6 Key Solar Lighting System Design Questions

We receive a tremendous amount of phone calls and emails expressing interest in our high performance off grid solar powered lighting systems. In order for our solar lighting specialists to provide a solar lighting system design and quote that will best meet the customer's needs, we need to gather additional information by posing a series of project-related questions.

Answers to these questions offer the information needed to provide a comprehensive solar lighting system design and quote specifically designed to meet customers' lighting needs. Let’s take a look at these questions and see why each of them is so important.

Project Location

Question 1 is always, where is the project located? This provides the solar lighting specialist with so much valuable data. It gives us the ability to determine the availability of sun, the length of the night, etc. This is the most basic part of sizing up a solar system.

An exact address allows the specialist to be able to assess the area that needs illumination and see any possible obstacles that could be in the area. The exact address allows one to do a visual assessment of the site using Google Earth or by allowing for a site visit by a local lighting rep. It also allows the lighting designer to determine if there are any obstacles, such as trees or buildings for shade, medians, entrances, exits, and so much more.

Fixture Style

What style of fixture does the customer want? Obviously, you wouldn’t put a small flood for a roadway project, and a decorative acorn fixture doesn’t do well for a sign, but having a general idea of the style of fixture the customer wants is important.

Some projects require specific fixtures to do a job – such as a large floodlight to shine a light far from the pole. Others require a more aesthetically pleasing fixture, such as the SolarUrban, for example. Maybe you need a ground flood for a sign – the SolarRFL is perfect for that. Depending on the needs of the project, the light fixture style can vary.

Getting a good understanding of the project lighting needs and the type of fixtures a company has offered allows you to better choose the light needed. Another thing to consider is the light distribution pattern, as these vary by fixture type. Knowing which fixture type will work best for a project allows you to pick out which fixture will work best for a specific solar lighting application.

Light Level Requirements

Getting clear on the light level requirements is key to ensuring you provide plenty of illumination for the lighting zone of the project that is going to be installed. Each lighting zone has its own requirements, and the more ambient light in the area, the brighter the light will need to be to provide the corresponding light output.

My favorite analogy for this is lighting a candle in a dark room. If you have a completely dark room and you light one candle, it produces a LOT of light. However, if you were to turn on a couple of lamps in the room, that one candle doesn’t produce quite as much light. Understanding light level requirements is quite similar.

If you have a street, parking lot, sign, pathway, etc. in a dark area without a lot of other lights around, using a lower level illumination will provide plenty of light for people to see clearly. If you have an area that has a lot of ambient light, say like a park that is surrounded by well-lit roadways and buildings, you will need a higher light output to produce a noticeable light.

If none of this is known, the project installation location can help the lighting designer understand what is in the nearby area. It can also help by just having a lighting objective, such as illuminating a parking lot with 4 ADA parking spaces that may need extra light to ensure it meets minimum ADA requirements.

Area of Illumination

The next key piece of information is the area of illumination. The area of illumination tells the person designing the lighting project how large of an area requires to have light. This can be as simple as a 5 foot by 8 foot sign, a 300 foot by 100 foot parking lot, 2 miles of a two-lane roadway, or a quarter-mile footpath. Every one of those projects would require completely different solar lighting system designs.

Sometimes, just knowing the area that needs to be illuminated isn’t quite enough information to provide the correct design. In these cases, an AutoCAD file may be requested. This provides information to the designer about any obstacles that are in the area, where light placement needs to be focused and much more.

If an AutoCAD file isn’t available, Google Earth can be the next best tool to use when designing a light. Google Earth Pro allows you to not only see the site, but also the historical data, take measurements, see things in 3D, and so much more.

Finally, there is the ability to work on a rough sketch. This is the least preferred method but still can give some details and allow for the overall understanding of the project to be realized.

System Operation

The next design question to focus on is the system operation. Do the lights require full output all night, from dusk to dawn? If so, make sure that is very clear when you are speaking to your lighting designer. Many companies state that their system provides all-night illumination, but then in the fine print, state that the system operates at a reduced output, usually around 10-30% for the entire night, and only full output when motion is detected. If maintained illumination is required, state that and make sure it is well understood, or you could be left in the dark.

If sustained light levels are not required, many different operation schedules can accommodate most lighting applications. These include:

• Dusk to dawn at a reduced output with motion to full intensity
• Dusk to dawn off and motion on
• Dusk for a set period of time, say 6 hours, and then off for the remainder of the night
• Dusk for a set period of time, off, and then on again a set period of time before dawn
• Occupancy sensors or spring-loaded timers

These are the most popular ways to operate a solar lighting system. Each of these has its own pros and cons, and working with your lighting designer will help you determine the best operation profile for your project.

There are many times when the operation profile is not achievable and needs to be adjusted. For example, solar is not capable to operate a 200 Watt fixture from dusk to dawn; however, it can for a couple of hours. Either the load or the operation must be adapted to fit into a solar solution. Not budging on either will ensure you have a project that is way outside the budget scope of the project.

Poles

The final question is about the poles for the system. Overhead lights have everything located on a single pole and it is one to three feet at minimum higher than the fixture mounting height. Remote solar applications can have the solar system low to the ground or up high, depending on the service needs and aesthetics of the area.

The first thing to answer is how high the solar needs to be. Once this question is answered, the next is what is the preferred mounting – direct embedded or anchor bolt.

A direct embedded pole has the pole dug down about 4-8’ and can be made from metal, concrete, or wood. These are used in many cases, such as where the solar power assembly is remote and would require some wiring to occur underground. They can also be used as a lower-cost option.

An anchor base pole requires a foundation to be poured, taking into account the placement of anchor bolts to the orientation of the system and using the proper base plate dimensions. These systems can have either the base formed on-site or done by a company such as Precast which forms bases per the structural requirements of the setup.

The precast bases can also be good for projects where there needs to be part of the base above grade. Many parking lot applications have the pole bases above grade around 3 feet to ensure that they can take an impact by a vehicle without disturbing the light pole. They are also good for applications that are temporary and will need the system to move in the future.

Finally, there are auger foundations. This setup combines a direct embedded option with an anchor base option. It allows the pole base to be screwed into the ground by using an auger and then the pole anchors directly to this auger piece. This type of pole system is great for temporary setups as well as allowing for a quick installation.

All of these questions play an important role in helping the solar lighting designer set up the system that best works for your project. Every piece of data provides another stepping stone on the path to a successful project. Pay attention and provide all the needed data to the lighting designer during the beginning design stages of the project.

Bonus Questions

There are other things to consider when setting up a system design. These questions may apply to all applications or are application specific. Let’s take a look at those questions and see if they apply to your next project:

System Finish

The finish of the system can change depending on the aesthetics of the project requirements. Does the system need a specific finish, or is raw aluminum and galvanized steel okay? If there is a specific finish, is it a standard finish provided by the solar lighting company? Or does it require a specific RAL?

A raw / galvanized finish will be the least costly, followed by a standard finish and then a specific RAL. The more difficult the process, the more costly the finish will be. To keep costs down, most people typically opt for the standard silver look of raw aluminum and galvanized steel or upgrade to a standard finish.

Sign Projects

For a solar sign lighting project, there are a couple of specific questions. These include:

• What are the dimensions of the sign?
• Is the sign single or double-faced?
• Does the sign require floods or does it have LEDs inside a cabinet?
  • If there are LEDs inside the cabinet – the specifications need to be provided
• Any other requirements such as landscape lighting or mounting restrictions.

Flood applications are much lower cost than internal illumination applications in most cases. A flood-illuminated sign requires somewhere between 8 and 50 Watts of load; whereas internal illumination setups start at 25 Watts usually and can go up to 100 Watts or more. Working with your lighting specialist can help get the system sized up properly and to help fit within your budget.

Flagpole Projects

For a solar flagpole project, the questions are simple.

• How tall is the flagpole?
• How large is the flag?
• Where does the solar need to be mounted?

Sometimes the solar can be mounted directly to the flagpole itself, but in some cases, it requires a remote solar power assembly. Both of these options provide their own benefits depending on the installation location.

Bus Stop / Shelter Projects

There are a few things that need to be configured with a solar bus stop or shelter project. If a bus stop project is without a structure, a pole-mounted system is provided. If a bus shelter structure is on-site, then the project manager should provide details on the structure and how they expect the solar panel, battery assembly, and light fixture to be mounted and incorporated into the structure.

Off-Grid Power Projects

The final bonus section is questions for off-grid solar power projects. With these projects, the designer needs to completely understand what the solar is required to power, for how long, and all aspects of the operation. This allows the designer to figure out the load to ensure that the system is set up to be reliable. Leaving even the smallest detail out can cause the system to not be sized correctly and possibly have failures down the line, especially during the winter months.

All additional details that can be provided for a project will help the engineers and solar specialists ensure that the project is sized accordingly and meets the needs of the project. Providing as much information as possible at the beginning of the project will help speed the process along and get your project worked up quickly.

Have a project you want to get quoted? Send us the details today and we will get working for you. We are excited to work with you to find a cost-feasible solution for your next solar lighting project.