When planning solar lighting and determining the maximum possible luminous flux at a specific location, it is important that the parameters energy yield, energy storage, and energy consumption are well-coordinated and considered as a complete system. Below is an overview of all the factors to consider. Our Aeto Solar online configurator assists you in quickly and easily determining all relevant data for your specific project.
Energy yield
The energy yield of a solar luminare depends on the location, the number of sunlight hours, the orientation of the luminare head, shading, and photovoltaic performance.
Location
The geographic location determines how much solar energy is available. The closer you are to the equator, the more consistent the day lengths are, making the energy yield more similar in both summer and winter. The farther you move north or south from the equator, the greater the differences between summer and winter become.
Sunlight hours
The total number of daily sunlight hours throughout the year determines the amount of energy available for solar lighting. More sunlight hours means more energy. We obtain the average number of sunlight hours at the location as well as other parameters, such as global horizontal irradiance, from the Photovoltaic Geographic Information System (PVGIS), provided by the EU. Depending on the location, we have access to data history of up to 20 years.
Orientation
The orientation of the luminare also impacts the energy yield. In the Northern Hemisphere, there is minimal sunlight coming from the north, while in the Southern Hemisphere, sunlight from the south is minimal. Solar luminaires with vertically integrated solar units are easier to plan because the PV modules always obtain energy due to their 360° configuration.
Shading
Shading of the solar unit by trees or buildings also reduces the energy yield. A corresponding shading reduction factor is integrated into our Aeto Solar configurator.
Objects in the South & West & East — Very heavily shaded, 40% yield
Objects in the South & (West or East) — Heavily shaded, 50% yield
Object in the South — Moderately shaded, 65% yield
Object in the West or East — Lightly shaded, 80% yield
Photovoltaic performance
The greater the PV performance, the more energy can be generated, stored, and then used for lighting purposes. The solar unit of Aeto is therefore available in 4 heights: 1 m, 2 m, 3 m, and 4 m. The peak performance, or the highest output that a solar module can generate under optimal conditions, ranges from 84 Wp to 420 Wp.
Peak performance with one luminare head
1 m solar unit — 84 Wp
2 m solar unit — 196 Wp
3 m solar unit — 308 Wp
4 m solar unit — 420 Wp
Peak performance with two luminare heads
1 m solar unit —
2 m solar unit — 168 Wp
3 m solar unit — 280 Wp
4 m solar unit — 392 Wp
Energy storage
The generated energy yield is stored in the battery and is available for the lighting task.
Battery capacity
The storage capacity of the battery limits the maximum amount of energy that can be stored. For Aeto, we offer two battery sizes: 312 Wh and 624 Wh. NiMH batteries are used, which are particularly temperature-stable and charge even in poor weather conditions. The battery does not need to be buried in the ground but is integrated directly below the luminare, making the luminaire flood-resistant. The short distance between the battery and the controller also minimizes energy loss due to cables.
Energy Usage
The available light output, or luminous flux of our luminare, depends on the chosen lighting profile, light distribution, the use of a motion sensor, and the light colour. Essentially, energy consumption refers to the energy used for the LED illumination. Since the available amount of energy is a fixed value (location-specific and battery-dependent), this energy must be allocated accordingly. How can you calculate the maximum LED power? Simply divide the available energy [Wh] by the lighting duration [h]. For example, if we have 100 Wh of usable energy, it can be used as 10 W for 10 hours or as 20 W for 5 hours.
Lighting profiles
The maximum available energy depends on the location and battery size. This can then be divided using our predefined lighting profiles. The energy consumption of lighting is mainly influenced by the duration and the intensity of the illumination. Simply put, lighting can either be very bright for a short period of time or less bright for a longer period of time, with both scenarios consuming the same amount of energy in watt-hours. Aeto offers 6 predefined lighting profiles to meet different project requirements. The continuous profiles are suitable for lighting throughout the entire night. The temporary lighting profiles are particularly useful in areas where complete darkness is desired at night.
Lighting profiles for Aeto Pro
Temporary Brightness #1
Temporary Brightness #2
Temporary Brightness #3
Continuous Light #1
Continuous Light #2
Continuous Light #3
Lighting profiles for Aeto Basic
Temporary Brightness #1
Temporary Brightness #2
Temporary Brightness #3
Continuous Light #1
Continuous Light #2
Continuous Light #3
Motion sensor
Some of the previously mentioned lighting profiles include a scene where the luminare is switched off at night in order to protect the environment. You can optionally integrate a motion sensor to simultaneously address safety and orientation needs for people during this period. It is important to note that the frequency with which a motion sensor is activated will naturally affect the system's energy consumption.
Low Activity
Up to 6 triggers per hour
Medium Activity
up to 15 triggers per hour
High Activity
Up to 30 triggers per hour
Light colour
Finally, the available luminous flux of the solar luminare is also influenced by the choice of colour temperature. Different colour temperatures have varying efficiency levels. LEDs with cooler colour temperatures are more efficient. When selecting the light colour, it should be noted that warmer light colours have less of a negative influence on nocturnal creatures, which can aid to the protection of their habitat. Aeto is available in the colour temperatures of 2200, 2700, 3000, and 4000 Kelvin.
