When it comes to technical terms used for solar lighting, many may be confused at first. Industry-specific words are used which can make it hard to understand the advantages of one light over another. LED stands for Light Emitting Diode. They can use up to 90% less energy than traditional lighting and last up to 25 times longer (ref. US Dept. of Energy LED article below). When talking about Solar LED Lighting, there is a combination of two newer technologies that involve jargon from both industries. “Lumens” is a measure of the quantity of total visible light emitted by a source. This is the best way to measure how powerful a light is. To see how much energy it takes to create a given level of Lumens, Wattage is primarily used. Wattage is a measure of power comprised of AMPS X Volts. To understand the overall efficiency of a light relative to how much light it produces, Lumens per Watt is the industry standard. Soltech Smart Solar lighting provides 200 Lumens for every 1 Watt of stored sunlight, up to double the efficiency of many solar lights. It is this one of the performance breakthroughs that make our solar lighting a viable and realistic alternative to traditional lights on city streets, especially during sub-optimal sunlight conditions. Many municipalities have a minimum wattage requirement for lighting, but this measures consumption of energy, not performance relative to efficiency.
US Dept. of Energy LED Article: https://www.energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/led-lighting
Color Temperatures Explained
The Kelvin Scale is another helpful unit of measurement when trying to understand light. Generally, the lower the Kelvin rating, the more yellow or warm the light appears. High Kelvin ratings appear as bright white light, but actually have more blue light in them. Soltech can adjust lights to be more or less warm by adjusting the LED’s output from 3,000K Kelvins to 5,700 Kelvins. High Kelvin, less warm lighting is generally used in parking lots, street lights, & football stadiums. It appears more bright. Lower Kelvin ratings with a warmer color actually penetrate darkness further, can be less harsh to look at, can circumvent particles in the air (fog), and are more suitable for residential or marine applications. Some might ask, if yellow light penetrates darkness further, why isn’t the ocean yellow? In water, absorption is strong in the red and weak in the blue, thus red light is absorbed quickly in the ocean leaving blue. Red does not absorb as quickly as blue because blue is scattered more than other colors-it travels as shorter, smaller light waves. The higher the Kelvins, the more blue light is visible. The International Dark Sky Association officially recommends lights to be 3000 Kelvins or less. Some of the reasons they list include the harsh glare high Kelvin lighting can create, the suppression of natural melatonin production in the brain (part of the reason smartphones now have low Kelvin night modes), and the conservation of nightscapes/nocturnal wildlife. Some places, like southern Arizona, are aware of these factors, as well as others, and require all outdoor lights to be 3000 Kelvins or below.
The IDA Kelvin Article: https://www.darksky.org/our-work/lighting/lighting-for-citizens/3k/
NASA Article on Ocean Color: https://science.nasa.gov/earth-science/oceanography/living-ocean/ocean-color
Solar Panels/Photovoltaics Explained
Photovoltaics is the direct conversion of light into electricity at the atomic level. Listed below is a NASA published article describing the basics of photovoltaics which can be a great reference. They also cover the future of photovoltaics, “Multi-junction” solar cells, which capture a broader spectrum of the rays emitted by the sun. This technology could create roughly twice the efficiency of current solar tech.
All of our certifications are available upon request. Some may not be familiar with the international certifications Soltech lights have. We are currently CE rated, which stands for “Conformité Européene”. This means we conform to health, safety, and environmental protection standards for products sold within the European Economic Area. We are IP65 rated, which is a ranking for how much external particles our lights can resist. The 6 in the 65 certifies we are “protected against dust that may harm equipment” and the 5 certifies the light is “protected against water spray from all directions”. We are windspeed level 12 tested and we also have UN38.3 and MSDS certifications which are international battery safety standards.
Necessary Amount of Light Explained
Soltech has a full team of technical project managers that can recommend a lighting plan given the specifications of a certain space. We use IES (Illumination Engineering Society) files with data on how our lights act in the dark, and combine it via specialized software with project specs to mock up exactly how our lights would look in your space. Generally we can recommend lights based off of the type of application. Our Sunlike range is the most versatile, but our Cegonia is best for casting light over a wide surface area in lots. Our powerful Satelis range is strong enough to be mounted up to 125 feet apart, and is mostly used for freeways. Below, there is a height and spacing guide that can help you get a quick idea about what you need based on the height off the ground lights and the distance between poles.
Low Total Cost Explained
Some might compare the sticker price of regular outdoor light, LED outdoor lights, and solar lights to our a municipal-grade solar lights, and not understand the value behind the fluctuations. But up front sticker price is not what the lights will eventually end up costing. Soltech has industry leading low total cost, listed below.
High Performance, Even In The Rain
Our lights last for seven full nights given only one day of sun because our efficiency is at an industry-leading 200 Lumens per Watt. The lights aren’t weaker towards the end of the week because the battery uses a segmented reserve system with a programmable light output. Even if there is only two half days of sun in half a month, the light will still perform. If the lights were put in a dark room for any longer, they would shut off once their total charge would reach below 10%. The City of Detroit bought many of our lights for a public park early in 2018, and they have just ordered another sizable shipment. Even Detroit winters do not compromise the performance of Soltech Solar Lights because of ambient light collection and efficient operation. The seven full nights of light offered by our lineup is under total darkness for seven full days-in reality, day will never be pitch black, even the rainiest days have ambient light. This means the actual working performance of the lights is in a different class than other solar lights, a cut above.