And Now . . . Some Good News

​ Mark Twain is often quoted as having said “Everyone talks about the weather, but nobody does anything about it.” In reality, the United States and other developed nations spent the entire 20th century pumping more carbon dioxide into the earth’s atmosphere than its forests could absorb. This caused heat from the sun to be trapped in our atmosphere which is now giving rise to a host of detrimental weather patterns. This was first realized in the 1960s and only in the past ten years have significant efforts to curb global warming even been pursued.  These efforts have largely consisted of exploring various ways of harnessing renewable sources of energy, principally the power of the winds and the energy embodied in the light of the sun.

  Progress in developing renewable sources of energy has been slow in coming largely because the fossil fuel industries and their allies in U.S. Congress embarked upon a series of efforts dating back to the 1970s. First, they denied the very existence of global warming and then they denied that rising atmospheric and ocean temperatures were being caused by human activity. Even following the 2015 Paris Accord in which 194 nations agreed that global warming must be immediately addressed, fossil fuel lobbyists prompted the Trump administration to cause the U.S. (the second biggest emitter of carbon dioxide) to withdraw from this accord. In doing so, Trump proclaimed that too much of the burden of addressing global warming was being placed on the U.S. Fortunately, other countries took the lead in deploying solar panels and wind turbines as well as other efforts to harness renewable sources of energy.

  Windmills have long been a source of energy and have come a long way from the quaint structures that have lined the coast of The Netherlands (Holland) since the 11th Century. Today’s windmills are much larger and stand atop metal towers rising to heights of 40 meters or more.  The biggest problem facing the use of wind turbines, however, are not technological, but rather finding suitable sites for locating them. In many countries there is significant public resistance to having them located in developed areas and situating them in remote places entails additional costs of transmitting the energy they generate to where it is needed. Wind turbines also suffer from the fact that they are mechanical devices which require constant maintenance. Still, wind turbines are currently providing more than twice the amount of solar energy harvested in the U.S. That may soon change owing to new developments in solar and battery technology.

  The idea of capturing energy emitted by the sun dates back to the Romans. It was not until 1838, however, that Alexandre Edmond Bacquerel discovered the photovoltaic effect, i.e. when light strikes a semiconductor material it energizes the electrons within that material. It took another 45 years before Charles Fritts, a New York inventor, constructed a device that generated electrical energy from the light of the sun. Seventy years after that Bell Laboratories produced the first commercial photovoltaic (PV) panel. Over the course of the next 60 years PV panels would be improved and over the last decade they became commercially viable products as the need for renewable sources of energy became more acute and the costs of producing them dropped by over 90%. Today, China is the world’s largest producer of PV panels which are based upon two different semi-conducting materials: monocrystalline silicon and polycrystalline silicon.

Monocrystalline panels, which are a more refined version of polycrystalline panels, operate at a roughly 50% greater efficiency, converting into electricity up to 29% of the solar energy striking the panel. They also have a longer useful life (up to 40 years) than polycrystalline panels. Their downside is that monocrystalline panels are roughly 50% more expensive. Both varieties of these solar panels are still less cost-effective generators of electrical energy than fossil fuels and are still only commercially viable as a result of government subsidies which are justifiable owing to the fact that, unlike fossil fuels, they pose no detrimental effect on our planet’s environment.

  Most of the new developments in solar technology have taken two distinct directions. One path pursued by solar engineers is to find ways to improve the efficiency of existing types of solar panels. The other is to explore new semiconductor materials that are more efficient converters of solar energy.

  One of the principal short-coming of the solar panels currently being produced is that they are less efficient in high temperatures. This discovery led to the practice of creating solar panels that float on water which is sometimes referred to as “floatovoltaic panels.” By situating PV panels over water, their temperature is moderated thereby allowing them to operate at greater efficiency. This technique is said to raise the energy conversion efficiency of solar panels by roughly 10%. Floating PV panels on water has two other important byproducts. First, it eliminates the necessity of locating the panels on valuable farmland. Secondly, the panels absorb much of the sun’s energy and limit the amount of water that is evaporated into the atmosphere. Covering reservoirs is a proven technique developed by Israelis to preserve valuable freshwater supplies in arid areas.

As a young lad growing up in Atlanta, Georgia, I would occasionally spend my summer afternoons around a swimming pool, stretched out for an hour or more soaking up the sun’s rays. When I tried doing this on a family vacation inMiami Beach I made a painful discovery in the form of a bad sun burn even though my time in the sun was actually less than on previous occasions. This taught me that as you move closer to the earth’s equator, the rays of the sun are both more direct and deliver more energy. This same principle also has an impact on solar panels; i.e., those facing directly into the sun absorb more energy than those positioned to receive the sun’s energy at an oblique angle. It also explains why the location of a solar panel array will significantly affect its efficiency.

  Because the angle at which the sun’s rays strike the earth varies as the day progresses, the amount of energy absorbed by solar panels will rise as the sun reaches its apex around noon and will diminish as the afternoon progresses. This phenomenon has led to the practice of constructing sun-tracking solar panel arrays; i.e. placing solar panels on a rotating framework that tilts the panels to cause them to continuously face the sun as the earth rotates. This technique has been shown to increase the efficiency of a solar panel array by 25-35%.

  Another significant short-comings of silicon solar panels is that they only operate in a limited portion of the spectrum of light emitted by the sun. This can be best understood by directing sunlight through a glass prism and seeing the sun’s light broken into the same spectrum of colors that is visible in a rainbow. This phenomenon is caused because sunlight consists of light energy with varying wave lengths, ranging from short wave lengths (representing ultraviolent light) to long wave lengths (representing infrared light). This has led to a search for semiconductor materials that can absorb and convert a greater breadth of light frequencies. It has also led to creating solar panels in multiple layers with each layer capturing different frequencies of sunlight.

  The principal recent improvements in solar technology are based upon the use of perovskite crystals which can be 20% more efficient than solar panels made from silicon crystals. Perovskite is not a chemical, but rather an architectural structure similar to that found in a semiconducting mineral which was discovered in 1839 by L.A. Perovski, a Russian mineralogist. The three-dimensional structure of perovskite crystals facilitates the layering of materials that absorb and convert a variety of light frequencies. In addition, by adjusting the thickness and chemical composition of the perovskite crystal films, solar panels can be selectively “tuned” to specific wavelengths of light to be absorbed and converted into electricity.

  Perovskite crystals can be made of a variety of chemical compounds, the most studied of which is methylammonium lead trihalide. In addition to having a high rate of energy conversion, this variety of crystals is easier and cheaper to produce than silicon solar panels and can be made in films no thicker than a piece of paper. They can even be made transparent. As such, they can be attached to existing surfaces such as windows, roofs, billboards and highway sound barriers. This opens the possibility of heating buildings and powering factories without erecting dedicated solar panels or even detracting from the architecture of those facilities.

  At present, perovskite crystals suffer from chemical instability, but this problem is expected to be overcome over the next few years. It is therefore expected that solar power will soon surpass all fossil fuels as the least expensive source of electrical energy.

  The major problem with solar energy is that it is an intermittent source of energy; i.e. energy is only produced while the sun is shining. Key to making solar energy more useful is creating energy storage systems so that solar electricity can be relied upon around the clock. Fortunately, electrical storage technology is also rapidly advancing. These improvements have proceeded along four fronts: (1) increasing the storage capacity of batteries in relation to their size, weight and costs, (2) improving the speed at which they can be charged and the number of times they can be recharged, (3) extending the useful lives of the batteries and (4) reducing the costs of disposing of them after they have ceased to be of use.

 Most of today’s electronic devices (cell phones, computers, etc.) tend to be run on energy stored in rechargeable lithium-ion batteries. While this class of batteries is generally satisfactory for small devices, it has serious limitations when used in conjunction with tasks that that consume large amounts of electrical energy such as heating homes and commercial buildings and powering factories and electrical grids.

  Because of their relatively small storage capacities and extended charging times of today’s lithium-ion batteries, the most popular electric vehicles (EVs) are hybrids, with gasoline engines supplementing the car’s electric power train. Even homes factories and commercial buildings that currently use solar panels to generate electricity, tend to do so in conjunction with electric utilities. The excess electrical energy which the solar panels produce during the day is transmitted to the power company which, in return, supplies building owners with electricity when their solar panels are not covering their energy needs. Utility companies are able to participate in these symbiotic relationships by relying of fossil fuels to produce added electrical energy when and as needed.

  Currently, the main focus of battery technology are the needs of the transportation industry. This is because vehicles powered by fossil fuels are responsible for roughly 29% of all carbon dioxide emissions in the U.S. As things now stand, battery technology has only advanced to the point that, even with government subsidies, electric cars and light trucks (referred to as “EVs”) are only marginally economical. The most efficient EVs on the road only have an operating range of roughly 300 miles on a single charge and require at least 30 minutes to be fully recharged. While this is sufficient for many individual car owners, most Americans rely upon their cars for occasional long trips and the thought of having to stop for 30 minutes or more every 300 miles is an inconvenience that most are not willing to suffer. Some potential electric car buyers also have concerns about where they can stop to recharge their car’s battery. This presents a “chicken-and-egg” type situation—you need to increase the number of EVs on the roads before you can create sufficient demand for more charging stations. This problem is being addressed by government subsidies of EV purchases.

Battery technology is now being propelled both by the U.S. Department of Energy and by private companies. Batteries expanding an EV’s driving range on a single charge to 500 miles have been developed and will soon be readily available. This improvement has been achieved by downsizing current batteries so that more storage cells can be fit into a vehicle. Future improvements will involve new component materials. Solid-state sodium-sulfur batteries are reported will provide four times the storage capacity of lithium-ion batteries. In addition, new types of EV batteries that can be recharged up to 3,000 times have been developed and will soon be commercially available. Another advancement is that new types of batteries will be rechargeable in as little as five minutes; however, there remains an inverse relationship between charging time and the number of times a battery may be recharged. Stated another way, the faster a battery can be recharged, the less the number of times it will take a recharge. Even these issues are likely to be overcome in the next two to three years and it is currently estimated that by 2030 roughly 65% of the all cars in the U.S. will be powered by electricity alone. Even this estimate might be conservative if solar films are incorporated into EVs as a means of recharging the vehicle’s battery.

  There is clearly a tendency to focus alone on the costs of producing a kilowatt of electricity (i.e. the costs of creating and operating the system of producing that electrical energy). This explains why coal remains the dominant fuel for generating electricity around the world as the costs of combatting global warming are difficult to estimate and are rarely considered. Battery technology also entails some back-end expenses in the form of the costs of disposing of spent batteries. To address this problem, ways of extending the lives of spent batteries are being developed as well as ways of recycling the components used in constructing EV batteries.

Despite these new developments in solar and battery technology, the quest of eliminating the use of fossil fuels is still a long way from being realized. As of 2021 fossil fuels by far remained the dominate source of energy consumed in the U.S. In particular, petroleum represented 36%, natural gas represented 32 % and coal represented 11%. All renewable sources of energy (which also includes nuclear fission, hydroelectric and geothermal) together only represented a mere 12% of the energy consumed in the U.S. and wind and solar energy represented a scant 3.25% and 1.5%, respectively. To eliminate the use of fossil fuels these technologies will have to undergo further improvements so they can be used to power homes, factories and commercial buildings. It will also require major investments in energy transmission systems.

You have undoubtedly heard or read that history was recently made at the Lawrence Livermore National Laboratory earlier this month when a nuclear fusion reaction took place that produced more energy than it took to start the reaction. This is clearly an important achievement that could have important ramifications for the future because nuclear fusion offers the promise of creating vast amounts of energy while occupying a small space and leaving no contaminating residue. Still, it will take several decades, not years, to make fusion technology commercially viable. Unfortunately, we are in a race to restore our environment before it is rendered uninhabitable by global warming which means that our attention and resources must be focused on those forms of renewable energy that might be brought to fruition in a more timely manner.

Just as the Trump administration used the power of the federal government to speed the creation of the mRNA Covid-19 vaccines that have saved millions of lives, the Biden administration is pouring money into research and development projects that will speed the world’s transition to renewable forms of energy. Virtually all of the developments discussed above were produced by universities and research entities funded by governments, not by private enterprises. This is not only an appropriate undertaking for governments, it is a necessary measure. Admittedly, privately-owned companies act with greater efficiency than governmental entities, but the urgency of time rarely is factored into their strategic plans. More importantly, for the past 150 years private industry has been leading our nation away from developing renewable sources of energy.

The race to mitigate the effects of global warming also has two other important ramifications. The nations that develop the technology to combat global warming will also create the industries to achieve that goal and those industries will power those nations’ economies for the next generation. By contrast, those nations, like Russia and the oil-rich kingdoms of the middle east, that continue to rely heavily on their production of fossil fuels will experience drastic declines in their economies and standards of living.