Devices and techniques relating to landfill gas extraction

A method for controlling extraction of landfill gas from a landfill, the landfill comprising a plurality of wells coupled to an aggregate gas output, the method comprising:

• performing, with at least one controller:
• determining, based on one or more measurements made by at least one sensor disposed at the aggregate gas output, whether to adjust a flow rate of landfill gas being extracted from one or more wells of the plurality of wells, the determining comprising:
• obtaining, from the at least one sensor disposed at the aggregate gas output, a measure of a first characteristic of landfill gas collected from at least some of the plurality of wells;
• determining that the first characteristic of the landfill gas collected from the at least some of the plurality of wells is outside of a global range for the first characteristic;
• and
• determining to adjust the flow rate of landfill gas being extracted from the one or more wells of the plurality of wells when it is determined that the measure of first characteristic of the landfill gas collected from the at least some of the plurality of wells is outside the global range for the first characteristic;
• when it is determined to adjust the flow rate of landfill gas being extracted from the one or more wells of the plurality of wells, selecting at least one of the one or more wells to adjust based on one or more measurements made by at least one second sensor, the selecting comprising:
• determining that a measure of a second characteristic of landfill gas collected from a first well of the one or more wells is outside of a local range for the second characteristic;
• and
• when it is determined that the measure of the second characteristic of landfill gas collected from the first well is outside of the local range for the second characteristic, selecting the first well;
• and
• adjusting a flow rate of landfill gas being extracted from the selected at least one of the one or more wells including the first well, wherein:
• the first characteristic comprises oxygen concentration and the second characteristic comprises oxygen concentration, or the first characteristic comprises nitrogen concentration and the second characteristic comprises balance gas concentration.

A system for controlling extraction of landfill gas from a landfill, the landfill comprising a plurality of wells coupled to an aggregate gas output, the system comprising:

• at least one controller configured to perform a method comprising:
• determining, based on one or more measurements made by at least one sensor disposed at the aggregate gas output, whether to adjust a flow rate of landfill gas being extracted from one or more wells of the plurality of wells, the determining comprising:
• obtaining, from the at least one sensor disposed at the aggregate gas output, a measure of a first characteristic of landfill gas collected from at least some of the plurality of wells;
• determining that the measure of the first characteristic of the landfill gas collected from the at least some of the plurality of wells is outside of a global range for the first characteristic;
• and
• determining to adjust the flow rate of landfill gas being extracted from the one or more wells of the plurality of wells when it is determined that the measure of the first characteristic of the landfill gas collected from the at least some of the plurality of wells is outside the global range for the first characteristic;
• when it is determined to adjust the flow rate of landfill gas being extracted from the one or more wells of the plurality of wells, selecting at least one of the one or more wells to adjust based on one or more measurements made by at least one second sensor, the selecting comprising:
• determining that a measure of a second characteristic of landfill gas collected from a first well of the one or more wells is outside of a local range for the second characteristic;
• and
• when it is determined that the measure of the second characteristic of landfill gas collected from the first well is outside of the local range for the second characteristic, selecting the first well;
• and
• adjusting a flow rate of landfill gas being extracted from the selected at least one of the one or more wells including the first well, wherein:
• the first characteristic comprises oxygen concentration and the second characteristic comprises oxygen concentration, or the first characteristic comprises nitrogen concentration and the second characteristic comprises balance gas concentration.

A system for controlling extraction of landfill gas from a landfill, the landfill comprising a plurality of wells coupled to an aggregate gas output, the system comprising:

• at least one controller configured to perform a method comprising:
• obtaining, using at least one sensor disposed at the aggregate gas output, a measure of a first characteristic of landfill gas collected from at least some of the plurality of wells;
• obtaining, using at least one second sensor configured to measure a concentration of a constituent gas in landfill gas collected from a first well of the plurality of wells, a measure of a second characteristic of landfill gas collected from the first well;
• and
• when it is determined that the measure of the first characteristic of the landfill gas collected from at least some of the plurality of wells is outside of a global range and the measure of second characteristic of the landfill gas collected from the first well is outside of a local range, adjusting a flow rate of landfill gas being extracted from the first well, wherein:
• the first characteristic comprises oxygen concentration and the second characteristic comprises oxygen concentration, or the first characteristic comprises nitrogen concentration and the second characteristic comprises balance gas concentration.