How Solar Works
Solar power really is fantastic!
It all starts with solar panels that are usually installed on your roof. The solar panels use the UV rays from the sun to generate electricity. Solar panels work best when they are in direct sunlight however they do still produce electricity on cloudy and overcast days.
Solar panels produce Direct Current (DC) power, but to be able to be used for most household appliances the power needs to be converted to Alternating Current (AC). The inverter converts the DC power into AC power so that it can be used in your home.
When your solar power system is making more power than you use, the surplus electricity is generally sold back into the power grid so that it can be used by someone else. Your electricity retailer will credit you for this on your electricity bill.
Overview of a standard PV system
Although there exist a variety of different solar photovoltaic (PV) technologies on the market (grid-tied vs. off-grid – rooftop vs. ground-mounted), most systems adhere to the same basic format, with minor variations.
Starting with the solar panels, the following outline provides an overview of how the individual parts and components of a standard PV system work together to bring you clean and free energy from the sun.
The Solar PV Panels
The solar cell is the backbone of any standard system. You’ve undoubtedly seen these signature blue or black tiles on everything from calculators to highway signs to entire rooftop systems. They capture direct sunlight, converting it into electricity via a process known as the photovoltaic effect.
However, because each individual solar cell can only produce a fraction of the energy needed to power most home appliances, they are linked together in series and enclosed in protective, weatherproof casing to produce a solar module or panel.
These, in turn, are further joined in sequence to create a solar array – what you typically see on rooftops across the country.
The number of arrays for any given installation is one of the most important determining factors for total power output. The more arrays you have on your property, the more electricity you can produce from your installation.
Mounting and Tracking
These solar arrays are then securely attached to your rooftop using any number of mounting solutions. The exact mounting approach depends on the size, slope, and orientation of your rooftop.
In some cases, property owners opt for ground-mounted installations if the rooftop is unsuitable for clean energy production.
Many installations further maximize power output by using tracking technology – manual or automatic guidance systems that follow the sun’s path throughout the sky, thus, ensuring optimal direct exposure.
Solar PV Inverters
Although the electricity captured by solar panels is direct current (DC), the vast majority of home appliances use alternating current (AC). And thus, most solar PV systems come with an inverter that safely converts DC to AC for residential and commercial use.
Once the solar energy has been converted into usable AC electricity, you now have 3 options:
- Use the electricity immediately to power your appliances
- Store the electricity for later use
- Feed the electricity into the utility grid to offset your energy bill
Let’s look at these 3 options in turn.
1. Using the Electricity Right Away
In most cases, homeowners and businesses choose to use the clean energy right away to power their appliances and electronics. No additional components are necessary since the energy feeds directly into the electrical wiring behind the walls.
Immediate energy consumption is especially important for those who live off the grid and have no direct access to utility power. RVs, remote homes, and isolated workstations all use this approach. During the day, the sun acts as “the” utility company, providing direct electricity from dawn to dusk.
But what happens at night when the sun isn’t shining?
2. Batteries for Storing the Electricity
Using any number of battery technologies, you can store clean energy for later use. So when your panels capture energy during the day, a portion of the electricity goes to your appliances right away, and a portion goes directly into battery storage for later use.
Again, this approach is necessary for those who live off the grid. However, many urban and suburban homeowners also use on-site storage for emergency backup, even if their properties are directly connected to the local utility grid.
3. Meters for Feeding the Electricity to the Grid
Many home and business owners tie their solar PV installations into the utility network. When the sun is shining, you can send excess electricity into the grid (sometimes at a profit). And when the sun is down or you need emergency power, you can buy electricity from your utility company.
In effect, the entire utility grid acts as storage for the clean energy your system produces. Depending on the incentives and regulations in your area, it is possible to dramatically reduce your monthly electricity bills, sometimes reversing them altogether. In other words, you can begin generating positive cash flow from your installation.
To help monitor energy usage, your utility supplier installs a digital meter that measures incoming and outgoing electricity to determine net power consumption.
Depending on where you live, you might consider using both on-site battery storage and grid-tied metering at the same time. This not only helps to maximize your monthly energy bill savings, but it also decreases the likelihood that you’ll ever be without power – even if the rest of your neighbourhood goes dark during a blackout.
Did you know? – Solar works because when light strikes particular metals, it causes the surface of the metal to emit electrons.
This characteristic – called the photovoltaic effect – is the basis of solar power. The efficiency of a solar cell may be broken down into reflectance efficiency, thermodynamic efficiency, charge carrier separation efficiency and conductive efficiency. The overall efficiency is the product of each of these individual efficiencies.
Solar panels can generate electricity without any waste or pollution, or and the energy is entirely renewable. Solar panels have no moving parts, so they are reliable and have a long life span. Solar panels are relatively easy to install and are very low maintenance.
The efficiency of solar panels continues to increase. As research is poured into solar farms and renewable systems, the cost declines while the power increases.
Solar systems now save more than they cost, which is ideal, because not only are you saving money, you are reducing your reliance on the coal-fired generator grid.