Clean Energy- Quick facts

Renewable energy renews it self – it doesn’t deplete, can be used repeatedly and once the infrastructure is in place, it becomes practically free and pays for itself after some time – also it’s pollution-free. Come to think of it even fossil fuels like petroleum and coal can also be considered renewable sources…only if we can wait for another ice age!

According to a number of estimates, the world population will reach 9-10 billion people by 2050 and so the global energy demand will also rise to 2-3 times the current consumption. So what are the carbon mitigation measures that have the potential to transition us into the carbon constrained world?

Naturally, the fossil fuels alone will not fulfill that demand –not because we will reach ‘peak oil’ or run out of these resources. Oil is still in plenty – only in places hard to get. Coal is also readily abundant. But because these cause green house gas emissions, we need a combination of renewable, nuclear, fossil fuels and carbon capture and storage (CCS) going into the sustainable energy mix. Sun always doesn’t shine and wind always doesn’t blow…and our needs are 24×7! Here’s a quick primer assimilated from various sources.

Solar power

  • Germany is the leader in solar power production
  • Solar produces 8600 times more energy than humans need, capturing it is the challenge
  • Photo voltaics are the semi-conductors made of Silicon (most widely used) that converts solar rays into electrical energy.
  • Silicon in raw form is not expensive, but converting it to be used in photo voltaics is.
  • Solar is regional in nature and weather dependent
  • Capacity factor problem (how much energy it can store when the sun is shining)
  • High land use- 5 acres land/ MW
  • High installation cost

Wind Power

  • US and China lead in wind power
  • Wind provides 50 times more energy than humans need- capturing it is a challenge
  • 1 wind turbine produces 2-3 MW. A typical coal fired plant generates 800MW…so, humungous land use for a wind farm
  • Capacity factor is low(about 33% is useful energy)
  • Needs a back up energy source
  • Can be built off-shore on the sea
  • High land use – 50 acres/ MW

  Bio-mass – Corn ethanol, Cellulosic ethanol, wood chips, garbage etc

  • Brazil leads in bio-fuels, US is 2nd.
  • Bio-mass produces 6 times more energy than human need – at all the plants in the world used at 100% efficiency
  • Corn ethanol eats into the food chain and bio-diversity resources
  • Cellulosic ethanol – by burning garbage, wood chips…problem is the fuel density. Once all garbage and chips are burnt, garbage needs to be transported to the facility…makes it expensive and not a sustainable fuel.
  • High land use: 500 acres/ MW

Nuclear Power

  • Provides 16-20% of world’s electricity
  • Capable of major expansion with stable base-load supply
  • Currently 450 reactors in 31 countries exist keeping 3 billion tones of CO2 out of atmosphere
  • Challenge of nuclear waste to be buried in deep saline formations. Though some countries like France and Japan recycle more than 90% of their nuclear waste.
  • Thorium reactors and Fast Reactors – China and India are looking at 700 of these in the coming years. There is a ‘Nuclear Renaissance’ going on with Sweden, Finland, Britain, Italy, India, China and Japan going for these. Even Japan plans to go 60% nuclear from its current 30% usage.

Hydrogen

  • Doesn’t exist by it self. Needs to be extracted from water (H2O), which is currently an expensive process.
  • Widely being used in fuel cells and batteries
  • Huge storage required
  • High in energy yet causes no pollution – used to fire space shuttles into space

Tidal/Wave Energy

  • Clean source of energy but geographically limited
  • Works with the rise and fall of sea level – high tide to low tide
  • Security of supply is an issue
  • Wave energy needs only 1/200 the land area of wind and requires no access roads
  • Low infrastructure costs

 Carbon Capture and Storage (CCS) aka Clean coal technology

  • Keep operating the coal-fired power plant and sequester the CO2 emissions
  • Carbon is captured – pre combustion/post combustion and stored in deep saline formations, and oil reservoirs
  • Currently being done at places like North Sea- Noway (most effective), N.America, Europe, middle of Sahara desert and parts of China and Australia
  • Long terms affects are not known on leaks and water tables
  • CCS will add to the electricity bill users pay – cost has to be lower than coal
  • Cost of technology is it self up to 40% of the energy produced by a power plant

Some of the statistics may vary. The idea is to get more out per square km. The attraction to go for unconventional fossil fuels is also there. Even if there is a price on carbon, there is lot of Shale gas and oil left to be extracted. Current oil companies like BP, Shell, and others have investments in clean technologies, but will not give up the already mature oil industry in near future.

Surely, no one technology is a silver bullet to the energy needs. It’s got to be a combination of the above. Currently, only 2-3% is renewable energy. All the above technologies are experiencing a growth in terms of installed capacities. But whatever it is, it needs to be accessible, affordable, and a robust system of energy to meet our growing needs.

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