The Green Space | Let’s Talk Renewable Energy

You’re using electricity, right now, to read this article on an electronic device. I’m using electricity to write it on my laptop. Your lamp is shedding warm electric light, your fridge is humming in the kitchen, electrically generated hot air warms your room. We use electricity constantly, without even thinking twice.

We often think of electricity as being clean — a silent, invisible stream of energy generated by some unseen force. Out of sight, out of mind. Yet, in 2019, 63% of electricity generation was from fossil fuels, including coal, natural gas and petroleum. Nuclear provided 20%, and only 18% came from renewable sources, including wind, hydropower, solar, biomass and geothermal. Considering how much cheaper and more ubiquitous renewable energy has become, why is well over half of our electricity still generated using carbon-emitting fossil fuels?

The short answer is that our grid is not equipped to handle renewable energy. Electricity, unlike other resources, must be used the moment it is generated. As of now, it can only be stored on a small scale, in batteries like the ones we use in our phones and other electronic devices. There is no reservoir of excess electricity, waiting to be tapped, and serious problems can occur when the electricity provided is too much or too little to fulfill demand.

Too much electricity can cause blackouts as power lines shut down to prevent dangerous power surges, while too little electricity can result in engineers bringing the oldest, dirtiest, least efficient machines online to make up the difference. Or, in the worst cases of peak demand, which occurs only a few times every year, too little power could also result in a protective blackout to prevent an overtaxing of the grid. Electricity production must always match demand exactly, which necessitates a system of generation that is predictable and easy to control. Renewables, many susceptible to the whims of weather patterns, don’t provide such a system of generation. Fossil fuels do.

Let’s look at a hypothetical example. Back in the pre-pandemic days, when people regularly left the house for a nine-to-five job, energy consumption would begin peaking in the evening when people arrived home, switched on lights, tuned into their favorite TV program, cooked dinner on an electric stove and cranked up the air conditioning.

Simultaneously, as the sun inched toward the horizon, solar power would peter out, leaving the evening’s activities entirely dependent on fossil-fuel generated power. Even when renewables are part of the equation, because their generation is so variable — wind being even less predictable than solar — fossil fuels still have to fill in the gaps.

Our vast grids, with nine interconnected systems covering all of North America, are built to rely on centralized production of electricity, which is then distributed widely to households many miles away. Private ownership of renewables — think solar panels on the roof, wind turbine in the yard — creates a challenge to that system. The utility companies that hold responsibility for distributing electricity are legally obligated to purchase excess electricity from private owners, as long as they produce a certain baseline amount.

At the same time, utility companies cannot force any private owner to power down their wind turbines or cover their solar panels when too much electricity is coursing through the grid, or control when owners draw energy from the grid, if a cloud happens to drift over the sun or the air suddenly stills. Our grids necessitate precise and constant control, and renewables wrest that control away from the utilities that are charged with keeping the lights on.

Despite the problems that renewable energy presents, there is no question that we must increasingly transition away from fossil fuels and toward wind, solar and hydropower. The good news is that there are many potential solutions, only one of which I will mention here.  

One of the most obvious shortfalls of renewable generation is that there is practically no way to store excess energy produced by a particularly gusty day or the bright summer sun. So, what else is there? Well, if you can’t control supply, control demand.

As our homes and workplaces become more and more electrified, all those devices can be bundled together into one unit with separate parts that can be automatically tweaked to keep demand at more consistent levels. Many electric processes, like heating up water for a shower or automated factory work, can be moved to low-demand times to soften the peaks of high-demand times, reducing the amount of fossil fuels needed to keep up with that demand. Such processes could also be modified to correspond with energy surges and dips from renewable generation. Because water holds thermal energy for a very long time and many factories no longer require human input, changing the timing of these processes would not create many inconveniences in daily life, while still making a positive impact on the grid.

The grid’s vastness here serves as an advantage — it would only take a few tiny tweaks here and there to make a huge difference. Of course, many logistical hurdles still remain in implementing such a plan, and though it would certainly decrease the need for fossil fuels, the question remains: would it be enough, and would it come fast enough?

Ultimately, there is no easy solution, no quick and painless way to incorporate more renewables into the grid. That doesn’t mean it’s impossible, and it certainly doesn’t mean we should stop trying. In fact, such a problem presents an opportunity for beautiful innovation, for many solutions, small and large, for a new and improved way of producing and using electricity. 

If you’d like to know more about this topic, I would highly recommend “The Grid: The Fraying Wires Between Americans and Our Energy Future” by Gretchen Bakke. It’s a fascinating read.

Sarah writes primarily about trees, climate change and walking. You can reach her at sas503@pitt.edu.