by Devin Rice | San Juan del Sur

The sun is simply mind blowing when you stop to consider it. Through internal nuclear fusion, light is created and propelled nearly 100 million miles through space, penetrates our protective atmosphere, and provides us with a comfortable warmth, enough light to see by, and life sustaining energy for every living creature on this plant. Think of what we could accomplish if we were only able to utilize all of this energy from the sun in a significant way. That is what researchers in the solar energy industry intend to do. There have been many lofty claims of life changing solar concepts that have outright failed such as Idaho’s solar road or the visually impressive Ivanpah plant in California. Despite these failures, there still exists a huge potential for a solar revolution. In this article, we will examine the current state of solar energy in the world. In many ways, a solar revolution has begun.

Solar Energy Input

Every efficient electrical system requires an input to be able to deliver an output, so what exactly is the raw input energy from the Sun provided to the Earth? The Earth’s’ system, which is the land surface, water surface, and surrounding atmosphere, absorbs 71% of all solar radiation from the Sun. The remaining 29% is reflected back into outer space by cloud coverage, particles in the ozone, and bright surfaces such as snow or ice. All this amounts to a total energy absorption of approximately 340 watts per meter squared every second. That sounds like a lot, but really how much energy does that amount to in our daily lives? Well, if we were able to utilize all the energy produced at this exposure level in an area the size of a football field, in one hour we would produce 541 times more energy than what the average American household consumes in an entire year. The sun, as a power source, provides more energy than anything that can be achieved from all the tapped and untapped fossil fuels (oil, coal, and natural gas) combined.

That amount of energy is mind boggling, but one fact of the solar energy is that we can only utilize a small fraction of it. The United Nations Development Programme performed an assessment in 2004 that took into account the usable UV spectrum, historical weather data, geographic location, time variation, and the amount of surface area that is suitable for development. They found that in the most ideal solar locations could only use 13% of this raw energy while in the least ideal locations a meager 1% could be utilized. However, what is important to keep in mind is that the total raw input energy from the sun is so vast that even at 1% our football field would still produce 5.4 times more than what the average household would need annually.

Solar Energy Adaptation

A system is required for energy input to provide energy output. Obviously, more solar power systems are needed in the world for us to produce more solar energy. While solar energy adaptation has been increasing in recent years, as of 2016 solar energy only accounted for 1% of the energy consumption in the United States and just over 6% in Germany, the world’s leader in solar adaptation. This leads us to the question, just how fast is the solar revolution occurring?

Fast. In the United States, solar energy adaptation is growing at a rate of about 60% per year since the year 2006. To put that into perspective, the U.S. is currently generating nearly 100 times more electricity from solar energy systems than what the country was only a decade ago. While this sounds like great progress, solar energy still only accounts for 1.1% of global energy consumption – but the rate of adaptation is reassuring. In fact, a 2014 study by the International Energy Agency projected that solar energy would surpass coal, oil, and nuclear to become the largest source of electricity by 2050, meeting 16% of the world’s consumption needs.

Solar energy is a controversial topic in today’s world. Common arguments used against it are that it is too expensive and, of course, only works during the daytime. Following this trajectory, solar energy is mostly useless during periods of peak energy consumption, which are commonly during the late afternoon and into the night. In recent years, these arguments cease to be relevant due to decreasing costs and technological advancements.

Solar Energy Costs

Let’s take a look at the average cost of a solar panel from the early years of solar to 2016. Adjusting for inflation, the cost of a solar panel in the 1970’s was $96 per watt. Over the years, solar technological advancements were pioneered by Japan and a few European countries which led to more efficient and less costly solar panels. Also, thanks to economies of scale which is an economics term that applies to the idea that the more an item is produced the less expensive it becomes, the average solar panel in 2016 is less than $0.50 per watt. Since 2013, solar cells have been given a Moore’s Law equivalent called Swanson’s Law. It states that solar cell costs will decrease by 20% every year global shipments double.

Today, Europe and Japan continue to play a large role to further develop the global solar industry, in recent years China and the United States have come to dominate the market. Together, these two countries installed 21.3 gigawatts worth of solar panels in 2015, just under 40% of the total worldwide solar growth that year.

As long as both countries continue to place a high importance on solar development, economies of scale shows us that the cost per watt will continue to rapidly drop.

Solar Energy Advancements

Cost reduction is also attributed to many new breakthroughs in advanced solar technology and 2016 may be priming us for the golden age of solar energy development. Many new advancements have been announced every month that it is nearly impossible to keep count of all of them. Within a matter of months, the bar for a more efficient solar panel was advanced three times when Silevo took the title of “most efficient panel” from SunPower, but in turn lost it to Panasonic only a week later. As of writing this article, SunPower again has the distinction of producing the world’s most efficient solar panel at 24.1%.

Researchers in China have manufactured a solar panel that produces electric energy from both sunlight and rain. While it only produces about 30% of the energy it would on a normal sunny day, it is an amazing step closer to all year-round solar energy generation. MIT has started to build three dimensional solar panels based on an optimized computer algorithm that offer a more stable output from different angles of the sun. Initial results have shown that these 3D solar panels can provide anywhere between two to twenty times the solar energy output when compared to their 2D counterparts. But that isn’t the only solar advancement to come out of MIT this year. It was recently announced that researchers at that school have created the world’s smallest and lightest solar cells – light enough that they can be placed on top of a soap bubble and thin enough that they can be applied to nearly any surface or material.

Solar energy advancements are also taking place in the transportation sector. In 2013, an autonomous boat called Scout was launched with the goal of being the first solar vehicle to cross the Atlantic Ocean. Unfortunately, contact was lost with the ship shortly into its voyage due to bad weather. In 2016, a solar aircraft called the Solar Impulse became the first manned flight to travel the circumference of the world using only solar energy. Also in 2016, Toyota released an updated version of the Prius with a solar panel roof that actually helps power the car as opposed to the previous versions that were mainly for show.

Solar Energy Drawbacks

When speaking about solar energy it is impossible to avoid talking about some of the drawbacks the technology currently has. In most households, energy demands will fluctuate on a day by day basis. One of the key issues of solar is that there is no simple means to alter the output to match these fluctuations. As mentioned above, peak energy demand generally happens in a household at night and this is the exact opposite time to when peak energy input occurs from the Sun. Energy storage battery systems like Tesla’s Powerwall can store solar energy generated during the day for use at night to help bridge the gap between these peak times. Since this is still a relatively new technology, more time is needed before Tesla can produce a large enough supply of batteries to make this energy storage technology universal. Thanks to the rise of electric vehicles, the Tesla Powerwall and similar batteries are now much safer, better for the environment, and cheaper compared to the early generations of energy storage devices.

The second drawback of solar is that the best panels on the market only have an efficiency rating of 24%. That means for every kilowatt of input from the sun, only 240 watts of usable solar energy is generated. There is still a ways to go for solar efficiency, but it does not have to go far to catch up with other energy sources. Coal, the most efficient of the fossil fuels, is only 48% efficient. We have surpassed huge efficiency benchmarks in the last decade alone, and it is expected to continue to rapidly improve as technology advances in the coming decade.

Lastly, a major drawback specifically in the United States, is the aging electrical infrastructure. A great deal of financial investment is required to retrofit or replace the current infrastructure to account for outdated electrical engineering design in order to make them compatible with large scale solar energy. Without this investment, no matter how many solar panels the United States manufactures, there will be a hard limit on how much solar energy the country can utilize. For instance, HECO, the primary electric utility company in the state of Hawaii, did not allow any additional solar systems to be interconnected to the power grid during 2013 – 2015. HECO feared that an energy surge from the exportation of excess solar energy would have severely damaged the electrical grid. Since 2015, a short term solution was found to allow additional households to go solar, but Hawaii and the rest of the country still must face their energy capacity problem in the near future.

Solar Energy Success

While an immense amount of work is required in order to create enough solar energy to meet our current energy consumption needs, we are already seeing success stories from the solar revolution around the world. On a two particularly sunny days in May, Germany generated a combined total of 22 gigawatts of solar energy per hour. That is the output equivalent of 20 nuclear power plants. This may seem strange as Germany is known for its overcast skies. However, solar panels will not stop producing energy just because the sun is blocked by a cloud. Clouds reflect light and lower the temperature coefficient, allowing solar panels to perform more efficiently than what they can on sunny hot days and make up for lower energy input. Solar panels will continue to generate energy as long as they are not covered by hard shade, debris, snow, etc.

Germany isn’t the only country in Europe with a long term focus on solar energy. Since 2014, the United Kingdom has converted four former coal mines into solar farms. Once all four solar farms come online their total output is expected to be 75 gigawatts annually. This is, admittedly, only a third of the energy produced by coal mines, but there is the added benefit of saving the U.K. 375 tons of carbon pollution over the next 25 years. In fact, while doing research for this article, the U.K. announced that it will be closing all of its remaining coal powered electrical plants by 2025 and opting for other energy sources, including solar energy. While on the surface their plan to leave behind one of the dirtiest energy sources looks like a selfless act for the environment, it actually has more to do with the cost to generate energy from the fossil fuel. For the first time in history, solar energy is cheaper to implement than coal fueled electrical plants.

Meanwhile, in the United States a recent census report identified that 1 out of every 78 new jobs created in 2015 were in the solar industry. Compared to the rest of the U.S. economy, the solar industry is growing at a rate of nearly 20 times fast than the national average. Not only has solar been instrumental in employing nearly a quarter of a million Americans, but major cities across the country are heavily utilizing solar energy with the goal of being 100% powered by renewable sources. San Francisco has implemented a law requiring all new buildings with 10 stories or fewer to install grid-tied solar panels. This law is part of the city’s plan to be fully energy independent by the year 2030. San Francisco is one of the more notable U.S. cities to take the plunge into 100% renewable offset, but smaller communities such as Burlington, VT, Aspen, CO, and Georgetown, TX have already achieved their goals of being fully energy independent.

Private companies are also shifting to solar energy. Apple constructed a new solar farm in the sunny Nevada desert with the idea of generating enough solar power to offset its data center in Reno. Due to land restrictions, Apple opted to use an experimental design when constructing their solar farm. By using mirrors to highly focus the sun’s rays onto solar panels, they were able to generate more solar energy than a similar sized solar farm would normally generate. In fact, Apple is generating more energy than the company can use and seeking approval from the Federal Energy Regulatory Commission (FERC) to become a certified energy provider under the name Apple Energy.

The Future of Solar Energy

Solar energy is far from perfect, but there are plenty of smart people working out the kinks. With a global growth rate of 40% per year, huge progress is being made to lower the cost of adapting solar energy systems to our present energy infrastructure. Seeing the rise in global climate change, many world governments have a renewed sense of urgency for solar. Germany wants to be 30% solar powered by 2020, China wants 20% by 2030, and the city of Sydney in Australia wants to be 100% solar powered also by 2030.

While this is encouraging, many fear the political climate in the United States will either stall or cause a domestic solar recession. It is easy to believe that the president dictates what forms of energy we use in the United States, but it is the individual states that hold the real power. Each state has the power to set net-energy metering rules, solar access laws, as well as have the ability to provide renewable energy incentives. The federal government does have a certain grasp on energy via the FERC, but can only regulate the interstate transmission of energy through the utility grid. The FERC does not have the ability to restrict homeowners from installing solar panels on their roofs or private businesses from building solar farms in the middle of a desert. Presidents do not have much say over the energy markets. The solar industry is too cost competitive, has overwhelming support from both individual citizens and state governments, and provides too many jobs to ever truly be in danger.

Here is the big take away from this article: while solar energy will not become a standard overnight, it is becoming more desirable with every passing year. The individual companies that make up the solar industry are each highly motivated and capable to continue to expand their market. Already they have made incredible breakthroughs in technological advancements which decreases costs and makes solar increasingly viable for the average household. There is still work to be done, and the industry now needs the partnership of national governments in order to succeed in the solar revolution. With their combined efforts, what we commonly know today as solar panels may quickly become an outdated concept as solar cells become smaller and are integrated more into our daily lives.