From solar panels to a black, sun sponge — Experts develop new laser-ignited tech but end up creating a strange effect

When you picture solar panels, what comes to mind is probably flat, black rectangles on a roof. They’re functional and efficient, but hardly exciting.

That design hasn’t changed much, because physics has favored the traditional technology. But now, researchers have something new on offer.

It’s a material that behaves like a “sun sponge,” absorbing heat in a fresh way.

Are you ready for a form of solar technology that challenges the familiar, including a new effect?

Solar panels are flat, black and boring

If there’s one thing most people picture when they think “solar panel,” it’s a flat, dark rectangle sitting on a rooftop. That look hasn’t changed much in decades — and there’s a reason for it.

Solar panels are typically made from silicon crystals that are most efficient when they absorb sunlight instead of reflecting it.

Black surfaces are the best option. Monocrystalline silicon material is dark black, letting panels capture as much light as possible, which is turned into electricity. This is why the design is the most common form.

You might have seen blue panels before, which were made from a different type of silicon crystal, but newer panels are almost always black. Some are incorporating gold but they are still black in color. This is because they perform better and generate more power per square foot.

In other words, solar tech hasn’t stayed “boring” because engineers lack imagination. It’s because the flat, dark design still works best with today’s physics and manufacturing methods.

Experts develop a “sun sponge” to absorb sunlight 

When you think of next-generation solar tech, it’s unlikely that what comes to mind is a black sponge.

However, that’s exactly what scientists from the University of Rochester have been developing: a radically redesigned solar thermoelectric generator system that can be compared to a sun-soaking sponge.

Unlike traditional solar panels that rely on silicon, this system uses a device called a solar thermoelectric generator (STEG).

It doesn’t convert light directly; it turns the heat from sunlight into a temperature difference between a hot side and a cold side to generate electricity using the Seebeck effect. This is where heat flow creates a voltage that can be drawn as power.

But here’s the clever part: the Rochester team used femtosecond lasers to etch metals into an ultra-black surface that traps sunlight like a sponge. The amount ofheat the device can capture and convert is boosted.

It’s a new way of thinking about capturing solar energy; less about panel technology and previous shortcomings, and more about soaking up heat itself.

It’s like turning on 15 solar panels. Or maybe it’s beyond that

This isn’t your typical solar panel upgrade, it’s a completely different way of harvesting sunlight. Instead of conventional photovoltaic cells that turn light directly into electricity, researchers have been working with STEGs. The breakthrough comes down to the material at their heart.

At the core of this new tech is a laser-etched “black metal” surface. The metals, for example, tungsten, are blasted with laser pulses at ultrafast speeds. That process turns the surface pitch black. The ability to absorb and retain heat from sunlight is enhanced. Traditional STEGs have problems with efficiency, often converting less than 1% of sunlight into power.

With this black metal approach, the energy conversion performance jumps to about 15 times higher than what earlier STEG designs could manage.

For decades, solar meant flat, black, predictable.

This “sun sponge” idea flips that expectation. Instead of just catching light, it traps heat and squeezes more usable energy out. That 15-fold jump in performance for thermoelectric systems isn’t a small tweak — it’s a new way to harness sunlight.

You won’t see spongy rooftops tomorrow, but you may start seeing solar installations that look and work differently than you’re used to.