How can technology help us
to reduce our carbon emissions

In order to eliminate the majority of greenhouse gas emissions from human activities we must either change our way of living quite dramatically or use technology to help us find a balance between the most drastic of lifestyle changes and continuing to live 'comfortable' but sustainable lives.

Technology doesn't have all the answers and some apparent saviours have hidden costs that need to be understood to allow pragmatic choices to be made in terms of their use.

Alternative
Fuel Sources

There are a number of fuels being developed as alternatives to coal, natural gas and oil but some of their production processes can generate carbon dioxide (CO2) as a by-product, which means natural or man-made carbon capture and storage (CCS) processes would need to be employed to make them carbon neutral - which is not ideal.

Because huge R&D resources around the world are being applied to the development of renewable fuel production we can expect to see a steadily changing scene, which means in 10-years’ time the cost effectiveness and environmental impact of alternative fuels may be different from what we see today.

Hydrogen


Hydrogen is a gas at normal room temperatures and can either be burnt to create heat or used in an electro-chemical reaction to produce electricity in a fuel cell. Whilst we can expect it to become a cost-effective, renewable fuel for heating buildings and for some limited transport applications, improvements are needed in the way it is produced and converted into electricity, if it is to offer a realistic alternative fuel for all our needs.

When used as a fuel it creates no carbon emissions or noxious fumes, just water. However it can be produced in a number of different ways, some of which do produce carbon emissions as a by product. The different versions may be referred to as green, blue, grey or brown, according to how it is produced, which refers to the amount of carbon emissions created by each method. Green hydrogen, produced using electrolysis with renewable energy, has the lowest associated CO2 emissions and brown the highest.

The cost of hydrogen also depends on the way it is produced, with the lowest cost being around £2 per kg (about 6p/kWh). This means that today hydrogen would cost much more than natural gas at its current price of around 3.8p/kWh) but have a lower cost than electricity at around 14-15p/kWh (day tariff).

Hydrogen is likely to be used as a replacement for natural gas (methane), for heating, cooking and certain other industrial processes, where heat is required.

No information is currently available on the cost of getting hydrogen to industrial and domestic users but the 'H21' project being undertaken by Northern Gas Networks in Leeds is designed to demonstrate the feasibility of using hydrogen in place of natural gas, including the safety, cost effectiveness and acceptability to customers, on a national scale.

 

The national gas network is also currently being upgraded to replace metal pipes with plastic, which is more flexible and will minimise the breaks and joint leaks that metal pipes are prone too; caused by earth movements, which are common in Harrogate due to the clay subsoil. As well as being more flexible plastic should last for 100 years or more, but testing is required to ensure material compatibility with hydrogen over long time periods.

As a fuel for transport, it is stored under pressure (at about 10,000 kg/sqm) and either used to produce electricity via fuel cells or in the case of aircraft jet engines burnt directly.

Hydrogen could be an important fuel for heavy goods vehicles, where the size and weight of batteries makes electrical power impractical. However, it is possible that liquid biofuels may prove to be more cost effective but potentially not as environmentally friendly.

 

Hydrogen could also become an important source of power for ships, the main benefit being less pollution than using biofuels.

 

The Hydrogen Council is however already promoting the use of hydrogen as a fuel.

 

Hydrogen


Hydrogen is a gas at normal room temperatures and can be either burnt to create heat or used in an electro-chemical reaction to produce electricity in a fuel cell.

 

We can expect it to become a cost-effective, renewable fuel for heating buildings and in some transport applications, but improvements are needed in the way it is produced and converted into electricity, if it is to offer a realistic alternative fuel for all transport needs.

Hydrogen is likely to be used as a replacement for natural gas (methane), for heating, cooking and certain other industrial processes, where heat is required. The cost of hydrogen depends on the way it is produced, with the lowest cost being around £2 per kg (about 6p/kWh). This means that today hydrogen would cost much more than natural gas at its current price of around 3.8p/kWh) but have a lower cost than electricity at around 14-15p/kWh (day tariff).

No information is currently available on the cost of getting hydrogen to industrial and domestic users but the 'H21' project being undertaken by Northern Gas Networks in Leeds is designed to demonstrate the feasibility of using hydrogen in place of natural gas, including the safety, cost effectiveness and acceptability to customers, on a national scale.

 

The national gas network is also currently being upgraded to replace metal pipes with plastic, which is more flexible and will minimise the breaks and joint leaks that metal pipes are prone too; caused by earth movements, which are common in Harrogate due to the clay subsoil. As well as being more flexible plastic should last for 100 years or more, but testing is required to ensure material compatibility with hydrogen over long time periods.

As a fuel for transport, it is stored under pressure (at about 10,000 kg/sqm) and either used to produce electricity via fuel cells or in the case of aircraft jet engines burnt directly.

Hydrogen Cars

Hydrogen powered cars have a range of 3-400 miles and can be refuelled quickly and simply in a similar way to petrol and diesel, which gives them a major benefit over battery technology, although this is also moving forward very quickly. Due to the absence of combustion no pollutants, such as nitrogen oxides are produced. 

There are only three commercially available cars currently available. The Toyota Mirai, the Honda Clarity and the Hyundai Nexo which are all priced in the range £60-80,000. Other manufacturers are working to develop models and costs are likely to come down as production increases. 

There are two main drawbacks to using hydrogen currently as a fuel for cars are;

  • Producing hydrogen and then electricity from hydrogen are both inefficient, making it a costly option. 

  • Small number of refuelling stations. There are only 13 in the whole of the UK, compared with 85 in Germany, the most of any country.  

 

Hydrogen could be a good option for heavy goods vehicles, where the weight of batteries makes them impractical and for use in .

They can reach a potential efficiency of 80%, but the current cost is very high. The Toyota hydrogen powered Mirai car for example costs £66K.

 

 

The construction of hydrogen filling stations is a pre-requisite for the large-scale use of hydrogen powered vehicles.

 

California is leading the way in this respect.

For further information on the Toyota Mirai go to:

 

For a review of prospects for hydrogen powered cars go to:

www.autocar.co.uk/car-news/industry/analysis-do-hydrogen-powered-cars-have-future

Hydrogen could be an important fuel for heavy goods vehicles, where the size and weight of batteries makes electrical power impractical. However, it is possible that liquid biofuels may prove to be more cost effective but potentially not as environmentally friendly.

 

Hydrogen could also become an important source of power for ships, the main benefit being less pollution than using biofuels.

 

The Hydrogen Council is however already promoting the use of hydrogen as a fuel.

Hydrogen may be referred to as green, blue, grey or brown, according to how it is produced. Green refers to the lowest CO2 emissions and brown the highest. Brown hydrogen is made from coal or lignite (as in the old gas works) and is not considered here.

The CO2 emissions (kg equivalent) per kg of hydrogen for the different production methods are tabulated below.

At best, carbon capture will remove 90% of the CO2 produced, although some energy is required to do this.