The autonomy of a solar lighting fixtures indicates the working duration at night until its battery runs out due to insufficient daytime charging.
There are two autonomy types:
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The autonomy of a solar lighting fixtures indicates the working duration at night until its battery runs out due to insufficient daytime charging.
There are two autonomy types:
It tells us the number of hours the luminaire battery would take to discharge when the battery recharge during the day is 0% due to insufficient or no solar irradiation absorbed by the corresponding lighting fixture photovoltaic panels. Autonomy indicated in the lighting fixture technical datasheets.
It tells us the number of hours the luminaire battery would take to discharge when the battery recharge during the day is different from 0%. The level will depend on the solar irradiation absorbed by the corresponding lighting fixture photovoltaic panels. This means that the average autonomy will differ every month with a minimum in winter and maximum in summer.
• 24h with enabled PIR sensor and standard regulation profile
• First 5 hours: sensor enabled (100% flow with movement detection, 30% flow without detection).
• Next 5: Sensor disabled, flow 30%.
• Rest of the night: Sensor enabled (100% flow with movement detection, 30% flow without detection).
According to 2019 NASA data, the average winter peak solar hours in Villaviciosa on December 21 is 1.5 PSH (horizontal plane). There is thus insufficient daytime solar irradiation to fully recharge the battery. Consequently, the battery will be completely empty after 27 hours (1.77 nights, since the night lasts 15 hours). The charge the next day will be only 5.86%, which will only allow us to have the lighting fixture on for 1.49 hours in the ensuing nights. This will continue until solar irradiation improves during the day.
The following chart shows the lighting fixture's mid-winter behavior:
According to NASA 2019 data, the average summer peak solar hours in Villaviciosa on June 21 is 6.2 PSH (horizontal plane). There is thus enough daytime solar irradiation to fully recharge the battery (100%), requiring only 9.17 hours out of the 15 hours of solar irradiation in the summer to complete the charge. A fully charged battery (100%) is more than enough to keep the lighting fixture on throughout the 9 nighttime hours. This would go on indefinitely for most of the summer, spring and fall months. We can say that, at least in summer, the average autonomy is infinite.
The following chart shows the lighting fixture's mid-summer behavior:
