Solar street light
Solar street lights are raised light sources which are powered by photovoltaic panels generally mounted on the lighting structure. The photovoltaic panels charge a rechargeable battery, which powers a fluorescent or LED lamp during the night.
Most solar panels turn on and turn off automatically by sensing outdoor light using a light source. Solar streetlights are designed to work throughout the night. Many can stay lit for more than one night if the sun is not available for a couple of days. Older models included lamps that were not fluorescent or LED. Solar lights installed in windy regions are generally equipped with flat panels to better cope with the winds.
Latest designs use wireless technology and fuzzy control theory for battery management. The street lights using this technology can operate as a network with each light having the capability of performing on or off the network.
Solar street lights consist of 5 main parts:
Solar panel is one of the most important parts of solar street lights, as solar panel will convert solar energy into electricity. There are 2 types of solar panel: mono-crystalline and poly-crystalline. Conversion rate of mono-crystalline solar panel is much higher than poly-crystalline.
LED is usually used as lighting source of modern solar street light, as the LED will provide much higher Lumens with lower energy consumption. The energy consumption of LED fixture is at least 50% lower than HPS fixture which is widely used as lighting source in Traditional street lights. LEDs lack of warm up time also allows for use of motion detectors for additional efficiency gains.
Battery will store the electricity from solar panel during the day and provide energy to the fixture during night. The life cycle of the battery is very important to the lifetime of the light and the capacity of the battery will affect the backup days of the lights. There are usually 2 types of batteries: Gel Cell Deep Cycle Battery and Lead Acid Battery.
Controller is also very important for solar street light. A controller will usually decide to switch on /off charging and lighting. Some modern controllers are programmable so that user can decide the appropriate chance of charging, lighting and dimming.
Strong Poles are necessary to all street lights, especially to solar street lights as there are components mounted on the top of the pole: Fixtures, Panels and sometime batteries. And wind resistance should also be taken into consideration when choosing the pole.
Each street light can have its own photo voltaic panel, independent of other street lights. Alternately, a number of panels can be installed as a central power source on a separate location and supply power to a number of street lights.
- Solar street lights are independent of the utility grid. Hence, the operation costs are minimized.
- Solar street lights require much less maintenance compared to conventional street lights.
- Since external wires are eliminated, risk of accidents is minimized.
- This is a non polluting source of electricity
- Separate parts of solar system can be easily carried to the remote areas
- Initial investment is higher compared to conventional street lights.
- Risk of theft is higher as equipment costs are comparatively higher.
- Snow or dust, combined with moisture can accumulate on horizontal PV-panels and reduce or even stop energy production.
- Rechargeable batteries will need to be replaced several times over the lifetime of the fixtures adding to the total lifetime cost of the light.
Implementation in the Sunderbans
Solar street lights were installed in the Sundarban Tiger Reserve (STR) in August 2008 and April 2009 with assistance from the Forest Protection Committee and the STR officials. Each household in the region were provided with a home light connection by the WWF so that the people feel responsible for the security of the installed solar street lights.
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- "A New Intelligent Control Terminal of Solar Street Light". ieeexplore.ieee.org. Retrieved 2011-07-12.
- Danny, Peng. "Solar Street Lights". Greenshine New Energy. Retrieved 20 March 2014.
- "A Study on energy efficient & Solar PV street lighting system". fosetonline.org. Retrieved 2011-07-12.[dead link]
- "Lighting lives in remote areas of Sundarbans". wwfindia.org. Retrieved 2011-07-12.
Warrnambool City Council's energy efficient street lighting project By admin on May 9, 2013 in Green Zone
The Warrnambool City Council expects to realise annual savings of over $100,000 at current prices, with the new globes expected to reduce energy usage by up to 68 percent.
The Warrnambool City Council has committed $872,500 to the $3 million Great South Coast Street Smart Lighting project. About 2200 lights will be installed in residential streets in Warrnambool over the next couple of years as part of broader plans by six local government authorities to replace more than 7600 mercury street lights with more efficient lights, according to Warrnambool’s mayor, Michael Neoh. While Warrnambool’s street lighting is owned and operated by Powercor, council pays for maintenance and operation. “By working with Powercor on this upgrade we’re expecting to realise annual savings of over $100,000 at current prices, with the new globes expected to reduce energy usage by up to 68 percent,” Neoh notes. Low Carbon Australia will provide finance for just over 50 percent of the Warrnambool City Council’s $872,500 commitment to the larger $3 million Great South Coast Street Smart Lighting project. Warrnambool will fund the balance of the costs of the street lighting project through an Australian Government Community Energy Efficiency Program (CEEP) grant of up to $1.4 million for the group of regional councils, which also include Shires of Colac Otway, Corangamite, Moyne, Southern Grampians and Glenelg. According to Low Carbon Australia’s CEO, Meg McDonald, the cost savings from the Warrnambool street lighting project would be greater than the loan repayments, meaning that Warrnambool ratepayers would be better off from day one. Low Carbon Australia also recently assisted Richmond Valley Council in New South Wales with finance for a project that helped that council reduce its street lighting energy costs by about one third.
More Information: Warrnambool City Council - www.warrnambool.vic.gov.au The Great South Coast - www.greatsouthcoast.com.au The Community Energy Efficiency Program - www.climatechange.gov.au/ceep Low Carbon Australia - www.lowcarbonaustralia.com.au