Solar hot water diverters vs solar batteries

Fast read

Two ways to utilise extra solar energy generated by a solar system are solar batteries and solar hot water diverters.

While a solar battery stores excess energy that can be utilised later. Such as at night when the solar system is not producing electricity. A solar hot water diverter directs excess energy to the immersion heater in a hot water tank to heat the water.

While solar batteries can be used in every home to reduce energy expenses. Solar hot water diverters are particularly effective for homes with significant hot water demand.

Before choosing between the two solutions, it is vital to take into account aspects like energy consumption, regional feed-in tariff rates, and power rates.

What are the differences between solar hot water diverters and solar batteries?

In many cases across Australia, solar systems produce more energy than your home consumes, especially during generation peak hours between 11 am and 3 pm.

Any excess energy produced is then sent to the grid, and you can get 5 to 10 cents per kWh for it. Unfortunately, as a homeowner, you will have to repurchase this energy from your retailer in the late afternoon. Sometimes up to 10 times the price they bought from you.

This is why it makes sense to use as much solar energy as possible or find a way to store it. There are two main ways that this excess solar energy can be harnessed. Either through solar diverters or solar batteries, two very different technology processes. 

While your solar system is busy producing energy from the sun’s light throughout the day to be used by your home’s appliances, solar batteries and solar diverters begin to work when excess energy is produced. They both prevent this extra energy from being exported and aim to use it within the property before it gets exported. This is usually for a low payment per kWh, such as 5 to 7 cents.

So how do these two pieces of technology work?

Solar energy diverters for hot water versus a solar home storage battery

A solar diverter is usually installed next to a conventional electric hot water tank. So to take advantage of this technology. One needs a conventional electric hot water system to start with.

Solar diverters are constantly monitoring the amounts of energy used in your home versus the amount of energy your PV system generates. When you reach the point where more energy is generated than consumed. A solar diverter will jump into action as follows: 

  • Excess energy will get diverted to the immersion heater, which is located in the hot water tank; 
  • The water in the tank will then get heated with surplus solar energy. Instead of expensive grid energy; 
  • Hot water will continue to be produced until another home appliance needs energy 

Therefore a solar hot water diverter allows you to use your excess solar energy to heat your water. This saves you from using energy from the grid to heat your water. Before purchasing a solar hot water diverter, you need to consider whether or not it is worth the money. You should speak with a professional and weigh up your hot water consumption, the local Feed-in Tariff rate, the electricity rates you pay, and general technical considerations.

Solar batteries explained

In contrast, a solar battery follows a different procedure when there is excess energy produced:

  • The solar battery stores the excess energy that is being produced. Charging up until it has reached total capacity; 
  • After the battery is full, excess energy will be sent to the grid; 
  • The energy stored in the battery can then be used when your solar system is not producing any energy. For example, at night – instead of using grid-provided electricity. 
sonnen solar battery in home instead of solar hot water diverter
Solar batteries support your home by storing energy for rainy days

The benefit of a hot water-producing diverter

If your solar system is large and your hot water consumption is not too high, your electric hot water system may be powered entirely by solar electricity. While this looks pretty doable on paper, in practice, it is not so simple during winter when solar production is lower and hot water generation is higher.

Along with this, diverters can have other features. One is that they can supply other household appliances, such as a pool pump, with the power they need if there is an excess of energy. This feature is called threshold power because it only supplies power to these appliances once it reaches a certain point.

So is one better than the other to save money?

Both of these technologies offer specific benefits that also overlap. For example, a solar diverter allows you to work your way towards producing free hot water as your heating system enjoys free solar electricity. As a result, solar diverters are much cheaper to add to a home energy system than a battery. At the same time, it saves the same amount of electricity going to the grid as a medium-sized battery. A diverter fully installed would cost only about 20% of the cost of a family-sized battery, or even less. In the industry, the diverters are called “The budget man’s battery.”

A solar battery allows your solar system electricity to be stored and reused so that you can slowly work towards being independent of the grid. Furthermore, in the circumstance that there is a power outage. If your battery system includes backup technology, you should have enough energy to keep the lights on during a blackout. 

These technologies will not allow you to become completely independent from the grid. However, they allow you to work towards lower importation of grid electricity – and if you have a very large solar system, it could even lead to self-sufficiency.

Is battery backup important for you?

If battery backup is important- then the battery wins out. If, on the other hand, price is a significant factor in your decision, then choosing a solar power diverter is the better choice. 

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