Solar Panels for Your Home - How to Choose The Best

Solar panels are the most essential components of the solar power system. To choose the best solar panels (also called solar modules) is the most important thing for every homeowner who has decided to go solar. In this post, you will find some directions on how to choose the best solar panels for your home.

First of all, you have to choose the type and the brand of solar panels. There are four key technical specifications you have to consider: panel efficiency, temperature coefficient, the materials warranty, and the performance warranty. 

There are two main types to choose from when it comes to solar photovoltaic panels: monocrystalline solar panels and polycrystalline solar panels. Monocrystalline solar panels (black color) are more efficient because they are manufacture from the purest silicone. Each solar cell here is cut from a single, continuous piece of silicon crystal. Monocrystalline solar panels are also more expensive. They cost between $300-700 USD per panel. Monocrystalline solar panels produce the most waste when they're manufactured. 

Polycrystalline solar panels (dark blue color) are considered to be less efficient and this is due to the method of production. Manufacturers melt multiple silicon fragments together to produce the wafers for this type of solar panel. They are the most commonly purchased solar panels, simply because they are the most affordable option. Polycrystalline solar panels usually cost between $200-500 USD per panel. They are an environmentally-friendly option because they utilize all of the silicon material they are manufacture. 

There is also another type of solar panel - thin-film solar panels. Thin-film panels are cost-efficient and most sustainable to produce and they are least expensive. However, they are also the least efficient (commercially available generally have efficiency in the 10–13% range) and degrade faster. Thin-film panels need more space, even twice as much room as a mono- or polycrystalline solar panel with the same energy output. These types of solar panels usually cost between $175-300 USD per panel. It is rare to see thin-film panels on the roof. Thin-film photovoltaic cells are used for large and small PV application such as a calculator, solar-powered charger for smartphones, solar-powered purse, solar-powered backpack, curved surfaces on buildings and cars, even on clothing to charge small electronic devices. They are also used to power traffic and street lights, and for commercial and industrial projects (solar farms).

You may have heard about bifacial solar panels, which can absorb light on both the front and the back of the panel. They have higher rates of power output and higher efficiency than traditional solar panels. But these types of solar panels aren’t typically used for residential solar installations. They are more expensive and they are more suitable for large ground-mounted projects.

The second thing to consider is the brand. Some of the best quality and most reliable panel manufacturers are LG, SunPower, REC, Solaria, Panasonic, and QCells. You can see the list of the best manufacture at Top 10 Solar Panels - Latest Technology 2020 — Clean Energy Reviews. Another review of solar panels you can find at Best Solar Panels in 2020 [Complete List] | EnergySage. The best brands of solar panels have the best solar panel efficiency and temperature coefficient.

Solar panel efficiency means the percentage of sunlight that hits the surface of solar panels converted into electricity for your home. Currently, most solar panels have an efficiency between 15% to 22%. The average efficiency of solar panels is between the 17% to 19% efficiency range. The higher the efficiency rating, the more sunlight your solar system can turn into electricity to power your home. SunPower’s A-Series Residential Solar Panels are 22.8% efficient at their maximum and they are the best solar panels available on the market today. Keep in mind, however, that efficiency also depends on factors like placement, orientation, shading, time of year, dust and dirt, weather conditions, etc. If you have enough roof space you may choose less efficient and not so expensive solar panels.

The temperature coefficient tells you how well your solar panels will work on hot summer days. Solar panels operate most efficiently when they are kept cool (ideally around 25° C or 77° F panel’s temperature). The temperature coefficient usually ranges between -0.3% and -0.5 %/°C. Solar panels are tested according to international technical standards at 25°C, and that is why this is used as the reference point. For every degree above that temperature, your solar panel’s electricity production will decrease by the temperature coefficient. If the temperature coefficient is -0,3% and your solar panel’s temperature increases by one degree Celsius (from 25° C to 26° C), its electricity production will fall by 0.3%. If the temperature increases ten degrees Celsius to 35° C (or 95° F), the panel will produce 3% less electricity. So, a lower temperature coefficient is better. The temperature of the panels depends on your location, roof material (some absorb more heat than others), and the installation of the panels (if they are angled or mounted flat on the roof). In many instances, a solar panel’s surface can get as hot as 50° - 65°C. If the installation is a typical rack-type, you will have a gap of greater than 150mm between the roof surface and the panels. It will allow airflow to have a cooling effect on the panels.

Thin-film solar panels have a lower temperature coefficient than traditional monocrystalline or polycrystalline panels. Their temperature coefficients are closer to -0.2% / °C.

Another important thing is a solar panel’s materials warranty which protects against failure due to manufacturing defects. Solar PV manufacturers provide a minimum 10 - 12 years product warranty but many solar panel manufacturers offer 15, 20, and even 25-year product warranties. This means the manufacturer must either replace or give you a refund for solar panels that fail within the product warranty period.

The performance warranty is different from the solar panel’s materials warranty. The performance warranty is called also the 'power output warranty' and it ensures that the solar panel still produces a minimum power output after a specific amount of time. The common industry standard is 80-83% power output after 25 years. Some top manufacturers such as SunPower and LG guarantee 88-92% power output on most modules after 25 years of use.

Besides the top solar panel brands, many manufacturers are offering a wide range of quality, affordable panels. The most well known of these manufacturers are Jinko Solar, Canadian Solar, and Trina Solar. See other brands at Choosing a quality Solar Panel - Reliability, warranty and efficiency — Clean Energy Reviews

And finally, to determine the number of solar panels you need to do some calculations regarding current energy consumption in your home, and how it will change in the future.

When you choose your solar panels it is important to know, that a solar power system is a complex system of several components and the overall performance depends not only on solar panels. All components should be compatible with each other (solar panels, solar inverter, battery storage, charge controller). Also, the homeowners should carefully consider their unique house and household circumstances and maybe even seek the advice of an expert before choosing the right solar panels for their home. 

Sources: wikihow.com, cleanenergyreviews.info, energysage.come & Internet

Read also: Basic Things to Consider Before Buying a Solar Electric System
                   Applications of Photovoltaic PV Power Today

Hybrid Solar Power System - the Best of Grid-Tied and Off-Grid Systems

The hybrid solar power system is a combination of grid-tied and off-grid solar power systems. This system is described also as off-grid solar with utility backup power, or grid-tied solar with battery storage. The hybrid solar power system comes with a special hybrid inverter (sometimes referred to as a multi-mode inverter) that can transmit direct current (DC) power to and from your batteries and provides alternating current (AC) power between the grid and your home when necessary. The hybrid inverter can simultaneously manage inputs from both solar panels and battery storage, charging batteries with either solar electricity or electricity from the grid.

The hybrid inverter takes advantage of changes in the utility electricity rates throughout the day. You can temporarily store whatever excess electricity your solar panels produce in batteries, and put it on the utility grid when you are paid the most for every kWh. And you can rely upon your battery stored solar electricity while electricity is expensive and switch to the grid when it is cheap. 

The ability to store and use your solar energy when desired is known as self-use or self-consumption. 

In case you have already installed a grid-tied solar panel system you also have a traditional inverter (solar inverter) which converts DC into AC. If you would like to have a hybrid solar power system you should buy battery storage and a separate battery-specific inverter. 

An option is to buy a hybrid inverter for your grid-tied solar panel system if you are planning soon to add battery storage. Thus you won’t need to purchase a separate battery-based inverter. The hybrid inverter can function as both an inverter for electricity from your solar panels and a solar battery. It combines a solar inverter and battery-specific inverter, so it can charge and discharge battery storage. On the other hand, there are some modern energy storage systems, like the Tesla Powerwall 2, which comes with an inverter already built-in, eliminating the need for a hybrid inverter. 

The hybrid solar panel system is configured in such a way that your home uses solar power first, then stored power in the battery, and then grid power. With a solar hybrid system, you are less reliant on the grid and solar battery storage is used as a back up when solar power is not available. When the stored energy is depleted, the grid is there as a backup, allowing consumers to have the best of grid-tied and off-grid solar systems. And the battery storage is discharged less frequently, which extends its life. It needs to be replaced less often and saves you the cost of purchasing a backup generator. 

The hybrid solar power system is at least half the price of an off-grid system but they are more expensive than an on-grid system – typically double the price of the grid-connected solar power system. The hybrid solar power system is also more complicated for installation and takes more space. 

In summary, the hybrid solar power system has the following advantages: 

• gives you a continuous uninterrupted power supply 
• stores solar electricity or low-cost electricity 
• allows using solar power during the peak times of the electricity grid 
• solar power is available during a blackout or grid outage 
• reduces the power consumption from the grid 
• you are not dependent on the weather conditions 
• gives you more independence than on-grid solar power system

Off-Grid Residential Solar Power System

There are three main solar power systems - grid-tied (on-grid, grid-connected), off-grid (stand-alone power system (SAPS), and hybrid solar (battery storage with grid-connection). Since I’ve already written about grid-tied systems, in this post I’ll give some basic information about off-grid residential solar power systems.

An off-grid solar power system is a solar panel system not connected to the grid. This means that you are completely independent of the utility grid and your solar system produces clean electricity for all your energy needs. The system consists of solar panels, an off-grid inverter, charge controller and rechargeable battery storage. An off-grid backup generator is an optional component. 

Before buying and installing an off-grid power system you should know your daily power needs. This will help determine which size system is appropriate for you. You can check out this off-grid system calculator to determine the size of the system for your off-grid home. Your solar panel system can be mounted on the roof or on the ground. 

The off-grid solar power system just like the other solar power systems works by generating electricity from solar panels. That electricity is direct current (DC), so it is converted using an inverter to alternative current (AC) and then it powers your home electronic appliances. AC is the standard form of electricity for anything that “plugs in” to utility power and it is a necessary form for the household appliances to work. 

When solar panels generate excess electricity it charges a solar battery (DC) via a charge controller. The charge controller is an essential component because it regulates the voltage and current that solar battery storage receives, to prevent overcharging and damage. And by saving the solar power in battery storage, it is possible to run your home appliances with energy from the sun, even at night or on cloudy days when solar panels produce less electricity. 

The off-grid solar power systems are much more expensive then on-grind systems due to the high prices of the batteries. It is suitable for one family home if you would like to gain complete energy independence, holiday houses, and especially for houses and farms in remote areas far away from the electricity grid. But although the off-grid solar power system is expensive this is a long-term investment that will save you money and deliver green, reliable power for decades.

See also: Solar Power Calculating Tools Online

What is a Solar Panel Kit for Home?

Solar panel kit is pre-packed solar equipment that after installation can form an operating solar power system for your home. Almost all solar kits come with everything you need to have a working solar system (complete equipment). For some kits you may need to buy additional items, so you should be careful. 

Solar panel kits can vary in price depending on their build, power generation, size, and components. Therefore, they can cost from a few hundred up to thousands of dollars. Once you choose and buy a solar panel kit, it will be shipped to your home and all you have to do is install it yourself (DIY- do-it-yourself).

Before buying a solar panel kit, you should do some research and calculations regarding current energy consumption in your home, and how it will change in the future. Thus you will know how much solar power and how many panels you will need. You should also decide whether your solar power system will be grid-connected, off-grid or hybrid.

Here are the basic components that you can expect in most solar panel kits: solar panels, solar inverter, batteries (off-grid), charge controller (off-grid), mounting hardware, wiring and connectivity parts. You can choose between two types of solar panels: polycrystalline and monocrystalline. Monocrystalline panels are more expensive, more efficient, and more heat resistant.

Solar panel kits are suitable for small homes. There are solar panel kits for large homes but as you go up in size (1,000W and more), solar installations become more complicated. It doesn’t make sense to install a large solar panel system yourself. And If you are not sure about your knowledge it is recommended to seek professional help. Installing your solar panel kit may save you money but keep in mind that it can be time-consuming, challenging, and even risky in terms of safety and how to do it right. Also, if your solar panel kit is grid-tied you have to check whether your utility company allows self-installed solar systems to connect to the grid. 

If you are absolutely beginner to solar electricity it is a good idea to buy a solar starter kit. Starter solar panels kit won’t be able to fully power your home but it is just a few hundred dollars and includes the parts you need to start seeing if solar is right for you. It can power some of your electric appliances and it is usually grid-connected, which means that it will work with the existing grid. Typically solar starter panels ranging from 50W - 400W.

Solar panel kits are a good option for garages, farms, boats, caravans and off-grid cabins.

More detailed information you can find here:

https://www.letsgosolar.com/solar-panels/solar-panels-kits/

-----------------------------------------------------------------------------------------

GoGreenSolar.com - The #1 Online Destination For DYI Solar Kits - Shop Now

Solar Power and Net Metering

Grid-tied solar power system (with net metering) diagram

Net metering, or also known as net energy metering (NEM), is another big reason why the solar panels are a good investment for your home or business.

Net metering is possible when your home maintains a connection to the grid even after you install solar panels, and of course, when the net metering is available in your area. The grid-connected (grid-tied) solar power system with net metering consists of solar panels, a grid-tied solar inverter that converts DC (direct current) to AC (alternating current), and net meter. DC generated from your solar panels is converted into AC, which is the type of current that is used by the electrical appliances in your home.

Let's explain simply what is net metering and how it works.

When your solar panels produce excess power, it goes to the grid. The utility company compensates you for the excess grid supply with credits added to your electric bill. For the time, when your solar panels produce less power than your household is needed, you can draw electricity from the grid. A net meter (bi-directional meter) is installed to register both the excess solar energy that you export to the grid and the energy that you consume from the grid. This ensures that consumers are only charged for their “net” energy use (energy consumed minus energy sent to the grid). 

Monthly net metering allows consumers to use solar power generated during the day at night. Similarly, during the spring and summer, when the sun is shining, and your solar panels are producing more electricity than you need, that extra energy goes to the grid. Then in the winter, when the days are shorter, you can draw on those energy credits to help offset some of your energy needs.

The grid acts as an energy storage system for your excess power and saves it for later use. The grid connection ensures that you still have power regardless of daily or seasonal variations in solar panels production levels.

So, with grid-tied solar power system and net metering billing mechanism, you save money besides that you help the environment and reduce your carbon footprints.

Net metering originated in the United States, where solar panels and small wind turbines were connected to the electrical grid, and consumers wanted to be able to use the electricity generated at a different time or date from when it was generated. In 1979 an apartment complex and a solar test house in Massachusetts were the first two projects to use net metering. Minnesota is commonly cited as passing the first net metering law, in 1983, and allowed anyone generating less than 40 kWh to either roll over any credit to the next month, or be paid for the excess. 

Keep in mind, however, that net metering policies can vary significantly by country and by state or province. It is not available everywhere in the U.S., which means that there is a need for other nighttime power supply options such as solar battery storage.

Net metering was slow to be adopted in Europe, especially in the United Kingdom, because of confusion over how to address the value-added tax (VAT). Only one utility company in Great Britain offers net metering. In Canada, some provinces have net metering programs.

Basic Things to Consider Before Buying a Solar Electric System

Installing a solar power system requires very careful initial planning. First of all, you need to know exactly how much electricity your home uses each month. You may look up in your old electricity bills but also you should think about how your electricity needs will change over the next 10 years.

Solar photovoltaic panels can be installed on the roof, along a wall of the property or as standalone systems. If you are planning to install them on your roof, you need to make sure that the roof is strong enough to hold a solar panel because some of these panels can be quite heavy. A roof inspection (and any necessary repair) is recommended prior to a PV installation. Another thing you need to know is that the more sunlight modules collect, the more electricity they produce, thus the more energy your home will receive. Make sure that the roof (or wherever you intend to install your solar panels) is clear of any obstacles, such as trees or buildings, especially during peak production hours between 10am and 2pm.

Ideally, a solar system will go on a south/southwest-facing roof, although east and west facing roofs are good candidates, as well.

You should decide whether your system will be grid-connected, off-grid or hybrid. With a solar PV system connected to an electric distribution system (grid-connected) you can receive back-up power from it when your system doesn’t produce enough energy for your needs. When your solar PV system produces excess power, that electricity can be send back into the grid, and your local utility is required to buy it from you.

Picture: apps1.eere.energy.gov

A grid-connected solar power system is easily integrated into the existing electrical infrastructure of a house and the system can provide decades of reliable and environmental friendly electricity production.

A stand-alone (off-grid) solar PV system is independent of an electricity distribution grid operated by a utility. The electricity is provided by solar power alone and stored in a battery for later use. Such systems typically make sense in remote locations.

The average solar PV panel last approximately 30 years and many manufacturer warranties last for up to 20-25 years. Solar PV panels are designed and installed to be low-maintenance. However, it is very important to have your solar panels cleaned regularly because they benefit from being hosed off with water twice a year, especially after long periods without rain. Dust or dirt may cause a 10-15% reduction in their efficiency.

Before buying and installing the panels it is also essential to make sure that you understand the installation regulations in your local area. In most cases it is wise to check with the local authority before installing your solar electric system.