Solar 101 | Beginners Guide to Solar
What is solar energy?
The sunlight that reaches earth constitutes 50% light (visible), 45% infrared radiation, ultraviolet rays, and electromagnetic radiation. The heat radiations trigger chemical reactions that produce electricity.
The energy generated from the sun is what is captured in the form of thermal or electric power. The latter captures the sun’s energy via flat plate collectors used in solar heating, which converts them to thermal energy. With electric energy, the sun radiations are captured through photovoltaic cells and directly converted into electricity.
Semper Solaris Solar Panel Facts Infographic
What are the components in a photovoltaic (P.V.) solar panel?
Converting solar radiation to electric energy is a complex process. The photovoltaic panels are the root of the successful energy conversion process to occur. But on their own, they are incapable of producing a reliable electric current. The panels require a channel of more components to make safe and usable energy. Check out those elements below:
- Photovoltaic module
This, as stated earlier, is the core element that houses solar cells. Every cell acts as a conversion unit that produces D.C. voltage when light from the sun hits it. Note that the P.V. modules can generate a voltage from any source of light, not just sunlight.
- D.C. & AC wiring
The DC and A.C. are responsible for switching on/off power to and from the inverter.
- Inverters
The solar inverter is responsible for taking D.C. from batteries and turning them to A.C.
- Batteries
These store electric energy chemically in renewable energy entities. They are also known as solar battery storage.
- Solar controllers
As its name suggests, the solar controller’s work is to regulate the current fed into the battery tank.
What are the benefits and setbacks of using P.V. solar panels?
Solar panels are what comes into our minds when solar energy is mentioned. Here are some of their upside and downsides:
Advantages
- They provide cheap, clean, and renewable energy.
- The maintenance costs for P.V. panels are relatively low compared to other energy sources.
- Photovoltaic systems are quiet, thus reducing the effect of environmental noise.
- Solar energy can be harnessed locally, thus reducing environmental disruptions associated with transportation.
- Solar power reduces the electricity bill as it costs you only a fraction of what you pay to the utility companies monthly.
- Solar power plants have fewer safety risks compared to fossil and coal plants.
Disadvantages
- Photovoltaic modules produce variable energy. They cannot absorb energy during the night, and the amount of energy collected during the day also varies with weather seasons and time of the day.
- Though not significant, there’s the production of toxic chemicals like arsenic and cadmium during the production process. These pollutants cause slight environmental impacts that can be tamed through responsible disposal.
How do solar photovoltaic panels work?
The solar P.V. unit houses 60 or 72 solar cells. When the cells are hit by light, electrons are scattered from the cell’s silicon atoms. The electrons then flow through the cell triggering direct currency (D.C.) electricity.
The DC electricity is then sent to an inverter, which then converts it to alternating current (A.C.) electricity. The A.C. electricity is the kind mostly used in offices and homes. In the case of solar power, the electricity can either be used in either way:
- Meet the electricity needs of a home
- Charging a battery storage unit
- Saved to the power grid for future use
How large are solar panels?
Traditional P.V. solar panels have a 60 and 72 cell configuration with the following dimensions:
- 60 cell PV panels: 39" x 65" equivalent to 3.25 x 5.5 feet
- 72 cell PV panel: 39" x 77" equivalent to 3.25 x 6.42 feet
How do I calculate the solar panel efficiency?
Solar panel efficiency is a widely misunderstood concept. People assume that the 15–25% efficiency of P.V. solar panels means that the panel produces only a fraction of the rated power. In reality, the efficiency represents how much of the sun’s energy is converted to electricity.
You should go for high-efficiency panels if you have limited mounting space as they produce more power per unit area.
Smaller R.V./mobile use panels are available. Some companies are also experimenting with 96-cell solar panels, but they are not very common.
What types of P.V. panels can you find in the market?
The most available P.V. solar panels are monocrystalline, polycrystalline, and thin-film. Each has its own unique properties, and they vary in appearance, performance, and even costs. For instance, monocrystalline is highly efficient, unlike Polycrystalline and thin-film, which perform inefficiently.
Are batteries necessary for a solar energy system?
The inclusion of batteries depends on the type of solar system that you have installed. If the system is grid-tied, you do not have to include the batteries, unlike the off-grid systems.
Off-grid systems work without connection to the grid.
This means you have to store energy using a battery. This makes this system considerably more expensive to install as opposed to the grid-tied system. This option is viable in very remote areas where running grid cables to that area would be costlier.
Grid-tie systems, on the other hand, use the national grid to store power.
With this system, the consumer pumps out energy to the grid and is credited for it. The consumer can then use those credits to withdraw power from the grid.
Can batteries work with the grid-tie system?
You can install optional batteries in your grid-tie system to cushion against grid outages, especially in areas with adverse weather conditions. This is simply a backup plan.
During outages, the batteries can maintain your lights on, but you cannot pump power to the grid at that time. Any grid-tie solar system must have an auto shut down function when grid power goes out to protect line maintenance workers.
Still, if you have battery storage for your grid-tie system, you can sell the power back to the grid during peak times when the rates are higher. An optimally designed system will cut down your grid usage by up to 95%.
What’s the best type of battery for solar?
There are essentially three types of solar batteries; flooded lead-acid accumulators (FLA), sealed lead-acid accumulators (SLA), and lithium-ion batteries. FLA are the cheapest and the oldest but require regular maintenance for best operation. You just need to top up the battery with distilled water to account for the evaporation.
SLAs are advance FLAs, where the battery is sealed to prevent evaporation. They are a little bit more expensive than the FLAs but do not need maintenance.
Lithium-ion batteries represent the best tech in batteries. These are known to charge much faster than the other two types. They also withstand deep discharge cycles and last the longest, in addition to being maintenance-free.
Where should you mount the P.V. solar panels?
You can mount your solar panels either on the ground or on the roof. Roof mount is usually the cheaper option, especially if you do not have much ground space for such a project. Roof mount utilizes the rooftop as the support structure, so you do not have to build a foundation for mounting. You can consult your roofing company if you intend to mount an array of P.V. panels on the roof. They can then decide the best type of roofing for you.
As the term suggests, a ground mount is built on the ground as a separate metal structure to hold the solar panels. These structures are preferably aluminum, which makes such a project costlier. The advantage is easier accessibility during repairs and maintenance.
Are pole mounts viable options?
Pole mounts are still a viable option in countries experiencing icy winters. A pole mount is essentially a tall-standing pole that raises the solar panel above the ground. The high height ensures the winter ground snow doesn’t bury the solar panels array. The poles also allow the solar panels company to tilt the panels so that snow can easily slide off. The poles may be of variable height depending on proximity to obstructions.
Solar trackers: what are they?
You might have observed some solar panels tilting towards the changing position of the sun in the sky. This is done by a solar tracker to maximize exposure of the solar cells to sunlight.
But is this investment worth it? It depends on your needs. Typically, the tracking hardware costs way above the solar panels! So if space is not much of a concern to you, simply invest in more solar panels.
Large-scale solar power farms can use this technology as the cost will drastically reduce as you scale the operation.
What is the right solar energy system size for me?
It is just like the phone bill. You need as much airtime as your monthly bill shows. Similarly, your system size depends on how much power you need. This information can be found from your monthly utility bill.
The bill is not all you need- honestly, the sizing process is complicated, but you can leverage several online tools for that. There are both grid-tie and off-grid systems calculators. The most grid-tie calculator will ask you for your location and energy usage data. The system size is shown to you at the touch of a button.
For off-grid system sizing, you’ll be required to track your daily power usage for, say, a month and feed the data in a given sheet. You then upload the sheet or send it to your provider to determine what size you need.
If you feel like taking the challenge, you can also read about sizing a grid-tie or off-grid solar system by yourself.
Does the local climate affect system size?
P.V. solar modules convert sunlight into electricity. This means the more the sunlight, the more the power produced. Different areas experience different exposure times during the day. Regions near the equator experience most extended exposure hours while Polar Regions may go without sunlight for days.
In the U.S., for example, the exposure varies between 3–6 hours. If you receive only three hours of sunlight, your system’s size would need to be twice that of a region receiving about six hours of exposure to sunlight.
How much do solar installers charge?
A solar installer will charge you depending on several factors. Going by the law of demand and supply, the higher the number of locally available qualified solar installers, the lower the rates charged.
A good installer should not charge less than $0.75 per watt of solar power installation. On average, a 5kW system should cost you between $3,500 and $5,500.
Can you install the solar by yourself?
Definitely yes, even if you do not have any experience in it. This is because most of the components are designed to plug into dedicated ports. You should only expect to lift slightly heavy objects and tightening screws.
You can perform the above by yourself and then hire an experienced electrician to hookup to the panel for you. This way, you’ll significantly bring down the overall cost of installation. However, if you want things right from the bat, hiring an experienced solar panel installation company is the way to go.
Is it worth it investing in solar?
Definitely yeah. In the majority of the cases, the solar option is cheaper than the grid supply. Depending on the grid entirely hooks you to an eternal monthly power bill. Should you go solar, you only incur a high capital cost, which breaks even in a few years. After that, your only charges will be taxation, maintenance, and repairs, all of which are far much less than the utility bill.
Originally published at https://www.sempersolaris.com/resources/solar/solar-for-beginners/.
