Solar water heaters, also known as solar domestic hot water systems, can be a cost-effective solution to create hot water for your home. Mainly, because it converts sunlight into energy, a naturally renewable resource. Installing a solar water heater is a common way for homeowners to lower their electric or gas expenses. These systems use renewable energy to reduce the need for grid power and make a lot of hot water at the same time.
Solar water heaters work by receiving energy from the sun’s rays and transferring it to heat water stored in a tank using roof-mounted solar collectors. Ground-mounted direct systems move water through the system with the help of an internal circulator, while roof-mounted systems use a natural process called “thermosiphon.” Water flows through the solar collector, where it is heated, before exiting the collection and entering the tank. The water in the tank steadily heats up until it reaches its maximum stored temperature. Indirect systems absorb heat from collectors using a specific heating fluid rather than water. A heat exchanger transfers the heat to the water in the tank.
Solar hot water systems are devices that use solar energy to heat water for domestic or commercial use. They can be classified into two main types: active and passive systems.
Active systems use pumps and controls to circulate water or a heat-transfer fluid through the solar collectors, where it is heated by the sun. Active systems can be further divided into direct and indirect circulation systems. Direct circulation systems pump household water directly through the collectors and into the home. They work well in climates where it rarely freezes. Indirect circulation systems pump a non-freezing, heat-transfer fluid through the collectors and a heat exchanger. This heats the water that then flows into the home. They are popular in climates prone to freezing temperatures.
Passive systems do not use pumps or controls, but rely on natural convection or gravity to move the water or heat-transfer fluid through the collectors. Passive systems are generally less expensive and more reliable than active systems, but also less efficient. Passive systems can be further divided into batch systems and thermosiphon systems. Batch systems are also known as integrated collector-storage systems. They consist of one or more tanks or tubes that are heated directly by the sun and act as both the collector and the storage. They are simple and inexpensive, but not suitable for cold climates. Thermosiphon systems consist of a storage tank that is placed above the collector. As the water in the collector is heated, it rises to the tank, while cooler water from the tank flows down to the collector. They are more efficient and reliable than batch systems, but also more expensive and require a strong roof to support the tank.
There are also different types of solar collectors that can be used in solar hot water systems, such as flat plate collectors, evacuated tube collectors, and heat pump systems. Flat plate collectors are the most common type of solar collector, being inexpensive and durable and composed of a dark-colored metal that absorbs heat from the sun. Evacuated tube collectors are more efficient yet fragile and costly, consisting of vacuums and metal absorbers inside glass tubes. Heat pumps go a step further by extracting heat from the atmosphere with electricity, though they require more energy to operate as well as backup power sources in case of failure.
By utilizing solar energy, solar hot water systems offer advantages such as decreased reliance on the power grid, reduced carbon emission and greenhouse gases, and long-term savings in electricity and gas expenses. Requiring less maintenance than standard hot water systems – typically just once per five years – solar systems also help to conserve time and money. Nonetheless, to obtain an accurate servicing plan, it is essential to evaluate the safety documents prior to buying your equipment.
Small-scale technology certificates (STCs) are available for solar and heat pump projects in all Australian states. Similar to solar feed-in tariffs, customers who put in solar pumps can get cash rewards for using clean, renewable energy. As one of the sunniest countries on the planet, it’s not surprising that more Australians are turning to the sun for clean, free energy rather than costly electricity or gas. If you live in a warm and dry climate, installing solar hot water should be a no-brainer. While solar is more expensive initially, the energy savings should pay for themselves quickly. The decision to install solar hot water is more difficult for individuals living in cooler locations in Australia’s southern states. Most households in cooler areas should be able to recoup their investment in a solar hot water system over time, but if you’re unsure, obtain a personalized quote to verify that you’re making the best decision for your budget.
Fully installed, a solar hot water system costs between $3,000 and $7,000. Prices vary according to system type and installation costs:
Gas-boosted solar hot water systems may cost around $400 to $1,000 more than electric-boosted systems. Split systems are more expensive than roof-mounted tanks. In comparison, non-solar hot water systems typically cost between $300 and $2,000.
When taking into account the cost of operation, a solar hot water system can save a typical household between 50 to 75 percent on its water heating consumption in milder weather due to more economical energy rates.