Soaring energy costs and growing concern about environmental damage from fossil fuel emissions have sparked a renewed interest in alternative energy in recent years. The sources we’ve come to rely on for heating our homes and businesses no longer seem affordable or sustainable in the long term.
Solar panels take one of our most plentiful resources – sunlight – and transform it into energy that can be used to produce heat, electricity, or hot water. Because sunlight is a free and abundant resource that produces no emissions, solar power is an eco-friendly alternative to conventional sources of power that will never be in short supply.
Whether you’re looking to make a difference in the environment or save money on your monthly energy bills, there’s a lot to consider when deciding if solar panels are the right option for your home or business. Buying and installing solar panels requires a significant investment, but it’s one that will eventually be recouped through energy savings.
Types of solar panels
There are two basic types of solar panels, and it’s important to understand the difference between the two because they produce different types of energy. There are also distinct advantages and disadvantages to both.
Photovoltaic (or PV Solar) solar panels convert the sun’s power into electricity. Metal conductors are placed on top of individual solar “cells” made of silicon to generate an electrical current in reaction to sunlight. Banded together into a grid and covered with glass, these cells make up a solar panel.
PV solar panels can be connected to the regular electricity grid, connected to the building and batteries that will provide power when there’s no sun, or both.
The three basic types of PV solar panels are mono crystalline, polycrystalline and amorphous.
All three are made with silicon, but they vary in expense and efficiency.
Mono crystalline, cut from a single crystal, are priced highest, but produce the most energy. Amorphous, made with a non-crystal type of silicon, are far less expensive, but less efficient. Polycrystalline varieties fall somewhere in between.
PV solar panels have a long life span and require minimal maintenance. They’re ideal for the home or business owner who is willing to pay a little more up front for decades of hassle-free use. They can be installed quickly and in a variety sizes. However, their performance is directly affected by the amount of sunlight on a given day, and they are less efficient in cloudy conditions. They also absorb only a fraction of the sunlight energy – typically around 10 percent with the most efficient models nearing 20 percent.
Thermal solar panels are used to heat air or water. They can be used to heat the inside of a home or commercial building, a building’s water supply, or even a swimming pool. They work simply by absorbing the sun’s heat.
Passive thermal systems require no mechanical equipment. These systems can be used to heat building in sunny, warm climates. Solariums also work this way.
Active thermal systems require a collector to absorb the sun’s radiation and concentrate it into a small area. Mechanical or electrical equipment such as pumps or fans are used to circulate the heat, and they typically have a storage system similar to conventional heating systems. Often, these systems are used along with a supplemental heating system that runs on traditional fuel like oil or natural gas. They are better suited for climates that experience freezing.
Collectors can be non-concentrating or concentrating. Concentrating collectors can increase the sun’s power many times over, and are used for larger applications. Non-concentrating collectors are more suited toward residential and business use. A flat plate, which is an insulated box that absorbs sunlight with built in pipes that transport warm air or water, is the most common type of collector.
Overall, thermal solar panels are considered more efficient than PV panels. They are also less expensive, produce higher temperatures, and cover larger areas.
Solar panels are typically installed on the roof of a home or building, but they can also be mounted on stand-alone supports. Before installing solar panels or having them installed, make sure to remove any objects, such as trees or signs, in the path of sunlight. Solar panels work best in direct sun, so your panels will not perform at maximum efficiency if there are obstructions.
You'll need to research your city or town’s building codes, zoning ordinances, and/or homeowner’s association rules before installing solar panels. Some place restrictions on the size, placement, or number of solar panels you can use. Many towns also require a building permit for solar panel installation.
Installing solar panels yourself – while not impossible – can be difficult. It involves wiring, piping, and installing complicated control systems with switches, motors, and/or sensors. Solar panels also must be installed at specific angles to ensure maximum sun exposure at peak times.
If you’re not familiar with this type of work, you'll probably want to hire a contractor that has experience installing solar panels. A skilled contractor should also know how to keep the panels cool during the installation process, which is critical to protecting them.
If you decide to tackle the project yourself, most solar panels will require some kind of mount – be sure to research which type of mount you need before beginning work. If you’re confused about any part of the process, don’t be afraid to spend a little extra time studying up or ask an expert to walk you through the installation process. It will be much less expensive to properly install them the first time around than to fix them later.
How much do they cost?
Generally speaking, solar panels systems can cost anywhere from a few thousand to tens of thousands of dollars. However, the price for each project varies, based on how many solar panels you plan to install and which type.
For example, active thermal solar panels for commercial use tend to cost between $30 and $80 per square foot of the collector area.
Mounting just a few solar panels to supplement your conventional heating system will be far less expensive than a system designed to meet most of the energy needs of your home or business.
Builders or businesses can take advantage of federal or state tax credits designed to encourage the use of solar panels. Homebuilders may find their homes sell faster than comparable properties without solar panels because they are less expensive to operate.
- Make sure to ask about the warranty before purchasing solar panels. Commercial varieties should offer a warranty of at least 5 years, although the panels should actually last decades longer.
- Don’t expect a solar panel system to provide 100 percent of your home or business’ energy needs: it's very rarely economical to install that kind of system. Most systems provide between 40 and 80 percent of a building's energy, with a supplemental system providing the rest.
- When checking the local laws regarding installation of solar panels, it helps to ask the clerk or building inspector about common problems they encounter. Some may include: the weight of the panels exceeding the acceptable workload or incorrect wiring.