A new plug-and-play solar thermal. Researchers at Lund University have invented a solar heating system that can solve the two biggest problems in solar technology: profitability and simplicity. The research aim has been to develop a solar heating system to connect to the existing water heater. This ensures that when the solar system is installed it is not required to be replaced. There is no need for new solar accumulator or drivetrain, which are two of the most expensive parts to purchase. So, no big changes in the house, making the system simple and cheap.