Solar air conditioners

Regular air conditioners are known to be something of an energy hog, drinking power to cool down or heat up your house. So how could a solar air conditioner help?

What is a solar air conditioner?

A solar air conditioner is an air conditioner that runs off of its own dedicated solar panels, rather than one that's hooked up to a regular solar system or the main electricity grid. Effectively, it runs on its own self-contained circuit.

How does it work?

The solar air conditioner consists of three main components:

1. Solar panels. Four or more solar panels are installed on your roof, generating power during the day. This is like a normal solar system, but it lacks an inverter and thus only produces DC current.
2. Outdoor hybrid unit. The outdoor unit connects directly to the solar panels, the main grid and the indoor unit. It can be powered by DC current from the panels during the day or AC power from the grid during the night.
3. Indoor DC unit. The indoor unit can function as either a cooler or a heater as long as it is fed DC power from the solar panels. It will automatically switch itself on when there is enough solar power and switch itself off when there isn't.

What type of savings can you make?

There are two points at which you may be able to save with a solar air conditioner:

Installation

Let's compare the costs of installing a 3.5kW solar air conditioner from Solar ACDC to installing a normal solar system and separate air con unit.

Solar system + air con

• Installation + purchase cost of 3kW solar system: $4,230¹
• Purchase cost of 3.5kW reverse cycle air conditioner: $1,350²
• Total cost: $5,580

Solar air conditioner

• Purchase cost of 3.5kW solar air conditioner: $4,000

1. Estimates are from this calculator.
2. Figure is from this site.

Running costs

For this comparison, assume that you run your 3.5kW air conditioner for 4 hours every day during all 90 days of summer, keeping it set to 22 degrees Celsius³. Then, if energy from the grid costs 30c/kWh, running an air conditioner on mains power will cost you:

$0.25 (hourly cost of air con) x 4 (hours per day) x 90 (days in summer) = $90

This means your solar air con will save you about $90 in running costs annually, if you don't have to rely upon mains power. For larger air conditioners, this might stretch up to $200 annually.

With this in mind, the solar air conditioner will save you about $1,600 on install and $100 to $200 yearly, for each year you run it. Heating has been excluded from this analysis, since it's most required in late afternoon or evening, after the sun has set and your solar air conditioner is inactive.

3. Calculations are based on this site.

How does it compare to a typical solar system?

While the solar air conditioner is great in concept, there are a few drawbacks to be aware of compared to just using an air conditioner with a normal solar system:

• No solar for other devices. The solar air conditioner's solar system exists purely to feed it power. This means that you'll be paying full mains power price for all your other energy use without a separate solar system.
• Low roof real estate. The smallest solar air conditioner from Solar ACDC includes four solar panels, with other units having more. This might make it difficult to install a regular solar system alongside it.
• Few savings on heating. The solar air conditioner runs during the day, which is great for cooling in summer. However, heating is needed most in the afternoon and when the sun has gone down, which is when your solar air conditioner will either be inactive or running on mains power anyway.

How can the elderly benefit?

Solar ACDC claims that some elderly Australians may be able to cover the costs of solar air conditioner installation under the My Aged Care benefits scheme. This scheme is designed to give financial assistance to older Australians who need extra care or services to live safely and independently in their home.

However, Finder's analysis of the requirements for My Aged Care funding suggests that getting coverage for a solar air conditioner is unlikely at best. You should check the scheme's requirements before making any financial decisions.

EXCLUSIVE: A new type of air conditioner could make expensive summer power bills a problem of the past. It comes with its own built-in solar panels and once installed, it won't cost you a cent.

December 8, 2020