Time Is Energy

Array Control example

Here is an example of how a PV array owner might use the ability to control the output.

Let’s set up two arrays side by side; the second one has my control technology, and the first one doesn’t. Otherwise the two arrays are identical. The control technology allows a range of power outputs for any given light level, for comparison purposes, we’ll assume the default operating setting is in the middle of its range.

Summer day with full sun:

PV array 1: produces 90 units of power
PV array 2: produces 95 units of power (range can be set anywhere from 80-110 units)

Cloud blocking 10% of the sunlight comes along

PV array 1: production drops to 81 units of power
PV array 2: production drops to 85.5 units of power (range can be set from 72-99 units)

The cloud remains in the sky, and the operator decides to set PV array 2 to produce 95 units of power (again)

PV array 1: produces 81 units of power
PV array 2: production increases to 95 units of power (range can be set from 72-99 units)

The cloud goes away

PV array 1: goes back to producing 90 units of power
PV array 2: production increases to 104.5 units of power (range can be set from 80-110 units)

The operator decides to put PV array 2 back on default setting (i.e. to the middle of its range) just as things were at the start of the example.

PV array 1: produces 90 units of power
PV array 2: produces 95 units of power (range can be set anywhere from 80-110 units)

The default need not be placed in the exact middle of the range, I just did that to help illustrate. One could increase production to meet a demand spike just as easily as offsetting a decrease in light levels…but in that case PV array 1 would produce 90 units continuously, and PV array 2 can produce more power—say 105 units—for as long as necessary. Although now PV array 2 would be operating near the top of its range, and could only increase output by 5 more units at most.

posted by Daniel @ 9:51 AM