May 06

Solar Renewable Energy – Is Solar Energy Renewable and Can it Meet our Energy Needs?

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Solar Renewable Energy - Is Solar Energy Renewable and Can it Meet our Energy Needs?

Solar renewable energy, is solar energy renewable is a question many people ask us. It is also a question which is both easy and hard to answer, if that makes sense. It is clean energy, and it is sustainable, and at face value it is renewable, as the sun shines every day. However it is not renewable in the traditional sense that it can’t be replaced or regrown, like biofuels. However it is fairly consistent, and is present every day for up to 16 hours a day in some areas, and at the northern and southern poles, sometimes is visible 24 hours a day, which lead to great opportunities to harness that energy. For more on this aspect, see Renewable and Non Renewable Energy Sources.

The Earth receives an incredible supply of solar energy. The sun, an average star, is a fusion reactor that has been burning over 4 billion years. It provides enough energy in one minute to supply the world’s energy needs for one year. In one day, it provides more energy than our current population would consume in 27 years. In fact, “The amount of solar radiation striking the earth over a three-day period is equivalent to the energy stored in all fossil energy sources.”

There are a few downsides however to solar energy. One of which is it is not always there, the sun and solar energy that is, like coal or water for hydro-power. We have clouds and storms, which can either reduce or block us from collecting the energy, and then we have nighttime, in which obviously there is no sun at all. The other problem that could be associated with the sun is that it will not last forever, which could deem it non-renewable, however the expected life time of our sun is estimated at billions of years, so that is something we won’t have to worry about for a long, long time. There are advancements in technology though that could eliminate the hours of no sunlight problem, as Space solar power and Space solar power plants could be possible in as little as 10 or 20 years. See Solar Power Advantages and Disadvantages for more in depth analysis of these issues.

Space solar power plant satellite

Space solar power plant satellite

Solar renewable energy storage

Solar renewable energy storage

Another problem associated with solar renewable energy is storage. Since the source is not available at night time, energy storage is important because our demand for energy is 24/7, not just during daylight hours. This is where storage of the harnessed power becomes critical, as they can store excess energy from the day to use during the periods of no sunlight. This problem can also be associated with wind power too. Currently, there are gains being made in the storage technologies for solar energy, and grid-scale energy storage is gaining momentum as batteries, flywheels, compressed air systems are advancing and can regulate frequency and ancillary services with the same efficiency of “spinning reserves” from coal and gas fired power plants.

According to Brad Robers, the executive director of the Electricity Storage Association (ESA);

“We still hear people say storage isn’t ready for prime-time, but that isn’t the case because we already have 20-MW storage plants being built all over the country.”

Nevada solar farm

Nevada solar farm

Serpa Portugal Solar Farm

Serpa Portugal Solar Farm

Duke Energy is installing the country’s largest battery storage system, a 36-MW unit, near its 153-MW Notrees Windpower Project. The system will regulate frequency and store excess energy for use during peak demand. In Texas, where nearly 11,000 MW of generation comes from wind farms, grid operator Electric Reliability Council of Texas relies on standby gas turbines and steam coal generators to ramp frequency up or down as wind generation changes.

Greg Efthimiou, spokesman for Duke Energy, which operates more than 1,000 MW of wind farms stated:

“We are interested in the potential of battery storage to be a game changer in our industry in both regulated utilities and commercial businesses.”

Energy companies don't want us to leave them for solar because it is free!

Energy companies don't want us to leave them for solar because it is free!

Solar energy is a free and for the most part, an inexhaustible energy resource, yet harnessing solar renewable energy is a relatively new concept. The ability to use solar power for heat was the first discovery made by Swiss scientist Horace de Saussure, who built the first thermal solar collector in 1767, which was later used to heat water and cook food. The first commercial patent for a solar water heater went to Clarence Kemp of the US in 1891. This system was bought by two California executives and installed in one-third of the homes in Pasadena by 1897.

Producing electricity from solar energy followed and was the second discovery regarding harnessing the energy of the sun. In 1839 French physicist Edmund Becquerel realized that the sun’s energy could produce a “photovoltaic effect” (photo = light, voltaic = electrical potential). In the 1880s, selenium photovoltaic (PV) cells were developed that could convert light into electricity with 1-2% efficiency (“the efficiency of a solar cell is the percentage of available sunlight converted by the photovoltaic cell into electricity”), but how the conversion happened was not understood. Photovoltaic power therefore “remained a curiosity for many years, since it was very inefficient at turning sunlight into electricity.” It was not until Albert Einstein proposed an explanation for the “photoelectric effect” in the early 1900s, for which he won a Nobel Prize, that people began to understand the related photovoltaic effect.

Solar Renewable Energy

US Energy sources breakdown for 2008

US Energy sources breakdown for 2008

Solar energy technology advanced to roughly its present design in 1908 when William J. Bailey of the Carnegie Steel Company invented a collector with an insulated box and copper coils.” By the mid-1950s Bell Telephone Labs had achieved 4% efficiency, and later 11% efficiency, with silicon PV cells. From then on, interest in solar power intensified. During the late 1950s and 1960s, the space program took an active role in the development of photovoltaics. “The cells were perfect sources of electric power for satellites because they were rugged, lightweight and could meet the low power requirements reliably.” Unfortunately, the cells were not practical for use on earth due to the high cost of making them efficient and lightweight, so further research was necessary.

Efficiency has improved and surpassed 40 percent with multi-junction solar cells in lab environments, most mass-produced cells can only boast a conversion rate of around 15 percent. Now SunPower Corp., a Silicon Valley-based manufacturer of high-efficiency solar cells, solar panels and solar power systems, has claimed a new world record solar cell efficiency of 24.2 percent.

Solar park with visitors

Solar park with visitors

Solar renewable energy building near park

Solar renewable energy building near park

Solar power plant farm

Solar power plant farm

Solar renewable energy may have had great potential at one point, but it was for the most part shelved when coal and other fossil fuels became more readily available and cheaper. Only in the last few decades when growing energy demands, increasing environmental problems and declining fossil fuel resources have given us reason to look to alternative energy options and we are only recently focusing our attention on truly exploiting this tremendous natural, renewable, sustainable, free resource. For instance, the US Department of Energy funded the installation and testing of over 3,000 PV systems during the 1973-1974 oil embargo. By the late 1970s, energy companies and government agencies had invested in the PV industry, and “a tremendous acceleration in module development took place.” Solar energy improvements were again sought during the Gulf War in the 1990s.

Solar energy, which is radiant light and heat from the sun, has been utilized by humans since ancient times using a wide array of continuously expanding technologies. Current solar energy technologies include solar heating, solar photovoltaics, solar thermal electricity and solar architecture, all of which can make significant contributions to aid in solving some of the most urgent problems the world now faces due to climate change and greenhouse gas emissions of which the primary contributors are coal fired power plants.

solar farm

solar farm

large solar farm

large solar farm

Solar power is considered the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. PV converts light into electric current using the photoelectric effect.

Solar technologies can be categorized as either passive solar or active solar depending on the way they capture, convert and distribute the solar energy they collect.

Solar thermal energy plant Barstow CA

Solar thermal energy plant Barstow CA

Active solar technologies include the use of photovoltaic panels and solar thermal collectors to harness the energy from the sun. In addition to photovoltaic panels, active solar techniques uses pumps and fans to convert sunlight into useful outputs. Active solar technologies increase the supply of energy and are considered supply side technologies.

Passive solar technology include orienting a building in regards to the position of the Sun, selecting proper materials with favorable thermal mass or light dispersing properties, and designing interior and exterior spaces that naturally circulate air. Passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.

France solar panel farm

France solar panel farm

Thermal solar power farm

Thermal solar power farm

The International Energy Agency in 2011 claimed that:

“The development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase nations energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating climate change, and keep fossil fuel prices lower than otherwise. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared.”

Average Surface Solar Energy (Watt/m 2 )

Average Surface Solar Energy (Watt/m 2 )

In 2011, the International Energy Agency said that solar renewable energy technologies such as photovoltaic panels, solar water heaters and power stations built with mirrors could provide a third of the world’s energy by 2060 if politicians commit to limiting climate change. The energy from the sun could play a key role in de-carbonizing the global economy alongside improvements in energy efficiency and imposing costs on greenhouse gas emitters. “The strength of solar is the incredible variety and flexibility of applications, from small scale to big scale”.

US solar energy potential

US solar energy potential

India solar energy potential

India solar energy potential

Future of solar renewable energy is bright!

Future of solar renewable energy is bright!

While the question of whether or not solar energy is renewable, I think that it is safe to say that it is renewable, and sustainable and an important part of our energy future that should not be ignored or wasted anymore. As technologies advance and new ones are developed, I am sure that solar renewable energy will play a significant role in our future energy needs! Peace my friends!

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