When my tenants in a rural setting mentioned how dark it was on the path to their lakefront home, I had to consider new lighting sources to alleviate their concern. Since all the electrical wiring had been hidden underground in trenches, adding new traditional lights would have been really expensive in relation to the task. So, after some research, I decided on a series of solar lights along the path — a bit like a Hansel and Gretel trail of well-lit breadcrumbs. Voila! Happy and safe tenants.
Outdoor solar lighting systems use photovoltaic technology — solar cells — to produce electricity. The electricity is stored in batteries for use at night. That means that as you convert sunlight into electricity, you can eliminate conduits, wiring, and trenching.
Solar lighting has no emissions or by-products from generating energy from the sun. It’s cost effective — in sun-drenched locations, these lights have a 5-day autonomy. That means they can operate on battery power without any recharging for 5 cycles. Moreover, when the power goes out, these lights continue to shine, as there’s no connectivity to power grids. And if you’re situated away from the grid, solar lights are ideal. You can even purchase portable styles, depending on your needs.
Where Can Solar Lights Be Installed?
As you look around your local streets, shopping centers, municipal parking lots, and airports, you’ll probably notice solar lighting. It’s everywhere! Here are some of the typical places you can find solar lighting these days.
- Streets: There’s no major construction hassle to install solar lighting on city streets, unlike traditional lighting.
- Parking lots: Solar lighting adds safety to often solitary areas easily.
- Construction sites: The ease of recharging eliminates the need for generators and refueling.
- Military applications: Whether it’s for a training area, armory, or remote installation, solar lights are appropriate. They can even be integrated into a satellite monitoring system.
- Airports: Solar lights can illuminate dark access paths for commuters on the tarmac, near construction sites, or in areas without distinct exterior connecting gates.
- Retro-fit street lights: Abandoned, non-functioning streetlights are now being rejuvenated with solar lights.
- Solar signs: Without the need to dig trenches to run power, solar signs draw attention to business road messaging.
Why Solar is Less Expensive than Traditional Lighting
Solar energy is the most important and widely available source of renewable energy available in today’s market. With tremendous environmental benefits such as being a safe, renewable source of energy that reduces harmful greenhouse gas emissions, that shrinks the carbon footprint, and that doesn’t put a strain on water resources, solar seems to be a win-win energy selection. However, the economic benefits of solar energy are less understood. In fact, for years the high cost of solar has prevented many businesses as well as homeowners from making the switch to solar. But the economics are changing.
Due to recent advances in solar cell technology, solar powered lighting has become increasingly popular for those looking to save on energy and installation costs at their residence or business. For the most part, solar lighting is outdoor lighting which charges during the day and then emits light at night.
Because solar lights are autonomous and off the main grid system, consumers avoid the long and costly process of trenching and wiring. The price of the total cost of the lighting systems reduces significantly as a result, driving down the total cost for solar. For example, since solar lights gather their energy from the sun, there are no energy costs. Standard lights, on the other hand, accumulate about $1,200 in energy costs over 5 years by drawing power from the main power grid, and that’s the energy cost of one street light.
The Database of State Incentives for Renewables and Efficiency offers a list of financial benefits that are available to you after your solar project is installed.
The Elements of a Solar Light
There are many components involved in creating a commercial solar street light system. Here is a quick overview of what components are used in most typical solar light systems. Of course, each manufacturer has their own approach to the elements contained in their solar street lighting systems.
- Panel: a combination of solar cells, aluminum frame, tempered glass, and multi-layered encapsulation
- Fixture: contains the light — comes in arrays of several LED fixtures
- Energy management system: controls the power between the light fixture, panel, and battery
- Poles: various materials can be used, including galvanized, powder-coded steel poles, wood, or concrete
- Battery: includes wiring, battery box, and wiring materials in addition to the physical battery profile. Solar lights work on a daily cycle of gathering and utilizing energy, so the battery needs to charge and discharge constantly.
- Design: Many styles of solar lighting exist, including cobra head, decorative, bollard, light bar, all-in-one, spotlight, and floodlight.
- Driver and controller: The energy management system consists of the driver and controller. Controllers regulate power load between the panels and the batteries, preventing the batteries from over-charging and stopping the reverse-current flow, or when electricity flows back from the batteries to the panels at night. The driver takes incoming voltage (12V DC) and alters it to 85 volts for the fixture. Controllers tell the drivers how to adjust the light level.
Admirable Solar Lighting Projects around the World
Together with the Global BrightLight Foundation, the Global Sustainable Energy Project has provided over 60,000 solar lamps to off-grid households in 8 countries around the world. Priced comparatively to similar kerosene lanterns, they provided the solar lamps to the communities through a pay-as-you-go program. Replacing kerosene, candles, or animal waste with clean solar lamps improves indoor air quality, facilitates greater access to education, enhances personal safety, and enriches the quality of life of these communities. The simple provision of solar lights will generate social, educational, and economic opportunities that many currently lack.
Liter of Light is a global, grassroots movement that uses inexpensive, readily available materials to provide high quality solar lighting to people with limited or no access to electricity. Researchers in India discovered in 2014 that 70% of discarded laptop batteries have enough capacity to power an LED light bulb for 4 hours per day for a year. The idea was to help facilitate the donation of solar lights for free, which, rather than compromising the efficacy of solar lights, discarded batteries could augment solar light batteries because they are much larger.
There are 2 billion people in developing countries without adequate sources of light. A project of SourcePoint Global Outreach brings some light to the world, providing high quality solar powered flashlights to villages in developing countries without access to electricity or healthy, sustainable sources of lighting.
Lighting Africa has already enabled 28.8 million people across Africa to meet their basic electricity needs. Lighting Africa is part of the World Bank Group’s contribution to Sustainable Energy for All (SEforAll). It is implemented in partnership with the Energy Sector Management Assistance Program (ESMAP), the Global Environment Facility (GEF) and the governments of Australia, Austria, Canada, Denmark, Finland, France, Germany, Hungary, Iceland, Italy, Lithuania, the Netherlands, Norway, Sweden, the United Kingdom, and the US.
USAID installed over 1,200 solar streetlights in 12 different cities throughout Somalia. In Mogadishu alone, roads in 11 out of 17 districts now have light. “Since the lights are working, we can walk freely at night to shop and visit our neighbors without fear,” says Amina Hussein Haji, a local resident. Solar lighting is new to Somalia. USAID is pursuing the introduction of renewable energy throughout the country as an alternate and reliable source of power in areas where electricity is sporadic or even nonexistent. “My business has doubled,” says Mohamed Ahmed, a local business owner in Baidoa. “Many people now shop at night with young people enjoying coffee in outdoor cafés due to the newly installed lights. Children are also playing along the side of the main road.” Local technicians are trained in solar lighting maintenance and installation, creating an industry that is sustainable and contributes to economic growth.
Don't want to miss a cleantech story? Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!
Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.