’s architected for peak load, i.e. that hot day when everyone turns their AC on, or when everyone is cooking dinner and charging their Tesla.

2) It’s premised on being a predictable and controllable system. Grid operators forecast demand, and adjust supply as needed.

Over the past few years, two important changes have occurred that jeopardise grid predictability: the shift towards renewable energy sources and electrification. While both trends are positive for the environment, they introduce volatility and unpredictability in a system premised on its consistency.

On the supply side, renewable energy sources increase volatility because their output can’t be controlled or predicted. You can’t crank up the sun’s intensity to boost a solar panel’s output, and it’s hard to predict weather and solar intensity. Weather forecasting is difficult.

This is different from traditional energy sources like gas, coal, or oil plants, which can be turned on and off.

Electrifying everything on the demand side creates unpredictability by increasing the peak load and adding variability. When cars go electric, you have to account for the fact that there are times when many people will charge them - that will create spikes in demand.

Increased volatility leads to wasted energy. Excess demand is more problematic because it leads to blackouts with consequences ranging from mild inconvenience to large-scale economic damage (e.g. in South Africa) or even fatal harm.

There are no easy solutions. Right now, utility providers use temporary fixes. They pay ‘capacity payments’ to generation facilities not to shut down, even if they are not producing power, in case they are needed. These, however, are mostly based on fossil fuels.

There are other alternatives, like batteries, and we’ll explore that in another post.