Every day, Sempra enables the delivery of energy to over 36 million consumers, and we understand the critical role our infrastructure will play as we transition to an energy system that is lower carbon. The development of a lower-carbon energy system will result in dramatic changes in that system over the next 30 years.
Natural gas and its infrastructure will play a continuing role in enabling the energy transition and creating a more circular economy. According to many recent studies, optionality and flexibility will be needed for economy-wide decarbonization. This includes resources that can be used on demand when seasonal wind and solar power is unavailable. Natural gas is available, affordable and well-positioned to meet this need.
Shifting from Coal to Natural Gas
Coal-to-gas switching in the power sector was the largest driver of the sector’s emissions reductions in 2016, accounting for 33% of the reductions. This will continue to reduce emissions in the future. According to the U.S. Energy Information Agency (EIA), 23% of U.S. electric generation is still produced from coal; a switch from coal to clean burning natural gas can help further drive down emissions within the electric sector.
U.S. Emissions Reductions as a Result of Increased Use of Natural Gas and Renewables
in million metric tons of CO2 | data source
Enabling and Maximizing Wind and Solar Energy
Natural gas has and will continue to play an important role in the increased use of solar and wind energy. These renewable energy resources are intermittent — they must be used when the sun is shining or the wind is blowing. Once the sun begins to set or the wind dies down, solar and wind production decreases and natural gas fills the gap.
Additionally, natural gas generation provides the majority of California’s nighttime load, critical when high temperatures cause customers to use energy-intensive air conditioning units. Natural gas supports renewables by providing the flexibility for intermittent wind and solar resources to be seamlessly added to the grid without service interruptions to customers.
Texas provides a strong example of this relationship: the state is now number one in the U.S. for wind power — an achievement made possible, in part, by the availability and growth of natural gas generation: natural gas fills the gap when renewable resources are not available.
Adding Hydrogen from Renewable Resources to the Energy Mix
Because of the importance of wind and solar energy resources to a lower carbon energy system, we need to find ways to store the energy so that it can be used when needed. Battery storage is often thought of as the solution, and it will certainly play an important role. But even with advances in battery technology, batteries alone cannot replace the need for long-duration renewable energy storage solutions. This is where existing gas infrastructure can serve an important role.
A technology known as power-to-gas (P2G) is being deployed throughout the world as a complementary storage solution to batteries. P2G works by taking the electricity generated from solar and wind, combining it with a small amount of water and running it through electrolysis. This process converts the electrical energy into chemical energy, splitting the water molecule into pure hydrogen and oxygen. The hydrogen can either be used as a fuel or it can be blended with natural gas and delivered to customers through the natural gas system.