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Everything To Know About Solar Signages

solar street signage

What are solar sign lights?

Solar sign lights are lights used for the illumination of different signboards. Development and advancement in LED lights have made a way for the application of solar sign lights at a wider scale.

What makes this combo more interesting? The low power consumption of LED, high illuminating properties, low return of rate of solar PV, renewable solar energy, and green solar energy.

High-Intensity Discharge (HID) lamps, often High-Pressure Sodium (HPS) lamps are these days are being replaced by low power Light Emitting Diode (LED) lamps powered by solar PV.

Where Solar Lights are installed?

In solar lighting technology, the use of LED solar lighting has gained a lot of attention these days. These lights are being used for outdoor lightings such as garden lighting, street lighting, highway signals, and traffic signals as well as for interior lighting.

These solar lights have replaced bulbs thus reducing the energy consumption as well as cost.

Due to its low cost and low energy consumption, it has been widely adopted by solar energy as well as the green energy industry.

Lights used for commercial signs are costly due to many reasons including the cost of underground wiring, cost of system connection, taxation on grid electricity, and losses during transmission.

This results in hundreds and sometimes thousands of dollars paid by businessmen for commercial signs.

The use of solar lights for these signs helps the businessman to get rid of all these costs as solar power lights are under a compact standalone system in which all system requirements are present.

In rural areas, the cost of commercial signs rises further as remote areas are located far away from gird. Thus solar power lights are the best solution for illuminating the signs, billboards, and signals.

Figure 1: Solar Traffic Light

Components of system:

Typical system layout has been shown in the following figure:

Figure 2: Components of a solar traffic light system

From where they get power:

A solar system is a type of electronic gadget that absorbs sunlight and transforms it into electricity immediately. It has the size of an adult palm, a blue tint, and an oval form. Solar cells are frequently combined to form a bigger device known as a solar system.

Solar cells, like cells, are intended to produce electricity. Solar panels, on the other hand, instead of using chemicals to generate power, use sunshine to do it.

They’re also known as solar cells (PV) since they generate power from sunlight (“photo” means light in Greek). Light is made up of tiny particles known as photons.

The sun’s rays seem like a dazzling yellow fire of billions upon billions of flying photons. These active photons from the road are captured by the solar system and converted into electronic currents or transitions.

Because each cell produces different energy voltages, the solar collector’s job is to convert the energy generated by several cells into a usable amount of energy and voltage.

Almost every solar cell nowadays is composed up of silicon fragments (one of the most frequent soils a chemical element found in sand), but as we’ll see, there are a variety of different materials. It can also be used for other purposes (or rather).

When the sun shines on the solar system, the solar cell’s energy causes silicon electrons to travel through an electric circuit, resulting in electricity being available everywhere.

Figure 3: Working of a solar cell

How Much Power they produce:

Each solar cell can only produce so much electricity. Solar cells are made up of a large number of solar cells connected in series to form a solar module. The solar panels are the box made up of solar cells and wires that are weatherproofed.

The modules are then connected to the solar system. A 12-watt panel (module) contains 36 photovoltaic cells in series, whereas a 72 V panel (module) has 72 solar cells in series.

The modules are connected in series and parallel, specified as a photovoltaic field to produce the desired voltage and current.

The energy required for the illumination of LED solar light comes from solar panels.

The 100W solar panel is enough to charge the battery and power the signboards. It produces 12V and 5.56A currents. The cost of a 100W panel at the rate of $0.4/Watt is $40.

Figure 4: PV Module

LED (low power consumption) for illumination of sign boards:

A lot of advancements have been made in LED technology recently. The white LED seems to be the correct selection for use in solar power LED for signboards. 10W LED can be used for lighting signboards. It costs $6.99.

Figure 5: LED light

Does it Need battery backup:

Solar is not available all the time. Solar is available during day time only. Thus there should be some storage backup that may store surplus energy when production from the solar panels during daytime is excess than the energy consumption of Solar LED while this stored energy will be used during night time.

Without a storage system, there will be no energy available for solar LED during nighttime. Furthermore, this surplus energy will go wasted and will be lost of money as well [10].

A battery is used as a storage device in solar signage and is controlled with the help of a charge controller. The cost of 12V and 7.2 AH batteries is $15.63.

Figure 6: Battery system

Who protects battery from overcharging and undercharging?

Charge controllers are used to regulating the voltage and current produced from the solar panels and control the battery charging.

They help to protect the battery from overcharging and backflow of current during nighttime. Without a charge controller, the storage device’s lifetime will be affected due to overcharging.

The charge controller forwards the voltage produced from the solar panel to the battery.

During low irradiance voltage produced from the solar panel is low, then the charge controller helps to achieve the voltage equal to the required charging voltage by converting amperes into voltage.

While during peak sunshine hours, the charge controller converts the high voltage into ampere and charges the battery at a constant voltage. The cost of a 10A 12-24V charge controller is $27.98.

Figure 7: Charge controller

What is their Basic Working Principle:

The key part of solar signage is the solar panel. It captures sunlight, converts it into electricity, and makes it available for powering the signage.

The power produced from the solar panel is received by the charge controller. As solar panels produce power depending upon the availability and amount of sunlight thus the output power from the solar panels is never stable rather it keeps on fluctuating.

Thus charge controller is used to getting stabilized output power which is used to charge the battery. The battery is connected with signboards that get power from the battery.

Figure 8: working of solar street light

Estimated System Cost:

Table 1:

ItemCost in $
Solar Panel$40
Charge Controller$27.98
Grand Total$ 90.6

Defining of packages:

The packages have been defined based on the power consumption of lamps. The package will be selected based on the nature and size of the road for which the solar street light system is being designed.

Table 2: Types of Solar Street Light System:

Do solar signages perform better in winter?

Many people ask that why solar signage and lights underperform in winter. Also, they have been found to misguide other people about the reliability of solar signage.

But the story is entirely different. Yeah, they underperform in winter but this issue is not too hard to be solved. In winter, the intensity of solar energy starts decreasing, and sometimes at some places, we get no or very little sunlight.

Thus in winter, these lights do not perform well. But this is not an issue that can’t be solved.

As in winter, all days are not foggy days, we also get a lot of sunny days. So, by using the batteries having long discharge time we can deal with this issue.

With an extra cost of £10 for a Li-ion battery set, the performance of solar lights can be enhanced.

Dawn to dusk illumination:

Now let’s discuss the illumination of solar signage from dawn to dusk in winter.

If we talk about that signage those have battery backup then yes, they will be illuminated from dawn to dusk but in case of no battery backup, they may not be illuminated at dawn and dusk time due to low sunlight intensity at dawn and dusk time.

Can solar Signage be always ‘ON?’

It can be always ON but never should be claimed otherwise customers believe that if it gets turn OFF then it’s no more reliable. Let me tell you something.

The availability of solar energy for signage depends upon energy generation from the solar panels as well as storage system capacity.

No matter how large capacity we have for storage and generation, even though we can ensure 100% availability.

Especially in the rainy season, if cloudy days and rainy days come consecutive and get prolong then what?

Stored capacity will be gone and no sunlight will be available for battery charging. Thus, solar signage can be always turned ON but they are some exceptional cases that we must keep in our mind. 

Will charging in winter will be faster?

Let’s be clear first on parameters that affect the charging of the battery. The battery charging depends upon 3 primary parameters:

  • Charging voltage
  • Charging current
  • Battery temperature.

No doubt in winter, the temperature is low which not only reduces the battery losses but also increases the output voltage of the solar panel.

But charging time is the function of the current given to the battery. In winter, the sunlight intensity is low, so the current from the solar panels is also low. Low current means longer it will take to charge the battery.

Can Solar Signage work without sun?

So, this seems a little bit unrealistic but the answer is yes. Solar signage can work without the sun.

You might be thinking that how it is possible or is it any sort of trick. Let’s not make you wait and reveal the trick.

The solar panel does not use direct sunlight rather It can use diffuse light or reflected light from any celestial body. During cloudy days, there is no direct sunlight but diffuse radiations are available.

Similarly, on full moon night or any night when we have enough light coming from the moon, the solar panel will charge the light.

Of course, the output during the cloudy days will be quite low and on full moon night will be very minimum.

Color options and accessories?

They assign the right of way to road users by the use of lights in standard colors (red – amber/yellow-green), using a universal color code.

There is no additional accessory is required for its operation. All components are required for its installation and these are standard and must require.

Advantages and Dis-advantages:

The advantages and disadvantages of using solar-powered signage have been described below:


  • No Wiring cost
  • No transmission loss
  • No need of electric grid
  • Solar energy is renewable
  • Very reliable having life time of 25 years.
  • Solar energy is renewable and green source of energy.
  • Solar signage supports initiative taken for sustainability
  • No monthly electricity bills
  • Less expensive than conventional signage.
  • No carbon emissions
  • Immune to power outages

Restrictions / Drawbacks:

  • Security of solar systems especially in remote areas
  • Periodic replacement of battery after 6-8 years.
  • Dust and soil deposited on panels reduce the power production.
  • In rainy days and cloudy days, if they prolong then there will be no sunlight to charge the battery then signage will get turned OFF.
  • Sunlight intensity is not same everywhere so the system cost may vary with geographical location.