Ensuring distribution network reliability in the age of renewable energy

author avatar
Ensuring distribution network reliability in the age of renewable energy

As network reliability is increasingly tested by aging power infrastructure and the complex demands of renewable energy, cellular IoT provides timely solutions.

This article was first published on

blog.nordicsemi.com

As network reliability is increasingly tested by aging power infrastructure and the complex demands of renewable energy, cellular IoT provides timely solutions. LTE-M or NB-IoT provide a ready-made connectivity solution for smart grids because they are robust, wireless technologies tailor-made for large scale IoT deployments like sensor networks and smart meters. 

Feeling the heat 

Temperatures around 32 degrees Celsius are common in Northern India in July. Yet at 2:30am on July 30, 2012, two of the country’s four power grids were under such intense pressure circuit breakers began to trip. Soon India was in the grip of the largest power outage in history. And just when the grid returned to normal, it failed again on an even larger scale. An estimated 670 million people were affected in the ensuing chaos.  

At the time, India’s power network—like many countries—was aging and complex. It had been built to distribute conventional energy sources in straightforward ways. Constructed in the 1960s and 70s, the infrastructure was designed to support the one-way flow of energy from centralized power stations to consumers. It performed satisfactorily but lacked the flexibility and control to deal with new power sources.  

Renewables enter the energy mix 

Today, a lot of power in India and elsewhere is still generated using conventional power stations, but many other power sources are also used. Today, almost a third of electricity worldwide comes from renewable sources according to the International Energy Agency (IEA). Solar photovoltaic (PV) installations, wind farms, hydro power, geothermal and bioenergy all contribute.  

Many of these power sources are highly variable, so they need to be switched in and out quickly and efficiently as conditions dictate. But existing grids simply don’t have the inbuilt flexibility to manage all the added demands and intricacies renewable energy brings. And the rapid growth of the electric vehicle (EV) fleet, with its inherent recharging demands, puts even more strain on already struggling power infrastructure. So, how can the world’s distribution networks keep up with the increasingly complex nature of today’s mixed power portfolio yet still minimize outages? 

The IoT is the key 

Since its problems early in the last decade, India has invested millions in smart grid technology and smart metering to help prevent a recurrence of mass power outages. Smart grids use a network that supports the bidirectional energy flow and communication between many different generation sources and loads. Such a grid relies on the IoT to take advantage of information from sensors to encourage collaborative actions between the utility and its customers. 

For example, low power cellular IoT can be used to monitor grid conditions, detect faults, and trigger preemptive maintenance before an outage occurs. No matter how geographically remote parts of the grid might be, if there’s cellular coverage, LTE-M or NB-IoT connected sensors can be installed on network infrastructure to flag malfunctions, power surges, fires, and even a transmission tower collapse. IoT sensors can also be used to trigger reclosers and other switching equipment to rapidly connect and disconnect energy sources. 

The IoT also helps speed up the return to service after problems. For example, before the IoT, fault detection relied on customers reporting a problem. Maintenance crews were then sent to locate the fault (which could take hours), then isolate lines, and restore power. It was a lengthy process especially in remote areas. Now, by using the Global Navigation Satellite Systems (GNSS) capability built into cellular IoT devices such as Nordic’s nRF9160, the location of any faults can be accurately pinpointed and lines remotely isolated - saving time and resources. 

The non-cellular alternative for IoT 

DECT NR+ (“NR+”) a non-cellular technology which supports kilometer range and up to one million devices per square kilometer, is highly scalable and offers enterprises such as solar or wind farms a standardized IoT alternative to existing proprietary technology. The technology operates on the global and license-exempt 1.9 GHz band.  

Designed with an emphasis on ultra-high reliability and ultra-low latency, NR+ enables the replacement of low latency wired systems with equivalent wireless communications in enterprise applications across the energy distribution grid. A further advantage is that NR+ cuts deployment costs by eliminating data charges and the need for certification from operators. 

Machine Learning (ML) sifts out the important data 

Devices such as Nordic’s nRF9160 SiP incorporate powerful processors that can support machine learning (ML) at the edge of the network. ML models can be used to reliably distinguish between a significant and insignificant event on the grid eliminating transmission of unimportant data to the Cloud.  

Instead, the device only sends a notification when it determines intervention is required. This not only lowers costs, but it also reduces the power consumption of potentially millions of devices operating in remote environments where battery replacement is simply impractical. 

While wind can’t be relied on to constantly blow, and sunlight can’t be relied on to continuously shine on solar panels. But what is a little more reliable is the many years of historical data. Because of this data, variations in wind and sunlight are largely predictable allowing grid operators to program ML models accordingly. The models can then supervise energy source switches ahead of anticipated variability.  

Stabilizing the grid with the IoT 

While historical data can be used to predict variable energy inputs, at the other end of the supply chain, utilities can incentivize customers to shift or shed electricity demand to help with grid balancing. The IoT helps here too with cellular IoT-powered smart meters not only measuring and recording electricity consumption and generation, plus communicating this information to consumers and utilities, but also receiving signals from utilities or other service providers such as price changes or other incentives designed to limit consumption. 

Cellular IoT provides a ready-made connectivity solution for “demand response” strategies. Using the IoT, demand response can be controlled automatically and seamlessly to reduce peak consumption and enable the aggregation and remote control of smaller dispersed renewable resources. According to the International Energy Agency (IEA), the U.S. has 200 gigawatts of cost-effective load flexibility potential that could be realized by 2030 if effective demand response is actively pursued. 

The Internet of Energy 

With fast, high-quality wireless networks, energy consuming devices can be connected to the smart grid to form the ‘The Internet of Energy’. Such a network will allow energy companies to optimize resources and maximize grid performance. Governments can develop informed policies and regulation, and consumers can save money. It’s a win-win-win for the smart grid of the future, and the planet. 

More by Nordic Semiconductor

We play a key role in the realization of the wireless future. We remain passionately committed to ultra-low power wireless technology done right. We are the market leader in Bluetooth Low Energy connectivity, with a growing portfolio of wireless devices, LTE-M and NB-IoT being the latest augmentati...