According to the Clean Energy Council, more than 3 million Australian homes are now harnessing the power of the sun to power their homes. That’s 4 in 10 houses across the country – making Australia one of the leaders of installed rooftop solar in the world.
Last year saw a 40% increase in installations, with rooftop solar now making up 7% of the energy going into the national grid. But we’re now faced with a real challenge: Are we capturing all this renewable energy correctly?
Investment in renewables is heating up
For many Australian households, the ability to cut their energy bills and carbon footprint is high on the priority list. And with the amount of sunshine the country experiences all year round, it’s no wonder that solar energy is a popular choice. Combined with generous government subsidies and the plummeting costs of photovoltaic technology, investment in renewable energy is exploding.
So, then, what’s the problem? The challenge we’re now facing is that the increasing amounts of solar on roofs is presenting technical challenges for the grid. The dramatic surge in solar output has resulted in periods of massive energy oversupply, especially when the weather is nice and sunny.
This oversupply leads to energy being wasted due to the need for ‘solar curtailment’; when a solar system shuts down or stops exporting energy to the grid to counter the energy spike. And without careful management, energy regulators say grid stability could be at risk if there is more electricity going in than coming out. When demand outstrips supply, it can threaten the system’s reliability and stability.
And then, there’s little solar generation during peak times – for example, in the evening when the sun goes down. Which means other power generators, such as coal or gas powered plants, need to run to meet the demand.
Australia needs flexible management of energy exported to the grid
What if demand for energy could be better matched to coincide with the times when renewable electricity is cheap and abundant, when the sun is shining and the wind is blowing? If only it were that easy to convince 26 million people to only use electricity during the day, and make sure to turn off the power at night.
The alternative is to find a solution to harness all of the power that’s generated during the day and feed it back into the grid during the evening. Storing more energy from times of plentiful generation will help to balance fluctuations in supply and demand, and ultimately, help to balance the grid.
Electric vehicles offer a perfect solution for energy storage
The Australian Renewable Energy Agency (ARENA) is supporting a range of projects to find a more flexible way to meet energy demand. These include trials of programs managing the charging and discharging of batteries and electric vehicles, orchestrating consumer-owned energy devices, activating hydrogen electrolyses when energy is plentiful and cheap and undertaking more industrial processes onshore.
One of these trials, known as electric vehicle-to-grid (V2G) technology — is when a car battery can be charged and discharged based on different signals to help support the grid. This technology has the power to transform the energy system.
How vehicle-to-grid (V2G) technology works:
- The electric vehicle is plugged into the grid and is set up to automatically charge at a certain time.
- The battery is charged during off-peak hours when the vehicle isn't being used (the driver is either at work or working from home) and solar energy is high, typically between the hours of 11am and 3pm.
- The driver commutes to and from work and uses a fraction of the battery’s capacity.
- Once the driver gets home, the idle car is plugged into the grid at peak hours (typically after 5pm), and electricity is sold back to the grid if there is demand for it.
- Some of the battery’s capacity is reserved for the drive the next day, if required.
- The cycle is then repeated.
Unfortunately, the electricity grid system was never built to be omnidirectional. It was designed to take power from where it is generated to where it will be consumed. So vehicle-to-grid technology is still being developed, but it’ll offer the possibility of two-way energy management for the country.
Another project that is currently underway in Australia is vehicle-to-home (V2H) technology. Vehicle-to-home (V2H) is similar to the V2G, but the energy is used locally to power a home, instead of being fed into the electricity grid. This enables the electric vehicle to function much like a regular household battery system to help increase self-sufficiency, especially when combined with rooftop solar. Another benefit of V2H is the ability to provide backup power in the event of a blackout.
Going solar makes sense, if harnessed properly
Ultimately, looking to a future where renewables contribute more of our energy, there is a need for new ways to balance the grid. And Australia’s rooftop solar boom may only just be warming up, with BloombergNEF expecting total capacity to surge six-fold by 2050.
If coal-loving Australia were able to properly harness and store solar energy using electric vehicles, and push the energy back into the grid at peak demand times, it would not only help to stabilise the grid, it’d make our country a renewable energy powerhouse and a world leader in the technology.