The sun’s heat and light provide an abundant source of energy that can be harnessed in many ways. There are a variety of technologies that have been developed to take advantage of solar energy. These include concentrating solar power systems, passive solar heating and daylighting, photovoltaic systems, solar hot water, and solar process heat and space heating and cooling. Solar power can be used in both large-scale applications and in smaller systems for the home. Businesses and industry can... Read More

It seems impossible that a gallon of gasoline, which weighs about 6.3 pounds, could produce 20 pounds of carbon dioxide (CO2) when burned. However, most of the weight of the CO2 doesn’t come from the gasoline itself, but the oxygen in the air. When gasoline burns, the carbon and hydrogen separate. The hydrogen combines with oxygen to form water (H2O), and carbon combines with oxygen to form carbon dioxide (CO2). How Can A Gallon of Gasoline Produce 20 Pounds of Carbon Dioxide? A carbon atom... Read More

A hybrid car with a series configuration uses the heat engine or fuel cell with a generator to produce electricity for the battery pack and electric motor. Series hybrid cars have no mechanical connection between the hybrid power unit and the wheels; this means that all motive power is transferred from chemical energy to mechanical energy to electrical energy, and back to mechanical energy to drive the wheels. Here are some benefits of a series configuration: The engine never idles, which reduces... Read More

A hybrid electric vehicle (HEV) with a parallel configuration has a direct mechanical connection between the hybrid power unit and the wheels, as in a conventional vehicle, but also has an electric motor that drives the wheels. For example, a parallel vehicle could use the power created by an internal combustion engine for highway driving while using both the engine and electric motor power for accelerating. Some benefits of a parallel configuration are: A smaller engine provides more efficient... Read More

An energy storage system is an essential component in hybrid cars. Batteries used in hybrid cars should have high power (with high-peak and pulse-specific power), high specific energy at pulse power, high charge acceptance to maximize regenerative braking utilization, and long calendar and cycle life. See below to learn about hybrid car battery options, ultracapacitors (another energy storage device), and battery thermal management strategies. Lead-Acid Batteries Lead-acid batteries can be designed... Read More

Hybrid cars provide benefits to consumers, fleets, and the nation. These advanced cars cut fuel use and costs while maintaining performance, protecting public health and the environment, and increasing U.S. energy security. Cutting Fuel Use and Costs while Maintaining Performance Hybrid cars can drive 40 to 70 miles on one gallon of gasoline, much farther than a conventional car. Hybrid cars are cost competitive with similar conventional cars. What cost premiums there are for hybrid cars can be offset... Read More

Plug-in hybrid cars combine the benefits of pure electric cars and hybrid cars. Like electric cars, they plug into the electric grid and can be powered by the stored electricity alone. Like hybrid cars, they have engines that enable greater driving range and battery recharging. What is a Plug-in Hybrid Car? Plug-in hybrid cars can be charged with electricity like pure electric cars and run under engine power like hybrid cars. The combination offers increased driving range with potentially large... Read More

Electricity can be used as a transportation fuel to power battery electric vehicles. Electric cars store electricity in an energy storage device, such as a battery. The electricity powers the vehicle’s wheels via an electric motor. Electric cars have limited energy storage capacity, which must be replenished by plugging into an electrical source. What Is an Electric Vehicle? In an electric car, a battery or other energy storage device is used to store the electricity that powers the motor.... Read More

Light-duty natural gas cars work much like gasoline-powered vehicles with spark-ignited engines. This schematic shows basic CNG fuel system components. 2008 Honda Civic GX Natural Gas Car CNG enters the car through the natural gas fill valve (A) and flows into high-pressure cylinders (B). When the engine requires natural gas, the gas leaves the cylinders and passes through the master manual shut-off valve (C). The gas travels through the high-pressure fuel line (D) and enters the engine compartment.... Read More

Compressed natural gas (CNG) and liquefied natural gas (LNG) are considered alternative fuels under the Energy Policy Act of 1992. Natural gas cars are either fueled exclusively with CNG or LNG  or are capable of natural gas and gasoline fueling.   What is a natural gas car? Dedicated natural gas cars are designed to run only on natural gas; bi-fuel natural gas cars have two separate fueling systems that enable the vehicle to use either natural gas or a conventional fuel (gasoline or diesel).... Read More