Renewable energy

Renewable energy comes from resources that can be renewed in a reasonable amount of time and not from fossil fuels, which will run out. Renewable energy includes wind power, solar power, hydropower, biomass, biofuel and geothermal energy. I have already written detailed blog posts about wind power and biofuel so this is just a fairly quick post to summarize the remaining alternative energies that exist for humanity to use instead of crude oil.

According to renewable global status report, 19% of the global energy consumption in 2014 already came from renewable energy and 22% of all our electricity was generated from energy produced by renewable energy sources (Sawin, 2014). Worldwide investments in renewable energy were $214 billion in 2013 with particular interest in renewable energy shown by USA and China (Sawin, 2014). The main advantage of renewable energy is that production of energy this way is much more environmentally friendly and causes less GHGs emissions in comparison to the conventional crude oil recovery methods. Furthermore renewable energy is not geographically constrained unlike oil, deposits of which are only found in particular countries on Earth. Thus each country can generate one type or another of renewable energy making it independent of the volatile oil prices, economically more stable and secure as well as providing energy securities regardless of geopolitics conflicts occurring elsewhere in the world and making the country “green”.

Below there is a video of how renewable energy is produced by all the methods that I have not discussed in details however I feel like a little summary of each method is nevertheless required in this post. Firstly solar power produces energy by converting the thermal energy emitted by the sun and well as the light energy into electricity. This is mainly done using solar panels. Hydropower uses the kinetic energy produced by flowing rivers and oceans on our planet to convert it to electricity. This is done using dams and it is possible because water is much more dense than air thus any flowing body of it produces kinetic energy that can be converted and other types of energy making it more useful for humans. Biomass is the biological material that one gets from currently living or recently living organisms on our planet via either combustion thus converting biomass to thermal energy or by converting it to different forms of biofuels by biochemical processes. Finally geothermal energy uses the fact that the Earth’s core is much warmer than the surface and regardless of the season or atmospheric temperatures, the temperature below the surface is always warm. This is partially due to the radioactive decay of the minerals found below the Earth’s surface that release a lot of heat during the decay. Thermal energy derived from the decay can also be converted into electricity and other useful energies for the society.

Renewable energy has seen increased popularity in our society especially as oil prices are rising and crude oil is running out. Many more investments and research have been done into different types of renewable energy. Even the developing countries and emerging economies are now starting to explore the field of alternative energies treating it as long-term investments into the future. Below there is an example of an advert from a brochure in South Africa promoting renewable energy.

Figure 1.

Source. South African brochure advert promoting renewable energy.

Wind Power

One of the sources of renewable energy is wind power. The energy contained within wind has been utilized by humans for thousands of years starting with transport where wind power was used to fill sails and make the ships sail and continuing with agriculture- in wind mills. Today, wind power once again, is becoming reality. Wind spins wind turbines and produces electricity, which is an alternative source to energy, which we mainly obtain from fossil fuels. Whilst wind power is not the main source of renewable energy today, the demand for it sure is growing. Figure 1 below shows where our energy came from in 2009.

 Figure 1.

Source: Renewable Energy Policy,2011. Renewable energy share of global final energy consumption and the different methods of obtaining renewable energies and their share.

Although wind power currently does not represent a significant amount of the world energy, Renewable Energy Policy Report produced in 2011 reported that the market for it is rapidly expanding and in 2011 for the first time ever recorded, the majority of new wind power capacity was added in developing countries and emerging countries such as China (Renewable Energy Policy, 2011). Prior to that, wind power is mainly used in European countries such as Denmark, UK and Spain, as well as in the USA. Wind farms are now seen both onshore and offshore and investments are made into more wind power plants. Figure 2 below shows the rise of demand and energy generated by wind power.

Figure 2.

Source: Renewable Energy Policy,2011. Wind power, existing world capacity, 1996-2010.

The video below explains how electricity is produced from wind turbines.

However whilst there certainly are advantages to obtaining energy using this method, there are also some disadvantages. Below I provide a list of advantages and disadvantages of wind power.

Advantages:

• ·      Wind turbines only use 1-10% of the wind areas which allows for farming on the surrounding land (Fthenakis, 2009)- much less land is required compared to say, biofuels production.
• ·      The turbines don’t require anything except wind power to keep them going thus no emissions are produced and they are very environmentally friendly. J
• ·      The energy used for the construction of a turbine is re generated by one turbine within 6 months.
• ·      The lifecycle of a wind turbine is 25 years thus it can produce a lot of energy in those 25 year where each turbine can support up to 1219 homes per year.
• ·      Wind turbines provide the cheapest renewable energy.
• ·      Wind turbines also do not need any special conditions and can be used everywhere in the world thus they are abundant.
• ·      Finally each wind turbine produces the same amount of energy as 16,000 solar panels hence they produce plenty of energy.
• ·      Wind farms are cheap to operate.

Disadvantages

• ·      Wind turbines rely on wind to generate power and wind does not always blow. Although wind turbines spin 70-80% of the time, this still means that they are potentially unpredictable and one cannot rely on power purely from wind turbines alone unless power is stored (Holttinen, 2006). However the current storage methods available are very expensive.
• ·      Although wind farms are cheap to operate, they are also very expensive to build so governments don’t always want to invest in them, especially when there are cheaper and easier fossil fuel alternative still available.
• ·      The location of wind farms is often derelict open spaces that are far away from city centers, where energy is required therefore long transmission lines are required to get electricity to its final destination. These are expensive and provide visual pollution.
• ·      The wind turbines themselves provide visual and noise pollution thus not all members of the public support them. For example there were major protests against the wind turbines that were installed in three mountainous passes in California- the Altamount Pass, east of San Francisco; the Tehachapi Pass, northeast of LA; and the San-Gor-gonio Pass near Palm Springs as people believed the wind turbines ruined the scenery of mountainous landscapes (Gipe, 1993).

Considering all the advantages and disadvantages of wind power, I think it is safe to say that it is all just a matter of time until wind power becomes more widely used. The main disadvantages are costs and ramblings of the public who are unwilling to accept new things in their familiar landscapes thus these disadvantages are only significant whilst the oil prices remain low making building of wind farms expensive and the public having no troubles affording their energy.