With winter approaching, more and more people are painfully aware of hefty hikes this year in energy prices. One environmentally friendly alternative to gas or oil is geothermal energy. Conventional geothermal heating units have cost around 20000 euros — but that could change. Heating technology specialist Vaillant is hoping to conquer the market with a new drilling technique using high-pressures jets of water. Vaillant say the new procedure can reduce costs by up to 30 percent. On average, some 600000 home heating units come in for repair or replacement every year, and many customers want to switch to renewable energy sources. That could represent an opportunity for Vaillant to grow. Grit Hofmann checked out the new technology.