Your booster fuel is the final thing you will need to decide on for your new solar hot water system. So, electric or gas booster? The choice is up to you. But first, let us unpack it all for you to help you make the decision that is the most efficient for you.
A gas system is the most cost-effective, energy efficient, and green option for your solar hot water system.
The gas system will heat your water on demand as soon as you turn on your tap, so there’s no annoying waiting around for your nice warm shower to heat up. It the most efficient system as it runs from a very simple operating system, and is available in most areas of the country for a low cost as it typically runs off natural gas.
However, for those living in areas where only LPG (liquefied petroleum gas) is available, the use of a gas booster is more expensive and is not always the most straightforward option.
The electric booster is a relatively simple operating system. When the heat within the tank drops below a certain set temperature, the electrical element is automatically set into action in order to continuously heat the water.
The electric booster option is more expensive than its gas counterpart, and also lacks in energy efficiency and environmental cleanliness.
The electric booster option for your solar hot water system is often a much cheaper option for those living in areas dependent on LPG, therefore may be the best option for some.
Solar Heat Pumps
Solar heat pump systems are the main alternative for solar hot water systems to that of the solar panel. Solar heat pumps operate through a much more simple system than that of the solar panels.
Essentially the solar heat pump system works like an air conditioner. The air conditioning system runs in heat mode, and uses the heat it collects to warm a well-insulated water tank. The heat is transferred from the air conditioning system to a compressed refrigerant that flows through into a coil that sits inside the tank. The coil is then used to circulate cold water from the bottom of the tank towards the top where it is heated. This process is demonstrated with more detail through the diagram below:
The heat pump system differs a lot from what you may think of being typically “solar powered”. Although the system does not take its energy directly from the sun, it utilises the heat within the surrounding air, and transfers it into the system to create heat. Therefore it relies on natural sources to produce heat in the water system. With forces of electricity and solar heat combined, you’ll have a fighting fit system that is not only energy efficient, but environmentally friendly.
In fact, the CSIRO calculate that in some climates areas of Australia, the heat pump system uses less electricity in a year than solar panel system with an electric booster. So your heat pump system will be a mean, green, Co2 fighting machine!
Here are some advantages and disadvantage of the heat pump system:
- No roof mounted hardware necessary
- Easy to protect from harsh weather conditions
- Does not rely on direct sunlight, therefore is adaptable for all climates
- Simple installation process that costs almost 50% less than solar panels
- Is not affected by off-peak electricity tariffs
- Compressor can be noisy
- More cost-effective in warm climates than cold
- May use ozone-depleting CFC’s in the manufacturing of their coils
Are heat pumps the right choice for me?
Deciding on whether a heat pump system is the right one for you comes down to where you live. Differing climates and exposure to elements such as the sun or natural gas will affect the overall efficiency of a heat pump system. So, take a look at our diagram to help you to get your head around which system suits your climate better.
If you live in zones 2 or 3 (see diagram above) and you have access to reticulated gas, plenty of unshaded north-facing roof area, and live in a relatively cloud free area then gas boosted panel solar hot water system is the best option for you as you will gain the most benefit from your exposure to direct sunlight and from the heat of your climate.
For those living in zone 1, heat pumps are the better option for you. With less direct sun exposure due to a cloudier environment, lack of access to reticulated gas, and being susceptible to extreme weather conditions; a heat pump system will stay safe regardless of the weather and will make use of the inherent heat of your climate.
In zones 3 and 4, a heat pump system will be the cheapest solar hot water system for those without access to reticulated gas. A heat pump system is more cost effective for those living in these areas, as less reliance on a booster will save energy costs. In these zones, a panel-based system will rely directly on the sun to heat between 50 – 65% of your water, with the rest heated by a boosting element. However, with the use of a heat pump system 65 – 75% of the water is heated indirectly by the sun, meaning that you get more from your solar hot water system than from reliance on an external booster.
How big a hot water system will I need?
The size of the hot water system that you will need is dependent on a few things. The first is: how much hot water does your household typically use?
Once you’ve figured that out, it’s time to consider a couple of other things.
If you use more hot water on an average day than your solar panels can collect, your booster system will be working overtime, sending your bills and your CO2 emissions higher than they need to be. However, if you’re using less water than what your solar panels can collect, the up-front cost for your system will cost you more than necessary.
So how will you measure this to make sure you’re getting the most out of your solar hot water system?
Easy! Just use our guides to calculate your hot water use per day, and you’ll be ready to go!
Efficiency is key!
To get the best results from your solar hot water system, and to be the most environmentally friendly that you can, you’ll need to equipment. Investing in water-saving and energy efficient products will save you more money on the overall cost of the solar hot water hardware. The best way to get started on this for your new solar hot water system, is to install high quality low flow shower heads and taps.
These shower heads will reduce the amount of water by injecting air into the stream of water that is coming through. This reduces wastage, and still gives you the enjoyment of a full-powered shower.
Another way you can prepare for your new water conserving and environmentally efficient lifestyle is to invest in a water and energy efficient dishwasher and washing machine. There is a large variety of these machines on the market, and you’re sure to find one that will suit your price range, and help you to invest the best products you can into your sustainable home.
With the addition of water efficient taps, shower heads, and appliances in your home, you can easily cut the amount of hot water that you use without compromising your lifestyle.
A relatively water efficient family will typically need a system with the capacity to provide around 75 litres of water per person. Most solar hot water panels will collect 150 litres a day on average; so for a family of four, a hot water system using two panels with a 300 litre tank will suit you well.
When you consult with your installer on choosing eh right size system for you household, make sure you take into account eh information you have gathered from these tables so that you can speak with them about deciding on the system that you will get the most value from. Remember, it is an investment for you and your family’s future, and that’s why we’re here to help you get the best out of your solar hot water system through linking you with the companies best suited to your needs.
To learn more about how your home can be more energy efficient, click here