Most people who are considering switching to eco-friendly solar energy to power their homes often have one very important question:
“Putting up a solar energy system has a large upfront cost, how can I be sure the energy output is sufficient for my needs and when it will get back my money’s worth.”
This is a good question and the simplest answer is that a solar energy system is worth every penny you invest for up to 25 years. The solar energy system will return its value provided you pay close attention to solar panel efficiency before you buy.
Understanding Solar Panel Efficiency
In a photovoltaic solar panel, solar cells made from materials such as silicon are linked together in a panel and their job is to convert sunlight into electricity. When sunlight hits the panel, the light energy is absorbed as electrons from the material escape. These electrons are stored in batteries.
The rate of efficiency by which different types of photovoltaic solar panels convert sunlight into electricity does not range by much, so your shopping will actually come down to how much you are comfortable spending and how much space you have on your roof for the panels. However, narrowing it down, mono crystalline panels are the most efficient in that the produce the highest amount of energy in kW per square inch compared to multi/ polycrystalline and thin film panels. It therefore stands to reason that they are costlier and are most preferable.
If you are more concerned about generating energy in diffused light, such as in cloudy weather and seasons with poor sunlight penetration, you may want to learn more about thin film panels. These include amorphous crystalline, CIGS, and CdTe panels. While they are the least efficient in terms of amount of power generated per square inch, they perform much better in diffused light compared to mono-crystalline panels.
Factors that affect the efficiency of a solar panel
The capacity of a solar panel (rated in Watts) has a direct impact on its cost. Solar panels are typically priced and compared in the cost in dollars per watt. Since Watts are the output of each module in the solar panel, it is essentially the amount of electrical energy the panel will generate while operating under ideal conditions. This means that a panel with a 100 Watt rating can generate 100 watt-hours of power each hour… you get the idea.
The Wattage of the solar panel therefore affects its physical size. This means that a 200 watt panel will be about twice as large as a 100 watt one. The most important factor to consider when shopping for a solar panel is the amount of energy in watt-hours it can produce and whether it will be enough to power your devices, charge your batteries, and light your LEDs under ideal conditions.
There are four main factors that make your home not an ideal place to generate 100% wattage listed on the solar panel. In standard home environments, a 95% efficiency rate is acceptable but anything lower than that is an issue to address.
These main factors which you must consider when making future energy upgrade plans for your home are:
Direction the panel is facing: Most panels are installed in a fixed position for the whole year. This directly affects the intensity of sunlight hitting the surface of the panel and the amount of energy it produces. Some panels today come with advanced sun tracking system for maximum output throughout the day, throughout the year.
Tilt or angle of inclination: The tilt of fixed panels during installation will largely depend on the latitude of the place. Again, panels that track the sun are more efficient especially in places further away from the equator.
Shading of the panel: When a small part of the solar panel is shaded, it will affect the output of the entire solar panel system installed. Dust and building and tree shadows cause the most shading. During installation, all panels must be installed where no trees or buildings shadow them and they must be regularly cleaned to remove dust.
Temperature: Contrary to what most people believe, the higher the temperature, the lower the output from the solar panels. Panels are tested and rated in ideal conditions – 25 degree temperature, 1000W/m2 insulation, and 1.5 pressure air mass. These are not close to the conditions a typical solar panel is used in a home environment, but they are a guide to what you should expect.
While calculating how much it will cost you to upgrade your home energy system, also remember there is no better time than now to invest in a highly efficient system that will serve you for decades to come. Solar panels are made of high durability glass with high tolerance to heat, which is why it is not uncommon to have 100 Watts panels producing 105W energy in a home environment.