How Smart Grid Technology Is Driving Renewable Energy
There is a sense of urgency about finding effective integration between public and private renewable energy IoT grids. Some DERs currently link with local utilities, but the growth of IoT-based renewable installations threatens to outpace the utilities’ abilities to interact with those constituents. Particularly, there’s a lot of activity among colleges and universities. “Many of them run themselves as a small town or city. … They have their own cogeneration and electricity and heat generation on campus, so they’re ready-made to be campuswide or larger microgrids,” said Brett Murphy, senior director market development, industrial Internet of Things for the Industrial Internet Consortium.
There’s no shortage of available and proven technologies, but the trick is getting it all to work together.
“For the most part the technologies — the networks, the embedded compute nodes, the ability to move the data to where it needs to be moved where it can be acted on — those pieces and parts are all there, it’s really a big challenge in terms of system integration and the software application development,” said IIC’s Murphy.
With greater integration of campuses and utilities, operations get more involved. There are some new requirements and developments that may add complexity. “The biggest thing we’re seeing with renewables is something called Direct Transfer Trip,” said Sierra Wireless’ Warren Westrup. DTT requires a great deal of coordination between the two entities, particularly if one of them experiences a problem. “You have to eliminate both sources of power so that it doesn’t cause damage,” explained Westrup.
The lack of communications standards and common protocols continues to hamper interconnectivity efforts. Recently, the Smart Electric Power Alliance, a nonprofit group promoting carbon-free power generation, sponsored a Plug-and-Play DER Challenge. SEPA’s goal is to aid the industry in developing open standards to make interoperability among power generating microgrids easier and less expensive.
IoT Connectivity Developments
While the effort to define a workable lingua franca for IoT interconnectivity is in its initial stages, there are ample alternative technologies for knitting together IoT grids for renewable energy.
Traditional Ethernet over wires, fiber or Wi-Fi is still a popular grid connectivity choice, but can be pricey to implement and maintain. Other options such as WiMax provides sufficient bandwidth, but may not be supported in the future.
Increasing, the ubiquitous cell technology LTE has emerged as a viable alternative, checking off most of the requirement boxes such as coverage, security and cost. And two low-power wide-area (LPWA) LTE technologies are gaining interest as well: LTE-M and NB-IoT. Both promise improved coverage, lower power consumption and lower costs.
Yet another emerging technology — Citizens Broadband Radio Service — could improve IoT grid communications while lowering costs. CBRS is an LTE variation that operates in a low-spectrum band at 3.5 GHz.
“When you start looking at Wi-Fi versus CBRS, it takes about three to four access points of Wi-Fi to equate to the coverage of CBRS,” explained Sierra Wireless’ Westrup. Sierra Wireless has an FCC-approved CBRS module waiting in the wings for the initial commercial deployments of the technology.