What are the different types of solar energy technologies?
The three types of technologies most commonly used to harness solar energy are photovoltaics, concentrating solar power and direct thermal:
Often referred to as PV, this technology converts sunlight directly into electricity using panels. Most commonly used in residential homes, photovoltaic panels are made up of many solar cells that have semiconductor materials to capture the light. When the sunlight hits those cells, electrons are knocked loose, creating an electric current. The electrons flow through a circuit on the panels and generate electricity. The more panels on a home or business, the more energy that can be generated.
Concentrated solar power
Referred to as CSP, concentrated solar power is used mostly in large power plants and is not typically recommended for residential use. CSP technology concentrates sunlight using mirrors and reflectors to collect solar energy and turn it into thermal energy. This thermal technology harnesses the sun’s heat and converts it to mechanical energy before converting that to concentrated solar power to heat homes and water. This energy can be used to power turbines, which then makes electricity. CSP plants can also store their energy in order to produce electricity at all times of the day.
Also called solar heating, direct thermal is another type of solar technology. These systems, like water heaters for homes or pools, use solar energy directly as a source of heat. By using sunlight or collector systems, direct-thermal systems can also heat living and working spaces, which can reduce utility costs immensely. There are also solar cooling systems that can circulate air conditioning or liquid through an HVAC system, without the use of electricity.
Is my house a good candidate for solar?
If you have high electric bills and sun in your yard, solar panels might be a good investment for you. There are two questions everyone should ask when considering adding solar panels to their home:
How much is your energy bill?
In order to actually save money by going solar, your current utility bill needs to be at least $75 per month. Residential solar companies set this $75 threshold because if your monthly utility bill is less than that, you won’t really see energy savings by installing solar panels to your home.
What kind of roof do you have?
The best solar panels have a life expectancy of 40+ years, so you need to be certain your roof can last just as long. Solar panels require mounting hardware, which works best on composite or asphalt shingle, concrete tile or standing seam metal, or other sturdy material. If you’ve been thinking of replacing your roof, prioritize that over installing residential solar panels.
If you’ve got a sturdy roof and your utility bill is over $75 per month, then you should set up a solar consultation. A solar panel expert will come to your home to evaluate its potential for solar panels. Other considerations include:
The size of your roof
One solar panel is 5 ½ feet tall by 3 feet wide, so the area of available space on your roof could determine how much of your energy needs can be met by solar panels. On average, and under proper conditions, one solar panel produces about 1 kWh per day. If your daily kWh usage is 30, you would need 30 solar panels to generate all of your energy needs. – Flat Roof Mounting System
The direction of your roof
To get the best efficiency out of your solar panels, you must mount them toward the rotation of the sun. In the northern hemisphere, this means orienting it on a south-facing part of your roof. Pitched Roof Mounting System
How much sun you get
Solar panels produce more power when they get more direct sunlight, unshaded by trees or taller buildings. The more sun in your area, the more electricity you’ll be able to produce. Know that you also might end up using a lot of power for air conditioning. Solar energy companies calculate “peak sun-hours” unique to your home. Peak sun-hours are the hours on a typical day that determine how much of the day sunlight can reach your panels at 1,000 watts per square meter. Most homes in the United States have three to five peak sun-hours, with less in the winter and more in the summer.
Where you live
The climate will also affect how much energy you need. Keep in mind that if your home is surrounded by shade from tall buildings, large trees or other obstructions, this will interfere with the amount of sunlight your panels will receive, thus making it less effective. You can calculate your peak sun-hours by placing an insolation meter in direct sunlight, and the meter will inform you about the solar power supply and current light intensity in your area.
Finally, consider how much solar panels cost. It’s important to know whether the solar company offers solar leases or Power Purchase Agreements (PPAs), if they provide loans, or if they can help you get Property Assessed Clean Energy (PACE) financing. There are financing, leasing and PPA (power purchase agreement) options. As with most major purchases, there are pros and cons to consider before you install solar panels onto your home.