are the most common nonrenewable source of energy.

They are derived from the REMAINS OF DEAD PLANTS AND ANIMALS millions of years ago, sometimes exceeding 650 million years.

include coal, oil (petroleum or crude oil), and natural gas.

is a type of fossil fuel that is a nonrenewable source of energy.

It is a solid rock form of fossil fuels that originated from DEAD PLANT AND ANIMAL MATTER that piled up in LAYERS over millions of years ago.

Its material is primarily composed of carbon and variable quantities of other elements such as oxygen. hydrogen, nitrogen, and sulfur.

Coal usually occurs in rock strata as layers or veins called —. It can be extracted using two methods: —2

is the process of COAL FORMATION wherein the PLANTS in a swamp on the edge of a sedimentary basin, such as a lagoon or a lake, underwent CHEMICAL DECAY due to tectonic activities or other natural phenomena, which causes the level of water to rise and then cover and ultimately kill the vegetation.

The accumulated plant debris was buried UNDER LAYERS OF MUD and SAND in a process known as —, which occurs over a long period of time.

The most favorable conditions for the formation of coal occurred during the — (360 million to 290 million years ago).

This is PARTIALLY DECAYED MATTER found in swamps with low heat and low levels of carbon.

It contains low heat and sulfur content, limited supplies in most areas It contains about 40% carbon.

it contains less moisture than lignite, with 35- carbon content -45%

It is frequently used as fuel due to its HIGH HEAT AND LARGE SUPPLY. It has high sulfur content and 85% carbon.

it is a HIGHLY PREFERRED FUEL due to its high heat content and low sulfur content. It contains about 95% carbon

, also known as —, is a liquid type of fossil fuel composed mostly of hydrocarbons.

It is considered one of the most important sources of energy in the world.

Like coal, — originates from the remains of organisms such as marine plants, algae, and bacteria that existed millions of years ago.

These can be extracted by DRILLING ON LAND OR AT SEA. It can also be extracted through a method of surface mining, such as strip mining in the case of tar sands oil and oil shale.

Once extracted, this oil will be transported to refineries to transform it into usable fuel such as PROPANE, KEROSENE, AND GASOLINE.

It can be refined to make polymers for the production of PLASTICS AND PAINT PRODUCTS.

It is formed when the organic material (dead marine organisms) SETTLED ON THE SEAFLOOR faster than it could decay as sediments buried the material. As this material got buried deeper, the heat and pressure beneath the ground gradually transformed this organic material into oil by breaking down complex organic molecules into smaller hydrocarbon molecules.

In the Philippines, oil deposits are typically found in —.

, like other types of fossil fuels, originates from the remains of plants, animals, and microorganisms that lived millions of years ago.

It is a colorless and odorless hydrocarbon gas made up mainly of methane (CH).

— are gases found in POROUS OR PERMEABLE ROCK BEDS or mixed oil reservoirs, which can be extracted through drilling.

On the other hand,— are those that are too difficult or expensive to extract and require a stimulation technique, such as fracking.

is derived from the sun's radiation and converted into electrical energy through photovoltaic or solar panels.

Although this energy source is free and can last for a billion years, its production cost and energy storage are high.

It also needs a vast area of land to set up the— .

is a type of energy derived from GRASSY and WOODY plants, agriculture, and forestry residues, oil-rich algae. and other organic wastes.

The energy from types of ORGANIC MATTER is transformed into usable energy to produce HEAT, ELECTRICITY, AND FUEL for various modes of transportation.

It is a good alternative to fossil fuels because it is more eco-friendly and can easily be replenished in a short period of time.

Like fossil fuels, it is a rich source of carbon and hydrogen.

is produced from turbines in windmills- aerogenerators.

It is used to generate ELECTRICITY and pump GROUNDWATER.

It is an indirect form of solar energy.

This form of energy is expensive to produce and can only be used in windy areas.

Because — can be unpredictable, it is not a very reliable source of energy.

is when heat from cooling magma heats groundwater near Earth's surface.

It is a type of renewable resource because heat is continually produced underneath Earth's surface.

It is harnessed by capturing the energy from the heated water.

A large amount of energy can be generated only in geologically active zones. It is used to heat/cool houses and household water supplies.

— also known as —, uses the force of falling or moving WATER to produce electricity by converting the water's kinetic energy into mechanical or electrical energy

This type of energy is one of the PRIMARY SUPPLIERS OF ELECTRICITY in the world due to its reliability and low-cost production.

There are three main types of hydropower plants:

This type of hydropower plant works as a BATTERY for other sources such as solar and wind.

When there is an excess supply, it STORES ENERGY by PUMPING WATER uphill to a reservoir at a higher elevation. During periods where the demand for the supply is high, the water is pumped back to the lower reservoir and drives the turbine to generate electricity.

a facility that may NOT require the use of a DAM because, generally, it does NOT IMPOUND WATER in a reservoir. Instead, it channels a PORTION of a RIVER through a PENSTOCK or CANAL.

This is usually a large hydropower system capable of producing electricity up to more than 10 megawatts.

A DAM IS USED to store water in a reservoir that can be released as required to meet the demand for supply or maintain a constant reservoir level. Water released from the reservoir flows to a turbine to activate the generator and produce electricity.

Advantages of Hydroelectric Power - It emits — because fuel is not burned during the production of electricity. The water provided to power the power plant is a — resource. It has comparatively — operation and maintenance costs. It is proven to be a — energy source.

Disadvantages of Hydroelectric Power Investment cost is —. It is dependent on — because it uses water as its source of energy. It results in the — of wildlife and local inhabitants.