How Many Solar Panels Do I Need?

how many solar panels do i need for my home

Owning a home is expensive. Not only do you have to think about the cost of the home itself, but also the cost to keep it running. Electricity is pretty inexpensive, but if you have a very large house or a lot of electronic appliances, your costs could be higher. These costs are what inspire many homeowners to consider solar panels.

If your monthly electric bill is more than $100, installing solar panels could be a sound investment and a way to cut your electricity costs. Before you decide, take the time to learn a little more about how solar panels work, how much sunlight you need, and how much they cost.

How Do Solar Panels Work?

You might think you know how solar panels work, but the process is a little more complicated than you might imagine. A solar panel doesn’t just absorb sunlight and magically turn it into energy – it is a multi-stage process. Solar panels are comprised of myriad photovoltaic cells (PV). Each cell consists of two layers of semi-conductive material, typically silicone, which has been altered with a second material that gives the silicone either a positive or a negative charge. This is necessary to establish an electric field within the panel that allows the photovoltaic cells to absorb photons (particles of light) and to convert them into electricity.

Though different manufacturers follow different approaches, it is common for the top layer of silicone in a photovoltaic cell to be seeded with phosphorus. The phosphorus adds extra electrons to the silicone, giving it a negative charge. The second layer, the lower layer, is then seeded with boron which reduces the number of electrons, giving that layer a positive charge. Together, the two layers establish an electric field where they meet in the middle.

When the photovoltaic cell is exposed to sunlight, it absorbs photons which knock the electrons loose, pushing them out of the silicone junction. Other components of the solar panel then convert these free electrons into usable electric power. Conductive metal plates on the sides of each photovoltaic cell collect the charged electrons and transfer the energy to wires so the electricity can flow and be harnessed for use. This is the most common way solar panels work, though there are some other models which utilize solar thermal or concentrated solar power.

What are the Primary Components in a Solar Panel?

Now you know a little more about how solar panels work, but there are some other components to consider. Here is an overview of solar panel components:

  • Panels – The solar panels themselves consist of numerous PV cells which typically consist of two layers of silicone or some other material.
  • Battery – The batteries are used to collect the solar energy produced by each panel and store it for later.
  • Controller – This component protects the batteries, helping to regulate the flow of electricity.
  • Inverter – This component takes the stored energy from the batteries and converts it to the proper voltage required for use by standard electrical equipment.

Over time, the various elements of a solar panel may need to be repaired or replaced – that is what drives the cost of solar energy up. In the coming years, however, new technology is expected to help reduce the cost of residential solar panel systems.

Should I Buy the Panels Myself or Go Through a Provider?

solar panel professional installationA group of PV cells is referred to as a solar module, and a grouping of solar modules is called a solar panel. As you have already learned, a solar PV system requires some different components – this means that installing the system is a little trickier than the average homeowner might be equipped to handle. You might be able to save some money by purchasing the panels yourself and hiring someone to install them instead of going through a solar power company. Each case is different. If you decide to buy the panels yourself, you need to find someone who knows what they are doing to handle the installation – here are some things to look for when shopping for solar panels and installers:

  • A solid warranty – you want to make sure that your equipment (and the installation) is guaranteed for at least 10 years (20 years for the panels themselves).
  • Look for solar panels made by a U.S.-based company – if you buy foreign and the company goes under, you probably won’t be able to cash in on your warranty.
  • If you are using a solar panel provider, look for a company that uses in-house installers – if they outsource installation you might have trouble getting help if something goes wrong.
  • Make sure the company is licensed and bonded – you should also ask for references and check for online complaints and a solid BBB rating.

There are many factors to consider when deciding if you want to buy the panels yourself or lease them from a company. One thing to think about is the fact that there may be tax credits available to help offset the purchase price. The federal solar Investment Tax Credit (ITC) could give you up to 30% off the conversion to solar energy for both residential and commercial properties. There might also be local tax incentives offered by your state or municipality. Find out about leasing or buying solar panels here.

How Much Sunlight Do Solar Panels Need?

Because solar panels absorb sunlight, the placement you choose for your panels is vital. You want to select a location that receives as much sunlight as possible, but direct sunlight may not be necessary. What many people do not realize is that solar panels don’t just absorb direct sunlight – they absorb daylight. This means that solar panels can still create energy on an overcast day. In fact, many solar panels contain concentrators which utilize a complex system of lenses and mirrors to concentrate any and all light that reaches the PV cells, directly or indirectly. Direct sunlight is still the most efficient for the conversion of solar energy. However – solar panels are only about 40% as effective in cloudy weather as they are on a clear day.

In addition to considering how much sunlight your home gets, you also need to think about the type of roof you have when considering solar power. Solar panels tend to fare best when mounted on sturdy, durable materials like concrete tile, asphalt or composite shingle, and standing seam metal. You might be able to install solar panels on slate tile, wood shake, or clay, but it is a more delicate process, and it might require different mounting hardware. The orientation of your roof matters as well – south-facing panels capture the most energy, and you want to minimize interference from trees and neighboring houses. The angle of your roof will come into play as well.

How Much Energy Does a Solar Panel Produce?

power created by solar panelThere are some factors that come into play when it comes to the amount of energy a solar panel produces. To determine whether it is a good idea to install solar panels, you have to think about your current energy consumption and the cost of that energy – then you can make a comparison with solar energy to see if it is a viable option. As a general rule, the average American household consumes electricity at a rate around 1 kW (kilowatt) per hour. The average month contains about 730 hours, and the average national price of electricity is $0.10 per kWh (kilowatt-hour). This adds up to an average monthly energy bill around $73. Again, this is an average – some states have lower electricity costs around $0.07 per kWh while others have rates as high as $0.24 per kWh.

How Many Solar Panels Do I Need?

The number of solar panels you need to power your home depends on the amount of energy each panel produces. The amount of energy a solar panel produces depends on the size, the location, and the orientation – factors which determine the amount of light the panel absorbs which impacts the amount of energy it can produce. On average, a solar panel can produce about 10 watts per square foot. This means that you need about 100 square feet of solar panels to produce 1 kWh. Again, you’ll need to factor in things like average daylight hours, panel position, even the local climate. The amount of energy you can produce depends on the number of panels you have room for – the average home can hold anywhere between 400 and 800 square feet of solar paneling.

How Much do Solar Panels Cost?

Though having solar panels can save you a lot of money on your electric bills, you have to keep in mind the cost of purchasing and installing the panels themselves. The average price for solar panels (including installation) is between $7 and $9 per watt. If you take the example of a 5 kW system, then, you have an average cost between $25,000 and $35,000. There are some utility companies and independent service providers which offer incentives on solar panels – you might be able to purchase solar panels as cheap as $3 per watt, though you’ll have to also factor in the cost of installation. An extensive solar panel system could take twenty years or more to pay for itself, so you’ll have to think about it as a long-term investment to decide whether it is the best option for your home or not.

Solar energy is an eco-friendly alternative and a renewable power source, at that. Unfortunately, the cost of equipment and installation means that it may not be the most practical option for homeowners unless you plan to stay in your home for at least the next twenty years. You also have to consider the fact that city or county ordinances might prohibit the installation of solar panels in your neighborhood – you’ll need to look into that. If all of the stars align, however, solar power just might be the right decision for you.

What are the Pros and Cons of Solar Power for My Home?