Barcelona city council has installed Spain’s first photovoltaic pavement as part of the city’s drive to become carbon neutral by 2050.
The 50 sq metres of non-slip solar panels, installed in a small park in the Glòries area of the city, will generate 7,560kWh a year, enough to supply three households.
The city has contributed €30,000 (£26,000) towards the cost, the remainder being met by the manufacturer, Platio Solar. The viability of the scheme will be assessed after six months. “We’ll have to assess the wear and tear because obviously it’s not the same as putting panels on a roof, although they are highly resistant,” says Eloi Badia, who is responsible for climate emergency and ecological transition at Barcelona city council.
“As for cost benefits, with a pilot scheme like this it’s difficult to know yet how much cheaper it would be if it were scaled up. We’re keen to install more on roofs and, if this scheme is successful, on the ground, to power lighting and other public facilities.”
However, he points out that Barcelona’s high population density means it would be difficult to generate enough electricity within the city limits to become self-sufficient.
“If we’re going to reach a target of zero emissions, we’re going to have to think about supplying electricity to blocks of flats, but we’ll also have to think of using wind and solar parks outside the city,” Badia says. “But installations on the ground like this open up new possibilities, and not just for Barcelona.”
Most of Spain’s solar power comes from large farms in remote areas where land is cheap but which are a long way from centres of population. The move now is to increase capacity close to where it’s most needed, in cities.
“What we need to focus on is green policies to create employment, specifically to install solar panels on 1m rooftops,” says Fernando Prieto, executive director of the independent think tank Sustainability Observatory. “This would take five years, generate enough electricity for 7.5 million people, create over 15,000 jobs and cut CO2 emissions by 4.2m tonnes.”
He adds that it would lower the price of electricity and help citizens to become independent of the few power companies that dominate the industry.
“However, instead of this simple project, we are building installations of over 1,000 hectares on agricultural land and woodland, often with a negative impact on the environment,” Prieto says.
Under the previous conservative government solar installation came to an abrupt halt after punitive taxes were introduced. In 2018, the incoming socialist coalition scrapped the tax, triggering a boom in solar, with Spain now ranked 11th in the world for solar power and eighth for renewables overall.
Major retailers have got in on the act and now firms such as Ikea, electronics giant Media Markt and the department store El Corte Inglés are offering domestic solar installations at an average cost of €5,000 for a three-bedroom house.
Meanwhile, the government has announced plans to invest €1.5bn of EU Covid-recovery funds in the production of “green” hydrogen, using renewable energy to break up water molecules and release the hydrogen. Spain’s energy companies have said they will raise this to €8.3bn by 2030.
Some scientific achievements are large and flashy—like imposing robots—while others are incredibly small, fast, and nearly invisible. And as a record-breaking laser pulse reported by scientists in a new study shows, even these tiny-sized advances can pack a ton of power.
For the Korean research team led by senior author Chang-hee Nam, a plasma physicist and professor at Gwangju Institute of Science & Technology, their breakthrough in laser science may be a physically small feat (striking an area the size of a micron) but will have a huge impact on how we study not only cosmic phenomena from the beginning of time but how we treat cancer as well.
After ten years of toiling, the team has demonstrated in a paper published on Thursday in the journal Optica the development of a laser with record-breaking intensity over 10²³ watts per square centimeter. Nam told Motherboard in an email that you can compare the intensity of this laser beam to the combined power of all of the sunlight across the entire planet, but pressed together into roughly the size of a speck of dust or a single red blood cell. This whole burst of power happens in just fractions of a second.
“The laser intensity of 10²³ W/cm² is comparable to the light intensity obtainable by focusing all the sunlight reaching Earth to a spot of 10 microns,” explained Nam.
To achieve this effect, Nam and colleagues at the Center for Relativistic Laser Science (CoReLS) lab constructed a kind of obstacle course for the laser beam to pass through to amplify, reflect, and control the motion of the photons comprising it. Because light behaves as both a particle (e.g. individual photons) as well as a wave, controlling the wavefront of this laser (similar to the front of an ocean wave) was crucial to make sure the team could actually focus its power.
Nam explains that the technology to make this kind of precise control possible has been years in the making.
“We have developed ultrahigh power femtosecond lasers for more than a decade, reaching the output power of 4 PW (1015W) in 2017,” says Nam. “We then developed the laser technology to focus the beam size of 28 cm to 1 micron, for which we have to make the laser wavefront superb using a deformable mirror.”
Nam said that the ultrahigh power laser design played a role in this discovery by helping remove beam distortions while the deformable mirrors made it possible to have “extremely tight focusing without any aberrations.”
Beyond being a scientific breakthrough, Nam said that this high-intensity laser will open doors to explore some of the universe’s most fundamental questions that had previously only been explored by theoreticians.
“With such ultrahigh laser intensity we can tackle such phenomena as electron-positron pair production from light-light interactions… This kind of phenomena is supposed to happen in the early universe, plasma jets from supernova explosions and from black holes,” said Nam.
Thanks to these lasers, and even more powerful ones yet to come, Nam says that it will now be possible to explore these cosmic rays in the lab instead of just through simulations and theories. Using laser pulses, the researchers will be able to make and collide high energy electrons with photons, recreating the Compton scattering effect that scientists believe creates such high-energy cosmic rays.
Nam also said that these lasers have a more terrestrial purpose as well in the form of cancer treatment technology.
Proton therapy is a newer cancer treatment that directs positively charged proton beams to patients’ tumors using an accelerator. While this technique has shown promise, the use of an accelerator also requires a large, and expensive, radiation shield.
Nam proposes that using laser beams to direct these protons instead could be a more cost-efficient solution and may get this treatment into the hands of even more patients.
“The development of cheaper proton oncology machines will be exciting news for cancer patients,” said Nam.
The laser beam itself may strike and vanish in the blink of an eye, but it’s about to have a huge impact on the world of physics and beyond.