Energy, The Grid and Battery Storage - Battery Storage
Part 4 of 4
By Randall Pearce
The rapid uptake of new renewable energy sources including solar and wind is driving down the generation cost of energy but increasing the need for more storage to cover periods of low supply, at night or little wind.
A growing way of storing electrical energy within the grid is chemical batteries (by reversible internal chemical reactions). Many very large battery banks are being built in regional areas, to store generated renewable energy for rapid dispatch when the demand for power spikes.
Neighbourhood batteries, which are generally located “in front” of the meter (i.e. on the street side of consumers’ meters) are now being installed, which can locally store from 300 to 5,000 kWh of electrical energy, close to consumers. Local distributor Jemena is currently installing several such neighbourhood batteries for this purpose. These “solar soaker” batteries will store excess solar power for later consumption during late afternoon and evening peaks, which will have immediate direct benefits the grid. The main benefit of these to the local community might be the avoidance of future restrictions on new solar installs, although they may also offset and consequently limit the imposition of some of the charges for new infrastructure.
Village Power likes to refer to our neighbourhood battery as a true “Community Battery” due to our objective to return some financial benefit to those in our local community who take part in the trial project and subscribe to the battery. We plan to import low-cost green energy when available and to maximise the storage of locally generated rooftop solar energy, for reuse in our homes during peak periods. This will be achieved via an innovative retailer-administered business model for the benefit of the local Village Power community, as well as the local power grid, whilst also making the local grid more resilient to fluctuations in supply and demand. A true community battery has the potential to be a cheaper and more flexible way of storing energy than a personal behind-the-meter battery.
We hope that some of those who cannot generate their own renewable energy locally (such as renters or those in highly treed areas) will be able to source it at competitive rates via this battery, so they can also play a part in transitioning the local grid to clean energy. It is hoped that this trial project will lead to others adopting such community battery models, in order to rapidly modernize and debottleneck some aspects of the power grid. It should permit an acceleration of solar energy generation in built-up areas on houses, schools and commercial buildings, which each have their own peak load characteristics, which helps to share the stored energy cost effectively.
Consumers can buy and install their own “behind the meter” batteries (on their own premises) to store excess solar energy, for use when the sun is not shining, or to export back to the grid. Retailers normally pay around 5 cents per kWh exported, compared with 25 – 35 cents per kWh for imports.
But as time progresses, payments for exports will drop towards zero (or will become negative at times) as the exports from rooftop solar PV systems increase. The cost benefits of individual batteries in Victoria are somewhat limited due to their cost, with payback times of around 10 years.
When a new development site is being set up with a common power supply for a number of buildings, businesses, residences or community facilities; the combination of rooftop solar generation and behind-the-meter batteries, has been shown to reduce the overall cost of purchased energy, with internal metering for the individual consumers. For example, a large combined solar PV and battery bank was installed in the new Bellfield Community Hub.