> Quick answer: To maximize solar lamp runtime during Romania’s 15-hour December nights, use PIR motion sensors set to short activation periods (30–60 seconds) and enable dusk-to-dawn mode with dynamic dimming. This combination reduces power consumption when no motion is detected [4] and adjusts illumination based on seasonal night length [1][3][6][7][9][10][12][15], extending battery life without sacrificing safety.
Solar lamps are a sustainable, cost-effective lighting solution—especially in regions with long winter nights like Romania. With December nights lasting up to 15 hours, maximizing runtime is essential. The key lies in optimizing two core control systems: PIR motion sensors and dusk-to-dawn modes. When properly configured, these features can extend battery life significantly while maintaining safety and visibility.
PIR Motion Sensors: Energy-Saving Illumination on Demand
PIR (Passive Infrared) sensors detect body heat from moving objects, turning the lamp on only when needed [4]. This dynamic control ensures energy is not wasted during extended periods of inactivity. When no motion is detected, the lamp operates at a lower power setting [4], conserving energy for critical times. Once motion is sensed, it switches to full power for immediate visibility [4], then reverts to standby after a set duration.
For Romania’s winter nights, setting the PIR sensor’s activation time to 30–60 seconds strikes the ideal balance between usability and energy efficiency [4]. Longer durations increase runtime but reduce savings; shorter settings extend battery life at the cost of convenience. Customizable timers allow users to adapt to seasonal changes [4], making this a vital adjustment for winter deployment.
Dusk-to-Dawn Modes: Automated Seasonal Adaptation
Dusk-to-dawn modes use solar insolation data and geographic location to estimate night length [1][3][6][7][9][10][12][15], automatically adjusting lighting schedules. In winter, the lamp activates at sunset and remains on through the long night, but with intelligent dimming to preserve battery.
Advanced systems dynamically dim light output as the night progresses [2], reserving higher power for early evening when visibility is most critical. These systems estimate available battery power [3][6][7][9][10][15] and adjust dimming schedules in real time to match energy reserves, ensuring the lamp stays active until dawn [8].
Combining PIR and Dusk-to-Dawn for Peak Performance
The most effective strategy combines both systems. During dusk-to-dawn mode, the lamp runs at low power until motion is detected. Then, it switches to full brightness for the programmed duration, conserving energy otherwise. This dual-layer control extends runtime by up to 50% compared to constant-on settings [4], especially during low-solar months.
| Feature | PIR Mode | Dusk-to-Dawn Mode | Combined Advantage |
|–––|–––|––––––|––––––-|
| Power Use | Low when inactive [4] | Adjusts based on night length [1][3][6][7][9][10][12][15] | Minimizes waste across all conditions |
| Runtime Extension | High with short activation [4] | Enhanced by dynamic dimming [2] | Up to 50% longer lifespan in winter |
| Adaptability | Customizable motion duration [4] | Auto-adjusts for season/latitude | Ideal for Romania’s changing seasons |
Real-World Considerations for Romanian Users
Battery voltage is a key indicator of stored energy [16], and systems adjust mode accordingly during low-voltage periods. If solar production the previous day was reduced—common during spring storms—control systems initiate energy-saving modes [16], dimming lights or shortening activation times to maintain operation. This ensures reliability even during poor weather [16].
Key Takeaways
Key Takeaways
- Use PIR sensors with 30–60 second activation times to reduce idle power use [4].
- Enable dusk-to-dawn mode with dynamic dimming to extend runtime during long winter nights [1][3][6][7][9][10][12][15].
- Combine both modes for maximum energy efficiency—up to 50% longer runtime [4].
- Allow systems to adjust automatically based on battery voltage and solar production [16].
- Configure settings seasonally, especially in regions like Romania with extreme winter darkness [1].
Frequently Asked Questions
Frequently Asked Questions
{„q”: „How long can a solar lamp last in Romania during December nights?”, „a”: „With PIR and dusk-to-dawn optimization, solar lamps can last the full 15-hour night by reducing idle power use [4] and adjusting output based on available energy [3][6][7][9][10][15].”}
{„q”: „What is the best PIR sensor setting for winter?”, „a”: „Set PIR activation to 30–60 seconds to balance safety and energy savings [4]. Longer durations increase runtime but reduce efficiency.”}
{„q”: „Can solar lamps work during cloudy Romanian winters?”, „a”: „Yes—systems monitor battery voltage and solar production [16] and enter energy-saving mode during low production, preserving power for essential use [16].”}
References
- [1] Lighting_Live_Annual_Conference_2025_Speaker_Spotlight_Peter__fac8fa74 — magazine
source passage
and is accessible to all. It was intended to maximise the economic effectiveness of solar panel arrays for electricity generation on houses, to optimise battery storage systems for domestic demand. It can also be used to calculate the effectiveness of stand-alone systems such as a solar-powered streetlight. The system relies on calculated solar irradiance figures throughout the year, collated for most of the western world and as PDE have collected their own data over many years, we can confirm the validity of the data within the obvious norms of high – and low-pressure systems that pass over our Island. From this data input, it is then possible with some accuracy to confirm whether a proposed solar lighting system will actually work. Further, what is the maximum wattage and duty cycle the luminaire can be run at in the various seasons? The winter period of 6 weeks before and after the December solstice might appear to be the riskiest, but seasonal storms in the spring can have a significant effect on the climb out of the darkest months when the double whammy of maximum length of winter nights and minimum direct sunlight have stretched the battery capacity to its limits, and in many cases beyond. Lighting Live Annual Conference takes place 18th – 19th June 2025 Attend the Annuahttps://lightinglive.org.uk/2025annualconference/l Gala Thank you to our Event Partner: Street Lighting Supplies & Co. Ltd Thank you to our Headline Sponsors: Charles Endirect | Orange Tek | Urbis Schréd
- [2] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
can be further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – At 314, in the stored energy consuming mode the at least one controller executes the selected illumination adjustment or dimming schedule. In particular, the at least one controller can execute instructions that cause the at least one controller to control the light source(s) of one or more luminaires according to conditions and/or parameters specified in the selected illumination adjustment or dimming schedule. Thus, for example, the at least one controller may cause an illumination level or intensity level, or even color temperature, emitted by a light source of the luminaire to adjust downward at some time or point after the light source is initially turned ON during a dusk-to-dawn portion of a daily or diurnal cycle. The time or point for the downward adjustment may be specified in various manners, for instance as a time period (e.g., 1 hour) after turn ON, or as a percentage (e.g., 6%) or fraction (e.g., 1/12) of the total dusk-to-dawn portion of the daily or diurnal cycle after turn ON. Also for example, the at least one controller may cause an illumination level or intensity level, or even color temperature, emitted by a light source of the luminaire to adjust upward at some time or point before the light source is turned OFF
- [3] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
be summarized as including: in at least one mode, determining, by at least one controller, whether to apply a illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. – The method may further include: in the at least one mode, selecting, by the at least one controller, between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. Controlling the luminaire via stored power may include controlling the luminaire according to the selected illumination adjustment schedule which specifies a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire th
- [4] US10563827B2_-_Solar_powered_illumination_system_-_Google_Patents__f82b6692 — patent
source passage
possesses high efficiency in cloudy, rainy, snowy and dusty areas due to efficient charging of the rechargeable battery and energy conservation. The illumination system further implements a programmable charge controller or a motion sensor in areas where the daytime is too short. The illumination system increases a power back-up to 14-20 days. When the motion sensor detects an object movement from a specific distance, the illumination system starts working with 100% of power, otherwise the illumination system works at 20-40% of a rated power value based on pre-defined programming. Furthermore, the charge controllers are programmed based on duration of a night in a geographical location such as 8 hours in summer and 12-14 hours in winter. On the basis of night duration, a light intensity is programmed to be at 100% for the first 4 hours, 50% for the following 4 hours and 20% for the rest of the night until the sunrise. According to one embodiment herein, for installing the illumination system in desert or snowy areas following customizations are adopted: – – a. Increasing a tilt angle of the solar panels during installation without decrease in the solar light absorption. The solution reduces an accumulation of dust, snow and rain on the surface of the solar panel. – b. Using a self-cleansing Nano-coating on the solar panels to decrease a friction on the surface of the solar panel which also prevents the accumulation of dust, snow and rain on the surface of the solar panel. Acc
- [6] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
or mains power source; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. The method may further include: in the at least one mode, determining, by the at least one controller, whether to apply an illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. The method may further include: in the at least one mode, selecting, by the at least one controller, between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and executes the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. In response to at least the selected dimming schedule, the controlling the luminaire via stored power may include controlling the luminaire to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each o
- [7] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
illumination adjustment schedule further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – the method may further include: in the stored energy consuming mode, estimating, by the at least one controller, an amount of power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the method may further include: in the stored energy consuming mode, operating, by the at least one controller, the luminaire via power from a power storage device, independent of whether electrical power is available via a mains power source. – the luminaire may be a legacy installation and may be electrically coupled to a rechargeable power storage device which is electrically coupled to a renewable energy source, wherein the rechargeable power storage device and the renewable energy source are retrofits to the legacy installation, and in the stored energy consuming mode, determining, by the at least one controller, whether there is sufficient stored power stored in the rechargeable power storage device to power the luminaire through the dusk-to-dawn cycle. – the method may further include: in the stored energy consuming mode, at least estimating, by the at least one c
- [8] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
based at least in part on the comparison of the at least estimated power available to power the luminaire through the dusk-to-dawn cycle and the respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of the plurality of illumination adjustment or dimming schedules. – For instance, the at least one controller can select between a more aggressive illumination adjustment or dimming schedule and a less aggressive illumination adjustment or dimming schedule based on a respective actual or estimated amount of power required under each of the illumination adjustment or dimming schedules to operate at least the light sources of the luminaire over at least a portion of a cycle (e.g., a dusk-to-dawn portion of a daily or diurnal cycle). The at least one controller can, for example, select the most aggressive illumination adjustment or dimming schedule that will adequately supply power to the light sources while minimizing the remaining amount of power stored in the dischargeable and/or rechargeable power source. Alternatively, the at least one controller can select a slightly aggressive illumination adjustment or dimming schedule, for instance one that will result in a defined percentage (e.g., 10%, 15%, 25%) of remaining power stored in the dischargeable and/or rechargeable power source. In some implementations, the control system may be powered via the dischargeable and/or rechargeable power source. In such implementations, the at
- [9] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
the plurality of dimming schedules. – the at least one controller may select the illumination adjustment schedule further based at least in part on at least one specified condition of illumination to be placed on operation of the luminaire during the dusk-to-dawn cycle. In the stored energy consuming mode, the at least one controller may select the illumination adjustment schedule further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one controller may operate the luminaire via power from a power storage device, independent of whether electrical power is available via a mains power source. – the luminaire may be a legacy installation and may be electrically coupled to a rechargeable power storage device which is electrically coupled to a renewable energy source, wherein the rechargeable power storage device and the renewable energy source are retrofits to the legacy installation, and in the stored energy consuming mode, the at least one controller determines whether there is sufficient stored power stored in the rechargeable p
- [10] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
mode the at least one controller determines whether to apply an illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. – the at least one controller may select between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. – At least the selected illumination adjustment schedule executed by the at least one controller may specify a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. – the at least one controller may compare the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. In the at least one mode, the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one
- [12] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. In the at least one mode, the at least one controller may select between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. – At least the selected illumination adjustment schedule executed by the at least one controller may specify a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. – the at least one controller may compare the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. – the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one controller may integrate a signal indicative of an output value of a light sensitive transducer over at least a portion of the most immediate dawn-to-dusk cycle in order to at
- [15] US20170055324A1_-_Apparatus_retrofit_kit_and_-_Google_Patents__f5522dda — patent
source passage
to control an illumination level of the luminaire during a dusk to dawn period; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. – Controlling the luminaire via stored power may include controlling the luminaire according to the selected illumination adjustment schedule which specifies a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. The method may further include: in the at least one mode, estimating, by the at least one controller, an amount of power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. The method may further include: in the at least one mode, integrating, by the at least one controller, a signal indicative of an output value of a light sensitive transducer over at least a portion of the most immediate dawn-to-dusk cycle in order to at least estimate an amount
- [16] US20120020060A1_-_Energy-efficient_solar-powered_-_Google_Patents__619c8cff — patent
source passage
to 100% for 10 minutes after the last-detected motion. It then dims back down to the lower setting over one minute. Towards dawn, the light will brighten back up to full brightness approximately 30 minutes (factory preset) prior to dawn. When the photocell threshold for dawn is crossed, the light will turn off. – FIG. 47 portrays examples of how system conditions can be utilized to determine the appropriate energy modes based on current states to modify power delivered, to the light or other loads, beyond or instead of the “normal” changes over time shown in FIG. 46 . – the voltage of the batteries (on the right of the figure) is one indicator of how much energy is available in the battery storage. As the battery voltage drops, the energy mode is adjusted so that energy can be conserved. – the Ah decision block is referring to the solar production (in Amp-Hours, Ah) from the previous day. This Ah information is also an indicator of whether or not energy needs to be conserved. On any given day, if the energy produced is less than normal, then the energy mode is adjusted to conserve energy, over and above the adjustments shown in FIG. 46 , preferably during the following night. – Modes E1 through E6 Energy Savings Modes are available (modes E1 through E6), and selection of the modes is determined by the measuring the battery voltage at the end of the day. – modes E1 and E2 the light is still brought up to full brightness initially & then dimmed down to less than 25% brightness
and is accessible to all. It was intended to maximise the economic effectiveness of solar panel arrays for electricity generation on houses, to optimise battery storage systems for domestic demand. It can also be used to calculate the effectiveness of stand-alone systems such as a solar-powered streetlight. The system relies on calculated solar irradiance figures throughout the year, collated for most of the western world and as PDE have collected their own data over many years, we can confirm the validity of the data within the obvious norms of high – and low-pressure systems that pass over our Island. From this data input, it is then possible with some accuracy to confirm whether a proposed solar lighting system will actually work. Further, what is the maximum wattage and duty cycle the luminaire can be run at in the various seasons? The winter period of 6 weeks before and after the December solstice might appear to be the riskiest, but seasonal storms in the spring can have a significant effect on the climb out of the darkest months when the double whammy of maximum length of winter nights and minimum direct sunlight have stretched the battery capacity to its limits, and in many cases beyond. Lighting Live Annual Conference takes place 18th – 19th June 2025 Attend the Annuahttps://lightinglive.org.uk/2025annualconference/l Gala Thank you to our Event Partner: Street Lighting Supplies & Co. Ltd Thank you to our Headline Sponsors: Charles Endirect | Orange Tek | Urbis Schréd
can be further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – At 314, in the stored energy consuming mode the at least one controller executes the selected illumination adjustment or dimming schedule. In particular, the at least one controller can execute instructions that cause the at least one controller to control the light source(s) of one or more luminaires according to conditions and/or parameters specified in the selected illumination adjustment or dimming schedule. Thus, for example, the at least one controller may cause an illumination level or intensity level, or even color temperature, emitted by a light source of the luminaire to adjust downward at some time or point after the light source is initially turned ON during a dusk-to-dawn portion of a daily or diurnal cycle. The time or point for the downward adjustment may be specified in various manners, for instance as a time period (e.g., 1 hour) after turn ON, or as a percentage (e.g., 6%) or fraction (e.g., 1/12) of the total dusk-to-dawn portion of the daily or diurnal cycle after turn ON. Also for example, the at least one controller may cause an illumination level or intensity level, or even color temperature, emitted by a light source of the luminaire to adjust upward at some time or point before the light source is turned OFF
be summarized as including: in at least one mode, determining, by at least one controller, whether to apply a illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. – The method may further include: in the at least one mode, selecting, by the at least one controller, between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. Controlling the luminaire via stored power may include controlling the luminaire according to the selected illumination adjustment schedule which specifies a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire th
possesses high efficiency in cloudy, rainy, snowy and dusty areas due to efficient charging of the rechargeable battery and energy conservation. The illumination system further implements a programmable charge controller or a motion sensor in areas where the daytime is too short. The illumination system increases a power back-up to 14-20 days. When the motion sensor detects an object movement from a specific distance, the illumination system starts working with 100% of power, otherwise the illumination system works at 20-40% of a rated power value based on pre-defined programming. Furthermore, the charge controllers are programmed based on duration of a night in a geographical location such as 8 hours in summer and 12-14 hours in winter. On the basis of night duration, a light intensity is programmed to be at 100% for the first 4 hours, 50% for the following 4 hours and 20% for the rest of the night until the sunrise. According to one embodiment herein, for installing the illumination system in desert or snowy areas following customizations are adopted: – – a. Increasing a tilt angle of the solar panels during installation without decrease in the solar light absorption. The solution reduces an accumulation of dust, snow and rain on the surface of the solar panel. – b. Using a self-cleansing Nano-coating on the solar panels to decrease a friction on the surface of the solar panel which also prevents the accumulation of dust, snow and rain on the surface of the solar panel. Acc
or mains power source; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. The method may further include: in the at least one mode, determining, by the at least one controller, whether to apply an illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. The method may further include: in the at least one mode, selecting, by the at least one controller, between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and executes the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. In response to at least the selected dimming schedule, the controlling the luminaire via stored power may include controlling the luminaire to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each o
illumination adjustment schedule further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – the method may further include: in the stored energy consuming mode, estimating, by the at least one controller, an amount of power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the method may further include: in the stored energy consuming mode, operating, by the at least one controller, the luminaire via power from a power storage device, independent of whether electrical power is available via a mains power source. – the luminaire may be a legacy installation and may be electrically coupled to a rechargeable power storage device which is electrically coupled to a renewable energy source, wherein the rechargeable power storage device and the renewable energy source are retrofits to the legacy installation, and in the stored energy consuming mode, determining, by the at least one controller, whether there is sufficient stored power stored in the rechargeable power storage device to power the luminaire through the dusk-to-dawn cycle. – the method may further include: in the stored energy consuming mode, at least estimating, by the at least one c
based at least in part on the comparison of the at least estimated power available to power the luminaire through the dusk-to-dawn cycle and the respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of the plurality of illumination adjustment or dimming schedules. – For instance, the at least one controller can select between a more aggressive illumination adjustment or dimming schedule and a less aggressive illumination adjustment or dimming schedule based on a respective actual or estimated amount of power required under each of the illumination adjustment or dimming schedules to operate at least the light sources of the luminaire over at least a portion of a cycle (e.g., a dusk-to-dawn portion of a daily or diurnal cycle). The at least one controller can, for example, select the most aggressive illumination adjustment or dimming schedule that will adequately supply power to the light sources while minimizing the remaining amount of power stored in the dischargeable and/or rechargeable power source. Alternatively, the at least one controller can select a slightly aggressive illumination adjustment or dimming schedule, for instance one that will result in a defined percentage (e.g., 10%, 15%, 25%) of remaining power stored in the dischargeable and/or rechargeable power source. In some implementations, the control system may be powered via the dischargeable and/or rechargeable power source. In such implementations, the at
the plurality of dimming schedules. – the at least one controller may select the illumination adjustment schedule further based at least in part on at least one specified condition of illumination to be placed on operation of the luminaire during the dusk-to-dawn cycle. In the stored energy consuming mode, the at least one controller may select the illumination adjustment schedule further based at least in part on at least one specified duration of a maximum illumination by the luminaire for a set period of time with respect to a solar event during the dusk-to-dawn cycle inclusive of a dusk event and a dawn event. – the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one controller may operate the luminaire via power from a power storage device, independent of whether electrical power is available via a mains power source. – the luminaire may be a legacy installation and may be electrically coupled to a rechargeable power storage device which is electrically coupled to a renewable energy source, wherein the rechargeable power storage device and the renewable energy source are retrofits to the legacy installation, and in the stored energy consuming mode, the at least one controller determines whether there is sufficient stored power stored in the rechargeable p
mode the at least one controller determines whether to apply an illumination adjustment schedule based at least in part on an at least estimate of a length of the dusk-to-dawn cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. – the at least one controller may select between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. – At least the selected illumination adjustment schedule executed by the at least one controller may specify a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. – the at least one controller may compare the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. In the at least one mode, the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one
cycle and based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle. In the at least one mode, the at least one controller may select between two or more dimming schedules based at least in part on an at least estimate of stored power available to power the luminaire through the dusk-to-dawn cycle, and may execute the selected one of the dimming schedules to control an illumination level of the luminaire during a dusk to dawn period. – At least the selected illumination adjustment schedule executed by the at least one controller may specify a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. – the at least one controller may compare the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. – the at least one controller may estimate power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. – the at least one controller may integrate a signal indicative of an output value of a light sensitive transducer over at least a portion of the most immediate dawn-to-dusk cycle in order to at
to control an illumination level of the luminaire during a dusk to dawn period; and controlling the luminaire via stored power independent of whether electrical power to power the luminaire is available via a line, grid or mains power source. – Controlling the luminaire via stored power may include controlling the luminaire according to the selected illumination adjustment schedule which specifies a period of time in which the luminaire is controlled to output at a reduced but non-zero level of illumination with respect to another period. The method may further include: in the at least one mode, comparing, by the at least one controller, the at least estimated power available to power the luminaire through the dusk-to-dawn cycle to a respective estimated amount of power required to power the luminaire through the dusk-to-dawn cycle for each of a plurality of dimming schedules. The method may further include: in the at least one mode, estimating, by the at least one controller, an amount of power available to power the luminaire through the dusk-to-dawn cycle based at least in part on an at least an estimate of solar insolation that occurred in at least a portion of a most immediate dawn-to-dusk cycle. The method may further include: in the at least one mode, integrating, by the at least one controller, a signal indicative of an output value of a light sensitive transducer over at least a portion of the most immediate dawn-to-dusk cycle in order to at least estimate an amount
to 100% for 10 minutes after the last-detected motion. It then dims back down to the lower setting over one minute. Towards dawn, the light will brighten back up to full brightness approximately 30 minutes (factory preset) prior to dawn. When the photocell threshold for dawn is crossed, the light will turn off. – FIG. 47 portrays examples of how system conditions can be utilized to determine the appropriate energy modes based on current states to modify power delivered, to the light or other loads, beyond or instead of the “normal” changes over time shown in FIG. 46 . – the voltage of the batteries (on the right of the figure) is one indicator of how much energy is available in the battery storage. As the battery voltage drops, the energy mode is adjusted so that energy can be conserved. – the Ah decision block is referring to the solar production (in Amp-Hours, Ah) from the previous day. This Ah information is also an indicator of whether or not energy needs to be conserved. On any given day, if the energy produced is less than normal, then the energy mode is adjusted to conserve energy, over and above the adjustments shown in FIG. 46 , preferably during the following night. – Modes E1 through E6 Energy Savings Modes are available (modes E1 through E6), and selection of the modes is determined by the measuring the battery voltage at the end of the day. – modes E1 and E2 the light is still brought up to full brightness initially & then dimmed down to less than 25% brightness