How Many Solar Panels To Power A Hot Water Heater?

How Many Solar Panels To Power A Hot Water Heater?

How Many Solar Panels To Power A Hot Water Heater? Whether you are a renter or homeowner, you might find yourself wanting to lower your energy bill while helping the environment. The easiest way to do both is to add a solar water heater system to your home.

Although few people think about their water heater, this system makes a massive difference in modern living. For one, it allows you to enjoy hot showers. Secondly, it is one of the biggest drains on your utility bill.

So, adding solar panels to your home for your water heater can make a huge difference. In fact, it is a great place to start if you are thinking of transitioning to solar power.

Unfortunately, it can be difficult to calculate how many solar panels you need. This is because many factors affect the energy produced by solar panels and how much you need in the first place.

Read on to learn how many solar panels you need to power your water heater!

Can you run a water heater on solar power? Yes!

If you are just now thinking about powering parts of your home with a solar system, you need to know what parts are suitable for electric power. You can power your electric water heater and many other appliances with solar energy.

To make the process even easier, there are solar hot water system installations available. In other words, heating water for your home is easier than ever, thanks to the many solar water systems to choose from!

You will need to perform some calculations to figure out how many solar panels you need for your electric heater. Still, there are many solar water heating systems to choose from nonetheless.

About solar panels

Before we learn how many solar panels you need or which solar water heating system you should choose, let’s discuss solar panels specifically. In case you are unfamiliar, solar panel systems produce electric power via the sun.

The sun’s energy comes to our planet in the form of waves. The PV panels can capture that energy and then transform it into usable power.

Because of the PV system’s power production, you can use solar electricity to reduce your electric bill and help the planet at the same time. Some utility companies will even pay you for any extra energy you generate and put it back in the grid!

The biggest drawback of panels is that they require sunlight. In other words, the power production is limited to daylight hours. However, with the help of a battery bank, you can use more energy throughout the day and night.

Even when cloudy or the sun is down, you can use solar panels to use a battery system as a cost-effective energy source. Anything from your heated water to a space heater can be used day and night with a battery or grid-connected solar system.

To sum it up: PV panels use solar energy to heat water, power your TV, and more, all while using less energy than grid-tie options!

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What are my solar water heater options?

Even though solar water systems are relatively new for home use, there are plenty of options to choose from. These selections can help lower your electricity bill, though they might be a bit costly at first.

Types of solar water heater systems

There are different types of water heating systems you can have. The most popular include electric systems, storage tanks, and thermal/solar hot water.

Some thermal/solar hot water systems use a combination of the storage tank system as well. For many homes, this combo option serves as the most cost-efficient and reliable method.

If you are interested in powering your water heater with solar power specifically, you will have two categories of systems to choose from: active and passive.

Within both of these general categories, there are even more options to choose from. For example, if you want an active system, you can choose between active direct or active indirect, whereas you choose between integral collector and passive thermosyphon for passive systems.

We discuss below what these two types of systems entail and how they differ.

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Are solar water heaters worth the hype?

Solar systems are definitely worth the hype if you are looking for a way to lower your bills in the long run while lowering your carbon footprint. In addition, since water heaters need so much energy, solar power is a great way to retain some of the luxuries of modern living without the high costs.

Of course, there is a huge one-time expense associated with solar power. Panels themselves are costly. You will need to ensure that your heating system is hooked up with the panels too.

As you would expect, these are costly expenses. Even though the system can help you save money in the future, many people don’t have the current finances to afford the system.

Even if you have the money, buying a solar heater system may be an unwise financial choice. For example, you will not want to upgrade to a solar water heater system if you are about to move.

Although it will increase the value of your home, it likely will be too much of an investment that you won’t be able to experience the benefits from.

So, these systems are worth the hype if you can afford them and aren’t expecting to move any time soon. However, if you find you are strapped on cash or are thinking about moving soon, you should probably forgo these systems for the time being.

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How do solar water heaters work?

How solar water heaters work depends on the type of solar system you opt for. As we learned above, there are several options to choose from, and each one is different in its technicalities.

That being said, all options have the basic same approach. They use the sunlight to generate hot water.

This process may sound very straightforward, but it is not. Exactly how the sunlight generates hot water depends on whether you select an active or passive system. So let’s take a closer look at each of these categories.

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Active vs passive solar water heaters

If you add a solar water system into your home, it will either be passive or active.

Active systems have a pump that sends the hot water into your home from collectors where they are heated. Active systems are often used in cold environments because the water is stored inside a tank that you can place indoors to prevent freezing.

On the one hand, active direct systems heat the water in the collectors, where the water is then sent throughout your home. On the other hand, active indirect systems use heat transfer fluid to heat the water.

Passive solar water heaters work completely differently. First, they don’t require special equipment, making them cheaper. Instead, they rely completely on convection, a fancy term describing how hot water rises to circulate water.

Passive solar heaters come in two categories: integral collector and passive thermosyphon. Integral collector systems have openings so sunlight can get through. The sunlight is what heats the water in black tanks and then flows to your home.

Passive thermosyphon systems heat water on your roof. The water will then flow from your roof to your home for you to use.

Often, passive options are accompanied by a tankless heater to act as a backup source. Unfortunately, tankless systems are tough to discuss.

Should I get an active or passive system?

Many factors go into deciding which system is right for you. Both come with their own pros and cons.

Active systems are more expensive, but they guarantee hot water, and they don’t have to be located on your roof. As a result, these systems are best if your roof is not strong enough for passive systems or you don’t live in a particularly sunny area.

In contrast, passive systems are very affordable and don’t require much maintenance. They are best for those who live in sunny areas and who are on a budget. You should not get a passive system if your roof isn’t strong enough for the collectors or you don’t have enough sun to produce warm water reliably.

If you aren’t sure which option to get, talk to a professional installer. They will assess your home and give you specific recommendations based on your needs and home.

What is the best solar water heater system available?

Generally speaking, the best solar hot water system is a dedicated solar thermal hot water system. Pair that device with a heat pump, which is what we described with the active heater systems.

All around, this option is the most affordable in the long run and can help you keep your payments down now and in the future. In addition, if you live in an area with a lot of sunlight year-round, this is a perfect option.

Often, tankless systems tend to b difficult to estimate, which is why few people use them. In addition, though they can be a great option for some, they often require connection to the grid, using a combination of solar and traditional energy.


How many solar panels power a water heater?

The biggest trick to using solar panels to power your home system is finding how much energy your solar water heater requires.

Once you know how much energy your solar heater needs, you need to calculate power production for your panels. This second step compares energy production against energy usage to determine how many panels you need for solar water heating.

Finally, the last thing you do is calculate potential savings. This step gives you a good idea of what to expect, financially speaking, from the system.

Let’s take a closer look at each step.

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Step 1: Figure out how much power your water heater needs

To begin discovering the number of solar panels you need, you must know how much power your heater needs. Start by looking at the wattage of your water heater.

Checking out the wattage isn’t that difficult. However, it should be labelled on the package or heater itself so that you can easily uncover the information.

If you cannot find the wattage on the heater, you can search online based on your heater model. You should be able to find the information relatively easily.

Step 2: Figure out how much energy your solar panel can create in a day

Like in Step 1, begin Step 2 by looking at how much wattage your solar panel can produce. You will want to compare the wattages of both.

If the solar panel cannot produce enough energy compared to the heater’s, you will need to get a more powerful solar system.

Factor in your area’s average sunlight. Even if your panel can produce enough energy, it won’t do much good if you live in a rainy or cloudy area. You will need to get more panels if this sounds like your environment.

Most likely, you will need one or two solar panels to power your water heater. Assuming that your solar panel uses the most recent technology, one solar panel should suffice.

Step 3: Calculate savings

Finally, the last thing you should do is calculate savings by switching to the solar system. Expect to spend up to $5,000 for the system, but your utility bill will decrease after.

You can save between 50% and 80% on your bills. To calculate potential savings, you need to think about the following factors:

  • How much hot water do you use daily
  • Cost of your backup heater
  • Solar energy factor rating of the equipment you expect to use
  • How much water do you use during the nighttime
  • The life expectancy of the solar system


How many solar panels does it take to run a 1500 watt heater?

Most likely, you will need three solar panels, 300 watts each, to run a 1500 watt heater for your home.

How many solar panels do I need for a water heater?

If you select some of the most updated and modern solar panels, you will likely only need one to heat your water. However, high usage or an older panel may require you to use two or more.

Although many new systems only require one panel, don’t expect this to be true for you. Instead, it would help if you did the math yourself to determine your exact needs.

The number of factors will determine how many solar panels you need. The most important include:

  • Average sunlight
  • Power of the solar panel
  • How much hot water do you need
  • When you use the hottest water during the day or night

How much money can I save with a solar water heater?

Solar water heaters are a large investment. Expect to pay up to $5,000 initially.

Although this is a huge investment, it may be worth it down the line. After installing the solar system, you will start to pay less and less on your bill until you can make up the cost from the investment.

You will be happy to know that solar water systems can cut your utility bill by up to 80%. Even with the worst prospects, you can expect the system to save you around 50%.

Once you have finished your solar payback period, you basically have access to free hot water for the rest of your life.

Final thoughts

A solar water heating system can help heat water all with solar power and solar energy. Your hot water tank can be powered naturally using an electric water heater or an integral collector storage system.

The hardest part of heating water with solar power is knowing how many solar panels solar water heaters require. Since power relies on the sun, it can be a difficult number to estimate.

Whereas one power requirement is only single solar panels or a few panels, another requires a full solar system or several solar panels needed.

Ultimately, you will need to consider your unique situation and power requirement to heat your morning showers and avoid cold water.

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