Hybrid Power & Battery Backup Systems

The huge demand of Grid Connect solar systems across the globe, has led to the rapid technological advances in inverter technologies. These new inverters are known as hybrid inverters and allow the occupant of a grid connected house to take full control of where their house draws its power from. Although these systems are only new, their popularity is growing rapidly as electricity prices continue to rise.

The following diagram shows a typical Hybrid Power System.

Towards Tomorrow Energy has been actively developing these hybrid systems in the lead up to the Australian Solar Bonus Scheme finishing at which point many of our customers will be in a position where they want an alternative to simply feeding their excess power back into the grid under an unfavourable Feed In Tariff.

The following two applications best show where a Hybrid Solar System can be utilised;

Any existing SGU can be retrofitted with a hybrid installation. The current installation, including the Grid tie inverter, roof array and wiring strings are left un-touched and a new inverter/charger and battery bank are installed. This then enables the occupant to;

• Draw their power from the solar array and battery bank during the daytime;

• Draw their power from the battery bank rather than the grid during high shoulder periods in the evening;

• Automatically swing the house over to Battery Power during Black outs;

• Recharge their batteries using the grid during night time low shoulder periods;

• Recharge their batteries using the solar array for a specific time allocation each day.

In areas where regular black outs are experienced, hybrid installations can be an ideal solution. Not only do they allow the occupants home to remain with electricity during periods of extended black out, they also enable the occupant to significantly reduce their dependency on the mains power by subsidising their daily loads using the solar array and battery bank. This scenario enables the occupant to;

• Maintain power during periods of extended black out. Typically a hybrid system can be programmed to automatically swing the house over to battery power and/or generator backup should a mains electricity failure be identified.

• Reduce electricity consumption from the grid by enabling the house to source power from the solar array and/or battery bank during the daylight hours.

• Reduce electricity consumption from the grid by enabling the house to source power from the solar array and/or battery bank during peak usage times.

• Enable regular usage of the backup system to ensure it is maintained and available should a blackout occur.

The successful design of a Hybrid Power Systems relies on a well resolved balance between the house loads, PV array, Inverter/Charger and Battery Bank.

The HPS provides power to your house by either;

• routing electricity from the solar array to your house loads and/or;

• routing electricity from the solar array and battery bank to your house loads and/or;

• routing electricity from the grid to your house loads at set time periods during the day/evening to avoid drawing power from the grid during peak times and/or;

• routing electricity from the battery bank to your house loads during extended periods without mains power.

Should the array be incapable of charging the battery bank due to periods of extended rain or overcast weather, the HPS can also be programmed to auto-start a genset or direct power from the grid in off peak times to top up the battery bank. A full battery recharge typically takes 4-5hours of charging from the generator or grid to completely restore the battery bank to full charge. A typical battery bank specification can be designed to provide continual power to a house for anywhere up to 3 days without re-charge.

This system generates 16-18Kwhs of power per day and is ideal for a large efficient family home. It will run the basic load requirements such a large efficient 240V fridge, freezer, efficient chest freezer, LED lighting, 46”LCD TV, computer, stereo, washing machine, small toaster, coffee machine, ceiling fans efficient water pump and most modern conveniences for a standard home

Provided customer has not already had solar panels installed previously, this system is eligible for 4.5×1.382x1x15=93 STCs and includes the following basic setup;

• 24V

• 1330Ah Battery Bank

• 2x2KW inverter/chargers

• 4.5KW Solar Array

• 5.5KVA genset

This system generates 24-26Kwhs of power per day and is ideal for a large luxury family home. It will run all the load requirements of a typical mains connected house such a large efficient 240V fridge/freezer, efficient chest freezer, LED lighting, 2-3 LCD TVs, computers, stereo, washing machine, dishwasher, toaster, coffee machine, kitchen appliances, ceiling fans, electric kettle, efficient water pump and most modern conveniences for a standard home

Provided customer has not already had solar panels installed previously, this system is eligible for 6×1.382x1x15=124 STCs and includes the following basic setup;

• 48V

• 1700Ah Battery Bank

• 2x3KW inverter/chargers

• 6KW Solar Array

• 5.5KVA genset

The following kits are a guide only as to what can be achieved with stand alone solar energy. The systems are flexible and are typically tailored to suit the specific needs and budget of our customers. We recommend a custom design before purchasing a system.

Towards Tomorrow Energy happily take care of all the paperwork and offer Point of Sale Discounts up front for any applicable rebates.

With the solar market becoming over crowded with thousands of new solar products, Towards Tomorrow Energy has spend considerable time and expense purchasing new industry recommend brands and products in an attempt to offer our customers lower cost installations without sacrificing quality. Having installed numerous brands of inverters and panels over the past 4-5 years throughout the peaks of the Grid Connect incentive programs, we have opted to only use our preferred suppliers that we know and trust on all our installations.

These suppliers and brands include;

• Solar Panels – ET SOLAR, Poly and Monocrystalline PV Modules

• Inverters/Chargers – OUTBACK, Plasmatronic, SMA

• Batteries – Exide, Sonneshein, Hoppeke, industry leading german quality. The battery banks in the kits can be specified as either Lead Acid or maintenance free sealed batteries

The systems have been designed to run for around 3 days autonomy or with no solar input. A backup generator is required for extended cloudy periods.