The following column is the opinion and analysis of the writer.
Tucson Electric Power is significantly reducing carbon emissions from an energy portfolio that includes more renewable energy and less coal than ever before.
Our evolving energy mix will include 41% less coal and produce 35% less carbon dioxide by the end of 2021. And we’re not stopping there.
We’re working with our customers and other stakeholders, including climate experts at the University of Arizona, to develop a long-term carbon reduction target. That goal will build on significant advances already underway at TEP and is intended to help our company and community do our part to address climate change.
Renewable energy is already a big part of our plan. In addition to the resources we’ve already deployed, we’re currently developing two giant wind farms and a large solar plus storage system that will double our company’s community-scale clean energy capacity.
But renewable energy alone isn’t enough. Many people don’t realize the electric grid is a real-time operation; utilities must supply the energy customers need at the very moment it’s used. Wind turbines and solar arrays can only contribute to such a system when wind and sun are available. They must be supported by resources that can be quickly ramped up and down to serve changing needs.
Energy storage systems can help by holding on to the output of wind farms and solar arrays until it’s needed. Batteries are the most accessible storage option, and TEP is installing them at an ambitious pace. But they aren’t yet robust enough to replace traditional resources, and their environmental and safety impacts must be better understood before their use becomes more widespread.
While battery prices have fallen enough to allow development of some large solar plus storage projects, those systems can’t match the reliability of traditional resources. To provide some perspective, the largest grid-tied energy storage system in the world could serve just 5% of the energy that TEP’s customers use during a single hour of a hot summer day.
That’s why natural gas is critical to our transition toward more sustainable energy sources. Natural-gas-fired power plants produce about half as much carbon dioxide as coal plants while providing energy around the clock. Shifting from coal to natural gas has reduced the carbon intensity of the U.S. power generation fleet by 11% since 1990, according to Environmental Protection Agency data.
For TEP, the recent purchase of a unit at the natural-gas-fired Gila River Power Station provides an affordable, reliable replacement for retiring coal-fired units.Meanwhile, new natural gas-fired engines at our Sundt Generating Station will reduce the plant’s emissions and water use by 60% and 70%, respectively.
These efficient, flexible resources will be critical in helping us use even more wind and solar power. Together, they form the foundation of a more responsive and responsible energy portfolio. Their cost, which is reflected in TEP’s current request for higher rates, represents an investment in the long-term health of our community and our planet.
TEP is responding to the threat of climate change with immediate action. We would readily embrace a realistic opportunity to replace fossil fuels with massive solar and storage systems. But such systems simply aren’t ready, and we cannot afford to wait.
By replacing coal plants with a combination of natural-gas resources and renewables, TEP is taking positive and proactive steps right now toward a more sustainable energy future.
David G. Hutchens is chief executive officer of Tucson Electric Power.