If we want to slow the pace of climate change, we have no option but to move away from conventional sources of energy. Even without alternatives to coal and oil factored in, however, the future is set to see grids carrying more and more electrical energy as demand continues to rise.
In response to our move toward new forms of energy, the proportion of large-scale power plants (nuclear, coal, and gas) contributing to grids is expected to drop from 70 percent today to between 56 and 32 percent. This means that we will be able to produce 52 to 79 percent of electrical energy without emissions, depending on which 2040 scenario plays out.
Solar and wind power will account for the largest energy share, but the amount that these renewable resources are actually able to produce will fluctuate over the course of the year and day to day as local wind, sun, and water conditions change. As many of these plants are also much smaller than their conventional counterparts, the switch to renewable resources is set to have a noticeable impact on grids. The effects of this include:
New power control methods:
Grid operation will need to adapt to fluctuating electrical energy provision in order to cover demand. Where coal bunkers were once the storage solution of choice, there is now demand for short-term and long-term energy storage methods as a way of regulating the available power balance. The storage technologies with the most focus include power-to-gas plants, pumped-storage power plants, and batteries.
Structural changes in grids:
Most renewable sources of energy are installed in locations where the supply of primary energy (wind, sun, biogas, or biomass) is at its most plentiful — not necessarily where demand is highest. Supplies of energy are also becoming increasingly dispersed and renewable plants tend to be smaller than conventional ones.
Many producers are shifting away from transmission grids in favor of distribution grids. Due to the fluctuating supply of primary energy, the installed capacity (and therefore the connected load required) in relation to annual energy yield is much higher than it is in conventional power plants. This means that both distribution grids and transmission grids will need to be expanded in many cases.
Growth of power grids:
As the world moves toward alternative resources, demand for electrical energy is also expected to rise by 50% worldwide and power grids will be required to transport this additional energy. The capacity needed for transportation will depend on supply and demand over the course of the day. Renewable methods of generating energy create larger fluctuations on the supply side because, due to natural conditions, the operating times of wind power plants are only around 40 percent of conventional plants—and just under 15 percent in the case of solar plants.
As a result, much higher capacity levels need to be installed in order to deliver the same amount of energy. Integrating road transportation into the grid also brings new fluctuations on the demand side, which may result in a need to expand the grids, depending on their reserve capacities.
Increased grid flexibility:
Grids operate with reserves that they can use in exceptional circumstances and as a backup in the event of problems. As a result of structural changes and increased electricity levels, the capacity of grids will be used more intensively at all voltage levels and, in response, grids will need to be strengthened and provided with relief measures using a more flexible approach to supply and demand. Smart grids, smart meters, new electricity trading concepts, and more flexible price models will be needed to achieve this.
Expansion in grid technology:
Apart from the production and consumption of energy, a further technological development is taking place in electricity grids. Wind plants, solar plants, electric storage devices, electrolysis plants, charging infrastructures for electric vehicles, and numerous consumers all have one thing in common — they both supply and are operated with direct current. As a result of the move toward renewable forms of energy, the installed capacity of direct-current systems in many grids already exceeds that of conventional alternating-current systems (generators, drives, and alternating-current consumers).
The use of converters that work with power electronics is set to rise in the future. New equipment with power electronics and new conventional equipment can be used to face the challenging situations presented by operating the grids of the future. Grids are also likely to become more and more automated — but their requirements for reliable operation with high-quality current and voltage will remain the same.
Do you have any questions about the grids of tomorrow?
Stephan Rupp, Business Development Manager for Power Electronics, will be delighted to answer them:
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