The national energy regulator wants to stabilise Western Australia’s electricity grid by controlling the state’s home solar panel output.
One in four homes in Western Australia now has a rooftop solar installation. As a result, solar energy is flooding the grid and even causing over-supply at times, particularly during the day.
In the case of household solar, the Australian Energy Market Operator (AEMO) is proposing that WA energy retailer Synergy or distributor Western Power take over household solar systems and batteries to control when they feed power into the grid.
Managed solar output could also lower prices
According to AEMO CEO Audrey Zibelman, distributed energy (DER) control methods can reduce power prices.
DERs are small generators like solar that AEMO cannot “see” because they are privately owned and not regulated like the big energy generators.
If these remain “invisible”, AEMO argues, it can’t manage the thousands of solar-generated megawatts flooding the grid.
However, this extra residential solar energy could be part of our energy solution if it’s properly orchestrated, Zibelman told a Lower House parliamentary inquiry.
Solar panels should act like traditional generators: AEMO
Traditional coal-fired power plants adjust output to suit demand, under AEMO’s regulation. They scale back production when demand is low to ensure the grid does not overload. Then they boost generation to meet peak demand at night.
On a sunny afternoon, demand for power might be low, for example. AEMO could then intervene to peg back home solar panel output being pumped into the grid. Power could divert to charge home batteries or a commercial scale battery owned by the retailer.
Households would opt in to the scheme, those choosing to take part would be paid for their input like any other power generator.
Batteries can stop home solar panel output overloading grid
Increased battery uptake is promising because excess solar energy can then be stored for later use, Zibelman says.
Households can use it during the evenings to reduce pressure on the grid, which must use coal, gas or wind power at night.
Solar battery storage has previously been an expensive option. Yet prices are falling rapidly for popular home models like the Tesla Powerwall 2 and Enphase battery.