The reading notes record thoughts from things I read. 這網誌是我的一些閱讀後的思考和摘要記錄。My website 我的網頁: http://raympoon.playgroundhk.com

Renewable energy

Renewable energy has been a buzz word for several decades.  In the 1970s, there was a prediction that by 2000, 33% of America’s energy would be provided by small, decentralized renewable sources.  In 2008, Al Gore claimed that the country’s entire electricity supply would be re-powered within a decade.  In 2009, science journal published a plan on how to achieve sustainable energy by 2030.  All these turned out to be hot air spoken by politicians.  Scientific American in the first issue of 2014 posted an article explaining the realistic situation, and why renewable energy is still unable to take off.

The world underwent several changes of global energy source since human knew how to use fire.  The first fuel used was wood and plant.  It was until the middle of the 19th century that coal was mined in a large scale and used in industries.  Despite the great efficiency of coal over wood, it took about 60 years for coal to get to the point of providing 50% of the world’s energy needs.  The next breakthrough was crude oil.  It was brought into use at the beginning of the 20th century.  It also took 60 years for the consumption to reach 40% of world energy supply.  Coal is still being used in many large facilities.  Then came natural gas in the middle of the 20th century.  It has an advantage of being cleaner and more abundant than oil.  In 60 years, it supplied 25% of the world’s energy.  In 2012, modern renewable energy sources only account for 3.4% of the world’s energy.  From history, even with good intention and good effort, it is unlikely that renewable energy would provide a significant portion of the world’s energy in the next few decades.

From a realistic point of view, there are several reasons that modern renewable energy would still need quite some time to become mainstream energy supply.  Of the various types of modern renewable energy, only wind and solar energy have the potential of future growth.  However, the nature of the energy sources, sunlight and wind, make them unreliable to be used as a continuous supply.  Efforts have been made on the storage of surplus energy to be used between gaps.  But most of them are not scalable to be used at the industrial scale.  Unless there are major breakthroughs in technology, the pace of growth will remain to be slow.

Another barrier for growth is the infrastructure changes required to accommodate the distribution of renewable energy.  Both wind and solar energy generation require large area of land in remote area.  For the energy generated to be integrated with the power supply grid, new infrastructure is required to be built.  They usually are met with local resistance on which much time and effort are required to resolve.  The amount of investment needed to achieve effective distribution is very large, and could be larger than the energy generation installation.  At present, the pace of building such infrastructure has been very slow.

In replacing the present energy sources, it has to be borne in mind that the existing facilities are well established, working efficiently, producing good profits and that very heavy investment has been made on them.  Unless renewable energy could provide much greater benefits, and could be introduced with seamless transition, investors would not easily abandon their valuable assets and take unnecessary risks.

All these factors aside, the author pointed out one major reasons is the very rapid expansion of world energy consumption.  The demand increase is so fast that any new technology would not be able to fill up the void quickly.  Existing technology has to be deployed intensively to meet demand.  Progresses in developing countries show that fire-powered plants and nuclear plants are being built much faster than renewable energy facilities.

To speed up the use of renewable energy, the authors proposed that certain policies could be introduced.  These include providing funding for research into many technologies to facilitate competition, devising pricing mechanism to reflect the environmental and health costs imposed by energy sources, and improving energy efficiency worldwide to curb demand growth.