Designing a reliable grid edge for distributed energy resources

The smart grid today has pushed utilities to their limit. With the emergence of distributed energy resources (DER) and atypical loads, the operation and construction of the power grid needs revamping. The current approach for solving these challenges is based on a centralized architecture: deploy connected devices, communicate with the cloud, then have utilities make requests to those various clouds. But this method presents challenges for scalability, massive data collection, security and privacy, and stranded assets.

To address these challenges, Intwine, an IoT technology company, is designing a truly smart and reliable “grid edge” (also known as the broader network of homes and businesses that consume energy). Electric utilities are asking consumers to make more decisions and be more intimately involved in grid operations. This market trend requires decentralized decision-making in order to further grid optimizations like transactive energy, in which all levels of energy consumption and generation are able to interact with one another.

Intwine has worked with the National Renewable Energy Laboratory (NREL) for several years to develop a research platform and commercial product offering for delivering decentralized transactive energy services. The core of its system solution is Intwine’s grid edge controller, designated by the acronym HEMS (home energy management system) in the NREL systems architecture shown in Figure 1.

Figure 1: HEMS within the NREL system architecture

The HEMs lives at the grid edge in a home or building. It is responsible for managing local loads participating in utility-led demand response (DR) and ancillary services programs. At no point does the decision process leave the physical platform. This ensures that customer data such as load history, state and preferences remain on the HEMs. Keeping the decision-making local reduces the amount of data transmitted to the cloud, reducing bandwidth usage. The HEMs also enables the system response to be determined quickly without any cloud communication latency or risk of no connection. In fact, decision-making does not rely on an internet connection at all.

Together, Intwine and NREL installed and tested numerous device loads including water heaters, pool pumps, thermostats, relays and electric vehicle chargers. Intwine is actively engaged in industry research projects to integrate solar and battery storage inverters into the system, which will enable microgrids. Local coordination among these various loads and supplies requires the HEMS to locally execute decision-making algorithms and be flexible enough to communicate with a variety of standards-based and proprietary device connectivity schemes.

By partnering with Texas Instruments, Intwine was able to quickly convert TI’s BeagleBone development platform into a commercially viable smart grid edge controller/gateway. TI’s Sitara™ AM335x processor offered the processing capability to move beyond communications protocol translation and enable true edge intelligence/analytics. The TI development platform and support allowed for simple integration with the WiLink™ 8 family for Wi-Fi®/Bluetooth® and SimpleLink™ CC2530 for zigbee connectivity.

Intwine also pulled out the extra processor input/output (I/O) to an externally accessible connector, which enables connectivity support for additional wired or wireless standards-based communication protocols as well as proprietary implementations. Intwine’s Connected Gateway has not only become a preferred grid edge development platform for many energy research labs, it is also proving to be a commercial solution that addresses remote intelligence requirements in the smart grid market and beyond.

The Intwine Connected Gateway, based on the TI BeagleBone platform, turns the smart grid’s data into actions at the grid edge. These actions are based on unique consumer preferences and data from hundreds of sensors in each home. The reliable grid edge offers:

  • Scalability
  • Improved security
  • Increased privacy
  • Increased reliability

Who still thinks it is possible to cost-effectively and reliably manage thousands of locations with a server and a dashboard? To learn more, see