GUYANA has approximately 9,254 street lights which consume approximately 5.967GWh of energy per year at a cost of $316.25 million (US$1.5 million) annually. That’s according to the Guyana Energy Agency (GEA).Defective photocells and lamps have resulted in some areas being under-lit, while some lamps remain continuously lit (24 hours per day). Based on the current street lighting tariff of G$55.67 per kWh, for each lamp remaining lit during the day, the energy wasted per lamp costs about $60,958 per year.
To conserve energy, GEA’s engineers, with support from the Ministry of Public Infrastructure, Work Services Group (WSG), conducted a series of photocell replacement activities on the street lamps remaining lit during the day with the objective of replacing some 2,000 defective photocells.

AN IMPORTANT SERVICE
As Energy Week is being observed under the theme “Empowering our Sustainable Development” from November 8-14, 2015, the GEA underscored that street lighting is an important service that helps contribute to safety and security of the public, businesses, and residential spaces.
Street lights also aid in crime prevention and recreational activities, the GEA has noted. Over the years, this service has significantly contributed to the energy consumption from the utility at a considerable cost.
In order to enhance and conserve electricity used by street lights, the GEA has piloted Stand-Alone Solar-Powered Street Light.
Based on a study done by the energy agency, the main types of street lamps are the 250-watt high-pressure sodium vapour (HPSV) lamps, and 175-watt mercury vapour lamps.
In keeping with its mandate to develop and encourage the development and utilisation of sources of energy, and to carry out research into all sources of energy, GEA has explored the opportunities for using solar energy as an alternative to conventional street lighting powered by electricity from the public utility.

ALTERNATIVES
Through the use of stand-alone solar-powered street lighting and the use of light emitting diode (LED) lamps, GEA’s Chief Executive Officer (CEO), Mahender Sharma said it is possible to significantly reduce the cost that the current street lighting systems incur.
These lights utilize photovoltaic (PV) technology which harnesses the sun’s energy by converting it into electricity. The abundance of sunlight in Guyana, and the region at large, therefore makes solar-powered street lighting a very attractive alternative to street lighting powered by electricity from the public utility.
The LED lamps also have an estimated lifetime that is five times longer than conventional HPSV lamps, and energy savings of 80% or more.
“Converting HPSV street lights to solar-powered LED lamps incurs a capital cost; however this can be recouped from the monthly payments which otherwise would have been paid to the electric utility over the lifetime of the lights.

ADVANTAGES
Apart from monetary savings there are many additional advantages associated with the use of this type of street lighting,” Sharma noted.
Given that it utilises the sun’s energy, he said the power generated is continuously available. During the sunlight hours, energy generated by the PV panels is stored in batteries; at nights when sunlight is no longer available the energy stored in the batteries are then delivered to the lamp.
Additionally, because they use solar energy, which is renewable and sustainable, stand-alone solar-based street lighting is environmentally desirable. Another major advantage is that the LED lamp provides a truer colour representation, more depth of field, and greater peripheral vision, which improves safety for drivers and pedestrians.
GEA’s engineers designed and, with the assistance of Guyana Power and Light Inc. (GPL), installed one stand-alone solar-powered street light at the corner of Thomas and Quamina Streets in front of the Ministry of Indigenous People’s Affairs.

PILOT PROJECT
The stand-alone solar-powered street light consists of a 140W solar panel, 40W LED lamp, 105Ah battery, charge controller, timer, enclosure and mounts. This, the first unit installed by the GEA, cost $278,300. It is estimated that these costs can be further reduced to about $200,000 based on optimization of the design and lessons learned. The estimated simple payback for the stand-alone solar-powered street light is about 3 years.
Solar-powered LED street lamps have a major advantage in that they are not affected by utility failure and operate at low voltages, hence making them cost effective and a safe option for workers.
“GEA will continue to monitor, research and record the performance of solar-powered street lighting. The information obtained from data gathered, and experience gained from the installation process, will be used to guide decisions with regards to street lighting,” the GEA head noted.
The Ministry of Public Infrastructure is responsible for any lighting of the national main roads while local government organs are responsible for any lighting of local roads and streets.