Solar vs. Gas Hot Water Systems (To Heat Your Homes Water)

Electricity costs are increasing, and national grids are becoming stressed and unreliable. It is unlikely that this situation will improve. The prudent consumers who understand these risks are looking for alternative sources of energy, two of the most attractive options are solar and gas water heating systems.

Gas Hot water systems are better than solar water systems. Gas Hot Water heating is an efficient, low-cost, and flexible solution to heat your home’s water. Solar hot water systems are expensive and cannot supply a continuous flow of hot water once the stored water has been depleted. 

When disconnecting from the grid, heating water in a renewable and sustainable manner is one of the most challenging decisions. Both gas and solar energy are viable means of heating water in geysers. The difficulty with heating water is once heated, what happens with excess water is not immediately needed. How do you store it and maintain its heat?

Which Is the Better Technology To Heat Your Homes Water?

Although the sun produces so much power, which is easier to convert and store as electrical energy, current technology’s ability to transfer the sun’s thermal energy to water remains inefficient. The main issue with solar hot water systems is the heated water storage. 

Solar hot water technology needs to mature before competing with gas hot water systems. 

Gas is an old established technology that provides flexible, immediate, and cost-effective water heating solutions.

How Do Solar And Gas Hot Water Systems Work?

Before comparing the difference between solar and gas hot water systems, you must understand how each of these systems works. 

Solar Hot Water Systems


Solar water heating systems convert the sun’s light into heat-processed through a thermal collector.

Several technologies use the sun’s energy to heat water. Some of the different solar technologies include:

1. Evacuated Tubes As Part Of Solar Hot Water Systems

Evacuated solar tubes incorporate smaller glass tubes suspended in a vacuum within the primary device. The vacuum acts as a thermal insulation barrier; the lack of air molecules prevents unnecessary loss of thermal and kinetic energy. 

The coating inside of the tubes filters out unwanted light frequencies. Filtering in this way maximizes the efficacy of the evacuated tubes across a specific bandwidth of light rays. While evacuated solar tubes are the most expensive solar water heating system, they are also the most efficient. 

2. Flat Plate Technology In Solar Hot Water Systems 

A Flat Plate Solar system uses the sun’s energy to heat water indirectly. The sun’s energy heats a transfer fluid in tubes installed within the panel. The transfer fluid heats the passing water as water moves through the system. 

The system uses convection to move water within the panel. Heating up causes the water to rise,  and as it cools, it moves to the bottom of the panel, displacing warmer water. This cycle continues until hot water is needed.

3. Types Of Retrofit Systems Are Used In Solar Hot Water System

Two types of retrofit systems exist:

  • The first retrofit system replaces the existing electrical energy geyser element with solar panels. Solar panels generate electricity to heat the element.
  • The second type of retrofit system eliminates the water heating element as the heat source and replaces it with an evacuated tube or a flat plate system. The existing geyser continues to be used to store the hot water.

4. Hot Water Systems Using Close Coupled Solar Water Heaters

Close Coupled Solar Water Heaters are installed on the roof, and a tank is installed above the solar collector. The water passing through the solar collector is heated and continues rising. 

This action drives the heated water into the tank situated above. When the water cools, it sinks to the bottom of the tank and returns to the solar collector, starting the process over.

5. Thermosiphon Solar Geysers In Solar Hot Water Systems

Thermosiphon Solar Geysers are similar to close-coupled solar water heaters. The technology consists of a solar-driven water heating system that sends water to a geyser through an entry point at the top of the geyser. 

As the geyser’s water cools, It sinks to the bottom. The cooled water flows through an exit point at the bottom of the geyser and returns to the solar heating element, and the cycle starts again.

What Types Of Gas Geysers Are Available? 

Gas hot water system

There are three gas geyser technologies:

1. Standard Gas Geysers In Hot Water Systems

Standard, otherwise known as manual gas geysers, does not have an electronic control that controls how many burners come on. It is all or nothing! The all-or-nothing approach to burners makes the temperature control less precise.

Standard gas geysers are often criticized for their inflexibility. The system cant balance the gas flow to match the volume of water passing through the water pipes. The higher the water pressure, the less time it is heated by the burner; thus, the cooler the water temperature. The opposite holds; the slower the water flows, the more it is heated by the burner. 

2. Hot Water Systems Using Constant Temperature Gas Geysers

Constant temperature gas geysers regulate the amount of gas fed to the burner depending on the water flow, i.e., the stronger the flow, the greater the gas pressure. 

You can select the water temperature on the front panel of the geyser, and the control will regulate the heat the geyser produces to ensure that the water is at an ideal temperature. Constant temperature gas geysers allow you to dictate the water temperature and not your gas geyser!

3. Forced Fan Geysers As Part Of A Hot Water System

Forced fan geysers are the big daddy of all the current gas geysers on the market! These geysers use a fan mounted inside the uni. The fan assists in both the combustion and extraction of the gasses. Forced fan geysers provide all the benefits of the two gas geysers mentioned while reducing the cost of gas by reducing gas consumption. 

The Strengths And Weaknesses Of Gas And Solar Water Heaters

Solar and gas water heating systems have specific strengths and weaknesses.

Solar Hot Water Systems Pros And Cons


The obvious advantage of solar water heating systems is that it uses the sun’s energy. In human terms, this is a limitless power source. The sun produces enough energy in 60 minutes to supply the world’s energy needs for a year. 

The downside is that solar water heating systems are dependent on the sun shining, i.e., they are only fully efficient when the sun shines and not suitable for use in countries with limited sunny days

Another disadvantage to solar-powered water heating systems is the finite amount of heated water produced. The only useable hot water is in the tank; as this is used, it needs to be replaced and then reheated, which takes time. 

If you are parents of teenage daughters, relying solely on a solar water heating solution, it may be equivalent to starting a civil war in the house! A solar heating system is a solid option for couples or individuals living alone.

The high capital cost of a solar water heating system is the third major disadvantage when using solar hot water systems. Solar heating systems are more expensive to purchase and install than gas. However, once the system is installed, there is no recurring cost associated with running the system. 

The Pros And Cons Of Gas Hot Water Systems

Solar vs. Gas Hot Water Systems

Gas hot water systems beat out solar hot water systems on several fronts. Unlike solar hot water systems, gas geysers are available at any time of the day and in any weather condition. 

In addition to this, gas hot water systems heat water on demand and do not rely on heated water storage like solar hot water systems, i.e., gas geysers ensure that you always have hot water on hand. 

That means baths or showers for everyone and the end to the previously declared civil war; you can take on an Abraham Lincoln-type persona and be your family’s hero!

The cost of installation with a gas hot water system is generally lower than a solar hot water system. However, running costs are higher with gas hot water systems than solar hot water systems as gas will need to be purchased regularly. 

Many people may be put off-gas systems by the idea of having to replace gas bottles. However, this minor inconvenience is negated in many cities where gas is piped directly to the home. 

Gas is cheaper than conventional electricity IN most instances. It is over 70% cheaper than utility-supplied electricity. A win for gas!


With present technologies, Gas Hot Water systems beat out solar. Gas heated water is instantly available; it does not rely on being used only at a specific time of the day and can heat water in all weather conditions.

Gas Hot Water systems are easier and cheaper to install and make a viable alternative to sourcing energy from the grid.

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