Solar

The electrical grid is a set of wires, devices and installations. It is used to transmit, process, and distribute electricity generated at power stations and supply it to customers.

The electrical grid consists of:

• Power stations. Power stations are industrial plants that produce electricity from different primary energy sources, such as coal, natural gas, and oil.
• Electric power transmissions. Electric power transmissions carry electrical energy over long distances (high voltage).
• Substations. Substations transform voltage from high to low, or in reverse.
• Electric power distributions. Electric power distributions provide electricity to individual customers (low voltage).

Electrical grids are designed to supply AC current to their customers at largely constant voltages and frequency. In the United States, the nominal voltage and frequency of power delivered to customers are 120V and 60Hz. In Europe, the nominal voltage and frequency of power delivered are 230V and 50Hz.

The solar panel rated power.

All solar panels are sold with determined so-called rated power and this is the maximum power a panel can reach under strict laboratory conditions.

There are a few test conditions but STC (Standard Test Conditions) are the most popular.

STC requires the following:

• Solar irradiance 1000W/m2,
• Cell Temperature 25°C,
• Air Mass AM1.5

The solar panel rated power can vary based on technology and size from about 300W up to 600W. Unfortunately, modules are rarely reaching their rated power.

How much energy will a panel produce in one hour?

Energy generation varies on the weather and the time of day, but we can assume that when a panel is generating at 350W for one hour straight, it will produce 0.35 kWh of electricity. It can be simply calculated like so:

P x t = E

Where:

P - the power of solar panel [W]

t - time of generation at this power [h]

E - energy generated [kWh]

How much energy will a panel produce in one year?

Solar system energy generation is the highest in summer when there is a lot of sunlight and the smallest in winter months when the sun is low in the sky and for fewer hours than in the summer.

To estimate your system's annual energy generation we can use the production ratio of kilowatt-hours to kilowatt-peaks (kWh/kWp). These can be easily found on solargis.com.

On the map below, you can see which areas of the US have a bigger potential for generating energy from solar panels.

Map source: solargis.com

If we would place the same 350W panel in Phoenix and New York it would generate different amounts of energy.

In Phoenix, the production ratio is around 1900kWh/kWp while in NYC it would reach a value close to 1350kWh/kWp.

So in Phoenix, this panel would produce 665 kWh while in NYC it would produce only 472 kWh which is about 30% less.

To sum up!

Solar panels will produce different amounts of energy over the year in different locations in the US, but every location is good to invest in solar! The United States has good production potential in comparison to for example Europe where in different countries, the production ratio can vary from 800 to 1700 kWh/kWp while in the U.S.A those values vary from 1000 to 2000 kWh/kWp.

Solar modules are made from semiconductors, which convert solar radiation into electricity. This phenomenon is possible due to the photovoltaic effect. It is necessary to use the correct materials with proper properties. To achieve it, solar cells are mainly made from elements that are semiconductors. The most often used are selenium, silicon, and germanium. The most important is silicon which is characterized by having four valence electrons.

The widely used solar panels are made from many properly connected solar cells. Due to their appropriate combination, it is possible to obtain the assumed electrical output parameters. Each of the most used crystalline solar panels is made of 60 or 72 photovoltaic cells.

These are the following technologies for making PV panels:

• Crystalline – They divide into polycrystalline and monocrystalline solar panels, characterized by the highest efficiency.
• Organic – They are manufactured from organic polymers, mostly carbon.
• Thin-film – Their thickness usually does not exceed a few micrometers. The material they are made of is similar to crystalline solar panels.
• Multi-layer – Every layer of semiconductors absorbs a different spectrum of solar radiation. For its production, many differently doped semiconductors are used.

The mentioned above materials and technologies are connected only with solar cell manufacturing. To construct a working solar panel, the list of component parts is much longer:

• Frame
• Glass
• Encapsulant
• Solar cell
• Encapsulant
• Back sheet
• Junction Box

Solar cells or photovoltaic cells are the most important part of a photovoltaic panel. Different quantities of solar cells make up solar panels. Photovoltaic cells have many advantages. The types of benefits include sustainable, user-friendly, technological, and economic benefits.

One of the most lasting benefits is that solar cells provide clean and renewable energy because the sun is an inexhaustible energy source. Solar cells are long-lasting technologies. They can work with 80% efficiency for over 25 years without special maintenance.

Another benefit is that solar cells can be used in many smart applications to eliminate the need for changing batteries. Solar panel systems with backup can be used anywhere, including places where there is no electricity access.

Finally, solar cells have economic benefits. Installing solar panels will increase the value of your property significantly. In addition, you can reduce your electricity bills to almost zero because you are producing your own energy from the sun.

A solar panel's price depends on many factors, such as the type of solar panel, size of the system, rated power of each solar panel, and other technical issues. The average cost of monocrystalline solar panels, which are the most energy-efficient option on the market, starts from $1 per watt up to even $2 per watt. This price only includes the cost of the solar panels. The cost of a complete solar panel system with all the other parts like inverters, wires, mounting systems, and other things is usually between $3-4 per watt. To sum up, solar panels cost can be different depending on the solar panel brand, number of panels, and their type. Building a more advanced system with battery backup increases the system price.

The orientation of solar panels is an important factor to optimize energy production from solar panels. The direction that solar panels face depends on the part of the hemisphere. In the northern hemisphere, the main rule is to face solar panels true south. Mostly it is the best direction as long as there are no shadings affected by physical objects such as buildings, constructions, or trees during the day. In the southern hemisphere, solar panels should face the north. The other important consideration is the appropriate tilt. Solar radiation should hit the surface of solar panels perpendicular to produce the most energy.

Solar panels are devices with long “expiration dates” because they last between 25 to 30 years. However, this does not mean that the panel will suddenly stop working after that time – it means that energy production will drop significantly and may not be sufficient to meet demand. Nevertheless, there may be other reasons besides replacement to remove solar panels, for example: transferring our PV system to another home, patching a portion of your roof or installing an entirely new roof.

Solar power systems are complicated electric components. Due to their complexity, servicing them requires professional attention. Most states require permits to remove solar panels, which increases removal costs. Check your state requirements before the removal process. Your removal cost will vary depending on your site conditions, the full scope of required work, and the travel time for the crew. The total cost of removing solar panels is between $35-75 per panel. The solar panel removal process can be expensive for larger systems and will take more time.

What usually is included in panel removing price:

• Uninstalling and disconnecting solar panels
• Removing/replacing the mounting hardware
• Permissions and inspections

Off-grid solar systems do not connect to the electricity grid. Thanks to the off-grid feature, solar systems can be used anywhere there is access to solar radiation. Solar systems can also be used as an independent power source. Software located in the power software manages the electricity generated by solar panels during the day. The energy produced can be used for current needs, and the excess energy that is not needed is stored in battery packages. If energy production is low on a cloudy day, or there is no generation at night, the required load is met by energy from the backup in the battery packages.

There are two main types of solar panel mounting types:

• roof mount
• ground mount.

Roof-mounted systems utilize available space most effectively as modules on the same roof cannot shade each other. On the other hand, ground-mounted panels have to be installed in distanced rows so the first row's shade is not interrupting the second row's working conditions.

Roof-mounted solar panels.

A rail mounting system is the most common way to install solar panels on the roof.

These systems are made of:

• Roof attachments. There are various types of roof attachments depending on the roof type they are going to be installed on. Roof attachments are fastened to roof structure beneath roofing material or to the roofing material itself.

• Mounting rails.
  • When roof attachments are installed it is possible to add mounting rail to the racking system. They are solar panels support on the roof as PV modules lay directly on mounting rails.
• Module clamps.
  • To keep solar panels in place module clamps are used. They connect solar panels with mounting rails using bolts installed in mounting rail bolt channels. The main types of module clamps are end-clamps used where panel array ends and mid-clamps used where two solar panels meet.

Ground-mounted solar panels.

Ground mounting systems are all-in-one systems that include:

• module clamps
• mounting rails
• ground-mounted racking

Systems of this type usually either use mounting poles dug into the ground or a ballast system to ensure system stability and wind resistance.

Installing solar panels in your home has many advantages. The benefits from solar panel installation have a huge positive impact on your energy spending. In addition, from an ecological point of view, rooftop solar panels are a great way for you to help save our planet. So how do solar panels contribute to savings?

1. Free energy – solar energy is free energy because it comes from Sun. Therefore, you instantly start saving from the first day after installing a solar system.

2. Clean energy – solar energy is clean energy. Clean energy provides energy with little or no greenhouse gas emissions, reducing your carbon footprint. Going solar is one of the best options to help take care of the Earth.

3. Increased home value - the value of your home increases after mounting the solar system on it.

4. Secured investment – your solar panel home investment is secured because you have a guaranteed payback period. Solar panels start working instantly as you install them because they only require the Sun to produce electricity. These installations are really simple because they don't have moving parts and no service is needed to maintain their work. Saving from the time when the system was installed guarantee the payback due to lower electricity bills.

5. Superior performance - solar panels have superior performance because they use the best technology on the market. The technology used in solar panels is high quality and provide good working performance. The panels produce electricity during the day which can be stored or sent to an electric network.

These are only some benefits of buying solar panels for homes. Make your home a small power plant that helps you save both our planet and your money! To learn more about why you should go solar, click here.