Heat Pump vs. Solar Hot Water

Heat Pump Vs Solar Hot Water

The main methods of energy efficient and environmentally friendly water heating in homes are solar, gas, and electrical heating through the use of a heat pump. The Australian Government offers financial incentives for using either solar or heat pump systems, so let’s look at how a heat pump system compares to a solar hot water system, and which among the two is better.

Heat Pump Hot Water System

Much like home air conditioners, heat pump hot water systems use refrigerant to collect heat out of the surrounding air to provide hot water for the home.

But what if it is really cold outside, I hear you say? Well, for humans, a 10 degree day would be considered quite cold, however, if the refrigerant inside a heat is minus 25 degrees, for example, the surrounding air is actually quite hot compared to that of the refrigerant inside the system. As heat is always absorbed by anything that is cooler, in this case the heat pump hot water system will absorb 35 degrees of heat out of the air to provide FREE heat energy for your household hot water use. Such clever energy absorption results in creating on average 3 kilowatts of heat for every 1 kilowatt of energy it uses. Good systems will provide hot water efficiently in below zero temperatures. The average energy efficiency is 65-70%.

Solar Hot Water System

Solar hot water systems use the radiant heat of the sun to heat either water filled solar panels or evacuated tubes on the Northern face of a household roof. As the sun hits the collectors the water inside becomes hot and this is then held in a storage tank ready for use. As this type of simple technology relies on radiant heat, if it is night time or a cloudy day, the system will need to heat the storage tank via either a gas booster or an electric element booster. In this way the average energy efficiency is 65-80%.

Advantages of Heat Pump Systems

Low cost

The initial cost of heat pump hot water systems is generally less than half of that of the solar counterparts. This means the time it takes to pay for the system itself is much faster. Furthermore, the system is fully installed at ground level so there are no concerns about panels or tubes on the roof which can leak water or take up excessive room for those wishing to utilise this space for solar electricity systems.

Fewer carbon emissions 

As heat pump systems collect three times the energy they use, they are far more environmentally friendly than traditional electric systems.

Work efficiently rain, hail or shine

Heat pump systems absorb heat out of the air so operate efficiently without sunlight. This means the system can operate on cheaper off peak electrical rates further reducing your electricity bills.

Disadvantages of Heat Pump Systems

Non silent operation

Heat pump systems utilise an air conditioner compressor to transport refrigerant through the system. This means the system makes a noise like an air conditioner. It is important when deciding on installation location to not have it too close to bedroom windows for yourself and also please consider your neighbours.

Maintenance Costs

As heat pump systems have many more components than traditional electric element or gas hot water systems, the need for service is higher. Commonly a heat pump system will need servicing every 3-5 years whereas other systems will need to be serviced every 5-8 years

Advantages and Disadvantages of Solar Hot Water


  1. Higher efficiency when collectors are correctly placed.
  2. Roof mounted systems are simple and very reliable with lower maintenance costs.


  1. Very high-upfront installation cost
  2. Efficiency depends on weather, climate and season
  3. Solar technology is still in its infancy and needs further development
  4. Split system solar systems have higher maintenance costs.

Which is Better: Heat Pumps or Solar?

Heat pumps and solar heating have their advantages and disadvantages. Heat pumps are slightly less energy efficient but have much lower initial costs to buy and install. They also have the advantage of not relying on the weather as they can operate efficiently in all conditions. The downside is the systems are complex and can be expensive to maintain compared to roof mounted solar systems.

In the end, the main upside to opting for a renewable means of water heating is to relieve the environment from carbon emission burdens. So, start an eco-friendly lifestyle today and help promote the use of green energy today. If you are interested in getting either a heat pump or solar hot water system installed in your home, contact Hogan Hot Water on 0488 029 618 

Hogan Hot Water & Air Conditioning, Hot water systems, Refrigeration

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