Not all solar lighting systems are created equal. Each has their own unique qualities and benefits. Understanding system differences along with your own requirements will allow you to build the perfect solar lighting system solution for your project while working with your designer. The three strategies of designing the perfect solar lighting system below will help you best determine what you need and how to achieve the best outcome.
1. Know how much light is required
Does your lighting project require IES Standard light levels? Or is there more requirements in your area? Talking to local code enforcement will help you determine if there are any guidelines you must follow or if there is no set numbers to the type of lighting required. IES Standards are a good guideline for most projects; however, different municipalities have different variations to the standards that they can enforce.
If you are in an area where IES Standards are okay, letting your lighting designer know this information will help them work to determine what type of light, distribution and brightness will be required for your project. Providing the designer with additional information, such as the length of the roadway, size of the parking lot, dimensions of the area, etc, will allow for the designer to provide additional information such as a light layout to show uniformity and light levels across an entire project.
2. Understand system constraints
Depending on the installation area and system requirements, some projects are just more feasible than others. A 70 Watt LED fixture operating all night will require one size of solar power assembly to operate the fixture from dusk to dawn in one location, but a completely different size in another. This is due to the solar radiance that is available in any specific location. Instead of just looking at a certain wattage, looking at light level requirements should be the first step to determine what is required for the project. Decreasing the wattage and adding a pole or two in many cases can actually create a more feasible project in the end and still provide the correct light levels.
Storage requirements also vary from one location to the next. From the Tennessee / Kentucky border south, five nights autonomy is adequate for backup power; however, the further north you go, the more storage the system will require. Also, look at local weather patterns. How many days of cloudy / overcast weather does the area typically receive? Understanding this along with how cold an area gets will help determine how much is adequate for backup storage to ensure system operation and longevity.
3. Determine operation schedules
Solar lighting systems can be provided with multiple operation schedules to meet the needs of the project. Determining the operation schedule when initially designing the project will help ensure that the system will operate as needed and is sized accordingly. Dusk to dawn operation is the most popular configuration; however, split time and dimming helps reduce the requirements of the solar allowing for smaller power assemblies. Do not just assume that the fixtures will operate dusk to dawn, full intensity, unless this has been determined at initial system design. Many companies use control electronics that override the system to provide adaptive lighting controls that are outside the original design requirements. Instead, work with the design team to understand the exact controls being used for the system being installed. If dimming, split time, motion, or any other operation profiles are allowed, make sure to specify this initially.
Understanding these three important design requirements before getting a final system design will ensure that your system will operate the way it is required with the correct lighting levels, uniformity, operation and sizing for the specific project. One size does not fit all in any solar application, lighting or power, and should be specific to each individual project. This ensures you will never be left in the dark.