Due to its relative infancy however, the technology is yet to be optimized. In more mature markets, storage comes into its own through spot price trading, selective energy export and tariff arbitrage. Currently, the vast majority of consumers with storage are merely shaving off their evening peak and continuing to pay high flat-rate electricity prices. Of course, this approach is susceptible to weather conditions, and only allows one discharge per day. Without a guarantee of sufficient cover, customers avoid time-of-use tariffs (TOU), resulting in limited savings and extended pay back periods. Whilst a single discharge model has become the norm in the industry (reflected by warranty cycles rates as low as 6,000), it’s clearly not the most efficient use of storage technology.
Whilst every household’s consumption pattern or ‘load curve’ is different, the majority follow similar trends. Due to the current colder winter conditions for example, typical households will experience considerably higher peaks in both the morning and early evening. The added demand placed on hot water systems, heating and lighting throughout winter will often leave the solar coming up short, often resulting in less than one cycle per day.
Introducing Senec’s unique bi-directional inverter technology, intelligent battery management system and ‘peak-shaving’ software. This latest innovation from Senec allows users to draw a charge from the grid, giving them access to the cheapest off-peak power.
As shown in the diagram (left), drawing a charge overnight allows Senec customers to discharge their battery twice per day. With a warranted cycle rate of 12,000, the battery modules can handle this comfortably over a 10-year period. In a typical set-up, the battery would charge fully from the grid overnight, ready to power the house through the morning peak. Once discharged, the battery would then recharge throughout the day from solar, ready to supply the house through its evening peak. This model of ‘peak shaving’ represents the most economic utilisation of battery storage, however charging from the grid doesn’t have to be so regimented. Grid charges can also be implemented when making up for insufficient sunlight, on an overcast day. Through Senec’s intelligent battery management system, each customer can configure their battery to cater to their individual households needs, ensuring the peak power charges are avoided.