How Many Solar Panels Are Needed For A Hot Water Heater?

This article explores information about solar panels, solar heating, installation, types, uses, advantages, and how many solar panels are required for a hot water heater.  


What are Solar Panels and Why Do We Need Them?

Solar panels absorb sunlight directly from the sun and convert it into clean energy. Installing solar panels on your property helps combat greenhouse gas emissions entering our atmosphere and contributes to the reduction of our global dependence on fossil fuels. 


The burning of fossil fuels to generate electricity is one of the major causes of pollution that has adverse effects on our climate. To combat this issue, solar panels were invented. Solar panels, also known as photovoltaic (PV) panels, have been a staple in generating clean electricity through natural means for decades. These panels harness solar energy and convert it into electricity. 


Solar panels can be used in a wide variety of applications, such as remote power systems, telecommunication equipment, remote sensing, hot water heaters, pool heating, and electricity generation by residential and commercial solar electric systems.


There are various important reasons to opt for solar panels rather than grid electricity. One of the reasons solar panels are a good option is if you are living in a remote area that is off the grid. There is no need to install electric poles and waste money on cables that connect to the main grid for electricity. You can invest in solar power and save yourself both energy and money. 


While solar power lets you enjoy the perks of living in a remote area off-grid, you also get to benefit from this clean, renewable source of energy. And it also comes with the satisfaction of having lessened the pressure of greenhouse gases on the environment. 


Solar panels can be easy to install and can work for 20 years or more if maintained well. They are built ruggedly and are easy to clean. Even if you don't want to do it yourself, expert technicians can be hired for the installation and annual or bi-annual servicing of your solar panels. If you are looking for a solar contractor to install or service and regulate your solar panels, Everything Solar offers a wide range of solar-related services and has a team of experts to cater to all your needs.

Solar Hot Water Panel

Solar Panels for Hot Water Heaters

Solar panels are extremely versatile and can be used for a variety of different uses. One of their most common uses on a residential and commercial scale is to generate electricity and heat homes or workspaces. A cost-effective and smart way to use solar panels is to incorporate them into your water heaters to heat water and save on fuel costs! 


Solar water heating, also commonly known as solar thermal heating. It uses solar panels to absorb heat from the sun and transfer that heat to your hot water tanks. Solar water heating has been widely used in spas, pools, and homes to heat the water in a sustainable way that saves on electric bills. Solar water heating is worth considering as it provides you enormous ecological, economical, and energy sustainability benefits! If you are thinking of investing in solar heating systems, here are all the important things that you need to know before you proceed.


How to Use Solar Power in an Electric Water Heater?

Solar water heating systems work in coordination with conventional water heating systems. The solar water heaters include storage tanks and solar collectors (PV panels). The heat harnessed from the solar panels is used to heat the water in the storage cylinder. This article will tell you how many solar panels you need for a hot water heater and how to install it in your home. Two types of solar thermals can be used to heat water in homes, which are discussed next.

Solar Hot water Tank

Active Solar Water Heating Systems

Two types of active solar water heating systems exist:


  1. Direct or Open-Loop Circulating Systems 
    The direct or open-loop thermal system is exactly like it sounds. The water heated from the solar panels goes directly into the hot water cylinders to be used in homes.
  2. Indirect Circulating Systems 
    Most water systems that are used in areas of extreme temperatures are generally indirect. In these types of water heating systems, the liquid in the panels is a mixture of water and antifreeze. This is used to prevent the system from freezing for optimum deliverance of hot water. The heat trapped from the panels is transferred to the hot water cylinder via copper coils. 


Passive Solar Water Heating Systems

Passive solar water heating systems are generally more reliable, inexpensive, and long-lasting than active systems, but they are not as competent. They have to be installed perfectly by professionals to give you the optimum hot water output. They are of two basic types, integral collector thermosiphon systems:


  1. Integral Collector Storage Systems
    These kinds of passive systems are optimum for places where the temperature rarely falls below the freezing point.
  2. Thermosiphon Systems
    This system works on the concept of cold water being denser than hot water. Water flow through the system is made possible when hot water rises and cool water sinks. The collector has to be installed efficiently below the storage for this system to work. 


Expert help is required to install solar water heating systems. But if you need expert help, contact Everything Solar and get all your problems taken care of on: 407-545-3590.

Drainback solar water heating diagram

How Many Solar Panels Are Required for a Hot Water Heating System?

If you are thinking of killing two birds with the same stone: investing in sustainable heating systems and saving up on energy bills in the long run, some calculations need to be made before you install solar thermals. 


How Many Solar Panels Does It Need to Run a Heater?

On the average house, you will need to install three standard-size solar panels to power a heater that consumes 1500-watts of energy per hour.


Let’s suppose that a traditional water heating system uses 1500-watts per hour of energy. 1000-watts is equal to 1 kilowatt, hence, your heater uses 1.5Kw/hr of energy to heat your water. This becomes your base to calculate how many solar panels are needed to operate hot water heating systems.


Solar Panels or PV panels are made of different sizes, capacities, and areas for the collection of energy. There are solar panels that absorb and produce 100-watts, and others 300-watts. So, to run a water heater that uses up to 1500-watts, you need 15x100-watts or 15x300-watts solar panels. For 15x300-watt solar panels, you only need 3 panels which will save you roof space and will be easier to install. 


But before you make that leap, you need to determine if your home is suitable for the installation of solar panels and how many panels it can host.

Is Your Home Suitable for Installation?

There are a few factors that you need to look into before going all-in for solar panel installation. A few of the important ones are listed below. 


  1. Make sure the roof of your house is facing predominantly southwards. Due south is the most ideal location but it is also okay if it's facing towards the south-west or the south-east. This is important because naturally, the south receives the maximum intensity of sunlight for longer durations, especially during the summer months. This becomes an ideal prerequisite for the installation of solar panels. 
  2. The space on your roof where the solar panels are to be placed needs to be at least 2-5 square meters and away from the shade of neighboring buildings and surrounding trees. The solar panels require direct sunlight for maximum output. 
  3. To determine how many solar panels you may need, the area of your roof and the usage of hot water in your home is important.


All these factors combine to form an optimum environment for the solar panels to be installed.


How Much Energy Does a Solar Panel Produce in a Day?

There are a lot of significant factors that play a part in the energy generation from solar panels, including the following. 

Solar Calculation Start Here:


  1. Sunlight
    The amount of sunlight plays the most significant role in the generation of solar energy. The panel is solely dependent on the sunlight to produce or harness the solar energy and convert it into electricity. The amount of energy harnessed by a solar panel in a day is dependent on the amount of sunlight it receives. A solar panel will produce more energy on a sunny summer’s day than a cloudy or rainy day.
  2. Size of the Solar Panels
    The size of the solar panel also translates how much energy will be harnessed. The bigger the solar panel, the more surface area is available for the solar energy to hit and eventually absorb. The outer exposed part of the panels is responsible for harnessing solar energy and converting it into the desired electrical or mechanical energy. The average size of a solar panel is 65 inches in height and 39 inches in width. 
  3. Calculate Energy Needed and Its Cost
    The amount of energy produced by a solar panel also depends on its overall efficiency. A 300-watt solar panel is likely to absorb more sunlight and produce more energy as compared to a 100-watt solar panel. 


Initially, solar panels could only harness 6% of the solar energy, but with evolution in technology, they are now able to receive 25% of the solar radiation.  


If you have an ample amount of space on your roof, you may install 100-watt solar panels; however, panels of greater wattage are more efficient and will save you money in buying and installations. 


If you have any queries about the number of solar panels you may need for a water heater, feel free to contact Everything Solar today. We have several expert technicians with an in-depth knowledge of solar panels and their installation and usage. Customer satisfaction is our biggest priority! 


Frequently Asked Questions

  1. Are solar water heaters worth it?
    Solar water heaters cost a lot of money to install but they are worth it in the long run, not to mention the money you save on electricity after installing these solar panels for water heating. It is also a sustainable solution and produces clean and renewable electricity and heating which is good for you and the environment. It is better than conventional water heaters and you can take longer showers without the added costs!

  2. Can you heat water with a solar panel?
    Yes, you can heat water with a solar panel. 
    The one question people are generally confused about is whether solar panels can be used to heat water. The photovoltaic cells present on the surface of the solar panels trap solar energy and convert it into thermal energy. This process is used to heat water in the storage tanks through direct means or the use of storage tanks indirectly. Solar panels are an excellent way to heat water in a sustainable, eco-friendly, and economic manner. 

  3. How many solar panels does it need to run a 1500w water heater?
    If you use 100w solar panels, it takes 15 solar panels for you to turn on and use a water heater, although, the number of solar panels decreases as the wattage of the panel increases (# panels of 300w each, are needed to run a 1500w water heater).

  4. Do you need solar hot water if you have solar panels?
    Solar panels are only responsible to harness solar energy and convert it into electrical energy to power residential buildings. To establish a system of hot water heating, you will need to install a solar hot water system despite having solar panels. This system is designed specially to perform various functions to heat the water and save energy. 

  5. Can I run multiple heaters on one solar power source?
    The straightforward answer to that question is: yes, you can. But it depends upon the strength, size, and wattage of the solar panel and the energy needed to run the multiple heaters. 

  6. Do you need a battery to run a heater on solar power?
    It is necessary for you to have a battery attached to your solar panels, not only for heating but for other purposes too. There are options to make it work without the battery, but it is not recommended by the experts.


Wrapping Up

Solar systems are a thing of the present for a better future. If you can afford it and believe in a renewable, sustainable, eco-friendly, and economic replacement for fuel-generated electricity, you must invest in solar panels and solar hot water systems. If this article was unclear of how many solar panels you need for a hot water heater, contact Everything Solar for further details and get a free quote.


Everything Solar

Everything solar hires only qualified, certified, and experienced technicians who can cater to everything related to solar panels. Consider us for any queries, installations, cleaning, or other solar system maintenance services that you may require!