Today’s electrical power grid is over 100 years old, has been carefully designed and engineered and a number of operational standards have been developed to ensure a reliable electricity supply.
The Concepts Behind Traditional Power System Design
• Electricity generation is centralized in relatively few locations, generated by large power plants that can be easily controlled as needed
• Utilities and electricity system operators continuously work to meet demand for electricity; and this demand is relatively outspread, occurs at random locations and varying magnitudes and traditionally, not easily controlled
• The power system is like a gravity-driven water system, where the power flows “downhill” to electricity users; it is designed to deliver high-quality electricity to every user under all but extreme conditions and this delivery is controlled, for the most part, at the generating station
• Energy generally flows in one direction in the distribution network – from the sources of supply to the electricity customers
The Challenges of Today’s Evolving Electricity Grid
Today’s power system must deal with a number of stressors that power system engineers of 100 years ago would have never conceived of. Three major trends are pushing for a change in how the electricity grid is managed, giving utilities and system operators plenty of new challenges to solve to maintain reliability.
1. Renewable generation is intermittent and difficult to control – the wind doesn’t always blow and the sun doesn’t always shine when customers need electricity. Instead of a centralized location like traditional generation, wind turbines and solar panels are being installed at distributed locations across the grid. Although they are a low-cost source of clean and renewable energy, these resources may inject power into the grid at times and locations that can create difficulty for grid operators. Problems can arise, such as random changes in voltage on distribution feeders, issues with fault detection and unwanted generation capacity – which all affect the reliability and sustainability of the grid.
2. Energy-consuming equipment is changing with the advent of new technologies. Older electrical equipment such as incandescent lights, heaters and motors were designed to react to changes in voltage and/or frequency. In fact, conservation voltage reduction (CVR) is based on this concept. By reducing system voltage, the electricity demand from these devices will be reduced as well. Newer electronic devices do not respond to changes in system voltage or frequency, and they now dominate many homes; they include computers, lights (LEDs and CFLs), TVs, entertainment systems, etc. In addition to not responding to changes in grid voltage or frequency, these devices consume power in unusual patterns (called harmonics), which can affect the delivery of power and cause increased losses, equipment failure, and a few worst-case scenarios, building fires.
3. New protection systems and technologies have enabled the modern power grid to deliver more power than has ever been possible. For example, new wire technology has enabled existing wires to handle higher electrical currents for short periods of time; this can increase losses by more than 4 times the norm. While convenient and beneficial for today’s grid, these types of technologies have played a role in increased overall system losses from 5 to 7 percent to 9 to 12 percent.
So What Now? Addressing the Issues of the Modern Power System
The way that utilities and electricity system operators think about managing the grid has already begun to change. Instead of traditionally viewing grid management as one-directional and black and white (generation = controllable, demand = random and uncontrollable), grid operators are implementing demand management programs, which engage electricity customers to shift their electricity usage, improve their energy efficiency, enhance the reliability of the power system, and sometimes offer cost savings or other incentives for participation.
The next level of grid management involves taking this important step even further. With the use of new technology, utilities are now able to view the demand side as a single, controllable resource that can respond to the real-time needs of the electricity grid. The right intelligent demand management technology can help grid operators implement this type of control without impact to their customers’ operations.Follow @ENBALA