Is an East-West Roof a Good Idea?

South-facing solar panels generate the most energy—that’s a given. However, alternative orientations can also offer benefits. In fact, after upcoming changes to the net metering policy, an east-west configuration may even prove to be slightly more advantageous than a south-facing system. But how exactly does that work?

Roofs facing south receive the most sunlight throughout the day. As long as there are no trees or buildings casting shadows, these roofs are the ultimate solar power generators—it’s almost a crime not to install solar panels on them! With a peak around noon, a south-facing roof outperforms all other orientations in terms of total energy yield. However, as net metering policies evolve, it’s not just about total energy production anymore; the distribution of energy generation throughout the day is becoming increasingly important. And this is where an east-west system may have an edge.

Maximizing Self-Consumption

The reason behind the gradual changes to the net metering policy in the Netherlands is to encourage homeowners to use more of their self-generated electricity instead of feeding it back into the grid. The more solar panels are installed nationwide, the harder it becomes for the public electricity grid to handle the influx of decentralized solar power. By gradually phasing out net metering, the government is incentivizing homeowners to increase their ‘self-consumption’ by reducing the compensation for excess power fed into the grid, making it lower than the cost of purchased electricity.

Spreading Energy Production Throughout the Day

Self-consumption occurs when energy is used at the same time it is being produced. This can be tricky with a south-facing system, as energy production peaks around noon while household energy usage is typically higher in the morning and evening. With an east-west system, the distribution is different: east-facing panels generate more electricity in the morning, while west-facing panels produce more in the evening. This results in a more balanced energy supply throughout the day. The graphs below show the energy output of an east-west system compared to a south-facing system of the same size on the same day of the year: