Guide to Solar Water Heaters: How It Works & Is It Worth It?

Estimated Reading Time: 5 minutes

First, what are solar water heaters?

Solar water heaters, as the name suggests, are devices installed on one’s roof to heat water using sunlight. This device consists of 2 parts, namely solar thermal collectors & storage tanks.

How they work together is pretty simple: solar thermal collectors typically have black or dark blue absorbing surfaces or solar tubes that absorb radiation from the Sun, which transfer heat energy to water flowing within the storage tanks.

Do note that this is different from a solar panel system, where solar energy is converted to electrical energy and transmitted via your distribution board (DB) to power your whole house.

An example of a solar water heating system with dark blue solar tubes can be seen above.

There are 2 types of heating systems for solar water heaters, namely active solar water heating systems & passive solar water heating systems.

Active solar water heating systems

Active solar water heating systems comprise of pumps to aid with water circulation, as well as a set of controls which help to regulate the operation of the whole system.

In Singapore, direct circulation systems are the most common circulation systems you would find, where pumps circulate household water directly. This is compared to other colder countries with sub-zero temperatures, which rely on heat transfer fluids instead. Brr!

Passive solar water heating systems

On the other hand, passive solar water heating systems transfer heat through natural convection currents instead. Cold water enters through the bottom of the storage tank, is heated up by the solar thermal collectors, and finally rises to the top, leaving the system as hot water.

Choosing between an active solar water heating system & a passive solar water heating system ultimately depends on your priorities, as well as your current budget. This is because while active solar water heating systems are definitely more efficient compared to its passive counterparts, they are also pricier as a result.

To help you better weigh your choices, we’ve also written a post discussing whether it is worth purchasing energy efficient appliances in general, which could help provide some perspective to the matter.

How Are They Different From Electric Water Heaters?

Unlike electric water heaters, solar water heaters draw energy independently from the Sun, which means that output of hot water is largely dependent on weather conditions. In terms of size, you can also expect solar water heaters to be much larger in magnitude. The average solar water heater, for example, is about 2 metres in length & height, and about 1 meter in breadth.

So what are the benefits of getting a solar water heater?

Beyond solar being the best energy source in Singapore (and maybe the world), these are some of the other benefits to getting a solar water heater:

Potential Cost Savings

According to our folks at TheSmartLocal, an average water heater takes about 3,000 watts of electricity, which is approximately $548 a year. Having a solar water heater installed means you no longer need to use an electric heater as often (you might still need to use your backup heater), thereby making your overall electrical bills cheaper. Depending on how well-insulated your storage system is, water that is heated in the day can remain warm at night, giving you 24/7 access to hot water from your solar water heater.

Energy Independence

Having a solar water heater also helps to protect yourself against fluctuating electricity prices, especially in light of the recent global energy crisis where we saw prices of electricity rise by up to 60%. With a solar water heater in place, you may finally have a chance to enjoy your baths with a peace of mind, knowing that electricity prices won’t spike overnight ?

Potential Property Value Enhancement

Finally, investing in renewable energy solutions such as solar water heaters can potentially increase the value of your property, due to increasing demand for such technologies. Potential homebuyers increasingly appreciate eco-friendly features, and having a solar water heater installed may give your property an edge in the market. This added value can also be an advantage if you decide to sell or rent out your home in the future!

What are its drawbacks?

Unfortunately, installing a solar water heater in Singapore also has its own drawbacks to take note of:

Potential Roof Leakage

One of the major concerns for installing a solar water heater for most homeowners would be the possibility of their solar water heater leaking. This primarily occurs due to wear and tear over time as hot water passes through the valves, causing faulty or leaky valves. The damage caused by water accumulating on your roof over time can be potentially dangerous, which include permanent structural damage, mosquito breeding & possible allergy triggers.

An example of roof damage that can be done due to leakage

Hefty & unpredictable costs

When it comes to solar water heaters in Singapore, both the upfront costs and maintenance costs can be relatively expensive. A 270 litre solar water heater in Singapore is estimated to be about $2,500 upfront, excluding installation, shipping & other manpower costs. For maintenance, you can expect to spend about $200-$300 per visit.

Additionally, if your solar water heater starts to leak and requires removal, this would cost another potential $800. Overall, this could offset the promised savings from installing it in the first place.

Current technology is relatively outdated

Finally, solar water heaters in general also rely on dated technology from at least 10 to 20 years ago, which may result in issues such as clogged pipes from sediment buildup, water leakages or even the lack of hot water.

Our final recommendation

In theory, solar water heaters can help you to save money, increase energy independence as well as potentially increase the valuation of your own home. However, do keep in mind the practical drawbacks that come with installing a solar water heater, which include water leakage on your roof, the hefty & unpredictable costs that may offset your savings, as well as the technology being dated leading to common performance issues.

Rather than installing a solar water heater, a better option would be to install a full on solar panel system instead. A solar panel system would be able to supply your whole house with electricity instead of just your power heater, which enable higher costs savings and greater energy independence in the long run.

Furthermore, solar panels also come with safer financing plans than solar water heaters, such as the zero upfront cost Rent-To-Own model pioneered by yours truly in Singapore. Under Rent-To-Own, which comes with free servicing & maintenance, one can simply pay a monthly fee to enjoy his/her own solar panel system. This way, you would be able to guarantee your savings every month and get the best out of your solar panel system.

To find out more about Rent-To-Own, you can click here!

How much would it cost to install solar?

On average, this costs about $240 per month for a 10 year plan, but it ultimately depends on your roof. Curious to find out how much it would cost to install a solar panel system for you? Simply click here to get a free, instant solar quote within just a few minutes!

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