source of renewable energy on our planet, and it’s no secret that recent technological innovations have made solar power affordable for more and more people .
The amount of solar power added worldwide grew by 50 percent in 2016, with most installations occurring in the United States and China [2,3]. Despite the successful development and innovations in the solar industry over the last 180 years, there are still a couple of technological constraints regarding photovoltaic cell efficiency.
If you’re considering upgrading your home from expensive (and polluting) fossil-fuel energy to cheaper and cleaner energy, now it’s the time to learn more about the advantages and disadvantages of solar energy.
Pros of solar energy
1. Solar reduces your electricity bills
The main reason homeowners go solar is to save money. When generating your own electricity from the sun, you’re less dependent on the utility companies, which reduces your monthly electricity bill.
How much can you save?
According to a report released by the North Carolina Clean Energy Technology Center, the majority of U.S. homeowners who invested in a 5kW solar PV system saved between $44 to $187 per month in their first year after installation . Quite impressive, isn’t it?
2. Net metering – supplying energy to the grid
While producing renewable energy, you have the option to earn energy credits through net metering. When your solar system generates more power than is used by your home, you receive credits from the energy company for supplying this extra energy to the grid.
Then, on days with low or no power generation from your solar system, your energy needs are drawn from the grid and the cost is covered by using these credits. The good news is that you rarely have to pay extra fees, as the system often balances itself out throughout the year .
3. Financial support from the government
The U.S. government offers a 30 percent tax credit for the installation of photovoltaic systems or solar water heaters. This credit will decrease to 26% in 2020.
As of 2017, an average solar system costs around $17,000 before the tax credit. The 30 percent tax credit makes the cost of the solar kit come to just $11,900.
4. Return on investment
Based on the amount of money you save with your solar system, you can expect a return on your investment within the period of its warranty .
For example: Cutting $100 off your monthly energy bill translates to a savings of $24,000 within 20 years.
According to scientists from the United Kingdom, the potential of lowering energy bills is even higher. If houses could effectively store the solar energy generated throughout the day, energy bills could be reduced by more than 60 percent . So, in the near future, we can expect even faster returns on investments.
Solar Renewable Energy Credits (SRECs) are another way to get the return on your investment faster. The system of SRECs measures the overall production of your solar panels in a year, and you receive one SREC for every 1,000 kilowatt hours generated by your array. The value of one SREC varies but in some states can be up to $300 .
The difference between this and net metering is that you are not selling energy to the grid; you are selling your consent that the energy company can claim your clean energy production as their own. They do this to help adhere to the Renewable Portfolio Standard, which requires that energy companies generate a portion of their electricity from renewable resources. Buying this portion from private solar owners is easier than re-structuring the company’s whole grid.
5. Improving technology
Technological innovations in the solar power industry have advanced quickly over the last couple of years. As photovoltaics research continues to make solar energy harvesting more efficient, the potential to transform solar power generation in the near future is incredible.
Just recently, a team of researchers at Technion – Israel Institute of Technology made a breakthrough in solar cell technology that could improve the efficiency of photovoltaic cells by approximately 70 percent.
Another great innovation came from scientists who have developed super-efficient solar cells capable of capturing 99.7 percent of light. These high-efficiency cells are called “super black,” and their forte is the ability to perform at almost the same rate of efficiency in cloudy conditions as in the perfect sunshine .
6. Energy security
You probably don’t realize this, but we depend on grid power for almost everything. And grid power is mainly generated by fossil fuels, a nonrenewable source of energy that is being depleted much more rapidly than most people think . This means that our energy supply is susceptible to never-ending increases in energy prices.
When going solar, your energy supply will not be subject to international price fluctuations, and since no one can buy the sun’s energy to monopolize this resource, it is a very secure renewable energy source for the future.
7. Silent operation
Compared with the noisy generators and power plants of today’s world, solar panels are silent. This advantage makes solar power even better than other green energy options.
8. Solar is environmentally friendly
Solar energy generation significantly reduces air pollution and greenhouse gas emissions.
In 2014, the total amount of emitted greenhouse gases in the United States dropped by 17 million metric tons thanks to the increase in solar installations (especially in California). Such a high potential for reducing greenhouse gas emissions is a promising step towards mitigating human impact on the global climate.
While the majority of other power plants, including renewable geothermal power plants, require water for cooling, solar farms need no water. This decreases water pollution and conserves local water resources for other uses such as drinking and irrigation.
A recent study carried out in England demonstrates that solar farms also have a positive impact on biodiversity.
9. Solar is good for our health
Improved air quality comes with great benefits to human health. Lower concentrations of sulfur, nitrogen, and particulate matter in the air we breathe can reduce the premature deaths of between 25,000 to 59,000 people, according to the U.S. Department of Energy .
This number can be much higher if we take into consideration health problems caused by the impacts of climate change all over the world.
Some of these impacts are already visible in Bangladesh, which was hit by 70 climate-related natural disasters in the last 10 years, forcing hundreds of thousands people from rural areas to relocate.
10. Unlimited source of energy
The sun is the most abundant energy source available to our world, raining 173,000 terawatts of energy down on the Earth every second . This energy can be harvested at any location globally, for as long as there is sunlight.
This is a major advantage because solar technology can provide power in the most remote locations on Earth. For example, the Australian Antarctic Division relies on solar energy to power their radio installations and automatic weather stations in Antarctica .
Innovations in technology also allow easier use of portable solar power sources. Perhaps the most extreme example is the use of solar energy to power space exploration. Even the Hubble Space Telescope is powered by its own solar array .
Electricity generation is not the only use of solar energy. Solar water heaters are commonly used to heat and store hot water in warmer climates. The versatility of the sun’s energy is also put into action when desalinating seawater for drinking or even just warming up swimming pools by using a solar cover to trap the heat from the sun.
11. The maintenance of solar systems is minimal
Solar panels are durable, and because there are no moving parts, there is very little risk of wear and tear. Most solar panels nowadays come with a 20 to 25-year warranty, and even though they are made from tempered glass, they can withstand even moderate hailstorms without any damage.
The most common maintenance is regular cleaning of dust and dirt particles because they could decrease efficiency in the long run.
12. Increased value of your house
Solar installation is also a good investment because it adds value to your house. It is difficult to say an exact number, as the results depend on many factors regarding the state of your property and solar system, but according to a study in California, 1 kilowatt of solar power increases the value of a house by more than $5,000 .
With increasing awareness on the benefits of renewable energy, more house buyers are interested in buying a property with a solar system in place.
Cons of solar energy
1. High initial cost
Solar energy saves money in the long run, but one of the main disadvantages is the initial installation cost of the whole array, which could easily reach $15,000 or more.
Although solar power cuts off your monthly electricity bills instantly, the return on the investment comes after several years. This requires careful planning and a lot of research before deciding how to cover the upfront investment.
Luckily, there are a few options. You can choose from solar leases, loans, or power purchase agreements. Make sure you evaluate these options thoroughly before making your decision.
2. Intermittent nature
The intermittent nature of solar energy is one of the main reasons why it is difficult to rely entirely on solar power at the moment. Solar energy is generated only from the sunlight. At night or on cloudy days, your system will not produce power.
When calculating how much power your solar system will produce, you have to take into consideration the weather patterns in your area and shorter periods of sunlight during winter months because both of these factors will decrease the amount of energy generated throughout the year.
3. Low efficiency of solar panels
One of the drawbacks of solar technology is the low efficiency of solar panels when converting the sun’s energy into electricity, meaning that a great deal of energy is lost in the process. Most commercially available panels reach only 15 to 18 percent efficiency . This means you need more panels to cover your energy needs, resulting in higher initial installation costs and a larger area to mount it.
Additionally, low efficiency can be further compromised by manmade dust particles deposited on solar panels. According to a recent study, solar panels in areas with heavy air pollution generate 25 percent less energy than expected. This happens because some pollutants from our industrial activities are sticky and tend to block the sunlight.
On the bright side, however, this technology is still improving, and new materials are being tested to tackle the issue of efficiency under different conditions.
4. Space and roof material requirements
An average 5-kilowatt installation for a family house might consist of 25 solar panels. Each panel is around 65 inches long and 40 inches wide. This means you need an area of 135 feet in length and 83 feet in width to place the whole solar system, which can be a problem for some houses.
Another issue when it comes to system placement is the suitability of the roofing material to hold the array. Older roofing materials that might need to be replaced in the next couple years are not a good option. Similarly, roofs with skylights or other built-in elements make the installation of a solar system difficult.
If you are unable to fit the array on your roof, there is also the option to use ground-mounted solar panels.
5. Expensive energy storage
Solar power is variable in its output, producing in excess during peak sunlight hours and shutting down completely at night. Solar batteries are able to solve this problem by charging during the day and providing power at night.
The downside of their use is the hefty price and maintenance, including replacement when needed. The most commonly used batteries at the moment are lithium-ion batteries, which can be stored both indoors and outdoors.
6. Environmental footprint of manufacture
Solar energy is labeled as clean energy because it has a lower environmental footprint than fossil fuels, but manufacturing solar panels still comes with environmental implications.
Solar cells are made of rare and toxic materials such as cadmium telluride or copper indium gallium selenide. The use of these elements could pose health risk for people and the environment if not handled properly. Financial incentives encourage prompt recycling of these materials .
Even the purification of the most commonly used solar cell material, silicon, requires the use of hazardous chemicals such as hydrogen fluoride, hydrochloric acid, or sulfuric acid .
Solar panels do not emit greenhouse gases when producing energy, but the processes prior their installation—including the extraction of their manufacturing materials and their transport—do. It is estimated that the amount of emissions produced throughout the lifetime of a solar system ranges between 0.07 to 0.18 pounds of CO2 per kilowatt-hour produced. Coal, by comparison, releases 1.4 to 3.6 pounds of CO2 per kilowatt-hour .
Solar energy currently has its disadvantages, but the majority of these downfalls are technical in nature and likely to be overcome as technological innovation advances. Along with other renewable sources such as geothermal energy, wind, and tidal power, solar energy is a promising alternative to more polluting forms of energy. Used together, renewables can take us toward a brighter, cleaner future.