Using rooftop solar panels for hot water heating.
With increasing gas and electricity prices, the rising cost of living, and people’s desire to reduce their carbon footprint, we are often asked how people can use rooftop solar to heat their hot water.
Commonly called solar panels, photovoltaic collectors or solar photovoltaic (PV), are devices that convert sunlight into electricity. By converting the sun’s energy into solPV collectors can be used to harness the sun’s energy to run various appliances in our homes and workplaces.
In short, rooftop solar panels can convert the sun’s energy into electricity which can be used to run your hot water system.
First, we need to explain the difference between:
- rooftop solar panels »
- rooftop solar hot water systems »
- split solar hot water heaters »
- solar heat pumps »
Further reading: How do solar panels heat my hot water?
(Above) Rooftop solar panels convert the sun’s energy into electricity which can be used to run your hot water system.
Rooftop Solar Panels
How the sun’s energy, captured by rooftop solar panels, powers your hot water heater and heats the water.
Solar panels, typically installed on the roof of a house or building, generate electricity from sunlight. These panels are made up of many individual solar cells, typically made of silicon, are designed to capture sunlight and convert it into electricity through a process called the photovoltaic effect.
When sunlight hits the solar panels, the photons (particles of light) from the sunlight knock electrons loose from the atoms in the solar cells. This generates an electric current.
Solar panels are designed and positioned to capture as much sunlight as possible and are usually installed at an angle and direction that maximises their exposure to sunlight.
Now it gets technical… Electricity generated by solar panels is in direct current (DC) form. The electricity network along with most of our household appliances, including hot water systems, use alternating current (AC) electricity.
To convert the DC electricity from the solar panels into AC electricity we can use requires an inverter. The inverter allows the electricity to be used in your home or sent back to the grid. The inverter produced AC electricity is then fed into your meter box where it can be used to power your lights, appliances and hot water heater.
In short, it is not the solar panels that are heating your hot water system, it’s the electricity created by the sun’s energy via solar panels that creates the electricity that powers your hot water system and, subsequently, heats the water in the tank.
Solar panels save money by using the sun’s energy to power your hot water heater.
Instead of paying for electricity from the power grid, you save money by harnessing the power of the sun captured via your rooftop solar panels to operate your hot water system.
In short, it’s not the rooftop solar panels that heat the water, but the electricity they generate that powers your hot water heater. This clean and renewable energy source can help home and business owners reduce their electricity bills and carbon footprint.
Rooftop solar panel installation
The team at Cheapa Hot Water work with highly experienced, local, Sydney solar panel installers who can install solar panels and switch your home or workplace to solar electricity. Our hot water specialists can then connect any existing hot water system to the newly installed solar power or, if required, install a new hot water system.
(Above) A rooftop solar hot water system. The solar absorber panel and hot water storage tank are one unit.
Rooftop Solar Hot Water Systems
A rooftop solar hot water system uses solar collectors, typically installed on the roof, to absorb heat from the sun and provide hot water for domestic or commercial use.
There are two main types of solar collectors used in solar hot water systems:
- Flat-Plate Collectors: These collectors consist of a flat, dark-coloured absorber plate covered with transparent glazing. The absorber plate heats up as sunlight strikes it, and a fluid (usually a mixture of water and antifreeze) circulates through pipes or channels within the collector, picking up heat in the process. As sunlight strikes the absorber plate or tubes of the solar collectors, they heat up. The heat is transferred to the circulating fluid inside the collectors. The fluid can reach temperatures well above the ambient air temperature.
- Evacuated Tube Collectors: These collectors use a series of glass tubes with an absorber coating inside. Each tube is evacuated (vacuum-sealed), which provides excellent insulation and allows for efficient heat absorption. These collectors are often more efficient in colder climates.
The hot fluid from the solar collectors is then directed to a heat exchanger, which is typically located in or near the hot water storage tank. The heat exchanger transfers the heat from the fluid to the water in the storage tank, usually attached to the rooftop solar collectors, heating the water to the desired temperature. The hot water produced by the heat exchanger is stored in the insulated storage tank.
What if it’s night, cloudy or raining?
If it’s night time, cloudy or raining, a backup gas or electric heating element takes over the hot water heating process, ensuring a continuous supply of hot water – even when the sun isn’t shining.
Rooftop solar hot water systems are an efficient and environmentally friendly way to heat hot water using free energy from the sun. Solar hot water can significantly reduce your household or business energy bills. It will also significantly reduce your carbon emissions.
(Above) A Rheem split solar hot water system. The solar panel is located on the roof. The storage tank is installed at ground level.
Split Solar Hot Water Systems
A split solar hot water system separates the solar collector, which is usually installed on the roof, from the hot water storage tank which is typically installed at ground level or inside a building. Split solar hot water systems are a popular option when there isn’t enough roof space available to install a rooftop solar hot water system.
Split solar hot water systems work in a similar way to the rooftop solar option by using a solar collector installed on the rooftop to capture heat from the sun via a flat, dark-coloured absorber plate covered with transparent glazing. The absorber plate heats up as sunlight strikes it, and a fluid (usually a mixture of water and antifreeze) circulates through pipes or channels within the collector, picking up heat in the process. As sunlight strikes the absorber plate or tubes of the solar collectors, they heat up. The heat is transferred to the circulating fluid inside the collectors. The fluid can reach temperatures well above the ambient air temperature.
A pump circulates a heat transfer fluid (often a mixture of water and antifreeze) through the solar collector. This fluid absorbs heat from the collector as it circulates, becoming hot in the process. The hot heat transfer fluid is then pumped down to a heat exchanger or coil within the hot water storage tank which is located at ground level or inside a building.
The hot water produced by the heat exchanger is stored in the insulated storage tank ready for household or business use.
Solar Heat Pumps
Heat pumps use technology to extract and intensify the warmth that is naturally in the air around us then use that warmth to produce hot water. They don’t use solar collectors mounted on the roof like solar systems.
The heat pump consists of an insulated storage tank and a heating module. The heating module must be installed outdoors, but there are options to install the storage tank either outdoors with the heating module, or indoors separated from the heating module by up to 4 metres.
A heat pump works to heat water by transferring the intensified warmth from the air around it into the water, stored in the tank, via a heat exchange system that works in a similar way to an air conditioner.
When emptied, it takes time to reheat to have you back in hot water. Heat pumps draw less electricity than a traditional electric storage water heater, and in doing so, are more energy efficient. They do take longer to heat water, so consider a larger tank capacity to ensure you have enough hot water when you need it.
- Further reading : How do heat pumps work?
Speak to a hot water specialist
Solar hot water is our business! We are licensed solar system installers and repair technicians for all water heater makes and models. Contact our experience team for obligation-free advice about the costs of switching to solar hot water and start reducing your energy bills (and your carbon footprint) today.
Cheapa Solar Hot Water Sydney
Hot water is our business – it’s not a sideline. Each year we install and repair hundreds of hot water systems in homes and businesses across the entire Sydney area.
Don’t waste money employing multiple trades.
Did you know that a new hot water system is a big investment and often needs the installation and setup of plumbing, gas and electric components? This requires the experience and qualifications of both a licensed plumber and a licensed electrician.
At Cheapa Hot Water, we are licensed and qualified to undertake any plumbing and electrical work required to complete your hot water system installation or repair quickly, and within budget.
Plumbers who do not specialise in the installation of hot water heaters may need to outsource the electrical work required to another tradesperson, thereby holding up your hot water system repair or installation, adding extra expense due to additional call out fees charged by employing two tradespeople.
Don’t risk voiding your hot water heater warranty
Additionally, most manufacturers won’t cover the terms of your hot water system warranty if it isn’t installed by a licensed hot water technician or qualified plumber. Hot water tanks are an expensive appliance so why would you risk voiding your warranty by installing it yourself or employing the services of someone who isn’t licensed?
Save money today by calling our Sydney hot water experts. Our trucks are on the road right now stocked with thousands of spare parts to repair and service your hot water heater quickly.
Benefits to our residential customers
Hot water is our business – it’s not a sideline. Each year we repair and install thousands of hot water systems in homes across Sydney.
- We are a Sydney hot water company and can quickly provide onsite assistance to customers and businesses.
- We offer free delivery of your new hot water system and complimentary disposal and recycling of your old water heater (where applicable).
- As one of Sydney’s largest hot water system suppliers, our enormous buying powers and ability to buy direct from the manufacturer means we can pass attractive savings on to our customers.
- Our fully qualified, licensed hot water heater installers have over 25+ years of experience each. We are fully insured and pride ourselves on our old-fashioned customer service.
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- We are qualified to undertake all the plumbing and electrical work required to install a new hot water system. There is no need to waste time and money employing multiple trades.
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