Biomass energy

Biomass energy can be used for lighting, cooking, space heating, water heating and to fuel vehicles. Biomass energy is not usually on people’s minds as alternate energy sources such as wind, solar or hydropower energy are when thinking about renewable sources of energy. Notwithstanding, it represents very common and available forms of energy indeed. And it can reduce global warming.

Biomass energy can really come from so many sources, such as:

• wood
• woodchips
• paper
• trash
• agricultural crops
• animal waste (slaughtering)
• and others

Bio energy is renewable and solar in origin. It is renewable as the materials it comes from can be replaced, or grown, in a short period of time. Biofuels do not add to the net amount of CO2 already present in the atmosphere. This is because carbon in the biofuel is locked up only for the short period of time in plants or animals and can be considered as recycled as newly growing crops and animals once again take up the atmospheric CO2 used in burning.

Several technological processes can be used:

· Combustion means that biomass is burned, similar to coal and oil, to make electricity. When mixing biomass with coal, this co-firing process is very efficient. Solid municipal waste is also burned to generate electricity

· Pyrolysis is a chemical process of decomposition of biomass materials. It is a heating process without the involvement of oxygen. The recycling of used vehicle tyres uses pyrolysis.

• Gasification involves processes that turn parts of solid biomass materials into gas.

Geothermal Energy

Geothermal energy is a powerful energy source, right under our feet. Just as people in cold countries sometimes slept on top of their stoves at night, we live on top of a giant heater: the Earth.

"Geo", a Greek word, means "Earth." "Thermal" means "heat."

The deeper into the Earth, towards its centre, the hotter it gets.

Why is it so hot insides of the Earth? This heat comes from the Earth's heart is hot solid, iron core. Around the solid core is the molten core, which is magma. Its surrounding mantle is made of magma and rock. Capping all this is the Earth's crust.

All this hot activity under our feet goes back right to the Big Bang, some 14 billion years ago. The Earth first formed more than 4 billion years ago from these building blocks: gases and solid matter. The Earth has cooled down during that time, but is still simmering away underneath. Heat flows from the Earth's core into the mantle all the time. That's our earthy energy source: the Earth's heat.

Generally accepted estimates are of temperatures around 3,982 Celsius degrees at 4,032 km deep. More recent estimates say that at the boundary between the Earth's core and its mantle, heat measures around 3,677 Celsius degrees. That's at a depth of around 3,000 km.

Today's Earth's crust is of course the land that we live on. Where the mantle is close to the surface geothermal energy can be observed in the form of volcanoes, geysers, hot pools and mud pools. Iceland, New Zealand, Russian Kamchatka and America's Yellow Stone Park are known for their geysers and hot pools. So, these underground energy reservoirs are ancient in their origin, and are powerful, well-available sources of energy.

Now this source of heating energy has been used by people for many centuries. Hot springs have long been used for cooking and for healing properties. At ancient Pompeii the Earth's energy, carried by hot water, heated its buildings, using a simple form of geothermal heat pump.

Another way of getting at this energy is facilitated by humans. It involves injecting water at high pressures deep into porous heated rock formations and retrieving it as hot water.

Modern human use of geothermal energy derives two types of power.

· Using hot water directly

· Converting heat into electricity