Our Team in Action
Tesla’s in-house engineering team faces the demanding job of ensuring all mission critical manufacturing and research facilities operate flawlessly. They are committed to maintaining a facility that is 100% reliable to support a high-performing staff and the production of innovative products.
Before engaging with Carbon Lighthouse, Tesla’s onsite team had brought in utility and consulting engineering firms to reduce energy use. They also work regularly with quality equipment manufacturers and service providers like Trane for ongoing maintenance support. Given these previous and ongoing relationships, the Tesla team expected there would be few savings leftover for Carbon Lighthouse to capture.
Carbon Lighthouse engineers love a challenge that puts our experience, infrastructure, and processes to the test. The first step to tackling any project is to spend time on site learning about the building’s unique operations from the facilities team, the people who know the building best. The operational information from the facilities team was a necessary complement to the data gathered from the building management system (BMS). Our engineers have found that even the most sophisticated BMS will miss important measurements that reveal hidden savings opportunities. In order to capture this data, our engineers deployed our own data acquisition equipment around the facility, taking thermodynamic, electrical, physical, and behavioral measurements for six weeks.
During implementation of the project, our engineers detected the amperage displayed in the BMS was different from the amperage displayed internally in the chiller’s current transducer (CT). This data-mismatch threatened to jeopardize $30,000 per year in energy savings.
Working closely with Trane, the original manufacturer of the chillers, our engineers used data including kW/ ton curves measured in the field to troubleshoot the equipment issues. The data after calibration showed significantly different performance curves than design or factory testing indicated. Carbon Lighthouse used its data and analysis to inform careful PIO loop tuning which brought field performance of the underperforming chiller back in line with the design.
Our engineers dug into the issue and found that the errors were caused by a BMS CT being placed on the wrong side of the VFD as well as improper calibration. To resolve these discrepancies, our engineers collected a set of clean and reliable data for an additional six weeks during implementation. With this new baseline data, our team could confidently take action on how to resolve these issues.
In addition to cutting energy use at the chillers and at the cooling towers, Carbon Lighthouse optimized the interactions between the two. First, the cooling tower operation was optimized by adjusting flow and set point:
By looking at the plant holistically, in addition to carefully considering the operations of the cooling towers and chillers separately, Carbon Lighthouse delivered significant additional energy savings. Our team achieved this by optimizing the pumping energy use against chiller use and cooling tower fan use, using additional data not available to the BMS to accept penalties in cooling tower energy in exchange for efficiencies in the chiller, and both balanced against pumping energy.
The project at Tesla’s headquarters put our engineering methodologies to the test with an outcome that surpassed even our own expectations of the project. Our team not only delivered a project that exceeded predicted savings and an exceptional return on investment, but also one that improved building visibility and operations with minimum disruption.
Projects like the one completed at Tesla present an exciting challenge for our engineers. Our goal is to provide projects that deliver an exciting IRR for our clients. At Tesla, we accomplished this and then some. This type of project demonstrates how Carbon Lighthouse’s sensors and process allow us to uncover savings that other companies and building management systems are not equipped to find, and how we take action utilizing that data to cut energy use, deliver great financial returns, and improve buildings.