GEOTHERMAL ENERGY

NIGERIA’S FUTURE ENERGY

Geothermal energy: An overview

• Energy stored in the earth• Originates from planet’s formation and

radio active decay• Hot springs and space heating are the

earliest forms of geothermal energy used.• Today, 24 countries across the globe

generate about 11,400 megawatts (MW) of electricity

Do you know?

• China, England, Italy and France are the first to explore geothermal energy commercially

• The world’s first commercial geothermal power plant was built in Italy

• The pacific gas and electric in Geyser California is the first successful geothermal power plant in the United States.

Global Production

• The United States lead the world in geothermal electricity production with 3086 MW followed by Philippines with 1904 MW

• The largest group of geothermal plant in the world is located in California

• Kenya and Ethiopia are the only Africa countries using geothermal power plant to produce electricity.

• Chevron corporation is the world's largest private producer of geothermal electricity

Geothermal Resource

• Heat from magma produced as a result of radio active decay serve as the main resource in geothermal energy.

• It is Suitable in Volcanic areas with high underground temperatures which are earthquake prone.

• There is a steady supply of milder heat—useful for direct heating purposes—at depths of anywhere from 10 to a few hundred feet below the surface virtually in any location on Earth. Now that is good news.

AIM

• To determine if geothermal energy can work properly in Nigeria just like other nations.

• To devise a suitable method that should adopted in the industrial generation of electricity.

Hypothesis

• Nigeria certainly has the resources and finance, if African countries like Kenya and Rwanda can go for geothermal energy. Why should Nigeria be left behind.

Design

• Geothermal plants drill holes into each crust of about 5 to 6 km deep to effectively capture the steam

• There are three types of designs for geothermal plants

• Dry steam• Flash steam• Binary steam

Design contd.

• In dry steam, the steam directly winds the turbines that generates electricity.

• In flash steam, the Fluid at temperatures greater than 182°C is pumped into a tank at a much lower pressure, causing some of the fluid to rapidly vaporize, or "flash." The vapour then drives a turbine, which drives a generator.

• in binary cycle plant, a low temperature geothermal fluid and a binary reagent (isobutane) passes through a heat exchanger. The isobutane then vaporizes and turns the turbines.

Design contd.

Significance

• Geothermal energy has the potential to play a significant role in moving Nigeria towards a cleaner, more sustainable energy system. It is one of the few renewable energy technologies that—like fossil fuels—can supply continuous, base-load power. The costs for electricity from geothermal facilities are also declining.

innovation

• For dry places like Yola and other northern states of Nigeria, the  enhanced geothermal systems (EGS) or "hot dry rock“ can be adopted. Here, the hot rock reservoirs, are first broken up by pumping high-pressure water through them. The plants then pump more water through the broken hot rocks, where it heats up, returns to the surface as steam, and powers turbines to generate electricity.

Economic cost

• Drilling accounts for half of the cost.• Drilling alone cost about 1.5 billion naira

with 25% failure rate.• Plant construction cost about 300 to 700

million naira per megawatts of electricity.• It cost 600 million naira per megawatts of

electricity for enhanced geothermal systems.

Advantages

• Geothermal energy does not produce any pollution, and does not contribute to the greenhouse effect.

• The power stations do not take up much room, so there is not much impact on the environment.

• No fuel is needed.• Once you've built a geothermal power station,

the energy is almost free.It may need a little energy to run a pump, but this can be taken from the energy being generated.

Disadvantages

• The big problem is that there are not many places where you can build a geothermal power station. You need hot rocks of a suitable type, at a depth where we can drill down to them. The type of rock above is also important, it must be of a type that we can easily drill through. 

• Sometimes a geothermal site may "run out of steam", perhaps for decades. 

• Hazardous gases and minerals may come up from underground, and can be difficult to safely dispose of.

Conclusion

• In conclusion, geothermal energy is a safer alternative of energy due to its sustainability and affordability .

Reference

• U.S. geothermal power plants, Geothermal Energy Association

• Jump up to: Low-Temperature and Co-produced Geothermal Resources. U.S. Department of Energy.

• Geothermal Economics 101, Economics of a 35 MW Binary Cycle Geothermal Plant