From 2024, owners of solar installations in Brazil will face new tariffs with Law 14300, known as “taxação do sol”, which introduces a charge on specific components of the electricity tariff, such as the B wire. How to calculate the impact of this taxation on your energy bill, highlighting the importance of understanding these changes to efficiently manage the costs associated with the use of solar photovoltaic energy.

From 2024, those who own solar panels will face a new reality on the electricity bill. This occurs due to the implementation of Law 14300, popularly known as the “sun tax”. This legislation introduces a charge on certain components of the energy tariff, such as wire B, which were not previously charged.

For those who work in the photovoltaic solar energy sector or simply want to understand the impact of this change, it is essential to know how this taxation works and how to calculate its cost.

What is Wire B and how to calculate the Sun Tax?

The “B wire” refers to a component of the electricity tariff related to the use of the concessionaire's network. Essentially, it works as a “toll” that solar energy producers must pay to compensate for the energy they inject into the grid.

Charges for wire B will be made in a staggered manner until 2029, when new rules will be established by ANEEL. To calculate this tax in 2024, it is necessary to first understand the difference between the energy consumed from the grid and the energy injected by the solar installation. From there, the compensated energy is calculated and the percentage of wire B is applied, which on a national average is 28%. The specific charge in 2024 will be 30% of this amount.

Practical example

Let's look at a practical example: suppose a small trade injected 2100 kWh and consumed 2000 kWh from the grid in April 2024. The offset energy is 2000 kWh. If the value of a kWh is R$1 and wire B represents 28% of this tariff, the value of wire B is R$0,28 per kWh. In 2024, 30% will be charged on this value for wire B, which results in R$0,084 per kWh.

Therefore, each kWh injected will no longer be worth R$1, but R$0,916. If the energy compensated was 2000 kWh, then the balance in reais with the concessionaire will be R$1832. The trader will therefore owe R$168 to the concessionaire, an amount considered as the “toll” for using the network.

A new reality for those who have solar energy

The taxation of the sun by Law 14300 brings a new reality for solar energy users in Brazil. Despite the apparent complexity, understanding and calculating the impact of this legislation is crucial for everyone in the sector.

Whether you are a business owner, a resident, or a solar energy expert, understanding these calculations allows you to better prepare for the changes that will begin in 2024 and will continue to evolve until 2029. The key is to stay informed and prepared to adapt to new demands in a way that minimizes costs and maximizes the efficiency of your solar installation.