Last week, Broessel's project reached its $120,000 target on crowd-funding site Indiegogo, miles before deadline.
By Thursday he had raised $155,000.
The spheres, made from glass and acrylic, have no photovoltaic cells like a regular solar panel. They simply act like lenses to focus energy from the sun.
“We're in talks with manufacturers in Taiwan, and I think we have sorted something,” the 46-year-old architect told The Local.
Appearing to be a giant see-through ball hanging in a bracket, and known as Rawlemon, Broessel explained, it squeezes energy out of the sun, hence the name Rawlemon.
"The sphere collects sunlight and converts it into energy," he said, adding that it could even collect and convert moonlight, although not enough to power anything.
The idea came to Broessel one day at the breakfast table years ago.
“I was watching my daughter put a marble in an egg cup,” he said. “It was a Sunday and I saw the focal points moving on the sphere, and a project was born.” An eye, he said, works in a similar way.
And unlike regular solar panels, which not only take up a lot of space and do not, arguably, look as good as Rawlemon, a sphere can remain stationary.
“It was this optical tracking that was the real breakthrough,” he said.
In 2008 his clients started asking for smart, energy saving technology for the homes he was designing for them and he began putting his plan, inspired by his daughter playing, into action.
Nearly six years later with German government money and the crowd-sourcing campaign later, Rawlemon should soon be ready to power a house.
“A household with two adults and two children would need about three spheres to provide all their daily energy. This would cost about €10,000,” said Broessel. This would mean minimal to no energy bills.
Born near Düsseldorf, the father-of-two hopes that his invention will offer a more environmentally-friendly energy alternative that could prove especially popular as Germany shifts over to more renewable energy.
“I am currently waiting to see if I will get the model patented,” he said. “I was the first person to make something like this, and I'm sure I'll get the patent,” said Broessel. “I fought for it."
He admitted that what the company needed at this point was an industrial partner.
“We need this to overcome the costs of the first two to three years and to reach competitive prices,” said Broessel, who now lives in Barcelona.
But there is another problem that stands in Rawlemon's way.
“The energy industry is trying to block our project,” said Broessel. For now, all he can do is make contact with power companies - meetings with a few in Spain are already lined up - and hope for the best.
“If we want to reach the goals we have, we have to give it time,” he said. “Our team is growing and I hope in the future we can help make buildings more efficient, with lower operating costs.”