The phrase Solar Air Conditioning has been used very loosely in recent years. From the consumer’s perspective, you probably want to know if solar power can be used to run your air conditioner. Several products are on the market that are advertised as using the power of the sun to cool your Florida home. They are usually called solar air conditioners or solar ready air conditioners.
The solar air conditioning appliances on the market fall into three basic categories:
- Solar Thermal Assisted Air Conditioning – these systems use questionable science to “super heat” refrigerant to supposedly reduce the work of the compressor. They don’t work.
- Solar DC Air Conditioning – this is a traditional air conditioner with a DC (direct current) compressor replacing the AC (alternating current) compressor. While this works very much like a traditional air conditioner, it employs storage batteries, introducing a new inefficiency and maintenance component to the system. It is not a cost effective solution except perhaps in off-grid applications, and that is debatable.
- Solar Ready Air Conditioning – one major recognizable air conditioning brand is using creative marketing to pitch an air conditioner that uses solar energy. In reality, this is nothing more than a traditional standalone high efficiency air conditioner paired with a grid-interconnected solar energy system.
I won’t even address the first two, but the third has merit after getting past the marketing fluff and doing it properly.
Solar Ready Air Conditioning
Solar Ready Air Conditioning, or just Solar Air Conditioning, is the marketing idea (gimmick) of one the largest air conditioning brands in the U.S., and it is actively marketed in Florida. There is nothing revolutionary about this system, and it has distinct disadvantages over installing regular air conditioning and solar electricity separately. The idea here is to install a high efficiency traditional air conditioner rated at 17-21 SEER, and then install a standard microinverter based solar electric system. The only difference is that the solar energy system connects to your home’s electric system at the same location as the air conditioning disconnect. While this might sounds like a good idea, it has it’s drawbacks:
- Interconnecting solar at the air conditioning disconnect creates what’s known as a load side interconnection, which limits the size of the solar panel array based on your existing electric service and equipment.
- Your existing wiring may require upgrading to meet provisions of the National Electric Code.
- When your air conditioning system needs to be replaced, and that will undoubtedly happen before the life of the solar panels ends, you may have to buy an air conditioner at an inflated cost or make electrical changes to remain compatible.
- There is no cost advantage to this system over just installing a highly efficient air conditioner and solar electric system a la carte. In fact, the branded system may cost more than the a la carte components.
The manufacture claims that the solar panels will deliver power to the air conditioner first and then power other appliances and lighting in your home when excess solar energy exists. That is not exactly the case. Electrons go wherever there is a power draw in an interconnected solar electric system. Because your air conditioner is electrically connected to all other appliances and lighting in your home through the main distribution panel (circuit breakers), it doesn’t matter where the solar electric system is interconnected. You will save the exact same amount of electricity if the solar panels are connected to your main distribution panel or your air conditioner disconnect.
The bottom line is that you don’t have to install a “solar ready” air conditioner to enjoy the benefits of solar electricity in your home. You can connect the exact same solar electric system to your existing home with your existing air conditioning. In other words, every air conditioner is “solar ready!” The best solution, unless you air conditioner is grossly inefficient, would be to install solar panels now, and then upgrade to a more efficient air conditioner when your existing unit reaches the end of its serviceable life. At that time, use the advice of a reputable dealer to select a brand and efficiency level that balances efficiency and initial cost. Often that does not mean installing a unit above 16-18 SEER (at today’s prices).
My advice is for you to first understand the marketing fluff behind solar air conditioning, and then make a smart investment decision by installing each product individually based on the merits of each product.