From smart home automation to wide bandgap semiconductors, here’s everything engineers need to know to navigate the energy transition.
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Energy is changing. How it’s managed, where it’s stored and how it’s consumed are all in transition. Energy users are playing an active role in reducing energy bills, balancing grid supply and demand, and enabling green technologies like renewable energy and electric vehicles (EVs). All of this has massive ramifications for energy infrastructure—and the engineers designing these systems.
To ensure that the transition goes smoothly, engineers must understand the biggest factors impacting energy storage. From battery energy storage systems to smart home automation, from wide bandgap semiconductors to EV chargers, to the communication protocol tying it all together, here’s what engineers need to know to keep up.
The grid adapts to home energy storage
In the early days of residential solar, energy storage systems (ESSs) were so expensive that most installers recommended grid-tied systems with net-metering, effectively using the grid as “virtual storage.”
Now home energy storage is becoming much more affordable. Utilities are rolling out time-of-use billing, making it desirable for consumers—even those without solar arrays—to control their energy costs through load shifting, in which high-power devices run when electric demand (and rates) are lower.
Load shifting and energy storage help grid operators to balance production and consumption without necessarily adding capacity, flattening the so-called “duck curve” between supply and demand. Eventually, this will lead to renewable energy sources assuming more of the base load generation duties and decreasing the reliance on fossil fuels.
The grid wasn’t designed to be used as virtual storage on a large scale, so as rooftop solar becomes more prevalent and more energy consumers also become producers, grid infrastructure will need to adapt. But consumers can adapt too, thanks to home automation.
Residential load shifting can be done manually, but there are benefits to the consumer and the grid if the system is fully automated. Imagine a sunny day where a rooftop solar array generates more energy than the building needs. An automated energy storage system can determine whether to store the energy locally, run a large appliance or sell electricity back to the grid.
Automation will be key to the energy transition, and it’s crucial that engineers design for it.
A day in the life of smart home energy management
Picture an energy management system (EMS) in a smart home with a rooftop solar array and battery energy storage system. The EMS should talk to the smart electric meter to determine the current electric rate, and smart appliances should communicate with the EMS to let it know there’s a job pending (e.g., someone put a load of laundry into the washing machine.)
If the electric rate is high, the EMS could run the wash on battery power or, if there’s a lot of sunlight, it may direct power from the solar panels to the washer and dryer. But if rates are high and the consumer is participating in net-metering, it may be profitable to sell the solar electricity back to the grid and do the laundry using battery power. Or, it could defer the laundry until rates are lower (of course, this could be manually overridden in a situation where someone needs to go to work in a couple of hours and they’re out of clean underwear).
Overnight, when electric rates are low and the solar array isn’t generating anything, the battery can inexpensively charge from the grid, rather than relying on the solar panels as the only charging source. This lets the solar array contribute to the grid during high-demand periods, while also powering the home itself. Either way, the EMS has all the data it needs to make the best economic decision for the consumer.
From the consumer’s standpoint, the entire system and all of its devices can be monitored and controlled by an app, regardless of their brand, model or communication standard. The best system is one in which everything works together seamlessly. To address this, a consortium of players in the home automation market formed the Connectivity Standards Alliance (CSA) to develop a standard for interoperability: Matter. The goal is to provide consumers and engineers with components that are easily controlled, interoperable, secure and reliable.
Why Matter matters for energy management
Matter is a unified standard that allows appliances from multiple manufacturers to communicate with energy management systems and smart meters, with a single app for consumers to control and monitor everything.
Matter 1.0 was largely for simple home automation: controlling lights, smart outlets, door locks, HVAC, entertainment, shading and security sensors. These devices use different communication protocols, depending on their needed bandwidth and other features. For example, entertainment and security cameras use Wi-Fi because of its speed, while low-bandwidth battery-operated devices such as locks and sensors employ the energy-efficient Thread mesh network.
At its core, Matter is an IP protocol, including all the IP hardware-layer security. Matter is compatible with any IP-based protocol stack—including Ethernet, Zigbee, Bluetooth and others—offering flexibility and additional security at the network and application layers. Wi-Fi also enables secure and timely software updates to the system and its components.
The next revision of Matter will support larger appliances, robotic vacuum cleaners, energy management systems, air quality sensors, smoke and CO detectors and room occupancy sensors. A Matter-based EMS working as the microgrid controller can monitor and report device power consumption, handle real-time pricing, decide which appliances should run at any given time (unless manually overridden), and determine when to use grid power and when to sell power back to the grid.
In short: Matter matters. Don’t neglect it when sourcing components and designing energy solutions.
How EVs are impacting energy storage
An electric vehicle’s battery capacity is much higher than that of a typical residential energy storage unit. Instead of spending extra money on an ESS, EV owners can simply use their vehicle batteries to store excess energy. To ensure the car is available to drive, an energy management system can sync with a user’s calendar, so it knows when the EV needs to be charged and when it’s safe to be used as an energy source. Smart, EMS-integrated EV chargers will soon become the norm.
Think that’s pretty far down the road? Think again. Schneider Electric released a Matter-compliant smart EV charger in 2022 which integrates with the company’s Matter-compatible home EMS. The charger looks at utility rates, supply and demand, household loads and any variables that the customer has included (such as when the car will be needed). That allows it to optimize energy costs and performance by directing the flow of energy to and from the grid, rooftop solar or the EV itself. Users can monitor and tweak the whole system through an app.
Commercial EV charging is also in transition. According to Reuters, the world’s largest auto manufacturers will pump nearly $1.2 trillion dollars into the EV and battery industries between now and 2030, resulting in 54 million new EVs in 2030. At the utility scale, the current grid doesn’t have the capacity to handle the required influx of EV chargers, especially the fast and ultra-fast chargers.
Large batteries will be required as buffers between the grid and public EV chargers. Many public charging stations will be equipped with on-site renewable energy (solar and wind, primarily) to reduce the strain on the grid. At night, when grid demand and renewable generation are low, grid power can charge the ESS. Midday, when the sun is typically shining and grid demand is heavy, the ESS can charge EVs. Much like the home smart charger scenario, the EMS will factor in all variables and make the best decision in real-time.
As public EV chargers become more ubiquitous in parking lots, we could see shopping centers and municipal lots selling charging services to fleet vehicles, allowing them to charge overnight when the electric rates are low and the parking lots aren’t in demand. To increase local renewable generation, solar canopies can shade the cars being charged while generating at least some of the power needed for EV charging. Businesses that want to increase their environmental/sustainability/governance (ESG) ratings could put chargers in their office center parking lots as a perk for employees who drive EVs. With bidirectional capabilities, the plugged-in cars could feed power to the grid during high demand periods.
There are concerns that fast charging and excessive charge-discharge cycles can reduce a battery’s lifetime. Battery manufacturers are making headway in creating batteries that can be fast charged in ten minutes and withstand 1,200 fast charge cycles, both of which beat today’s state-of-the-art battery chemistries. Wide bandgap semiconductors are helping pave the way.
Wide bandgap power devices: SiC vs GaN
With the levels of current needed to charge and operate an EV, even a slight increase in component efficiency can result in a whole lot of energy savings. Wide bandgap (WBG) semiconductors like gallium nitride (GaN) and silicon carbide (SiC) offer a significant efficiency advantage over traditional silicon devices. Research group CEA and automaker Renault have developed a bidirectional charger supporting vehicle-to-grid (V2G) capabilities that they claim reduces energy losses during conversion by 30 percent, thanks to the use of WBG devices.
Charging times and range anxiety are the most common deterrents to EV adoption. Any improvement in charging times reduces the need for higher capacity batteries, as topping off the charge becomes faster and more convenient. Pay attention at an interstate service area; only a fraction of the cars will stop at the fuel pump, showing that more people stop to empty something than to fill their tanks. If they could top off the charge in the same amount of time that it takes to use the facilities, range anxiety would be irrelevant.
As such, consumers are willing to pay a little more for improvements in charging times and efficiencies, partly for the convenience, and partly for the long-term energy savings. For a home charger, the energy saving is the critical factor, since most cars can charge fully overnight. On the other hand, at public charging stations, speed is the need, but don’t discount the energy saving factor—the consumer may only pay for the energy that goes into the car, but the rate per kilowatt-hour will be higher if there’s more waste; the provider isn’t going to eat the extra cost associated with inefficiency.
According to Neil Willard, industrial technical manager at Avnet, SiC devices got a head start in the WBG market and will likely continue to dominate in large commercial charging stations. GaN is easier to manufacture, but so far has been limited to medium power devices. Willard expects that home DC Wallbox style EV chargers will use GaN, partly due to its higher switching frequencies, which allow for smaller inductors and capacitors that weigh less and fit into a tighter form factor.
How engineers can navigate the energy transition
As the Matter standard demonstrates, the energy transition requires partnerships and cooperation. Matter’s own partners run the gamut from companies providing communication solutions, microcontrollers, battery management systems, power devices (SiC and GaN), energy storage, network security and physical connectors, among others. These companies are helping engineers design Matter-based systems and components through a multitude of tools such as design guides, development hardware and software, application notes and product selectors.
Avnet, a global distributor and Matter partner, has over fifteen hundred application engineers across the globe to support OEMs through the energy transition. Avnet also offers supply-chain management tools so designers can be sure that parts are available when needed and at the best price.
Smart homes, EVs and grid infrastructure are evolving into a symbiotic relationship and Matter is poised to be the glue that ties them together. As always, it’s an exciting time to be an engineer!
To learn more, visit Avnet.com.
