A Good Guide to Off-Grid Solar LED Lighting Systems

In the enlightenment history of mankind, in the beginning there was only the Sun. That light was the only source of light for millions of years. Then we harnessed the power of fire to produce light at night. This we provided a way to get enlightened instead of the sun using fires and candles.

Over the last hundred years or so, we have found a way to produce another form of light using electricity. During the industrial revolution, we could manufacture all kinds of things. We have electrified our homes, offices and many outdoor spaces to power lighting, appliances and many other applications.

We still use much of the same technology today; however, efforts to find solutions or help current global warming problems due to rural areas and lack of electricity in a region lead us to renewable energy sources for many applications such as energy production. Additionally, off-grid solar lighting systems are gaining popularity as they can provide a green solution for many outdoor lighting installations.

Let's take an in-depth look at what sunlight is, some of the pros and cons of a solar system, and some other cool things about sunlight. This will give you an in-depth look at exactly what sunlight is and how you can use an off grid solar LED lighting system for your next installation.

Solar LED Lighting Terminology

There are many terms in the lighting industry. Below is a list of terms and their basic definitions to ensure you're not missing out when talking to someone in the industry, as these terms are more common in the solar and lighting industries.


A measurable measure of the power consumed. For example, if you have a 15-watt lamp, it consumes 15 watts per hour. The lower the wattage, the less energy is used and LEDs provide the most light with the lowest wattage required. Watts are not equal to the amount of light, but only to the energy consumed.


A lumen is the amount of light given off at a solid angle by a light source that radiates equally in all directions. Basically, the amount of light given off by a lamp/bulb is measured in lumens. Not all fixtures or lamps are created equal and each setup has a different lumen output.


A foot-candle is a unit of illumination given off by a light source one square foot away. This measurement is used to determine how much light is available at a given point, typically at ground level. For example, a foot-candle represents the amount of light from a single candle in a one-square-foot area one foot away from the candle.

Kelvin Kº (colors of light)

Kelvin refers to the colors of light and is measured in degrees. You can reach any color from bright white light at 6500K to softer yellow light at 3000K, and even dark yellow for desired applications below 2500K. In simpler terms, most kitchens and office spaces are lit with whiter light, closer to the sun, where living spaces can use warmer colors.

Color Interpretation Index (CRI)

CRI is a way to evaluate how light sources make objects appear. Any CRI greater than 80 has good color characteristics and is closest to the light provided by the sun. A low CRI makes it difficult for the eyes to see details such as colors.

Mounting height

Mounting height is the height at which the luminaire or lamp is mounted. In most cases, a fixture's mounting height is chosen arbitrarily as it plays a large role in the distribution of light and the number of foot candles it can provide. For example, the closer to the ground, the less scatter there is; however, the higher the installation height, the lower the foot candles will be below the luminaire.


This is the control of light distribution from a luminaire, sometimes controlled by aiming the light or using it in the form of a shield to direct the light in a certain way, creating various distribution patterns. This also ensures that there is no interruption when the light is radiated in all directions, half cut off when the light propagates below 90 degrees, and cut off when less than 2.5% of the light is allowed to exit the luminaire above 90 degrees.


Ampere is a unit of measurement that determines the amount of electric charge passing through a point in an electrical circuit. This is typically used to determine the amount of power produced by a solar panel to charge the battery and how much power can be stored in a battery. For example, an 85 Watt panel generates a charge of 5 amps per hour and charges an 82 amp battery that holds up to 82 amps at a time. In this example, an 85-Watt panel takes 16.4 hours to charge an 82 Amp-hour battery before it runs out.


Current indicates the flow of electrical energy. Solar generates DC (Direct Current) power and can directly drive DC powered devices without using an AC power source. Like most electronics, LEDs naturally run from DC current and do not require an inverter or ballast to generate an AC current for these fixtures. This is the most efficient way to power a solar light fixture or most small electronic devices such as cameras.


The number of days of storage an off-grid system has during bad weather or low sun. This can be determined by calculating the number of amps used per day divided by the number of amps in a battery backup system. A minimum of autonomy should be ensured to ensure that the system functions as expected on a daily basis and that system failures are avoided.

Discharge Depth

The amount of power drawn from a battery; i.e. if the battery is fully charged, the depth of discharge is 0%, if 25% is used to illuminate a fixture, the depth of discharge is 25%, and so on. Depending on the battery technology, the depth of discharge varies. Making sure you don't over-deplete the battery beyond the optimum depth of discharge ensures a long lifespan.

Benefit from Solar Energy

Sunlight refers to the amount of solar radiation that strikes a horizontal surface over a given period of time for a given location. This varies greatly from place to place, from less than 1 sun hour in some northern climates to as much as 5 in some deserts and equatorial regions. The amount of solar availability in a particular location determines how much solar energy is required to run a load, typically in Watts or Amps.


One of the things we focus on is the CRI – Color Interpretation Index. This is the quantitative measurement used to determine the color of a lamp's light. The higher the CRI, the closer the light is to accurate sunlight, and you'll get good vision when trying to see details. Different CRIs may be used in different environments for different reasons. Here are a few of them:

Indoor Lighting

Most indoor home lighting should provide softer, warmer light, typically around 3200 to 4500 Kelvin, and have a CRI of about 60. While this provides good lighting levels, it is not too bright for reading or illuminating the surrounding area if there is an indoor office. With a range of 5000 Kelvin to 6500 Kelvin and a CRI of 80 or higher, it is typically used in an office environment to mimic sunlight, especially those that do not receive sunlight from windows or skylights.

Outdoor Lighting

For outdoor lighting, from 4500 Kelvin to 6500 Kelvin, staying closer to sunlight and for night lighting a CRI of about 70-80 provides the best vision. Also, the bright white lighting outside at night can make you see better if you drop into more detail of distant objects. This is important for the safety of areas around homes and businesses.

There are situations such as coastal and wildlife friendly areas that require the light to be at a much lower CRI, for example around 30-40, due to the long wavelengths of light. The longer wavelength still allows humans to see, but animals, especially sea turtles and migratory birds, typically do not notice these lights.

Different Lighting Colors for Different Tasks

A study on the Effects of LED Color Temperature on Office Workers shows that people prefer a warmer light indoors when engaging in relaxing activities; however, it shows that they want a higher CRI when engaged in task-specific activities such as reading or office work. Also, participants in these studies reported feeling less tired and more eye strain in areas with brighter, whiter light than in warmer light.

In general, lighting CRI in different areas can affect your productivity and visibility. Choosing the appropriate light color can affect how you see as well as your energy levels.

What is Solar Powered Lighting?

Solar lighting can be thought of in many different ways. It stores sunlight directly as it enters through a window or skylight, and captures the sunlight for use at another time.

Each of these ways of harnessing the sun for our lighting needs has different variations, allowing you to find the perfect solution for your needs. For example, if you are illuminating an area within a house or building and you are looking for a natural way to achieve it, sunlight will be the best option. If you are trying to provide light to an outdoor area at night, off-grid solar lighting systems will still be the best option.

Pros and Cons of Solar LED Lighting

Solar powered lights have become very popular over the past decade as fossil fuels have become more expensive. As a result, more companies and people are looking for ways to offer a sustainable/green alternative. As a result, prices for solar LED lighting systems have fallen over the past decade as solar power has become more popular and production costs have fallen sharply.

Overall, solar light has many advantages such as no electricity bill and simplicity of installation, but are solar powered lights good enough to replace our off-grid lights?

Here are some key points about solar lighting:

Pros of Solar LED Lighting:

  • Solar lights are a greener and renewable option because they do not run on electricity and therefore do not require standard electrical power.
  • Since all wiring is placed on the same pole, solar powered lights are easily installed and moved to the desired location.
  • Solar powered lights provide a soft light as power is limited and LEDs operate more efficiently with 12 or 24 VDC power than AC power
  • Each solar powered light works independently of the next (except for certain applications such as signs, billboards, etc.).
  • Working with the low voltage provided by solar panels is safe and does not have the same dangers as AC lighting.
  • Directional illuminated LEDs provide more light where it is needed and less where it is not needed.
  • Fixture styles are versatile for many different applications and architectural requirements.

Cons of Solar LED Lighting:

  • Some cheaper units can be flimsy and not last as long as commercially designed systems; Do your research before you buy.
  • There is no solar power at night, so a battery storage is needed to run the lights.
  • Depending on the geographical location, the size of the solar panels, larger sizes may be needed for the same power generation due to the available sunlight in winter.

The key to a good outdoor solar lighting system is to get the maximum amount of light, or lumens, for the minimum electricity or Watts required. This is difficult as some lights illuminate as a byproduct of heat and use a lot of electricity relative to the amount of light produced (usually Metal Halide and Sodium lights). Having a lighting scheme completed by a lighting engineer is the best way to ensure any installed light meets lighting requirements.

Usage Areas of Solar LED Lighting Systems

Solar solar LED lighting can be used for many applications, from a single small LED light to be illuminated for a year, to large overhead lights for roads and parking lots. Each system must be designed for the specific application and to provide the required lighting levels. Good research on project implementation, design work and selecting the final product will ensure that the end user gets the type of system that fits their needs exactly.
Other area lighting applications use larger fixtures such as floodlight fixtures. These are much more powerful systems and can be used in parking lots, streets, perimeters, etc. Provides wide area illumination for Each of these systems has its own solar assembly to power the luminaire and operates as specified by the end user. These systems still need to be properly sized to ensure they are reliable and provide a long lifespan.

There is a significant amount of customization options on these larger projects, and discussing the needs of the project with the lighting designer will ensure that the light set for the project will meet the needs perfectly. Different distributions can be used for different lighting applications to customize the lighting system so that lighting can be installed where it is needed and not wasted. In addition, the control options provide dimming options that can be considered, or even specific lighting needs, such as sunset to dawn or specific timing. Before specifying any custom control electronics, always make sure the lighting company knows the final project requirements.

The next time you want to illuminate an area and need a solar option, consult Depar Energy, a solar lighting specialist, to help you design the perfect system for your specific needs. From big to small, solar LED lighting can be a great choice.