At SRP, we are committed to using cleaner energy to power your lives. With all the news about our solar energy plans lately, we thought now would be a good time to cover how solar works.
We recently introduced two of our biggest carbon-reducing renewable energy facilities – CO Bar Solar and the Bolster Substation. One a solar generation facility, the other a large-scale battery site.
Both facilities help to advance solar in the desert. But how?
The answer lies in better understanding how solar interacts with Arizona’s power grid and why there can’t be one without the other. Spoiler alert: One captures energy while the other stores that energy to be released the instant it is needed.
Here’s more about how Arizona’s grid works.
Power play: How solar is evolving our grid
Our communities are powered by electricity delivered through an interconnected series of power plants and wires. Together they form the grid.
Traditionally, large power plants located far away from customers send high-voltage electricity over long distances via a transmission system to smaller distribution stations located closer to customers. The distribution stations then reduce the electricity’s voltage so that it can safely travel into homes and businesses.
The grid’s components must harmoniously communicate with each other to ensure a constant flow of power. This means that the flow of power must increase or decrease to match the variable nature of customer demand.
Learn more about what “customer demand” means and how it affects how we provide power.
The variable demand requires SRP to maintain a reliable energy mix that can supply enough electricity to more than 1 million customers during peak hours.
Turning sunshine into electricity
So how does solar fit into this scenario?
Much like a plant’s leaves which turn sunlight into food, solar panels turn sunlight into electricity. During the process of capturing sunlight, electrons are knocked off atoms, directing the electrons onto SRP’s grid.
SRP collects solar energy from two sources:
- The excess from systems owned by SRP customers; and
- SRP’s contracts with large, or “utility-scale,” solar farms.
Customer-owned solar systems are stationary panels installed by residents or business customers typically on the roofs of their homes, buildings or even parking lot structures. Many find the investment to be worthwhile simply because it’s better for the environment, and we wholeheartedly agree.
SRP also signs contracts for utility-scale solar projects. Much like buying in bulk at Costco or Sam’s Club, SRP purchases solar energy in large quantities to get our customers the lowest prices.
Utility-scale solar, known to many customers as solar farms, may use big panels that slowly rotate and follow the path of the sun throughout the day. This allows them to generate energy for more hours of the day than fixed panels.
This type of solar is funded by a utility and mixed with other power sources. Thus, all our customers are participating in solar energy. Bonus: You don’t have to maintain the equipment!
Here’s why solar panels need battery storage
One thing to consider is that the time of day where solar energy output is highest does not align with when customer demand is highest. As you can imagine, the largest spike in customer demand is seen after work hours when customers are returning home.
The second-largest spike in demand occurs in the morning when customers are typically preparing to leave their homes for the day. Both rooftop and utility-scale solar systems decrease production right at the time our customers need it most.
Additionally, electricity must be available at the very moment you need it. You flip a switch, we send more electricity.
While the sun is abundant here in the low desert of the Southwest, cloudy days do occur and the sun does go down every night. So how do we provide reliable power with an intermittent resource like solar?
Battery storage to the rescue
Fortunately, battery storage systems like the Bolster Substation allow SRP and its customers to capture clean renewable energy produced during sunny hours and release it on demand. That way, solar power is available even when the sun is not shining.
Battery storage is still a new and expensive resource. Engineering experts around the world are working to better understand battery storage and help batteries sync with the rest of the grid.
As our learning progresses, we look to batteries as a flexible asset that will bridge the gap between when solar power is produced and when it is distributed. It also helps us keep power reliable while adding more renewable, carbon-free energy.
While solar energy is a critical step in combatting climate change and decarbonizing, it takes thoughtful planning to integrate it into our energy mix. That’s why we are taking a measured approach to keep our customers in power with other reliable and affordable sources while bringing more solar online.