Solar-Plus-Storage System can Increase Solar Power Plant Output
Florida Power & Light Company (FPL) today unveiled a new, cutting-edge solar-plus-storage system that is believed to be the first in the country to fully-integrate battery technology with a major solar power plant in a way that increases the plant's overall energy output.
By incorporating this new technology into the FPL Citrus Solar Energy Center, a solar power plant that was built in 2016, FPL expects to increase the amount of solar energy that the plant can deliver to the electric grid by more than half a million kilowatt-hours a year.
"Every day, we work on new ways to better serve our customers with technology innovations and efficiency improvements. That's how we continue to set the standard for advancing clean energy affordably – including building solar power plants at a lower cost than anybody. Now, with advances in battery storage technologies, we are looking at the next level," said Eric Silagy, president and CEO of FPL, at an event with environmental and community leaders in DeSoto County today.
"By harnessing more solar energy from the same power plant, this has the potential to further reduce our fossil fuel consumption and save our customers even more money on their electric bills,” Silagy added.
The new system features a 4,000-kW/16,000-kWh storage capacity comprised of multiple batteries integrated into the operations of the FPL Citrus Solar Energy Center. In addition to enabling the plant to provide more solar energy to the grid, the battery system is capable of storing the energy and dispatching it to the grid at a later time.
How the cutting-edge new system works
The new solar-plus-storage system unveiled today is the first large-scale application of "dc-coupled" batteries at a solar power plant in the U.S. It has the same advantages of other universal solar-plus-storage installations, such as the ability to store energy and dispatch it to the grid at a later time.
A unique advantage of dc-coupled batteries is the ability to harness extra energy that a solar plant generates when the sun's rays are the strongest.
During these optimal operating periods, a solar plant may generate more power than its inverters can process, resulting in some energy inevitably being lost – or "clipped" by the inverter. Unlike other batteries, a dc-coupled system can capture this extra clipped energy, thereby increasing the amount of energy the plant delivers to the grid.
The additional solar energy and the increased predictability afforded by battery storage can enable FPL to more efficiently dispatch other power plants, helping save customers on fuel costs.
This technology has the potential to harness millions of kilowatt-hours of solar energy a year that would normally be lost and improve the predictability of solar energy, which naturally fluctuates with the sun's availability. Increased predictability enables FPL to more efficiently dispatch other power plants, helping save customers on fuel costs.
The FPL Citrus Solar Energy Center is one of three solar plants FPL operates in Florida's DeSoto County – a community that boasts more solar panels than residents.
In addition to the FPL Citrus Solar Energy Center, DeSoto County is home to Florida's first solar power plant, the 25-MW FPL DeSoto Next Generation Clean Energy Center, which was the largest of its kind in the nation when it was built in 2009, and the 74.5-MW FPL Wildflower Solar Energy Center, which entered service on Jan. 1, 2018.
FPL is in the midst of one of the largest solar expansions ever in the eastern U.S. with more than 520MW – 3.5 million new solar panels – added in the last two years alone and nearly 300MW more scheduled to enter service by March 1. From 2016 to 2023, FPL expects to install a total of more than 10 million solar panels. These advancements continue to improve FPL's carbon emissions profile, which is already approximately 30 percent cleaner than the U.S. industry average.
Moreover, FPL's eight newest solar plants combined are projected to generate more than $100 million in net savings, over and above the cost of construction, for FPL customers. Investments like these help FPL keep rates low for customers over the long term.
Today, FPL's typical 1,000-kWh residential customer bill is lower than it was more than 10 years ago and approximately 25 percent lower than the latest U.S. average. (FPL rates are decreasing again on March 1.)
For several years, FPL and other NextEra Energy companies have been researching and testing battery-storage technologies to study a variety of potential benefits ranging from grid stabilization to improved solar integration. Currently, NextEra Energy companies operate approximately 130MW of batteries with more than 100MWh of storage capacity.
In 2016, FPL commissioned several battery-storage pilot projects to test different applications under real-world operating conditions. Systems are currently being tested at Everglades National Park's Flamingo Visitor Center, the Crandon Tennis Center on the island of Key Biscayne as well as other locations across south Florida. Learnings from these pilots are being applied to FPL's future plans.
Under the rate agreement supported by the state's consumer advocate and approved unanimously by the Florida Public Service Commission in 2016, FPL plans to develop 50MW of battery storage over the next few years.