How green is my free parking structure? Still, not very.

Panoramic view of the NREL garage which is covered in solar panels.

No matter how many solar panels it has, your parking garage isn’t green, and especially if you don’t charge for parking.

Almost five years ago, we called out the folks at the National Renewable Energy Lab for claiming that their shiny new LEED-platinum candidate parking structure was some kind of environmental marvel.  Despite a plethora of solar panels, the underlying purpose of the garage is to facilitate car trips, and because NREL doesn’t charge anyone to park there, it represents a massive subsidy to driving and carbon pollution–exactly the opposite of the Lab’s stated mission and values.

This is a table of NREL Lab Wide Commuter Survey Results. it shows that most workers drive and very few walk or take transit.
NREL Lab Wide Commuter Survey Results show 83% of workers drove alone and 60-70% of staff telecommuted in 2021.

With the help of our colleague Tony Jordan who runs the Parking Reform Network, we thought we’d take another look at the NREL garage, to see how it is performing. Tony contacted NREL, and the lab’s Emily Kotz provided the results of their regular commuter survey.  Here’s a table of that data:

The data clearly show that most lab employees drive alone to the lab—little surprise, given its suburban location and the provision of thousands of free parking spaces.  The lab made some progress in reducing the share of drive alone trips through 2014, but in 2017 (shortly following the opening of the new parking structure), the drive alone mode share moved up.  The 2021 survey reflects the impact of the Covid-19 pandemic. While a majority of lab employees worked remotely (and weren’t included in the survey that year), the share of drive-alone commuters edged up to 83 percent (the highest level reported in any of these surveys.  NREL modified its reporting almost every year, so to clarify the multi-year trend, we computed the percentage of all commuters to NREL reporting driving alone (i.e. after excluding those who worked remotely from the totals).  We also combined scooter/motorcycle commuters with other drive alone commuters, as NREL did in three of the five survey years.

Background on NREL and its Parking Garage

The researchers at the National Renewable Energy Lab are hard at work on a lot of cool ideas for reducing pollution and promoting greater energy efficiency. They’re figuring out ways to improve photovoltaics and increase the efficiency of wind energy generation, and are a research leader in integrating these renewable energy sources into utility scale energy systems. The staff are also developing biofuels that could one day replace fossil fuels in transportation and other uses.  They have an entire program dedicated to transportation:

NREL research, development, and deployment (RD&D) accelerates widespread adoption of high-performance, low-emission, energy-saving strategies for passenger and freight transportation. Dedicated to renewable energy and energy efficiency, NREL and its industry, government, and academic partners use a whole-systems approach to create innovative components, fuels, and infrastructure for electric, hybrid, fuel cell, and conventional vehicles.

When the scientists working on tough problems of how to maximize the use of renewables and minimize energy use and pollution are charged with building the place they work, you can bet they’ll put a lot of thought into how to make things as smart and efficient as possible. It’s festooned with arrays of photovoltaic cells to generate electricity on site. Because it’s one of the lab’s newest structures, they’ve extensively modeled the daylighting of the building to minimize lighting requirements, and made extensive use of recycled (and re-cyclable aluminum).  The building’s lights are mostly on only at night, and only when motion detectors recognize occupants. This new $31.5 million building is shooting to be LEED Platinum and even be a “net zero” energy structure.

Photo of the NREL Garage entrance.
Net zero, provided you ignore what its used for. (Haselden Construction).

But there’s one big environmental (and energy) problem with this shiny new structure:  It’s an 1,800 space parking garage.  Not only that, but (if you’re Don Shoup, please don’t read this) they don’t charge employees anything to use the garage.  The whole thing strikes us as utterly tone deaf and a flat contradiction to the organization’s mission statement. So, in addition to the lab being located in a suburban office park on the fringe of the Denver metro area, its employees are strongly incentivized–nay, subsidized–to drive their private cars to work.  And that’s exactly what an overwhelming majority of them do.

A giant, free garage encourages energy consumption and pollution

In 2017, we contacted the Lab to learn more about commute patterns and parking policies.  They shared with use the mode split from their latest (2014) commuting survey.  Not surprisingly, about two-thirds of all workers drive alone to work daily, almost ten times the share that either carpool or vanpool.  (The 2017 and 2021 data are included above).

  • Drive alone – 65%
  • Walk – 0%
  • Bicycle – 4%
  • Carpool – 5%
  • Vanpool – 2%
  • Transit – 14%
  • Motorcycle/Scooter – 1%
  • Telework – 9%*

These figures represent typical commute patterns. As many as a quarter of lab employees telework at least some days, and the lab estimates that telework offsets about 9 percent of commute trips.

We asked about parking prices for commuters.  In 2017, Lissa Myers, who is the Lab’s Sustainable Transportation & Climate Change Resiliency Practice Leader told us:

Parking is free on our campus and we have an abundance of it.

Lissa Myers, NREL Sustainable Transportation & Climate Change Resiliency Practice Leader

That’s the problem, really.  We have an abundance of proven technologies that are “high-performance, low-emission, energy-saving strategies”–they include dense cities, cycling, transit, walking and car pooling.  But technologies don’t work, or don’t work well if we subsidize people to use energy-wasting alternatives and locate large concentrations of workers in places where they have few alternatives but to drive single-occupancy vehicles.

Location, location, location

Walk-Score for the lab is 30 and Transit Score is 40.

And because the lab is located on the urban fringe, rather than in a central, transit served location (like say, downtown Denver) its employees have few nearby housing options that would let them bike, walk or take transit to work. The lab has a Walk Score of 30 (out of a possible 100) making it “car dependent”–the nearest coffee shops, restaurants and grocery stores are more than a half mile away, and generally on the other side of the I-70 freeway, meaning that if they leave the lab for errands or a meal, its most likely they’ll drive.

Promoting renewable energy is (and energy conservation and greenhouse gas reductions) is a matter of both technology and incentives. An agency that’s supposedly dedicated to these tasks ought to do a better job of aligning its policies with its mission. There’s little hope that people will use a non-polluting bicycle or take transit to work, for example, if they have free use of parking.

Panoramic view of the landscape near the NREL Laboratory. Most of the image is grassy fields, the Rocky Mountains are in the background, the garage looms in the middle right of the image.
The garage dominates the landscape.

Excess capacity

We also have to note the capacity of the NREL garage, relative to the size of the institution is enormous. The garage, completed in 2012, contains 1,800 spaces, while the lab has just 1,500 employees.  So that’s about 300 spaces more than are needed to provide one space per employee.  Based on the lab’s mode split, only slight more than 1,000 spaces are occupied per day (about 975 by single occupancy commuters, about 30 more by carpools (if we assume 2.5 workers per carpool), and about 6 spaces for van pools (assuming six workers per van pool) and the equivalent of 8 spaces by motorcycles and scooters (assuming 2 two-wheelers per parking space).  That means the garage has almost 75 percent more capacity (1,800 spaces supplied for about 1,025 vehicles) than is needed to house NREL’s worker’s vehicles–and that a price of zero to the users.  (To be sure, the garage also accommodates visitors, but that doesn’t materially affect our analysis.  According to the NREL’s economic impact statement, the lab gets about 25,000 visitors per year, which works out to about 100 visitors per day; if they each needed a parking space for an entire day, that would work out to about 100 parking spaces. In reality, typical demand would be less because most visitors stay less than an entire day and many arrive in multi-occupancy vehicles or via transit or hired vehicles).

Having built the garage, their are powerful bureaucratic incentives to see it as full as possible; that, and employee resistance to having to pay for something that they’ve been given for free, means this problem is likely to persist. It’s hard to say what’s worse: an over-sized garage that’s mostly empty (representing a waste of resources that could be better used for other things, like say research on clean energy) or a garage that’s nearly full of single-occupancy vehicles (because its free to users). As we’ve suggested, and as our colleague Tony Jordan reminds us, dedicated parking garages are likely to become big stranded assets with the advent of autonomous vehicles. But it looks like that’s not something that’s on NREL’s mind.  The agency’s construction manager Tony Thornton tells the American Galvanizer’s Association NREL wanted a building that would last  for a 100 years. Whatever they’re planning for renewable energy, it doesn’t look like they expect it to influence car ownership or driving patterns, if they expect their parking garage to be around through 2100.

Aerial view of NREL Parking structure and adjacent surface lot (Google Maps)
Aerial view of NREL Parking structure and adjacent surface lot (Google Maps)

The claim that a parking garage can be “zero net energy” requires casting a blind eye to the structure’s central purpose. It’s only zero net energy if you completely ignore the energy used by the cars it’s designed to store, and that you ignore how building garages and subsidizing their use prompts more driving, more energy consumption and more pollution.

This article was originally published on City Observatory.

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