Robin Smith, left, and sister Kimberly Smith drove from Pennsylvania last month to visit the project. (Michael Laris/The Washington Post)

When Kimberly Smith dragged her sister to Washington last month, their first stop wasn’t the White House or the Jefferson Memorial. It was a patch of tricked-out pavement in Dupont Circle.

The Smith sisters made the trek from the Poconos specifically to experience the District’s “Smart City” experiment in human­-generated power. But as they paced on sidewalk tiles designed to collect energy from their footsteps and turn on a strip of interactive lights, Smith couldn’t help being a bit disappointed.

“It’s a great thrill. But I have my questions right now,” she said.

While the underground generators beneath the pavers were capturing the Pennsylvanians’ energy, the interactive lights weren’t switching on as they walked. “They’re not working,” Smith said, dancing around just to make sure. “That’s unfortunate.”

Project boosters had bounced around on those same triangular tiles during an opening ceremony in November, prompting six little lights embedded in the pavement nearby to glow in sync with their footsteps.

It wasn’t exactly Michael Jackson tearing it up on a glowing sidewalk in his “Billie Jean” video. But it worked. And it highlighted the broader pitch from Pavegen, the British sustainable-energy start-up behind the technology, which touted its “ability to connect physical and digital worlds through a single footstep.”

The company says it is in talks with officials in Chicago, San Francisco and the Middle East about additional installations, and executives are raising money to spur production and drive down costs, which are far higher than those of traditional pavers. Washington is the first test case for the latest version of the company’s technology. And the real world has at times been humbling.

“We’ve got a crazy challenge, and there are tweaks being made,” said Laurence Kemball-Cook, Pavegen’s founder.

Among the issues: Washington’s winter weather has made energy production 5 to 10 percent lower than expected, Kemball-Cook said. “The main thing we will be doing is testing out some ‘DC’ optimized generators that should be better with the temperature variances,” he wrote in an email.

The system also is getting fewer steps — and thus less energy — than anticipated, Kemball-Cook said. People walking toward or coming from a nearby Metro entrance sometimes end up missing the strip of high-tech pavers or cutting across them.

“When pedestrians cut the corner they are only doing a few steps on the array rather than the expected 10 to 14 steps,” Kemball-Cook said, reducing by up to 20 percent the amount of energy piped into a big battery system. “We should have moved the whole thing two feet to the left.”

Another of the three patches of pavers had somewhat more traffic than expected, so the complete “footfall” numbers aren’t yet clear, he said.

Still, the company needed to do some triage.

The human-generated energy was intended to power two light displays — the interactive lights in the sidewalk and LEDs meant to glow at night under new park benches. There was also a relatively power-hungry digital uplink feature that was supposed to feed a Web page with data on energy production.

Kemball-Cook said the company made some temporary technical adjustments. The result: The Web page and interactive lights haven’t been working, but the bench lights have.

After delays due to the inauguration and a hang-up at customs, Kemball-Cook said, company technicians are expected to be on site as early as this weekend to investigate and make fixes.

The District Department of Transportation has overseen the $300,000 project, which includes new sidewalks, planters and benches as well as the 194 high-tech pavers in the city’s newest miniature park. Pavegen received about $100,000, city officials said.

“We continue to monitor the progress of the project and work collaboratively with Pavegen,” DDOT said in a statement. “We are aware of the technical challenges and have been informed that Pavegen staff will be here as soon as this weekend to address the issues.”

Leona Agouridis, executive director of the Golden Triangle Business Improvement District, which provided some of the funding, said she’s pleased to see the cooperation between the city and the company.

“The first couple tries, or the first couple months or whatever, is a learning experience for everybody,” Agouridis said. “Everybody hopes that this great innovation is going to be perfected to the point where it can be applied on a larger scale. This is a smaller scale. It’s kind of like a controlled laboratory.”

Not everyone is as patient.

“I’d just rather have a well-designed sidewalk that drains properly — and no gimmicks,” said Samuel Barber, a District-born dog-walker, who came by this week. “If we’re the test case, did we pay the full price or did we get a discount?”

Kemball-Cook said as with any innovation, the early days can be daunting.

But the partnership between the District and his company will benefit both, he said, and he can envision sharing later iterations with the city.

“We’ve got this shared vision to make this as great as we possibly can,” Kemball-Cook said. Whether it’s “a road that generates energy” or a related innovation in the future, “we’ll probably give them that to test as well, because there’s that relationship.”

Another letdown for Smith was that “no one knows what they’re walking on,” she said.

As she visited, many seemingly oblivious Washingtonians power-strolled their way through the winter chill, often ignoring the tiles. She noted that there was no placard informing pedestrians what was underfoot or that they, as the technology’s fans hope, could be on the vanguard of a sustainable-energy revolution.

Though Smith is eager for the kinks to get worked out, she remains a believer. The artist has been following Kemball-Cook’s progress online for years. “Laurence invented these in his bedroom — it’s really incredible,” she said.

“We drove four hours to walk on these,” said Robin Smith, who came along for the ride. “She’s my sister. What’s dear to her is dear to me.”