When engineer Rolf Wittwer retired in 2012, his dream project was designing an energy-efficient home near the town of Port Broughton in South Australia.
- More than 2 million Australian households have rooftop solar systems
- When solar systems feed extra energy into the grid, it can increase voltages on nearby power lines
- A UNSW study found voltages were already sometimes over the upper limit of what was allowed
Rooftop solar was a big part of his pl…