Once upon a time there was consensus that renewable energy is too expensive and too sparse to be a sustainable source of energy to power our proud, electrified societies. Since then, the prices of solar panels have risen and become more efficient along the way, and homeowners have installed them in droves on their roofs.
Where it used to be thought that we would never have enough solar energy, it is becoming too much in some cities. In South Australia, where solar output can be very large on a sunny day, the electricity authorities are struggling with grid stability and are taking steps to limit solar power to the grid.
Isn't more usually better?
The problem facing South Australian utilities is how to properly control a power grid with many thousands of distributed power sources. Typically, in conventional modern power grids, voltage and frequency are controlled within set limits by carefully matching the supply of large power plants to user demand. Fast-reacting plants can be brought online to fix deficiencies and turned off when demand drops and everything is going well.
Unfortunately, solar power is not that easy to throttle, and even less so when it comes from thousands of separate households, each with their own roof installation and an inverter that can be fed back into the grid. This has led authorities to consider measures such as asking homeowners to export energy to the grid at peak times in order to slow down the massive proliferation of residential solar systems. Export restrictions have also been proposed for suburbs with the highest concentration of solar energy, as substations in certain residential areas struggle to cope with the enormous inflows of energy. Continue reading “South Australia Vs. Too Much Home Solar”