How efficient are fuel cells

Fuel cells can operate at higher efficiencies than combustion engines and can convert the chemical energy in the fuel directly to electrical energy with efficiencies capable of exceeding 60%. Fuel cells have lower or zero emissions compared to combustion engines.

Are hydrogen fuel cells 100% efficient

Hydrogen fuel cells are generally between 40% to 60% energy efficient, according to the U.S. Department of Energy. This range compares to the typical internal combustion engine of a car, which is about 25% energy efficient.

Does fuel cell have maximum efficiency

Alkaline Fuel Cells

Operating at 60-70ºC (140-158ºF), AFCs are among the most efficient type of fuel cells, reaching up to 60% efficiency and up to 87% combined heat and power. Both the US and Russian/Soviet spaceships used alkaline fuel cells to produce electricity and drinking water for astronauts.

Can efficiency of fuel cell be greater than 100

Thermodynamic efficiency cannot be greater than 100% for fuel cell using A as fuel.

Why are fuel cells not efficient

The reason why hydrogen is inefficient is because the energy must move from wire to gas to wire in order to power a car. This is sometimes called the energy vector transition. Let's take 100 watts of electricity produced by a renewable source such as a wind turbine.

Why are fuel cells inefficient

20 – 30% of energy is lost in the process of creating hydrogen. The hydrogen must then be compressed and stored, losing another 10%. Finally, another 30% is lost when converting the hydrogen into electricity. This leaves you with 30 – 40% of the original energy used.

Why are hydrogen fuel cells inefficient

It's inefficient compared to battery electric vehicles. The reason why hydrogen is inefficient is because the energy must be transferred from wire to gas and then back to wire in order to power a car – known as the Energy Vector Transition.

Why 100 percent efficiency is not possible

A machine cannot be 100 per cent efficient because the output of a machine is always less than the input. A certain amount of work done on a machine is lost to overcome friction and to lift some moving parts of the machine.

Why the efficiency of heat engine can never be 100%

The efficiency of the heat engine is always less than 1. This is because in reality none of the engines can convert absorbed heat completely into work, as some of the heat will always be dissipated during the process.

Why are hydrogen fuel cells so inefficient

The reason why hydrogen is inefficient is because the energy must be transferred from wire to gas and then back to wire in order to power a car – known as the Energy Vector Transition. As an example lets take 100 watts of electricity produced by a renewable source such as a wind turbine locally.

Are fuel cells more efficient than batteries

It is no secret that batteries are more efficient than fuel cells, but when you make the comparison for heavy-duty, long-range trucks, there's a gamechanger that comes into play: weight. Hydrogen is significantly more energy dense than batteries, which means a fuel-cell pushed powertrain will weigh less.

Why hydrogen fuel is not the future

Scientists and analysts say that as hydrogen molecules are much smaller and lighter than those in methane, they are harder to contain. Once hydrogen enters pipelines, it can weaken metal pipes which can lead to cracking. Hydrogen is also far more explosive than natural gas which could create safety issues.

What are 2 reasons why the efficiency of a machine Cannot be 100

1. Apart of input is always used in moving the parts of machine. 2. A part of input is wasted in overcoming friction between various parts of machine.

What are the three reasons why motors are not 100% efficient

The factors that affect efficiency are:Conductor content – load dependent.Magnetic steel -mainly constant.Thermal design – mainly load dependent.Aerodynamic design – constant.Manufacture and quality control – constant.

Where is heat engine not 100% efficient

Concept. According to Carnot's theorem which states that: Any heat engine which is operating between two hot reservoirs is not as efficient as a Carnot engine operating between the same hot reservoirs. The efficiency of any heat engine is limited due to temperature.

Why is it impossible to design a heat engine with 100% efficiency q14

The efficiency of a heat engine can be 100% only if all the heat energy gets converted into work (or mechanical energy). The impossibility of converting heat energy completely into mechanical energy, limits the efficiency of heat engines.

What is the biggest problem with using hydrogen in a fuel cell

Fuel Storage

Hydrogen's energy content by volume is low. This makes storing hydrogen a challenge because it requires high pressures, low temperatures, or chemical processes to be stored compactly.

Why fuel cells are better than batteries

Hydrogen is significantly more energy dense than batteries, which means a fuel-cell pushed powertrain will weigh less. To illustrate, for a 800 kms range truck, the difference can be as much as 2 tons. Consequently, fuel cell technology allows for longer driving ranges and heavier payloads.

Why hydrogen fuel cells are bad

When used in a fuel cell, the only byproducts of hydrogen are heat and water vapor. Hydrogen can also be combusted, like gas,to produce electricity, which results in water vapor and nitrogen oxide (NOx), a harmful pollutant.

What is the biggest problem with hydrogen fuel

While not as bad as using electricity generated using fossil fuels, the process still releases huge amounts of carbon – each tonne of hydrogen produced releases eleven tonnes of CO2, equivalent to driving 72,000 km in a passenger car.

Why is 100% efficiency not possible

The second law of thermodynamics states that as energy is transferred or transformed, more and more of it is wasted. A machine cannot be 100 per cent efficient because the output of a machine is always less than the input.

Why is the efficiency of a machine always less than 100 percent _____ *

Efficiency in real machines will always be less than 100 percent because of work that is converted to unavailable heat by friction and air resistance.

Can any appliance ever be 100% efficient

A machine cannot be 100% efficient because the Second Law of thermodynamics forbids it. The Second Law of thermodynamics states that a transformation whose only final result is to transform to work, heat extracted from a source which is at the same temperature throughout is impossible.

Can a heat engine ever be 100% efficient explain why or why not

As absolute zero and infinite temperature cannot be achieved in practice, the efficiency of a heat engine cannot be 100%.

Can heat engines be 100% efficient

It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics. This is impossible because some waste heat is always produced produced in a heat engine, shown in Figure 1 by the term.