Sustainability of Solar Energy & Solar Panels
Making solar energy even more sustainable is one of the main goals that solar panel producers have to overcome to ensure that future solar cells are truly sustainable. Although there are some developments in the field of renewable energy technologies, more needs to be done to remove as much fossil fuels as possible from the industry and to be able to generate electricity from purely sustainable and renewable sources.
However, this is easier said than done. Simply being able to generate electricity from renewable sources does not mean that the electrical energy is 100% green. Quite on the contrary, we have to take into consideration more than the power output of your solar panels to really understand their impact on the environment. Environmental sciences warn that extracting Earth-abundant materials pollutes as well and that the recycling industry needs to ramp up its recycling of old solar panels. Still, that does not mean that we should give up on solar power or that we should not put solar cells on every square foot of space we have. Let’s learn more, as this is a complex topic.
What is Solar Energy?
Solar energy is energy that comes from the Sun. The Sun sends out massive amounts of energy to Earth every single second. So much in fact, that if we covered only 50% of the world’s roofs in solar panels, we would generate energy to cover all our needs and have a surplus. Solar radiation is, indeed, a powerful source of electricity.
As solar power travels to the Earth’s surface, it reaches your solar panels. These photovoltaic devices then convert sunlight into solar energy that we can use: solar electricity. Additionally, devices such as solar collectors can produce enough hot water for an entire household, including heating during winter. Made from abundant materials, these photovoltaic devices take the Sun’s energy and put it in your hands.
How Does a Solar Panel Work?
A solar panel works by converting Sun’s energy into green energy – mostly electricity. This means that no fossil fuels are used in the production of the electricity that can be used around your home or sent to the grid for others to use. As the US energy sector is quickly moving to these low-cost, sustainable energy sources, it is important to get to know them better.
Each solar panel consists of multiple solar cells. The cells themselves are made of multiple materials layered on top of each other. As sunlight hits some of these layers, they release electrons, which then take the path of least resistance to other layers and materials solar cells are made of. This effectively generates electricity that you can use to power your home.
However, as each solar cell produces only around 0.5 Watts of electricity, we need more solar cells in each panel and more than one panel on each roof to be able to generate some electricity. Solar technology has made significant improvements in the last couple of decades. Most of these relate to solar panel price, which has plummeted thanks to mass production, mainly in China, the EU, and the USA.
Solar Photovoltaic Technology of Today
Most solar panels used today reach an efficiency of around 8-22%. As such, they can only convert a part of sunlight to usable electricity. As the scientific community makes new breakthroughs, especially in the light absorbing materials used in panels, it is expected that more solar energy will be harvested, speeding up the transition from fossil fuels to a truly decarbonized economy. To optimize materials, scientists need more time and funding – both of which are scarce.
Solar Panel Cell Types
As solar PV modules gained in popularity, and as they were able to provide solid scientific grounds for energy generation, many Universities and researchers joined the race to produce the most efficient power photovoltaic devices. This has led to several types of panels being made: monocrystalline solar PV panels, polycrystalline solar PV panels, and thin-film amorphous solar panels. Let’s consider the differences between these types of solar modules and see what kind of development can be expected in the future.
Monocrystalline panels are made of solar cells, each of which is made of a single piece of silicone crustal, as their name suggests. “Mono” means “one” after all. These are the most efficient (and the most costly) panels we have on the market today. They reach efficiencies of 15-20%. Some high-end models can reach efficiencies of up to 23%.
Polycrystalline panels are made of several pieces of silicone crystals, as their name suggests. These panels are not as efficient as monocrystalline solar panels and can generally capture 13-16% of solar power that hits them. Although they are less efficient than their monocrystalline counterparts, they are the most widely used type of solar panels, especially because of their lower price.
Light-powered technology also gave us thin-film amorphous solar panels. These panels have the lowest efficiency of them all – less than 10%. However, as they are flexible, they can be placed on uneven surfaces and even wrapped around buildings and different types of objects. This means that they have a unique application that rigid PV modules are not a match for.
Factors Affecting the Quality of Solar Panels
Solar panels differ in their efficiency and their quality. Depending on your exact energy needs, you may choose one type of solar panel over another. You may also choose one brand over another, again, depending on your needs and energy habits. In general, there are a couple of factors that affect the quality of your solar panels:
- The efficiency of your panels,
- The temperature coefficient of your panels,
- The warranty given on the materials, and
- The cost of your panels.
When deciding on how to grade panels and determine the factors affecting their quality, we decided to assume that the cost is the least important one. After all, higher-quality solar panels do cost more, but they produce more power, and you will need fewer of them. Additionally, they will produce more power over their lifetime, saving you more money than low-cost, low-quality solutions.
Efficiency, or energy conversion efficiency, is the sole determiner of how much sunlight your panel will convert into electricity. Solar panel efficiency can be increased by:
- Increasing the absorption of light (such as can be found in hybrid solar cells),
- Decreasing reflection rate (by choosing the right type of uppermost coating),
- Increasing the conductivity of all conductors used in solar panel assembly).
The temperature coefficient of a solar panel is another factor that affects the quality of solar panels. Namely, solar panels are most efficient during fresh days with plenty of light – such as in late autumn and early spring. As the temperatures rise and your panels heat up, they become less efficient. A part of the reason why panels lose efficiency at high temperatures is that the electromagnetic properties of the materials they are made of diminish at high temperatures.
In addition to this, high temperatures also degrade the materials your solar panels are made of. This is the biggest flaw in perovskite solar panels: as they are made of organic materials, they degrade fairly rapidly. This is the reason why there are no commercially available perovskite panels.
Many manufacturers give a 20-25 year warranty on your PV panels. This means that your panels will keep up to 80% of their efficiency over the warranty period. Cheap panels with a ten-year warranty should be avoided, especially as they will degrade and become useless much faster than 20-year warranty solar panels. Remember, the longer the warranty, the higher the quality of your panels.
Finally, the cost can be a good indicator of the quality of your panels. Robust solar panels with high efficiency will cost way more than cheaper panels that could get damaged in hale or degrade under strong sunlight. Monocrystalline solar panels usually cost the most. Polycrystalline solar panels follow them by price, while thin-film panels are generally the cheapest. In some cases, this-film solar panels can be the most expensive kind because of their unique property of flexibility and the variety of surfaces they can be applied to.
Researching New Materials and Methods
To ensure that solar panels are the energy source of the future, more investment needs to be made into developing new technologies. The current state-of-the-art technology when it comes to solar panels is perovskite solar panels. Fundamental research combining experiments from different fields has given us these carbon-based solar panels, which combine organic compounds to produce solar panels.
As such, these solar systems ensure efficiencies of up to 24%. Multilayer technology can increase the efficiency of these panels up to 43%, although each new percentage is more difficult to achieve than the previous one. Molecular devices, based on molecular scaffolding of different materials, also show promise, as they can create small holes that photos cannot escape once they enter the material. Similar technology was developed for use in paint production – namely the Vanta black paint, the darkest material on Earth.
Future Research Possibilities
Future research in this field opens up many possibilities. Possibilities for carbon emissions reduction and a more sustainable energy generation are further supported by promises of reaching 30% efficiency in solar energy generation. Expanding on the existing perovskite technology is also a feasible approach, especially as this is the best bet we currently have to expand solar module efficiency. Regardless of the approach, future research promises a bright future.
Advantages of Solar Energy
As it goes, solar power has a lot of advantages to offer. Clean and renewable, it is our best bet against climate change. Abundant and endless, it is the best bet for an energy-safe and independent future for upcoming generations as well. Here are the benefits that solar energy can offer to you:
- It helps reduce or eliminate your electric bill,
- It can increase the value of your home,
- It can enable you to earn tax credits and rebates,
- It can limit the effects rising electricity costs have on your wallet,
- It can provide a better, environmentally friendly renewable energy source, and
- It requires low-cost or minimal maintenance.
Helps Reduce or Eliminate Your Electric Bill
As your solar panels produce electricity whenever the Sun is out. A part of this energy is then used by your appliances, and the rest is stored in your solar battery or sent to the grid. If you live in an area with net metering in place, you can rest assured that your electricity will get back to you – the dual smart meters are there to ensure that not a single kWh is lost.
Increase the Value of Your Home
Installing a solar array on your rooftop increases the value of your home. For every 1 kWh of solar PV modules you install (about three modules), you can expect the value of your home to go up by an average of $6,000. This added value is not counted towards your property tax.
Earn Tax Credits, & Rebates
Going solar has other perks to offer as well, especially in the form of solar tax credits, incentives, and rebates. The Federal Government offers a 26% tax credit by the end of 2023, while each state has its own solar rebates and incentives. The state of Connecticut, for example, offers $0.426 per Watt of installed DC power for solar systems up to 10 kW in size – an immediate $4,260 deduction from your costs.
Besides rebates, some states also exempt solar panels and other solar equipment from sales tax – this will help you save around 7% of the purchase price of solar panels. On the other hand, your state can also offer net metering to help reduce the price of your solar system by having you install no battery. Thirdly, in some states, you will also be able to enjoy the solar added value property tax exemption, where you only pay regular taxes without paying extra once your solar array raises your property value.
Solar Investment Tax Credit
The solar investment tax credit or federal ITC is a great way to save up to 26% on the cost of your solar panels. Although not a rebate per se, the program allows you to get 26% of the total investment into your solar array back in the form of a federal tax credit. To apply, you must be eligible to pay federal taxes. Otherwise, you may not benefit from the program. Another benefit here is that any unused tax credits can be rolled over to subsequent years, to a total of 10 years.
Solar Renewable Energy Credits
Solar Renewable Energy Credits or Solar Renewable Energy Certificates are another incentive that exists in the US. Under this program, you are eligible to receive one SREC for every megawatt-hour of solar electricity you produce. You can then sell these credits on an SREC market, for anywhere between $4 and $480 (July 2022 data).
Limits the Effect of Rising Electricity Cost
A solar array on your roof also protects you against rising electricity costs. As you can produce your own electricity, you become partly resilient to electricity price fluctuations. Light-powered technology produces electricity whenever there is sunshine, unlike gas and coal power plants which need thousands of miles of infrastructure just to keep running. As electricity prices rise, you will also be able to make some money by selling excess electricity or renewable energy certificates.
A Better Environmentally Friendly Renewable Energy Source
Most of the world’s electricity is produced in coal power plants or natural gas power plants. This means huge carbon dioxide emissions and a huge carbon footprint for every kWh of energy you use. With solar energy, you do not need to worry about your carbon footprint, as there is virtually none. Most solar panels produce enough electricity to offset all carbon released during their production stage in the first five years of service. They also pay off within 12 years at most.
Requires Low-Cost or Minimal Maintenance
Solar modules require very little maintenance, which is another added benefit of installing solar panels. Occasionally spraying them down with a hose should do the trick. The aim here is to remove dust, fallen leaves, or any other particles which could obstruct light and reduce the efficiency of your solar panels.
Disadvantages of Solar Energy
However, not all is a fairytale with solar energy. As it goes, solar energy has some disadvantages as well: most of those relate to the low efficiency and a (still) high price. Still, let us learn more about solar system disadvantages before we jump to any conclusions. Here are the disadvantages of solar energy:
Solar Panels Cost a Lot of Money
The initial cost of installing solar panels is very high – in the tens of thousands of dollars, to be more precise. This means that an average household may not be able to install panels on the shortest possible notice. However, this should not stop you from doing this, especially as you are eligible for a 26% solar tax credit and various local and state incentives available to those who are willing to go solar.
In addition to this, you can also expect to save in the long run – your solar panels will start saving you money the moment they are brought online. An average US household can expect to save $10,000-$25,000 over the course of 25 years – which is how long your panels can keep producing electricity. This is enough to send a kid through college in most states.
Solar Panel Efficiency Depends on Multiple Factors
The efficiency of your solar panels depends on multiple factors. For panels to be able to produce electricity, they need direct sunlight – something that is not available during night or on overcast days. Besides this, your PV panels’ efficiency also depends on other factors, such as latitude, the area available for solar panels, existing solar roofing, foliage cover and any nearby vegetation, time of the year, and the time of the day.
Your latitude determines the tilt of your solar panels. The higher the latitude, the higher the tilt of the panels. Note that in higher latitudes, you will not be able to receive as much solar power, so your solar PV array will take the longest to pay off. This is the reason it takes so long for solar panels in Alaska to pay off and so short in Hawaii.
The area that you intend for your solar panels should ideally be flat, oriented to the south, and at the perfect tilt for your latitude. Not many homes satisfy all these criteria, so you may end up installing solar panels on more than one roof slope if you have an east-west facing roof.
Any vegetation in the vicinity of your panels (especially trees) may cause a shade on your solar system. This, in turn, means lower electricity generation and a longer payoff time. All this should say that installing a solar system and designing one in the first place should be left to experts.
Storing Solar Energy is Expensive
Storing solar energy is expensive. The cost of a Tesla Powerwall 2 with 13 kWh of storage space is $5,500 as of July 2022. Considering that an average US household consumes 30 kWh of electricity every day, you will need 3 of these solar batteries. This is a staggering $16,500 to add to your cost of installing a solar system. If you live in an area where net metering is enabled, you can forget about this cost, as your utility company will take over any excess power and give it back to you when the Sun is not shining as brightly.
Why are Chinese Solar Panels cheaper?
Chinese solar panels are cheaper than those produced elsewhere for a variety of reasons. The cheap labor force, low safety levels, and loose regulations make Chinese solar PV module producers very competitive in the market. Furthermore, the density of production and locally sourced materials make Chinese panels even cheaper. Currently, China produces panels at the cost of $0.28 per Watt.
What happens to solar panels after 25 years?
After 25 years, your solar panels will keep producing electricity. However, they will produce electricity with less than an 80% efficiency rate. For example, if purchase solar panels with 20% efficiency, after 25 years of use, their efficiency will drop to below 16%. Alternatively, if your solar system can produce 3 kW of electrical power, after 25 years, this production level will drop to the maximum of 2.4 kW.
Do solar panels ruin farmland?
Solar panels do not ruin farmland. Quite on the contrary, panels are very often installed on land that is not suitable for farming practices. Experiments in Europe and particularly Italy and Spain, even open a new field in solar panel installation – Agrivoltaics. The approach consists of placing solar panels above arable land, mostly land that is under some kind of crop. Initial experiments showed that plants underneath benefit from the mild shading – tomatoes, for example, can produce up to 30% more biomass in agrivoltaic production.
Can solar panels be produced sustainably?
Yes, with sustainably sourced materials and renewable energy used during the manufacturing process, solar panels can be produced sustainably. This can include any form of renewable energy to power production facilities and materials that have been recycled or extracted by sustainable practices. This is the goal everybody strives for, especially as the end of life for the first generation of solar panels is fast approaching.
Solar panels are the perfect solution for powering your home or your business. Cheap and durable, they provide you with renewable power and reduce your carbon footprint. Less reliance on fossil fuels means greener products and services that you can charge more, but it also means having renewable certificates, which you can then sell to whoever offers the most.