Solar Hot Water Systems

The rising cost of living has driven many people to consider a range of alternative solutions to meet their energy requirements. Solar is one of the most popular alternative energy resources because it is free, readily available, and cannot be used up.

Australia is an ideal country to invest in solar-powered technologies because it receives ample sunlight all year round. According to Geoscience Australia, the country’s solar potential is 10,000 times more than the country’s current energy consumption.
Types of Solar Energy Systems

There are two types of solar power systems in use today. They are categorized according to how they convert the sun’s energy into usable power. These are 

  • Solar Photovoltaic (PV) Systems
  • Solar Thermal Systems.

Solar Photovoltaic Systems 

Solar photovoltaic systems convert sunlight into electricity. They can power household appliances, lights, charge batteries, and feed into electrical grids. In these systems, contain photosensitive solar cells that react by emitting electrons to create an electric current when exposed to sunlight. 


Solar Thermal Systems 

Solar thermal systems harness the sun’s heat into usable energy. They work by concentrating the sun’s infrared rays on a central focal point to heat a fluid with high thermal resistance. This fluid is passed through water to heat it or generate steam. The steam generated has several industrial applications and can be used to drive turbines and generate utility-scale electricity.

Solar thermal technology also has a wide range of domestic applications including drying timber and farm produce, heating water and cooking. This article focuses on how solar thermal hot water systems. 



Solar Hot Water Systems 

The average Australian home currently spends about 21% of its energy resources to heat water. It is also the highest source of household GHG emissions. This statistic was highlighted in the government’s publication of Australia’s guide to environmentally sustainable homes, ‘Your Home.’

Using solar thermal systems to heat your household water can significantly lower your utility bills and environmental impact. Modern solar hot water systems are made up of a variety of components. These include thermal collectors, heat exchanger, the hot water tank, and in some cases, a pump.

A Thermal Collector consists of a series of pipes or tubes through which a fluid with high thermal resistance flows. The tubes can either be exposed to the sun or housed in a metallic frame with a glass panel.

Keep in mind that the water in your taps does not circulate in the thermal collector’s tubes. Instead, it is permanently stored in the hot water tank where it is heated indirectly.

The heat exchanger is a coiled copper or steel pipe that transfers heat from the fluid to the water in your tank. The heat exchanger doesn’t allow the liquid to mix with your water. Once it is cold, the fluid is pumped back to the thermal collector where it is reheated.

A Heating Element, powered by electricity, is used to heat the water in your tank at night and on rainy days. This heating element is designed with an independent energy source. The backup heating option can be powered by the grid, solar PV panels, or gas, depending on your preferences.

Solar hot water systems are straight forward low maintenance technologies. They are versatile, easy to install, and operate. With a payback period of 5 to 15 years, a solar hot water system is a worthwhile investment for your home.