Remote monitoring and control of distributed generation is essential
Published on : Saturday 04-02-2023
Rick Rys, Director of Consulting, ARC Advisory Group, Boston
Green Energy is a buzzword today. How can automation and control help to scale up the Green Energy solutions to industrial levels?
Automation and control are required to run processes safely, efficiently, and securely. These characteristics apply to both process plants and electric grids. A refinery may have an ESD (Emergency Shut Down) system for safety, a DCS system for I/O and control, and higher-level software applications for MES functions. The central control rooms of grid operators cover a much wider range geographically and gather data from generators to consumers using a wide range of subsystems and communications protocols. Safety is implemented in various protective relays, and control must regulate frequency, voltage, and power. The electric grid is quickly shifting to renewables which demand new market-based controls to keep power flowing at low cost and high reliability to handle increasingly dynamic conditions. New communications standards at substations like IEC 61850 can ensure high speed, redundancy, and security. Remote monitoring and control of distributed generation is essential. Microgrids that can smoothly connect and disconnect from a larger grid are part of the future automation.
Power and Energy are frequently used (incorrectly) as interchangeable, but they are different terms. Power is the instantaneous quantity of energy. Many applications use energy out of a storage system, most common being batteries. The process of capturing energy in a battery at a time of surplus and using the energy at a time of need is an old concept, both in stationary applications and also in mobile vehicles. The hitch is that, both the storage and withdrawal have many losses involved. What are recent advances which drastically reduce such losses?
Energy is the capacity to do work and comes in many basic forms – potential, kinetic, chemical, and nuclear, for example. All these basic energy sources can be converted to electrical energy. Electricity has amazing ability to do useful work with highly efficient electric motors; but converting electrical energy into a form that can be stored for later use is one of the biggest challenges of the energy transition due to the high cost and efficiency losses. Capacitors and batteries are efficient with high power, and while lithium battery costs declined by 97 percent over the past 3 decades, they are still very expensive for long-term storage, and leakage cuts into efficiency over periods of days and weeks. Pumped hydro can provide both high power and can store massive amounts of energy but takes years to build. There is an unprecedented level of competition to find low-cost ways of storing electrical power for future use with different solutions.
Generation of electricity from fossil fuels is attributed with generation of over 40% of CO2 emissions. Automation can play a big role firstly in creating the dashboards and also helping with algorithms to reduce these emissions. What are the trends in this matter which is occupying the mind space of leaders the world over?
New EPA GHGRP (Green House Gas Reporting) rules require reporting of greenhouse gas (GHG) data and other relevant information from large GHG emission sources, fuel and industrial gas suppliers, and CO2 injection sites in the United States. Approximately 8,000 facilities are required to report their emissions annually, and the reported data are made available to the public in October of each year. Improved automation can slightly improve operating efficiency of existing gas and oil power plants, and while important, these gains are not at the scale needed to bring down emissions to the levels that meet global warming targets like the 1.5 degree goal by 2050. Only process modifications like CCUS (carbon capture usage and storage) or huge, but unlikely breakthroughs in direct air capture of CO2 can save fossil powered generation and still meet global warming goals. One important trend is the reduction of Scope 1 and Scope 2 emissions to produce fossil fuels by reducing methane leaks and finding ways to power fossil production with renewable power. There are new automation challenges to accurately measure methane leaks and to automate and optimise new fossil power processes that involve CCUS and hydrogen.
Traditionally power transmission meant transporting energy generated from large utilities to consumption centres located well away. But today, with various alternate means of generation, who also have an ambition to export energy to the grid, the patterns have changed. There are multiple points of generation of various capacities with different constraints, which might impact grid stability. What steps are taken to induct the new technologies of AI and ML into this challenging area?
One of the biggest new sources of energy in the US will be offshore wind off the shallow Atlantic coast with some 74 GW of power already in the queue. The plan is to have 30 GW in operation at a cost of more than $62 billion by 2030. Getting this power to shore is a project developer issue but upgrading the transmission system to move that power to where it is needed is in the planning for grid operators like ISO-NE, NYISO, and PJM. Grid operators are working with FERC (Federal Energy Regulatory Commission) to create new capacity markets and find ways to fund these new transmission investments. AI and ML applications that can accurately forecast the unpredictability of wind and solar energy production will aid in managing grid operations to improve grid reliability and minimise the emissions from other sources. Using machine learning, wind power will improve asset management and maintenance planning to maximise the capacity factor to keep these rotating machines healthy and thus more profitable.
One of the major challenges in power distribution is disruption to power supply due to faults in the distribution system. This forces many entities to resort to captive power generation systems, which are of a smaller capacity, and then usually of lower efficiency. One attempt all along has been to localise and repair faults rapidly. What new technologies have entered this field?
One of the technologies that have evolved from improved monitoring of transmission lines is dynamic line rating. With the use of synchrophasors, line temperature monitoring, and integrated real-time weather monitoring, power lines that previously had fixed power ratings can be operated with higher power if conditions allow. While some power lines will be upgraded by reconductoring using high performance conductors, dynamic line rating can be a much lower cost solution.
Utilities have increasingly used GIS (Graphical Information Systems), new secure and redundant communications standards like IEC 61850 to gather massive amounts of substation and IoT data, and sophisticated tools like RTCA (Real Time Contingency Analysis) to avoid outages. Utilities use various other asset management software to manage outages, manage repair part supply chains and to manage fleets of trucks, repair crews, drones, and satellites to keep vegetation trimmed, keep power flowing and to minimise repair time when outages do occur. With the advancement of lithium batteries, grid forming inverters, wind turbine controls, and more capable backup generators, previous solar and wind farms can form microgrids that increase the resilience of the grid and keep critical infrastructure operational.
In a smart city, metering of electricity consumed needs smart meters. These meters need to do more than just measure the flow of power; they may also need to track time-of-day consumption, maximum demand and such parameters. What are the latest techniques in this field?
The vision of smart meters was fantastic, but the result has been underwhelming so far. The reasons why are many, but involve regulations and development of new utility business models where competition has not always been welcome. In the US, FERC order 841 issued in February 2018 stated that barriers to distributed and behind-the-meter energy storage participating in wholesale electricity markets should be removed. This eventually opened the door for grid scale batteries. In 2020, FERC issued Order 2222 with the intent of opening the regional transmission organisations (RTOs)/independent system operators (ISOs) wholesale markets to aggregations of distributed energy and demand response resources, but due to slow roll out of these market rules, very few US utility customers can participate in the various grid service markets and get rewarded for the substantial value a large number of small players can provide. Utilities are adapting but so far only crude methods are employed to avoid all EV owners plugging in when they get home from work – only exasperating peak load issues. The early smart meter did little more than collect usage information for billing. Future smart meters will need to provide value for both the customer and the utility. The Sense Power Monitor application gives some indication of the valuable and well-presented data a smart meter could provide to the customer. That same meter can provide important information to the utility about the state of demand, the load on distribution lines, and issues with power factor, voltage, and power quality. Current and voltage measurement is easy, the problem is the aggregators are only just starting to be enabled with the various ISO/RTO rules where utilities finally give up some level of control and fairly share the value that a grid connected customer can provide with fun gamified software that gives customers the ability to control all their electric power consuming devices, support grid reliability and benefit from cheaper power.
(The views expressed in interviews are personal, not necessarily of the organisations represented)
Rick Rys is an expert process control engineer, familiar with instruments, valves, analysers, control algorithms, safety systems, software development, and project management. Rick has worked in chemical, oil, gas, power generation (including fossil & nuclear), power T&D, renewable energy, pharmaceutical, paper and building automation areas. At ARC he performs research into and consults with clients on technology areas such as energy management, advanced process control (APC), simulation, and optimisation.
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