# DC Energy System Layout
Most components in renewable energy systems (solar panels, batteries and loads like LED lights or laptops) are based on direct current (DC). The conversion to alternating current (AC) as used in conventional electricity grids includes considerable amount of losses, especially for small systems for off-grid energy access. This is why this OER focuses mainly on DC energy system components and distribution grids.
The following picture gives an overview of the DC energy system components:
The components will be described in more detail in the following chapters.