The future of green energy is definitely looking up as renewable sources increase in capacity and prices remain low. The global market size of the solar industry is projected to grow from $9.9 billion in 2018 to $16.9 billion by 2025.
Despite the positive outlook, solar energy still has a few setbacks. The most obvious is the fact that sunlight isn’t always available when you need it, and that capturing it and transforming it into electricity still requires a lot of effort. In the near future, battery storage could address this issue. However, even with batteries, there are still a lot of limitations. First, they’re not unlimited in capacity, and so you’ll always need an outlet to store the energy you capture. Second, they’re heavy and have a long recovery time. For example, the average lithium ion battery has a lifetime of three to five years, but it can only be stored for a half-hour to an hour before it needs to be recharged.
The solution for both issues is simply to use more batteries or solar panels. When sunlight isn’t available, the average solar panel can generate enough electricity for a few days, so having a lot of these is useful. Similarly, if you have a large amount of solar energy and don’t need the energy immediately, it’s a good idea to store it in batteries to use at a later date.
Another challenge for the solar industry is the fact that most people are not yet convinced that going green is the best long-term option, especially when investments are on the line. The future of clean energy still depends on market share and whether big businesses continue to support the sector.
Where does the energy come from?
The form of renewable energy around the world is constantly evolving, and different countries are taking a slightly different approach to producing clean energy. There are three main forms of renewable energy: solar, wind, and hydropower.
Solar power is the process of converting sunlight directly into electricity using photovoltaic cells or panels. It’s a popular option in regions with sunnier climates and lots of clear sky, such as California and Australia. In these locations, homeowners and businesses can get solar-power systems installed for free or at discounted rates through government subsidies.
In the United Kingdom, for example, government-subsidized solar-power systems can only be installed on new homes and businesses. Existing homes and businesses must pay for the installation themselves. In some countries, such as Germany, the financial incentives for going green are so high that households and businesses can afford to purchase their own installations. In other locations, such as China, the trend is to utilize public subsidies for large-scale solar projects, while smaller-scale residential solar power is often not economically feasible.
The pros and cons of solar energy
With increasing concerns over climate change, more people are considering the benefits of going green. The list of pros and cons for solar energy are as follows:
- Pros: It’s a form of renewable energy that’s always available.
- Cons: It can be expensive to purchase and maintain, especially if you’re installing it on your own property.
- Pros: Solar radiation levels always remain relatively high, even during the night. This means that solar power is available to be harvested 24/7, regardless of the weather.
- Cons: The days when solar energy dominated the global market were before the rise of renewable energy.
- Pros: The industry is constantly expanding, with many new installations being built every year.
- Cons: There is a high setup cost involved in building a solar-power system.
- Pros: Depending on the size of your system, you can either generate your own electricity or sell the excess power to a utility company.
- Cons: Batteries need to be repeatedly charged and maintained.
- Pros: Solar energy provides a stable and continuous source of power that’s not dependent on the grid.
- Cons: The land that the system is installed upon must have relatively unobstructed views of the sun, so that it can efficiently convert sunlight into electricity. This limits where solar installations can be sited.
Where does the energy come from?
Wind energy is derived from wind movements, either in a continuous or sporadic manner. When wind blows, it causes small particles in the air to swirl and dance around, generating electric current in the process. These tiny movements are what make up wind energy’s momentum, which can either be stored in a big battery or used immediately to power electronics. The two main types of wind energy are onshore and offshore, with the former being far more common and the latter being used for larger-scale projects such as ocean turbines and giant kites.
Onshore wind farms, or “wind farms,” consist of many small turbines spaced across a large area of land. The turbines are built on pylons or towers, and these structures can either be fixed into the ground or free-standing, as shown in the animation below. The exact size of a wind farm varies but can be quite large, with some estimates putting the figure at over 100 turbines per megawatt of installed capacity. The world’s largest onshore wind farm is the 575-megawatt (MW) Trump International Golf Course in Dubai, which features 126 Vindi turbines. When built, a wind farm usually has a lifespan of around 15 to 20 years.
Offshore wind farms are built upon islands or on large bodies of water, with many of them being located in the ocean. The wind is much more accessible over the water, which makes up the majority of their appeal. However, the location of an offshore wind farm also means that it is far more exposed to damaging storms and waves, which could potentially cause a lot of damage to the structures and their content, not to mention the clean-up cost. For this reason, many of these projects are also accompanied by costly insurance policies to protect against the unexpected.
The advantages and disadvantages of wind energy
The advantages and disadvantages of wind energy are as follows:
- Advantages: It’s a clean energy source that’s always available.
- Disadvantages: It can be difficult to site, especially in areas with lots of onshore breezes. This is because the wind always seems to be blowing somewhere else at the time, leaving you with no electricity. Also, the wind can sometimes be unpredictable, causing power cuts or surges.
- Advantages: The momentum of the wind means that it will continue to provide electricity even after the initial supply is exhausted. This makes it useful for applications such as backup power supply or load-shedding events.
- Disadvantages: There is a high setup cost involved in installing wind-power generation. This can range from a couple of thousand pounds to a few million, depending on the size of your system. However, if you’re looking for a steady supply of electricity, then wind energy could be a good choice as it will always provide power regardless of the weather or time of day.
- Pros: The industry is expanding, with many new projects being built every year. This makes it a steady source of job opportunities.
- Cons: The cost of wind energy is increasing every year, with turbines now being built to withstand greater wind speeds for greater potential energy generation. The faster the wind, the more power it will generate. For this reason, more money is often needed to build these taller turbines. This in turn causes the cost to go up, as you need to spend more upfront. Also, the maintenance costs for wind energy are quite high, with most turbines needing to be checked and serviced on a regular basis. This will increase the cost of electricity for the household or business.
How do solar panels work?
Solar panels work in a similar way to the familiar photovoltaic cells that are used to create solar batteries. However, instead of using electricity to store energy, solar panels use a photovoltaic cell to directly convert sunlight into electricity. The ability to store energy in this way is what makes the technology so attractive, as you don’t have to keep buying new batteries every month.
This form of renewable energy is extremely popular due to its wide use in regions with sunny climates, such as Australia and California, where homeowners and businesses can get solar-power systems installed at a low cost through government subsidies. These systems work by converting solar radiation directly into electricity using photovoltaic cells, as shown in the animation below.