Thermostat Temperature Offset Control for Peak Load Curtailment
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Solution Overview
Problem
Conventional thermostats fail to reliably reduce air conditioner operation during peak demand periods, as users often override utility-set temperature changes, leading to ineffective energy curtailment and increased energy costs for both consumers and utility providers.
Innovation Solution
A thermostat with a sensor and controller that periodically determines a temperature value for a space, incorporating a temperature offset when requested by a utility provider, allowing for reduced heating or cooling operation without altering the user-set temperature setting, thereby reducing energy demand without user awareness or intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the thermostat offsets the temperature set point to reduce air conditioner operation during peak demand periods, then energy consumption is reduced, but the user may override the utility change to the set-point temperature setting
Solution Approach 1:
Instead of changing the set-point temperature and risking user override, the patent inverts the approach by keeping the set-point unchanged and instead offsetting the measured space temperature. The controller measures the actual space temperature, applies an offset to create a modified temperature value, and uses this modified value for control decisions. This ensures load reduction while maintaining user confidence that their set-point is being respected.
Solution Approach 2:
The patent introduces an intermediary element - the offset value - that mediates between the user's set-point temperature and the actual control action. The offset is applied to the measured space temperature rather than directly to the set-point, creating an intermediate modified temperature value that guides control decisions without alerting the user to any change in their settings.
2Productivity
If the thermostat changes the set-point temperature to reduce operation, then energy demand is lowered, but user awareness leads to potential override of the setting
Solution Approach 1:
The patent applies the inversion principle by reversing which parameter is modified. Rather than modifying the set-point temperature (which users see and may override), the system modifies the measured space temperature. This maintains user acceptance while achieving the same control effect, as users continue to see their original set-point unchanged.
3Productivity
If the thermostat uses a predetermined temperature offset to reduce air conditioner operation, then peak demand is curtailed, but the method cannot always be relied upon to reduce operating level
Solution Approach 1:
The patent implements feedback by continuously measuring the actual space temperature and using this measurement as the basis for applying the offset. The controller compares the modified temperature value (measured temperature plus offset) against the set-point to determine control actions. This feedback mechanism ensures reliable operation reduction while adapting to actual space conditions rather than relying solely on predetermined offsets.
Data Source
AI summary
A thermostat is provided that is capable of reliably reducing the operation of an air conditioner and other systems to provide energy cost savings to the consumer and load reduction to a utility provider. The thermostat includes at least one sensor configured to communicate information indicative of the temperature within the space, and a memory for storing at least one temperature offset value associated with a request for reduced heating or reduced cooling operation. The thermostat further includes a controller in communication with the at least one sensor, which is configured to periodically determine a temperature value for the space and to control heating or cooling of the space until the determined temperature value has substantially reached the set-point temperature. The periodically determined temperature value is in part based on information received from the at least one sensor, and may include at least one temperature offset value when a request for reduced operation has been received by the thermostat.