1. Electricity from streets and parking lots
Much space for solar panels already exists above roads and parking lots, as well as on noise barriers and hard road shoulders. But its potential remains largely untapped in these places. This is slowly changing, partly because modules are becoming cheaper and more flexible.
For example, in southern Europe, supermarkets are increasingly covering their parking lots with solar panels, giving shoppers a shady parking space and a place to charge their electric car. The electricity can also be used to power things like freezers and refrigerators in supermarkets.
Solar energy is also being harnessed along roads by installing modules on noise barriers or hard shoulders. In Germany and China, the first solar roofs have already been installed on roads. As an added benefit, they also reduce traffic noise.
Solar modules are also being installed on the tops of buses and trucks to generate electricity for heating and cooling.
The next step is to integrate solar cells directly into the car body. This allows electric cars to generate some of their own power – and prototypes are already being tested.
2. Solar energy from railway track
In 2025, Switzerland begins testing its first solar power system installed on railway tracks. One day, the electricity generated on the tracks may also be used by the trains traveling along them.
The modules are placed using a special machine, can be easily dismantled if necessary and do not interfere with operation.
According to operator Sun-Ways, covering all 5,000 kilometers (3,107 mi) of railway track in Switzerland with solar modules could generate about 1 terawatt hour of electricity per year. This will meet approximately 44% of the electricity needs of Swiss Railways.
3. Masks with invisible solar cells
Installing solar cells on rooftops and small modules on balcony railings is now a widespread practice. But it is also possible to integrate solar cells into walls and facades. Solar glass facades come in many colors and are much less noticeable than traditional solar modules.
But their efficiency depends on their location. For example, in Central Europe, south, east and west facing facades produce 30% to 60% less electricity than comparable systems on rooftops.
Nevertheless, galvanic glass facades last for several decades and save on painting.
Rooftop solar energy options are also becoming more diverse. For example, instead of regular panels, building owners can opt for roof tiles with integrated solar cells.
According to calculations by the Leibniz Institute of Ecological Urban and Regional Development, Germany could meet its entire electricity needs if it installed photovoltaics on all its suitable roofs and facades.
4. Double cropping: power above, farming below
Farmers can harvest double crops by installing solar systems in their fields. Modules mounted on stilts generate electricity above, while crops grow below. In sunny areas, shade is especially welcome – it reduces plant evaporation and helps save water.
China is also using this combination to help green parts of the Gobi Desert. Solar farms produce large amounts of electricity, while the vegetation growing beneath helps prevent desertification and restore soil fertility.
Combining solar power generation and agriculture is just as cost-effective as generating electricity from large rooftop areas – and it’s profitable for farmers.
The global potential to generate solar energy on agricultural land is enormous. In Germany alone, about 80% of the country’s electricity demand could be met by combining solar energy production with crop growing on agricultural land.
5. Floating solar parks on lakes, seas and rivers
Solar energy isn’t just limited to land – it’s now making waves in the ocean. Floating solar panels and stilt-mounted structures are turning ponds, lakes and even oceans into clean electricity generators.
The world’s largest offshore solar power plant was completed last year off the coast of Dongying, China. Capable of producing 1 gigawatt of electricity, it rivals the output of a modern nuclear power plant.
Many of the world’s lakes and reservoirs hold untapped potential for solar energy. For example, in Germany, studies show that about 7% of the country’s electricity needs could be met by installing solar panels on flooded open-pit mines, gravel pits and reservoirs. This is according to a Study by scientists at Fraunhofer ISE,
6. Photovoltaics from space?
Solar modules have been powering satellites since the 1950s. Today, the International Space Station and other spacecraft also rely on electricity from the Sun.
But for decades, scientists have dreamed of not only harnessing solar energy in space, but also bringing it back to Earth.
One idea is to place giant solar sails in orbit that capture sunlight, convert it into microwaves and transmit the energy to humans. On the ground, huge antennas spanning several kilometers will receive microwaves and convert them back into electricity.
However, this extraordinary solar technology is still in its very early stages. This is incredibly expensive, and will leave behind millions of tons of space debris.
Some countries including America, China and Japan are doing pilot projects and research on extraterrestrial lightning. But whether it will ever make sense to use solar energy generated in space on Earth remains uncertain.
This article was originally written in German.