How Transmission Works
The need to develop renewable energy to mitigate climate change is more urgent than ever. In most cases, generation is not located near demand centers—this is especially true for renewable energy sources. Therefore, transmission is used to transport electricity over long distances.
As fossil fuel generation is phased out and renewable generation becomes the main source of electricity, detailed planning of transmission becomes essential to maintain reliability and resiliency, limit disruptions to communities and the environment, and remain cost effective for customers.
Getting Electricity to You
At Con Edison Transmission, we strive to source our electric transmission lines with renewable energy. There are six easy steps to understanding how transmission works and how electricity is delivered. Here’s an example of how transmission is used to connect customers to offshore wind power.
-
1. Source
Renewable generation can include solar, battery storage, onshore wind, or offshore wind.
-
2. Conversion
Offshore wind energy is delivered using Alternating Current over transmission lines, also known as “HVAC.” However, because offshore wind is often located at very long distances from demand centers, High Voltage Direct Current, known as “HVDC,” transmission is necessary. This requires an AC/DC offshore converter station to convert the power from the offshore wind turbines to HVDC before traveling over the long-distance underwater transmission line. Once it reaches landfall, the HVDC transmission is converted back to HVAC to be compatible with the existing electric grid, this requires another DC/AC converter station onshore.
-
3. Transmission Lines
Transmission lines operate at higher voltages (100 kV and above) to transmit a large amount of power, over long distances, with minimal losses. Transmission is used to both connect generation to the grid and provide more paths for energy to flow between generation and demand centers. Transmission can improve reliability, lower costs, and bring more clean energy to customers. Transmission lines connect substations and require transformers to step the voltage down before it can be used by customers. Depending on the project, transmission cables can be placed underground (often in a power corridor) or above ground with transmission towers.
-
4. Substation
Then when the transmission has arrived at the desired region, the voltage is stepped down to a lower level for distribution.
-
5. Your Community
Finally, the power makes its way to you, all with no delay, despite the journey.