Here in Massachusetts, solar energy is not yet a big deal. But it is a growing force, and in my recent explorations of how I might incorporate it into my own life, I ran into the Duck Curve. Why it’s named that is obvious, as you can see by glancing at the chart below.
Reading from left to right, it shows the net electric load on the electric grid throughout a typical March 31 in California, from midnight to midnight.
As the sun rises in the morning, and more and more solar panels begin to generate electricity and reduce the load on the grid, net demand drops, until at about 1 PM, net demand is lowest. Then as the sun sets and people arrive home and turn on their appliances, air conditioners, etc, net demand quickly rises.
Projecting current trends, the established utilities, who use the duck curve to spread their message, project that the spread of solar power installations will lead to a deeper belly for the duck (as more and more electric power is supplied by non-grid power) and thus an increased ramp up (the neck of the duck). And it’s the slope of that ramp up that utilities say could lead to big troubles, because the biggest, most efficient fossil fuel-burning plants can’t ramp up capacity that fast.
One of their suggestions (those bright guys at the utilities) is to constrain solar generating power at peak times. But that just doesn’t seem right. In fact, it seems plain wrong!
The answer, obviously (to me), is to find ways to store that energy generated during peak solar hours and then put it back into the grid a few hours later as demand grows.
And what’s the best way to do that?
Now, batteries are expensive today, but that doesn’t mean they’ll always be expensive.
In fact, there is one fast-growing supply of batteries right now, and as this supply grows, costs are guaranteed to come down. It’s electric cars, and the biggest concentration of them is in California. So, if all those electric cars had the ability (charging stations installed at workplaces would help), those cars could absorb some of that solar production during the day and thus make the ramp up the duck’s neck less steep in the evening.
Getting back to me, here in Massachusetts, I recently received a quote on installing solar panels on the roof of my house, and I’m going to go through with it, once I replace my asphalt shingles, which are nearing the end of their natural life. But as I was thinking through the possibilities, I realized that my Tesla Model S, which has a battery capable of storing 85 kWH of electricity could easily store all the power my rooftop array would generate during the day and then release it to my house at night—if my car were home during the day and if my car were engineered to put energy back into my house.
In other words, the parts to the solution to the (coming) problem are already on the way. And with the right incentives (rational pricing), I’m confident a solution will be found—provided that the utilities and their regulators allow such solutions.
So don’t let the duck curve scare you. Solutions will appear and in the long run, we’ll all benefit from the spread of cheaper, cleaner solar power.