Load Shifting Battery

The kinds of Battery Systems that are used generally in metropolitan areas are

  • Load-shifting (power on wall)
  • Peak-Shaving (maximising rebates for those on high feed in tariffs)
  • Back-up power (power in a blackout)

1. Load-Shifting uses solar power to charge a battery during daylight, then ‘adds’ power into the premises in the evening, thus reducing your imported power. This is what is otherwise known as the ‘power wall’ style system. These systems will become very popular in the coming years, please contact us to discuss your requirements.

2. Peak-Shaving (or Peak Levelling) uses solar to charge a battery during daylight, but also ‘adds’ power into the premises the moment that the premise's power usage exceeds what solar is produced. In this way, momentary import is prevented during daylight hours. The primary reason why people would want to do this, is to maximise exports during the day to get rebates.

Here is an example; Your solar is charging your battery during the day, now three things in your house are switched on at once. For five mins, your house wants more than whet your solar panels can provide. The battery supplies additional power for these five mins then goes back to being charged by the solar.

With either process, once the battery has exhausted its permitted pre-designated amount of power, it must switch to being idle and do nothing until spare solar power is next available to be used to charge the battery. When the battery is idle, your premises use power in the same way it would before you had a battery system installed. Even when some solar is produced first thing in the morning the battery will not be charged as your premises will use it to reduce import power instead.

Once solar production exceeds imported power, then the battery will start charging.

The concepts of Load-shifting and Peak-shaving are simple enough, BUT an implemented system "really has to know what it is doing" to be effective. Our business is aware of some systems being offered that will Load-shift, but not Peak-shave. Also systems that do not accurately sense and hence match what is being exported, thus becoming less efficient. Contact us to discuss your requirements.

3. Back-up power

Having a battery-system alone does not guarantee you will have electricity in a power-cut. This is due to the types and configurations of technology available. To drive electrical appliances in a power-cut adds additional cost. Note that achieving just load-shifting and peak-shaving can be very cost-effective.

We are aware of some battery-inverter systems in the market that are deficient if called upon to run appliances in a power-cut. For example, during a power-cut, appliance operation (typically pumps) may cause said inverter to fail. This is the reason why serious off-grid power systems typically use only very few brands - as they are the only ones that don't fail. We are aware of even reputable brands failing in some cases.

Talk to us regarding concerns of any inverter you may have.

What affects the purchase-price (investment cost) of battery systems?

  1. Usable capacity - how many kWh can you store or load-shift?
  2. How much power can you pass at once? Ie, the inverter size. A smaller inverter will pass less power, so it will take longer to load-shift of an evening, and in some cases may not shift all the power needed. In either case, the inverter has to be matched to the capabilities of the battery type.
  3. Battery lifetime - batteries are all rated for different lifetimes. This is where sellers can play fast and loose, offering a large power-shift, but very short life. An equivalent better-quality system may have the same power-shift capability, but longer life, and is more expensive initially. But is at equivalent unit-cost? ie it could be false economy to buy the cheaper system, as it will need replacing sooner - its true cost is found by extrapolating against the same lifetime as the more expensive system. But it is also true to say that future battery systems will inevitably decrease in cost over time.
  4. Warranty - how good is the installer and manufacturer their offer of the warranty? Will they help with questions, diagnosis etc? Our experience has shown that many suppliers do not provide adequate support, or information. EcoSouth provides lifetime advice, and warranty help for our customers.

We pride ourselves on the system design and matching of the systems we offer. For a simple measurement on your part, we can advise a choice of one or more systems that will achieve cost-effective protection against rising power-bills. If you are in Adelaide, please email or call us now for a no-obligation chat and quote.