1. Introduction
This research has been motivated by the application of solar
energy in public lighting with the intention to achieve an energy positive
street lighting sub-grid, briefly named E þ grid. The proposed
system architecture exploits all of the four possible approaches
defined in Ref. [1] to minimize the energy consumption
and the operating costs of the lighting system: advances in technology
(i) by applying energy-efficient LED luminaries, photovoltaic
(PV) panels for energy production, and batteries for intermediate
energy storage; changes in use patterns (ii) by adjusting the daily
switch on/off times to current meteorological conditions; modification
in the basis of design (iii) by applying adaptive lighting that
concentrates the lighting service to locations and times with
vehicle or pedestrian traffic; and finally, changes in contracts (iv) by
optimizing the energy management of the system subject to a timeof-
use variable energy tariff