Can an all-renewable grid power an all-electric economy?

A relative sent me a video clip the other day of a guy in front of a Tesla charging station, warning ominously about how much energy electric vehicles use. The point of the video seemed to be that charging stations draw so much power that the grid won’t be able to handle the increased load.

It's an important question: Can the grid handle switching all our cars and homes to electric? And that question rests on top of another: How will the grid, which was developed originally for conventional sources of energy under a different era, operate with far more wind, solar and distributed energy sources? 

Let me assure you that utility executives and electrical engineers are spending a lot of time trying to figure out how to manage this transition while keeping the lights on.

I recently spoke about this with David Bleakley, Vice President of Engineering at Holy Cross Energy. Holy Cross is actually in the forefront among utilities moving toward carbon-free electricity, and has set a goal of making the electricity it delivers 100-percent renewable by 2030 on an annualized basis.


By Dave Reed
This column was originally published in the Jan. 16, 2024 edition of the Glenwood Springs Post Independent.

Bleakley said that while he and his colleagues may not have all the answers today, they’re confident they’ll be able to solve the anticipated problems for Holy Cross to hit its 2030 target. It will undoubtedly take longer for the larger grid to get there, though.

Various factors are speeding the transition to a greener grid. To begin with, the cost of renewable energy has plummeted by about 90 percent in the past decade, which has completely flipped the economics of electricity generation. Simply put, wind and solar farms are now better investments than fossil fuel power plants in most situations, and the big utilities are bringing new renewables online and retiring old plants at a rapid clip.

Another game changer is battery storage. A decade or so ago, it was accepted wisdom that renewable energy could only ever meet a small portion of demand because of its intermittency, and fossil fuel plants would be needed to supply the “baseload.” Thanks to the increasing affordability of lithium-ion batteries and the advent of other storage tactics, utilities are able to utilize more of the electricity generated by wind and solar and lessen their reliance on fossil-fueled power. Over time, EVs are expected to function as additional battery storage devices on the grid, providing even more flexibility.

Meanwhile, the grid is getting “smarter,” giving utilities new tools for making more optimal use of the energy they’re already producing.

Running the grid is all about meeting peak – not average – demand. Every utility experiences demand spikes; for most it happens on summer afternoons, when AC units are working hardest, although in Holy Cross territory it’s winter nights. No utility wants to be caught short at those times (as has happened in Texas in recent years) so, as Bleakley said, they’re incentivized to “build the church for Easter Sunday.”

But thanks to smart meters, digital controls and an increasingly decentralized grid where electricity can flow both ways, utilities are better able to shape demand and shave off those peaks. If the utility avoids building another substation it can save the ratepayers millions. It’s the equivalent of adding a second service instead of building a bigger church.

Another way to even out supply and demand is to build more long-distance, high-voltage transmission lines to integrate the patchwork of regional distribution grids into one larger grid. Unfortunately it takes several years to get regulatory approval to build such lines, and they often face legal challenges. This is a major hurdle that grid operators are trying to overcome.

But going back to that video: will the grid be able to meet the extra electricity demand from EVs, heat pumps and all the other wonderful electric conveniences that are yet to be invented and that we’ll eventually believe we can’t live without?

I put that question to Bleakely, and his answer was a nuanced yes.

Local utilities are certainly anticipating increased demand due to EVs, he said, but extending power to new charging stations is really no different than extending power to a new subdivision – it’s what utilities do. There are predictions that the grid will eventually have to double its capacity to supply an all-electric economy, but Bleakley sees some promising signs that energy efficiency may be able to offset some of that increase. The annual rate of increase probably won’t be that much greater than what we’d expect just from population growth.

Along with the utilities, state and local governments and nonprofits are working behind the scenes to smooth the transition. Garfield County is currently developing an EV-readiness plan to guide the county on how to prepare for the expected growth in electric vehicles. The state of Colorado provides grant funding for the installation of public charging stations, and CLEER provides free assistance to grant seekers in our region.

The shift to electric vehicles will be entirely voluntary, so realistically it will take decades, as will the creation of the charging infrastructure to go with it. Fully electrifying buildings will probably take even longer. But there are a couple of things to remember.

First, these technologies aren’t going to increase our overall energy consumption – in fact, they’ll reduce it. Rather, it’s a reallocation of resources from certain forms of energy (fossil fuels) to others (renewables).

Second, while the transformation of the grid will require significant investment, it will take place over decades. That’s why utilities like Holy Cross think they’ll be able to adjust in time, even if they don’t know exactly how it will all work just yet. The flipside of this coin, though, is that this is why climate experts are so insistent that there’s no time to lose – we need to be making measurable progress every year in order to meet the US’s stated goal of being carbon-free by 2050.