Babcock Ranch solar array. FPL image.
George Harvey
The sun doesn’t always shine, but so what?
It doesn’t prevent solar power and batteries from providing electricity 24/7 during a hurricane that shut down the grid in Florida. The big thermal plants just could not deliver electricity on the failed grid. Some people say we need baseload power plants for reliability, but they had to shut down in the power failure. And as they showed us once more how unreliable they can be, a well-designed solar array with battery backup will just keep on delivering.
Baseload power plants, whether they burn fossil fuels or react nuclear fuel, are vulnerable in ways that solar power and batteries are not. Baseload power plants are designed to deliver electricity at full power or not at all. Without the load of an active grid, they have to shut down. And when they shut down, it can a long time for them to get back to full power. They have problems that a combination of solar power with batteries doesn’t have. And with those problems, there are reliability issues.
Hurricane Ian made landfall at about 3:00 on Wednesday afternoon near Fort Myers, Florida. The eye of the storm was nearly 35 miles across, and hurricane-force winds extended 15 to 25 miles beyond the eye wall. After landfall, Ian continued to make its way to the northeast.
About 25 miles to the northeast of Fort Myers, there is the planned community of Babcock Ranch (BR), with 2,000 homes. At the time Ian’s eye came ashore, BR may already have been experiencing hurricane-force winds, but the winds were sure to get stronger as the wall of the eye moved closer. BR, however, had an advantage that could allow it to beat the hurricane. That advantage was solar power with batteries.
By the time Ian left Florida, over 2 million people had lost power. We can easily imagine that much of the state was pretty dark that night. It turned out that there was one bright spot in the darkness. In BR, a community of 2,000 homes, the lights stayed on the whole time.
BR was designed to be resilient. To be resilient, a community has to have electricity regardless of the condition of the power grid, and that electricity is supplied by a microgrid. Two elements of the design are easily envisioned and vitally important. One is a solar array that will produce enough energy to provide for the microgrid’s needs; the other is a battery that will store power so it can be supplied on demand at any time. The microgrid also needs equipment that will isolate it from the grid so it does not send energy out onto a grid that is broken. One final thing is that it needs a distribution system to get the electricity to the places where it is needed, and for best resiliency, that distribution system is not vulnerable to weather problems.
Baseload power plants are inflexible and require other kinds of power plants to follow demand. By contrast, solar power is easy to control, so it can be cut off if there is no load for it to supply. Batteries can be controlled to provide for demand rather precisely. Together, they are very flexible, and the power adjustment can happen automatically, using computer controls. Solar plus batteries can adjust to changes in load demand instantly, where the old baseload system took several minutes at least. That gives solar plus batteries an important advantage over the old baseload system.
Looking at resiliency, however, we can see that a microgrid, powered by solar plus batteries, can be set up to keep going even when the grid fails. This is done by isolating it from the rest of the grid. One last is to make sure that the system will withstand whatever weather will hit it.
We do not yet know what the precise weather conditions were at Babcock Ranch during Hurricane Ian. We can be fairly sure they were hurricane conditions because of the community’s position on the storm path. One thing that we know is that the solar array and the batteries suffered a small enough amount of damage that they just went on working.
Designed to be resilient, BR also has had no interruption to its water supply or internet. It is the only community in Southwest Florida where these systems have continued to operate, according to reports.
We have an update of this article scheduled for the next print edition of Green Energy Times.
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