Solar hybrid battery for powering network devices over extended time intervals

Patent metadata

Field	Value
Publication number	US-11296539-B2
Application number	US-201816237554-A
Country	US
Kind code	B2
Filing date	Dec 31, 2018
Priority date	Dec 31, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A node within a wireless network is powered by a solar hybrid battery system. The solar hybrid battery system includes a solar panel, a primary cell, and a secondary cell. The secondary cell includes only enough power storage to be capable of powering the node during the longest daily interval of darkness in the region where the node is deployed. The solar panel is sized relative to the secondary cell to be capable of fully recharging the secondary cell during the shortest daily interval of daylight in the region where the node is deployed, even under conditions of limited solar irradiance (e.g. due to clouds). The primary cell can charge the secondary battery if the node is shelved or malfunctioning to prevent the secondary cell from becoming overly depleted. The primary cell can also provide the node with additional power during times of peak demand or to perform status reports.

First claim

What is claimed is:

1. A system, comprising:
a network subsystem configured to consume a portion of energy during a first time interval when performing network communications with one or more nodes included in a wireless network; and
a power subsystem that is coupled to the network subsystem and includes:
a power cell configured to store energy and has an energy storage capacity that is approximately 10 percent greater than the portion of energy, and
a solar panel configured to, when exposed to a level of irradiance during a second time interval, fully recharge the power cell,
wherein the first time interval comprises a longest interval of continuous darkness to which the system is expected to be exposed during use at a location of the system, and the second time interval comprises an interval of continuous daylight.

2. The system of claim 1 , wherein the second time interval corresponds to a daylight portion of a winter solstice at the location of the system.

3. The system of claim 1 , wherein the level of irradiance is equal to about fifteen percent of an average level of solar irradiance at the location of the system.

4. The system of claim 1 , wherein the power cell has an operational lifetime of at least 20 years.

5. The system of claim 1 , wherein the power subsystem further includes a voltage limiter that is coupled between the solar panel and the power cell, and wherein the voltage limiter is configured to (a) electrically isolate the solar panel from the power cell during the first time interval and (b) restrict a voltage level associated with the portion of energy during the second time interval.

6. The system of claim 1 , wherein the power subsystem further includes a primary cell configured to recharges the power cell when the solar panel does not generate any power for a threshold amount of time.

7. The system of claim 1 , wherein the power subsystem further includes a primary cell configured to supply power to the network subsystem during a spike in network traffic.

8. The system of claim 1 , wherein the solar panel is configured further to, when exposed to the level of irradiance during the second time interval, further generates a second portion of energy that is consumed by the network subsystem during the second time interval.

9. A system, comprising:
a network subsystem configured to perform network communications with one or more nodes included in a wireless network; and
a power subsystem that is coupled to the network subsystem and includes:
a power cell that stores power, and
a solar panel configured to fully recharge the power cell from a depleted charge level associated with a minimum charge level of the power cell to a maximum charge level of the power cell while powering the network subsystem during a daylight interval when the solar panel is exposed to about fifteen percent of an average level of solar irradiance in a location during the daylight interval, and wherein the power cell has a capacity that is 10 percent greater than an amount of power to power the network subsystem during a darkness interval that occurs subsequently to the daylight interval.

10. The system of claim 9 , wherein the daylight interval corresponds to a daylight portion of a winter solstice at the location and the darkness interval corresponds to a darkness portion of the winter solstice at the location.

11. The system of claim 9 , wherein the power cell has an operational lifetime of at least 20 years.

12. The system of claim 9 , wherein the power subsystem further includes a voltage limiter that is coupled between the solar panel and the power cell, wherein the voltage limiter is configured to (a) electrically isolate the solar panel from the power cell during the darkness interval and (b) restrict a voltage level associated with powering the network subsystem during the daylight interval.

13. The system of claim 9 , wherein the solar panel is further configured to generate a first portion of power to fully recharge the power cell while generating a second portion of power for powering the network subsystem when exposed to the about fifteen percent of the average level of solar irradiance in the location during the daylight interval, wherein the first portion of power is greater than the second portion of power.

14. The system of claim 9 , wherein the power subsystem further includes a primary cell configured to recharge the power cell when the solar panel does not generate any power for a threshold amount of time.

15. The system of claim 9 , wherein the power subsystem further includes a primary cell configured to recharge the power cell when a charge level associated with the power cell is less than a threshold value.

16. The system of claim 9 , wherein the power subsystem further includes a primary cell configured to supply power to the network subsystem when the network subsystem downloads a firmware update.

17. The system of claim 9 , wherein the network subsystem includes a computing device configured to monitor a power generation rate associated with the solar panel and reports the power generation rate to a control center via the wireless network.

18. A solar battery subsystem, comprising:
a power cell; and
a solar panel that, when exposed to an irradiance level, is configured to fully recharge the power cell from a depleted charge level associated with a minimum charge level of the power cell to a maximum charge level of the power cell during a daylight interval while powering a network subsystem, wherein the irradiance level is about fifteen percent of an average irradiance level at a location where the solar battery subsystem is deployed, and wherein the power cell has a capacity that is 10 percent greater than an amount of power to power the network subsystem during a darkness interval that occurs subsequently to the daylight interval.

19. The subsystem of claim 18 , wherein the network subsystem is configured to deplete the power cell during the darkness interval that occurs subsequently to the daylight interval, and wherein the darkness interval comprises a darkness portion of a winter solstice at the location where the solar battery subsystem is deployed.

Assignees

• Itron Inc

Inventors

• Edwards Bruce

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/342

  The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging (with circuits for polarity protection H02J7/68) · CPC title

• H02J7/35 Primary

  with light sensitive cells · CPC title

• H04W52/0296

  switching to a backup power supply · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title