The GridShare is installed in line with a household’s electricity meter. Two weatherproof boxes are mounted at each household’s electrical service entrance: one houses an emergency circuit breaker and the other contains the GridShare circuit board. A low-voltage cable connects the GridShare to an LED box within the house, which communicates to users the current state of the grid.
The GridShare LED display has a green and red light. If the system voltage is normal, the green light is lit and the user can use any appliance. During peak times, as more people begin using large appliances, the system voltage drops; if the voltage falls below a threshold, the GridShare enters brownout mode. When the brownout starts, if a high wattage appliance is in use, both the red and green lights illuminate, and the user is allowed to continue using large appliances for a preset time. This guarantees that users who begin cooking while the green light is on will be able to finish cooking.
A diagram showing a hypothetical brownout and the timing of GridShare’s logic and indicator lights for two separate houses over one evening.
Description of LED lights in Dzongkha, the national language of Bhutan.
After the timer expires, or if no large appliance is in use at the beginning of the brownout, the red light illuminates and the GridShare enters power-limited mode. If a large appliance is plugged in, the GridShare interrupts power to the house. The GridShare periodically reconnects the power and checks the current; if large appliances have been turned off, the power remains on. As usage drops and the voltage recovers, the GridShare returns to normal mode. As users shift the time of use of their large appliances, the community will even out their electricity use and reduce the occurrence of brownouts.