Electricity network augmentation by Distributed Generation

The growing need for competition in the utility and energy markets and South African government´s policy on the inclusion of Distributed Generation otherwise known as Embedded generation (EG)s in the future generation mix in South Africa will potentially mean that the numbers of generators being connected within the utility distribution networks will increase significantly. In March, 2009, the National Energy Regulator of South Africa (NERSA) released the renewable energy feed-in tariff (REFIT). The consequence of the REFIT is that renewable energy projects will become financially viable under the new tariff. This will in turn result in an expected increase in embedded generation (EG) applications expected to be connected to distribution networks. This paper explains the context of EG in South Africa, the status quo, types of EGs, impacts of EGs on grid connections, methods to address these problems and system studies for utility connected EGs. The EG network voltage considered in this paper are distribution medium voltage (MV) i.e. 11kV to 22kV and sub-transmission high voltage (HV) networks i.e. 33kV to 132kV. Note that throughout this paper, the term “embedded generation” or EG is used synonymously with DG.