Solar photovoltaic (PV), is a system of generating electricity from light through semiconducting materials.
A solar photovoltaic system works using solar modules comprising of solar cells to generate power.
There’re several ways to mount solar PV, such as rooftop-mounted, ground-mounted, wall-mounted, and floating.
Most mounting options are fixed but are not as effective as the movable mount, which follows the sun using a solar tracker.
Solar PV has become a common means of generating electricity in the UK, which can be contributed to low prices.
Decades ago, this system was not attractive due to high panel prices, but a few years back, the price started reducing significantly.
The shift to solar PV as a source of electricity helps the UK achieve its target of mitigating global warming.
If the level of emissions continues as it’s, it won’t be surprising that the emissions budget for CO2 would be used up before 2028.
As such, generating electricity from low-carbon systems, such as solar PV, is a good way to go.
Generating electricity through solar PV comes with an extra cost of transmission.
This system of electricity generation requires a distribution system of electricity by high-voltage direct-current power lines.
Another option here is to generate the energy individually and store it for use, which also requires a strong storage system, adding to the installation costs.
However, besides the initial cost of the installation, solar PV offers an array of advantages: once installed, there is no concern about pollution or greenhouse gas emissions.
Solar PV: Any Impacts on Electricity Generation?
Solar PV has been adopted in several applications and has proven effective as standalone installations.
The system has also been a great option for grid-connected PV systems since the 1990s.
Increased manufacturing scale and advances in technology have brought improvements to the solar PV system.
These include the system’s decreased prices, increased reliability, and increased efficiency.
Incentives from the government also contribute to the attractiveness of solar PV.
In 2019, the solar PV became the third renewable electricity source with a global capacity of 635 gigawatts (GW), coming after hydro and wind powers.
his figure takes 2% of the global electricity demand.
However, this figure is expected to increase by up to 880 GW by 2024, according to the International Energy Agency.
Decades ago, the common system was to mount the panels to face a fixed direction where they’re expected to absorb enough amount of energy from the sun.
However, the solar PV system has witnessed several improvements, including the introduction of solar trackers.
These trackers maximize the time the PV modules face the sun by moving them in the direction of the sun.
The efficiency of these trackers depends on the season of the year.
Solar trackers can increase the efficiency of the PV by up to 50% in the summer and 20% in the winter.
The efficiency of the static mounting system can also be increased by analyzing the sun path.
The modules are usually set to the angle of the latitude, which can be adjusted depending on each season of the year.
However, temperature affects the performance of the photovoltaic modules, such that performance goes down when the temperature is above room temperature.
Another common method of mounting the solar modules for increased efficiency is ‘ladder mounted’.
This system is where the panels are mounted above each other to form a tower, and the tower is turned horizontally to follow the sun path.
The method uses a turntable disc to turn the modules in the sun path.
Another development about the solar PV is the introduction of another material for the solar cells.
Some labs have discovered that perovskite is a better material than the common crystalline silicon.
These researchers stated that this new material has up to 25% more efficiency than crystalline silicon.
The electrical efficiency of a PV cell is the measure of the electrical power the cell can produce with a certain solar irradiance.
This is calculated by dividing the output power by the incident solar power.
When measuring the efficiency of a solar PV, it’s always done under ideal laboratory conditions, as temperature, spectrum, and irradiance all affect the actual efficiency of the PV.
PV efficiency is the highest achievable efficiency of the PV.
Multijunction concentrator is the most efficient type of solar cell to date, having an efficiency of 46%. The cell was manufactured by Fraunhofer ISE in 2014.
For competitive advantage, efforts are ongoing to increase the conversion efficiency of PV cells and modules.
One means of increasing the efficiency of solar cells is to choose a semiconductor material with a bandgap appropriate for the solar spectrum.
While this increases the electrical and optical properties, it’s also important to improve the method of charge collection.
Since they’re introduced in the 1980s, organic photovoltaic cells have witnessed several developments, which have impacted the power conversion efficiency of the cells from 3% to 15%.
Another method used in increasing the performance of the solar cells is adding power optimizers into the PC modules.
These modules measure performance data for monitoring, perform maximum power point tracking for each module, and serve as additional safety measures.
The modules also reduce shading effects on the solar modules, such as when a shadow falls on a section of the system, which can decrease the electrical output of one string.
Again, temperature affects the performance of the solar cells, such that overheating causes performance decrease.
Every 1-degree increase in temperature decreases the solar cell efficiency by 0.5%.
This means that a solar cell only needs a 100-degree temperature increase in surface temperature to reduce its efficiency by half.
One effective method to curb this is the use of self-cooling solar cells.
While energy can be used to cool the surface of the system, silica can be formed into pyramid and cone shapes and attached to the surface of the panel.
Since infrared rays carry heat, this method is effective as it reflects infrared rays and allows visible lights to the cells.
Photovoltaic technologies have grown rapidly since they’re introduced.
This system of electricity generation reached 515-gigawatts installed capacity in 2018, which represents 2% of the global electricity demand.
More than 100 countries use solar PV as a system of generating electricity, with China leading the chart and the UK on #8 with 13,300 233.
However, the installation in certain countries, such as Germany, is gradually slowing down.
The Future of Solar PV
The UK government has rolled out several schemes to promote the installation of solar PV, which are to encourage homes and businesses to shift to the renewable method of electricity generation.
However, certain barriers hinder the growth of solar PV, and these include limited transmission grid capacity, which stands as the major barrier faced.
Environmental Impacts of Photovoltaic Technologies
One common question people often ask is if photovoltaic technologies have any impact on the environment.
The truth is, there are no genuine metrics to measure the impact of the technologies on the environment.
Economic Value of the Solar PV
Over the years, the underlying cost, market prices, and industry structure of the solar photovoltaic technology have changed rapidly.
This makes it more challenging to know the exact shifts in the industry value chain.
There have been major changes in the underlying costs, industry structure, and market prices of solar photovoltaic technology over the years, and gaining a coherent picture of the shifts is difficult.
However, the prices of the PV have reduced drastically in the market that it’s now more affordable to many homes today than in 2008.
In 2011, the crystalline-silica photovoltaic saw a decrease in factory-gate prices, that the price went below the €1.00/W mark.
This new mark testifies to the influence of grid parity for PV.
With more technological advancement, industry restructuring, and improvements in the manufacturing process, there’re speculations that this mark is likely to reduce in the coming years.
Several financial incentives, such as feed-in tariffs, have been rolled out to encourage British homes and businesses to install solar PV technologies for energy generation.
These financial incentives also go to the PV industry to help it combat financial challenges that might hike the cost of PV-generated electrify above the cost of the existing grid.
These policies are put in place to encourage the installation of solar PV, which promotes territorial and national energy independence.
Other than this, the policies also help create more green jobs and reduce carbon dioxide emissions, a potential threat to the climate.
Due to the higher demands of solar PV, manufacturers can produce more units, reducing the prices. Also, since more homes and businesses still want to shift to this system, the price is expected to drop further in coming years.
Price per Watt History for Conventional Solar Cells
According to Solarbuzz’s survey in 2011, PV costs were marginally lower than the cost of nuclear power.
The survey reported that the retail price for solar cells dropped from €350/watt to €2.43/watt this year.
The more the installations increase, the more the prices slide.
As such, lower prices, such as €1.00/watt, are realistic for large-scale installations.
In April 2012, a large scale 5-year deal would cost 0.60 Euro/watt. In December 2012, module pride had fallen to €0.50/watt.
While some countries have achieved grid parity for PV, other countries are still struggling with funds for developing PV projects.
Are Solar PVs Worth It In the UK?
Solar PV installations are not a cheap investment, as they require high upfront costs.
With this, homes and businesses are initially skeptical of installing a solar PV system for generating electricity.
However, going by the numerous benefits of generating electricity from the sun, solar PV is a great investment in the UK.
Do Solar PVs Give a Decent Output in the UK?
The amount of sunlight in a region determines the efficiency of solar PVs.
While solar PVs can also generate electricity from daylight, the UK has sufficient amounts of sunlight to let PVs produce a decent output in the UK.
A solar PV system is expected to generate around 3,000 units of electricity yearly with the UK’s climate.
This unit covers up to 70% of the electricity demands of a typical UK home. As such, a modern solar PV system will yield decent output in the UK.
How Much Does Solar PV Save?
How much you can save with solar-PV technology depends on your electricity demands.
A household with high electricity consumption saves more money than a small family with low energy demands.
Generally, a solar PV system can save up to 50% on electricity bills.
You also increase how much you save with solar PV by reducing your dependency on the national grid.
One way to reduce how much you depend on the national grid and cut back your electricity bill is to install a solar battery in your solar panel system.
A solar battery is a mechanism put in place to store electricity generated from the sun during the day for use later in the evening and at night.
A solar battery can gear up this figure to 70%.
Note that solar PV helps save more money in the summer than in the winter.
How Much Do Solar Panels Cost?
Solar PV cost is determined by the size of the house or business and its energy demands.
A small family with low energy demand can install a small system with a budget of £6,000, while a larger household might need to budget up to £17,000 for a larger system.
However, with the SEAI grant, the cost can decrease to £4,500 – £14,000.
The lowest budget on this range can afford a 2kW of standard panels and a power diverter, while the highest budget on the range will cover a 6kW of premium panels, a large battery, and a solar diverter.
Solar Panels Vs Electricity Bills
Before investing in solar PV, it’s smart to know how much the system will save you against relying on the national grid.
You can calculate the economical difference between solar PV and power company’s bill by calculating how much you would pay on your electricity bill and subtracting it from the cost of solar panel installation.
When calculating this, bear in mind that a solar system has a life expectancy of 35 years.