How to produce hydrogen cleanly?
Hydrogen can be easily produced by passing electricity through water. The process known as electrolysis is a mature technology that can be easily implemented for small or large scale application.
Why do we need a small volume to store hydrogen?
For mobile applications, such as cars, the safety issue and accessibility of the energy storage is important. Currently, hydrogen is generally stored in its liquid or compressed gas form, which makes it unsafe and very difficult to refill the fuel. Therefore, a cheap, safe and efficient way to store hydrogen is necessary.
What is a fuel cell? How can Hydrogen be used as an energy source?
A fuel cell is device that can react hydrogen and oxygen to generate electricity from chemical energy. It can continuously provide electricity if there is a constant supply of hydrogen and oxygen.
Hydrogen can be burnt in a fuel cell to produce electricity, or in a combustion engine, just like petrol, to be transformed into energy to move a car or produce electricity and/or heat. It has the highest density of any fuel (3 times that of gasoline). It is used to send people into space, all while producing zero harmful emissions! Hydrogen energy can be used for transport, powering homes and businesses, portable electronics – it truly has potential to be used for all our energy needs!
How is Hydrogen produced?
Currently most hydrogen is produced from fossil fuels. The most common method is called ‘steam reforming of methane’, which involves natural gas reacting with steam to produce hydrogen, carbon dioxide and carbon monoxide. The problem with this is that it still produces harmful emissions including carbon dioxide (CO2). A way to avoid this is to use renewables solar and wind farms, for example, to produce electricity and split water (H2O) into hydrogen (H2) and oxygen (O2); a very clean process.
How are materials used to store hydrogen?
Materials like sodium borohydride can absorb hydrogen within their structure. Once, the hydrogen is absorbed is it safely held within the material. A small amount of heat needs then to be applied to release the hydrogen. This makes the process of using hydrogen as an energy source extremely safe. The advantage of sodium borohydride is that is can hold a lot of hydrogen (i.e. 10.8 mass %).
Is Hydrogen energy safe?
Hydrogen is often incorrectly seen as an unsafe fuel; usually due to the 1937 Hindenburg disaster (it has since been proven that the fire was inconsistent to that of a hydrogen fire!). In fact, while hydrogen is flammable it is inherently no more dangerous than other conventional fuels such as gasoline or natural gas. Hydrogen is 14 times lighter than air, which means that even in the event of a leak it will rapidly diffuse into the air into a non-flammable concentration – The pictures below illustrate this misconception. Even if there is a leak, hydrogen is non-toxic and non-poisonous, and does not contaminate groundwater or air.
Hydrogen powered vehicle on the left, gasoline-powered vehicle on the right. Time: 3 seconds after ignition. Hydrogen escaping from the vehicle (equipped with a 200 bar compressed hydrogen tank) is burning as a clean flame. Gasoline heavier than air, leaks under the car and burns down the entire vehicle.
Hydrogen powered vehicle on the left, gasoline-powered vehicle on the right. Time: 1 minute after ignition. The temperature at the wheel in the hydrogen powered vehicle did not exceed 40 °C. The driver can safely leave the vehicle.
What makes our technology even safer that compressed hydrogen is that the hydrogen is locked in solid materials: This is a well-established technology, and it is so reliable that hydrogen storage materials (called metals hydrides) are used as fire or overheat detector in aircrafts.
Can’t we just use renewables for our energy needs?
The main reason we can’t is that renewables have problems with intermittency: During times of low sun or wind there is not enough power being produced to meet demand. But other times there is much more power generated than is required. Hydrogen provides a way to smooth out these peaks; it can be stored, and then released when there is a sudden cloud or the wind speed drops too low. Essentially hydrogen allows for continuous, reliable power than renewables alone cannot provide!
Can’t we just use batteries to achieve the same purpose?
It is true that batteries serve much the same purpose as hydrogen storage, although there are a number of factors that make batteries a less effective storage medium compared to hydrogen. Hydrogen storage materials have a much greater energy storage capacity, which means that more energy can be stored in a smaller space compared to batteries. This becomes particularly important when dealing with storing energy for transport applications such as cars and planes; a smaller sized system is much more practical.
Batteries also are characterized by a relatively short life span (<5 years), required long time for charging (a few hours) and have negative environmental impacts upon disposal. Hydrogen storage requires no maintenance and have a much longer life span (> 20 years) in addition to being environmentally friendly; the storage systems contain no toxic chemicals.
The price of batteries also makes them impractical for large scale energy storage, – for example -, lithium-ion batteries cost about $2000/kWhr. Hydrogen is much cheaper than a battery, with a cost of 24¢/kWhr using water electrolysis. Even combined with the cost of a fuel cell, the cost of electrolysis hydrogen is approximately 48¢/kWhr, which is still less expensive than batteries.
Why is hydrogen currently not used as an energy carrier on a large scale?
The main response given when we surveyed people was that they think that it is simply too expensive to implement hydrogen as a major energy carrier. This is true – to an extent. Currently there is competition between traditional energy generation and new energy generation. The energy system is set up for fossil fuels and in order to change this, investment in infrastructure is required. But as stated above, eventually hydrogen energy will be a zero cost system, and so these investments eventually pay off!
When will hydrogen be ready to use?
Hydrogen can be used for energy applications now! The technology is developed enough to be able to use hydrogen for stationary applications and for small electronics. There are also demonstration models of cars, boats, planes that have been developed by different groups around the world. We have developed a working hydrogen powered bike – select this option in the rewards section and come to see us for a ride! We are not inventing the technology; we are simply improving it so that large-scale deployment is more viable.