How can we effectively store solar PV?
The Insight
One third of Australian homes are equipped with rooftop solar, generating energy during sunlight hours. This energy is typically fed directly into the home to power electrical fittings and appliances.
During the day, the energy supply can exceed the immediate demand for energy. This means the energy generated needs to either be stored onsite or exported to the grid. If stored onsite, typical stationary battery systems can store between 5 and 20 kWh. When excess PV generated energy is exported, two things can occur:
As coal-fired power plants don’t have the ability to modulate their energy production down far enough when there is no demand, the spot price of electricity can dive.
The localized network can be oversupplied with energy which can cause voltage fluctuations that can damage appliances and cause overheating of network infrastructure such as transformers.
Due to the erratic nature of renewable generation, oversupply to the grid regularly causes issues in certain regions.
So, how can we avoid excess renewable-generated energy from being fed into the grid to begin with? How can we effectively store solar PV?
The Impact
When installing solar, you likely have two key motivators:
Save money long term
Reduce your environmental impact
With solar, there are multitudes of scenarios where these motivators conflict.
If you are exporting excess power back into the grid, you will save money but you will increase your environmental impact.
If you invest in onsite battery storage, you will decrease your environmental impact but you will increase your immediate spending.
Electric cars are slowly taking off in Australia as our options diversify. Many of these cars have Vehicle-to-Load capability which allows your electric car to essentially act as a giant solar storage battery for your home. While your car is plugged into your solar-powered home, you can feed electricity in both directions. While purchasing a battery may not make complete financial sense, electric cars have many varied uses.
Virtual Power Plants (VPP) are currently being rolled out across the country by power companies. VPPs allow properties with battery storage to export power from their battery to the grid to meet peak demands at night. Many of these VPPs also offer discounts for the initial battery purchase and installation.
This technology coupled with Vehicle-to-Load capability will speed up the transition to 100% renewable energy. With enough momentum, fossil fuel-based energy generation can be eliminated in the residential and small to medium commercial sector.
Currently, 35% of Australia’s CO2 emissions are caused by energy generation for electricity. The more homes and commercial properties that rely on virtual power plants instead of coal-fired power plants, the closer we are to achieving net zero in this sector.