These are stand-alone power generators installed by consumers to meet their own needs, directing excess electricity to the public grid. The impetus for the development of distributed generation was introduction of the so-called Net Metering system. In a somewhat simplistic way, since 2012 owners of stand-alone generators can discount charges for electricity consumed from the public grid by the amount of electricity supplied to the grid. Initially, this rule applied to 1 MW biomass, solar, wind and hydropower plants (HPP) but in 2015, the bar for small HPPs was raised to 3 MW, and for all the other types of generators – to 5 MW. As a result, the capacity of distributed generation systems, which was close to zero ten years ago, grew almost to 10 GW by 2021, and to 19 GW by 2023.
The most common type of stand-alone plants are solar panels with the share of 99% in the total power mix of distributed generation systems, wind turbines and micro HPPs account for another 1%. State leaders in stand-alone solar generators’ capacity are located in the south and east of the country, including Sao Paulo (2.62 GW), Minas Gerais (2.60 GW), Rio Grande do Sul (2.08 GW) and Paraná (1.87 GW).
Solar panels are the most popular type of stand-alone generators in the world at large. According to the International Renewable Energy Agency (IRENA), they accounted for 40% of the global stand-alone renewable energy capacity, while small HPPs accounted for 14%, and all other sources accounted for another 36%. Innovations simplifying the use of wind generators in everyday life can change this ratio. For example, Aeromine Technoligies has designed a 5 kW wind turbine, which, thanks to lack of bulky blades would be suitable for mounting on a private house roof.