Fossil fuels currently supply roughly 86% of worldwide commercial energy. These fuels are easy and convenient to use, but they have environmental, political, and social costs. To reduce or even eliminate dependence on fossil fuels or nuclear energy, these sources have to be used more efficiently and new technology for renewable sources needs to be relied upon.

Solar energy is a vast and significant resource. Solar energy is responsible for other types of renewable resources such as wind power, hydropower, and tidal energy.

None of the renewable sources mentioned here are likely to completely replace fossil fuels, however, it is possible to use them in combination to make a significant difference in our energy needs.

Transportation is one of the biggest areas of energy use today, but it is also the area that shows the most promise for conservation and new technology.

Hybrid coal-solar plant

Incandescent

CFLs: Compact Fluorescent Light Bulbs

The best way to conserve energy is to improve energy efficiency.

Energy Efficiency is the measure of how much work we can get from each unit of energy we use.

84% of all of the commercial energy used in the US is wasted. 43% of this energy is wasted unavoidably because of what the second law of thermodynamics has taught us.

This 43% is wasted unnecessarily, mostly due to the inefficiency of incandescent lights, furnaces, industrial motors, coal and nuclear power plants, and motor vehicles.

Incandescent

Furnace

Motor

• Energy is transferred in natural processes. The study of these transfers is known as thermodynamics. While there are three laws, the only two that we’ll be using are the first and the second. Here is a summary:

The First Law:Energy is neither created nor destroyed as it moves through natural systems.

The Second Law:Energy is constantly degraded to lower forms as it is used. Entropy, a state of disorder, increases in natural systems.

• The ability to do work

Potential: Energy that is storedLake Mead is behind the Hoover dam, and represents a huge amount of potential mechanical energy

The energy stored inside coal, oil and natural gas (before it is burned) is potential chemical energy, just as the burger on your plate is…before you eat it.

In a perfect world, all the energy in that hamburger would be converted to something useful. Energy in=Energy out. This is, of course, not what happens. (2nd Law of thermodynamics)

Kinetic Energy: Energy in motion

On the American side of the border, the Robert Moses Niagara Power Plant and the Lewiston Pump Generating Plant, together generate more than 2.4 million kilowatts of electricity, enough to power 24 million 100-watt light bulbs.

Kinetic energy and electricity production is accomplished with the help of a technological breakthrough called a turbine. A turbine is a rotary engine that extracts energy from a fluid flowing and converting it into useful work, with the exception of photovoltaic cells, it is this technology that we employ to generate nearly ALL of our electricity.

Kinetic energy is based on an object’s mass and speed or velocity. We can use these “moving objects” to generate electrical energy.

So since energy in, rarely if ever is equal to energy out, we have to set a definition for efficiency.

Energy many times gets lost to the ecosystem in the form of thermal energy. (heat)

Energy efficiency is basically a measure of the usefulness of energy…using as much as you can without losing any!

The closer you can get to energy in= energy out, the more efficient the system is. %E=work out/work in · 100%Your jobs as adults will be to find ways to efficiently use the energy Earth has available.

Another reason for energy inefficiency is that so many of us live and work in leaky and poorly insulated buildings.

This thermal image shows the poorly insulated home losing heat energy.

The US and Canada, as well as most developing countries are extremely wasteful of energy resources. Only 5% of us rely on mass transit.

Japan, Germany and France, however, are two to three times more energy efficient than the US is.

Widely Used, and Largely Wasteful…• Incandescent light bulbs: Use only 5-10% of the electricity they draw to produce light. The rest is wasted as heat energy.

• Motor Vehicles with internal combustion engines waste about 94% of the energy available in fuel.

• Nuclear power plants producing electricity wastes about 83% of the energy in its nuclear fuel and probably 92% when we add in the additional cost of mining and processing the uranium, and storing the waste for thousands of years.

Resistance heating occurs when the passage of an electrical current through a conductor releases heat.

• Coal-fired power plants waste 66% of the energy released by burning coal to produce electricity and probably 75-80% if we include the energy needed to mine, and transport it to the plant.

How efficient are green plants at absorbing the sun’s energy? How much of the sun’s energy that strikes the Earth’s surface gets converted into carbohydrates by plants to feed consumers?

Would you be surprised to learn that less than 1% of the energy of the sun actually goes into manufacturing carbohydrates!

Even plants are inefficient!

By contrast, with passive solar heating, only about 10% of the incoming solar energy is wasted.

Passive Solar Energy homes are successful at dramatically cutting heating energy costs while providing a healthy environment to live in.

• Biodiesel reduces emissions of CO, and CO2

• Higher net energy yield

• Reduced hydrocarbon emissions

• Better gas mileage (40% better)

• Potentially renewableHow could biodiesel possibly be non-renewable?

Active solar technologies are employed to convert solar energy into usable light, heat, cause air-movement for ventilation or cooling, or store heat for future use. Active solar uses electrical or mechanical equipment, such as pumps and fans, to increase the usable heat in a system.

Biodiesel is produced from vegetable oil extracted from soybeans, rapeseeds, sunflowers, oil palms, and jatropha shrubs. We can also use animal fats to produce biodiesel.

We can even use waste oils and fats from restaurants to make biodiesel.

Algae grow naturally all over the world. Under optimal conditions, it can be grown in massive, almost limitless, amounts. Half of algae's composition, by weight, is oil. Scientists have been studying this oil for decades to convert it into algae biodiesel -- a fuel that burns cleaner and more efficiently than petroleum. Algae biodiesel manufacturers are building biodiesel plants close to energy manufacturing plants that produce lots of carbon dioxide, because the algae use CO2 to photosynthesize. Recycling carbon dioxide reduces pollution.