Energy Drift Defined
Energy drift is the gradual loss of efficiency after a Building Management System (BMS) is commissioned. After initial setpoints and schedules are established, changing site conditions, control overrides made by staff, and underperforming equipment can cause buildings to stray from expected savings over time. These issues can be combatted by identifying where drift is occurring and taking action to put efficiency back on track; however, the fundamental problem is that energy and building managers don’t have access to real-time, asset-level, and historical data to determine if there is an issue, what the issue is, and where the issue is coming from to do this efficiently.
The Solution: Asset-level Data in Real-time
Through its partnership with Energy United, GridPoint offers an asset-level submetering solution that aggregates structured data in a cost-effective, cloud-based software platform to provide real-time visibility into equipment energy consumption. The solution complements the existing BMS system with data to help users ensure that the control and operation of their building are efficient over the long haul.
Following a GridPoint installation, there are immediate actions that can be taken to mitigate BMS drift through tuning. These actions are intended to bring the building to its most optimized operating condition by improving the efficiency of major building and manufacturing support systems like HVAC, lighting, air compressors, equipment coolers, and motors. GridPoint’s data facilitates these actions by showing where energy efficiency is lacking. In one example, a large international media company installed GridPoint’s submetering solution after installing a BMS system. GridPoint’s solution quickly identified that a chiller was using 25% more energy after its BMS was installed, and the issue was pinpointed to an incorrectly programmed system. Once reprogrammed correctly, the chiller saved approximately 15% more energy than expected.
As building systems and manufacturing machinery are used, sites need to be continuously optimized to avoid drift. Key performance parameters will change, mechanical systems will wear, filters will clog, belts will fray, and all of these conditions eventually show up in the amount of energy used. GridPoint’s asset-level submetering provides real-time and long term trend information for major systems and subsystems so users can determine issues as they are occurring, facilitating immediate action. A large hospital suddenly experienced issues with negative air pressure in its lobby so that when patrons opened the doors a strong rush of outside, unfiltered air flowed into the building. This not only created uncomfortable conditions, but also forced the hospital’s HVAC system to work harder to bring the lobby back to the correct temperature. With GridPoint’s asset-level visibility into how the air handling units (AHUs) were operating, they were able to rebalance the units and correct the air pressure, which ultimately saved the hospital about 70kW in energy usage, which translates to over $30,000 per year in savings.
GridPoint’s Energy Management Solution takes asset-level submetered data and aggregates it in GridPoint Energy Manager, a cloud-based software platform that leverages big data analytics to enable valuable tools such as smart alarms, analytics and reporting, intelligent control, facility diagnostics, continuous demand management, renewables monitoring, and project and event tracking. GridPoint’s professional energy services complete the solution and provide the support and expertise customers need to fully optimize each site in their enterprise. GridPoint’s data has been leveraged at over 11,000 sites and has saved customers over $250,000,000.