Abstract
Photovoltaic (PV) Systems in Brazil are proven to be a great investment in a large variety of
situations. The main factors that contribute to it are the regulatory agency’s net-metering policy (since
2012), increasing cost of the electricity, reduction on system’s cost (R$/Wp), government’s credit
subsidies for legal entities, and other fiscal incentives and competition among the installers. The use of
batteries in grid-connected systems is not in the radar of those companies; however, they can be
economically viable in some situations. This article demonstrates where the integration between on-grid
PV systems and Tesla Power Wall 2 batteries for load shifting can be profitable, through economic
analyses of Net Present Value (NPV), Net Internal Rate of Return (net IRR), Discounted Payback Period
(DPBP) and other parameters.
In order to expand the reach of the analyses, several scenarios have been studied and compared,
for instance, commercial, residential and industrial load profiles, with different numbers of batteries,
regulatory changes, tariffs, percentage of energy consumed at peak tariffs, comparisons with diesel
generation at peak periods, battery costs, etc. The outcomes of the study provide arguments to state that,
in some occasions, the installation of batteries is economically viable, but the circumstances are specific
and must be analyzed carefully.
