With the maturation of renewable-energy harvesting technologies, green energy is gradually becoming a viable alternative to the conventional, environment-unfriendly power sources. However, this new reliance on green energy sources puts stress on grid stability. As a successful power grid relies heavily on balancing the supply of and demand for power, the unpredictability of green energy, however, brings several challenges. Hence, technology that allows a grid to respond quickly to power fluctuations is crucial to ensure a more resilient grid. This is where virtual power plants enter the power landscape.
A virtual powerplant (VPP) is a decentralized "Internet of Energy"—a concept that emerged after the maturation of IT and Industrial Internet of Things (IIoT) technology. Different from its predecessors, traditional centralized power plants, virtual power plants crowdsource energy from a variety of resources that are not limited to just centralized power plants. Ranging from renewable energy power plants, rooftop solar panels, energy storage batteries, to electric vehicles, etc., virtual power plants harvest energy from anywhere and anyone. However, to harvest and dispatch power successfully and flexibly from both conventional and unconventional sources, live monitoring is required. Imagine a world where electric vehicles are the main source of commuting. During power demand peaks, virtual power plants prompt the parked vehicles at charging centers to divert power back to the grid to solve urgent needs. Inversely, if an excess of renewable energy is produced, then the power can be stored in the vehicles.
VPPs also play a crucial part in reducing energy wastage by making sure the supply matches the demand. The most common instance of energy waste is discarding excess renewable energy generated for a specific area. In a virtual power plant setting, this can be avoided. For example, as soon as the supply of wind-powered energy exceeds the demand of the grid for a particular area, power usage can be stimulated by reducing the price through the time-price mechanism. Thus, solving the problem of power wastage caused by an imbalance in the power supply-demand.
Virtual power plants are clearly a solution to our future energy needs. But before this can become a full-fledged reality, a few kinks still need to be ironed out. To achieve grid resilience, a virtual power plant requires the collection of a large amount of real-time data. In other words, it must be able to “see” to be effective. Therefore, it needs to answer questions such as "How much renewable energy will be integrated into the grid?", "How much energy would the user need?", "How many electric vehicles are currently charging?, and more to “see” clearly. To answer these questions, humungous data is required. However, building the IIoT in the energy sector is not as simple as installing an API in your smartphone. To receive data, equipment may have to be installed next to a solar power plant in the desert, where it must deal with insufferable extreme heat, or adjacent to a wind turbine operating at sea, which faces not just the turbulent elements but also corrosive salty winds, or even in a substation with high, signal-confusing, electromagnetic waves. In addition to field devices being scattered across harsh environments, collecting the data requires professional manpower to integrate various unique industrial designs, making this an extremely difficult task. Let’s take a closer look at how IIoT technology can help virtual power plants ‘see’ by building a strong everlasting data stream foundation.
The Power to See: Demystifying Power Distribution Networks
To help distribution system operators (DSO) get the most out of a power grid, real-time knowledge of the load changes is critical, especially now that electric vehicles are becoming increasingly mainstream. A monumental task as a German DSO found out. As recent as 2020, this DSO was still unable to see the electricity consumption data for a low-voltage grid. Therefore, the operator turned to IIoT technology to achieve more transparency regarding the substation’s power data. The goal was to turn 21 categories of measured data, such as voltage, current, frequency, active/reactive power, etc., collected from the feeders every minute, into information that operators could easily view and understand. Such information combined with an optimized EV charging management system can maximize the existing power distribution system’s ability to deliver more power to the 2.3 million households it serves.
However, the feeders from substations not only vary in quantity but also come in different shapes and sizes while being dispersed in different areas. On top of which, to prevent the installers from accidentally touching other equipment during routine entries and exits, substations are often strictly controlled. Thus, posing two new challenges: First, how do we quickly install IIoT technology with less manpower? Second, how do we efficiently patch these IIoT devices scattered in different substations to ensure their safety? With these questions in mind, IIoT infrastructures need to meet the fundamental requirements of "easy to operate, safe, and can be seamlessly upgraded." Considering this, many system developers seek corresponding solutions.
In this case, the system integrator proposed an end-to-end solution that could quickly and securely deploy the IIoT devices without changing the design of the substation. Operators who are not familiar with IIoT technology can easily install it themselves. This system allows settings to be stored and managed remotely on a cloud device management platform. The settings can also be automatically imported into the field device after passing the security certifications, eliminating the need for tedious activation steps. In addition to resolving the issue with personnel expertise and resource scheduling, this solution also makes remote patches available. A powerful solution like this will accelerate the speed of grid upgrades and help promote the “Internet of Energy.”
The Power to Dispatch: Real-time Control
Historically, renewable energy generation is regarded as unstable and unpredictable. For it to be sustainable, the supply and demand needs be controlled and balanced. To achieve an optimal supply-demand balance, real-time monitoring and control is crucial. A feat that is easier said than done. For instance, under certain national grid codes, renewable power plants need to complete the adjustment of grid-connected power within 150 milliseconds. Since this window of exchange is so small, stable and reliable real-time data collection is imperative. However, stable data transmission is arduous due to the data-hosting equipment often being distributed in vast, mainly outdoors, terminal sites, where severe weather, salt erosion, or electromagnetic interferences are the norm. To prevent data loss and ensure the smooth transmission of data in real time, high-end network redundancy technology is in place. When one network is unavailable, data can be transmitted via the backup, ensuring uninterrupted data stream. Thus, creating a precise, 24-hour nonstop, real-time monitoring and control system. (Learn more about GreenPowerMonitor, DNV’s success story here.)
A Win-Win for Users and Operators
Besides monitoring the outdoor remote sites for operators, data can also be found in advanced metering infrastructure (AMI) that goes deep into homes and buildings. AMI makes electricity usage information fully transparent. Consumers can track their own electricity consumption down to the second through their cellphones, while grid operators can shorten repair time by using AMI to find abnormalities in real time without waiting for user notifications. Furthermore, after obtaining real-time user data, the "waveform" distribution of each household's electricity consumption can be calculated to better understand or even predict the consumption during each timespan. This information helps users avoid waste by turning off the air conditioner in a vacant space or even help providers match prices for specific time slots. However, to achieve this, electricity consumption information must be accurately returned to the operator's system. While household meters are not installed in environments as harsh as their outdoor counterparts, the layout of each deployment field is usually complex and diverse with a lot of human influence. Any tiny bit of carelessness could potentially affect the stability of communication. The operator could receive the wrong electricity usage information and miscalculate the electricity consumption. To avoid information loss, a store-and-forward technology is used when communication is down. The meter data can be stored first and sent out after the communication is restored to protect the rights of both users and operators.
Trading Virtual Power
When information becomes more transparent and the prices of renewable energy technologies become more affordable, users can also become producers. In other words, selling electricity to the grid in a timely manner is now possible. This shift makes supply-demand scheduling even more flexible. However, to achieve this level of flexibility, a secure and decentralized network is needed. Hence, more and more countries are combining virtual power plants with blockchain. Through blockchain’s smart transaction contract, safe and smooth purchase and the transfer of energy can by ensured due to blockchain’s decentralized, transparent, and nontamperable nature. Effectively, it gives consumers the freedom to choose from cheaper, sometimes unconventional sources, such as their neighbors, and skip the middle aggregators.
Through IIoT technologies, power grids are transformed from the experience-based management to data-driven management. Through multiple platforms and the participation of the general population, the grid can be more powerful. Power utilization rates will increase, power waste can be reduced, and a world with high energy efficiency can be truly realized.
For more on IIoT technology in virtual power plants, download our white paper here.