Heat Pumps vs Hydrogen Boilers

Scotland plans to be net-zero by 2045, and along with that goal comes some significant changes with regard to residential heating.With 81% of Scottish households relying on natural gas boilers for heat, it is clear that a lot of changes are required to revolutionise heating systems.

Fortunately, environmentally friendly heat options are becoming increasingly popular, two options being heat pumps and hydrogen boilers.But, how do these two heating options compare? Which one will play the biggest role in getting Scotland to net zero?

Overview

How Hydrogen Boilers And Heat Pumps Work

Before we can compare the two heating systems, let’s first get a better understanding of how they work.

Hydrogen boilers

100% hydrogen boilers are not available. At the time of writing, hydrogen-blend boilers are available. These rely on natural gas which is blended with about 20% hydrogen.

Hydrogen boilers are not yet common and are still in the prototype phase, with companies like Worcester Bosch working hard to develop hydrogen-ready boilers that can accept 100% hydrogen.

Hydrogen produces almost zero carbon and can be used similarly to natural gas to heat homes. There is an argument that hydrogen boilers would be able to be rolled out quickly as infrastructure for gas is already in place across the UK.

Heat pumps

These pumps use the ground (ground source heat pump) or air (air source heat pump) to absorb heat and transfer it into energy which is used to heat a property.

The heat is distributed as warm air or can be used to heat up water, which is pumped through radiators to warm a space.

Heat pumps are incredibly environmentally friendly, although electricity is used for the pump itself.

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Energy Efficiency – Hydrogen Boilers vs Heat Pumps

Hydrogen boilers

Hydrogen boilers themselves are very energy efficient, but the process of extracting hydrogen from water – through electrolysis – is not very efficient. Furthermore, compressing and transporting hydrogen is also very energy-intensive. This is because hydrogen is very light and requires a lot of compression – which uses energy – to store and transport it.

As for the boilers, when hydrogen is burned to heat the water, only a little bit of heat escapes as waste, making them an energy-efficient way to heat your home. These boilers are about as efficient as natural gas boilers, with an efficiency exceeding 90%.

In the end, the efficiency of the boiler will depend on the method of hydrogen production. As these boilers use green hydrogen, which is produced using renewable energy, it is considered an environmentally friendly option.

Heat pumps

Heat pumps are very efficient and also very sustainable if they make use of renewable electricity.

Pumps that use the Earth’s or air’s natural heat to warm a home can be up to 270% efficient. These heating systems are known for their efficiency. To break it down, for every unit of electricity consumed, they produce two to four units of heat.

They are especially efficient in moderate climates without severe temperature fluctuations. If the air or ground is very hot or cold, their efficiency decreases slightly.

When you consider the power needed to produce hydrogen, heat pumps are a more energy-efficient option.

heat pump snow scotland

Carbon Emissions Output

Hydrogen boilers

People commonly believe that using hydrogen for heating will result in zero carbon emissions. This is slightly incorrect.

When green hydrogen is used, there are almost no emissions; however, there is currently not enough renewable energy infrastructure in Scotland or the UK to produce green hydrogen for many years into the future. That means that grid electricity will also have to be used, which does produce carbon dioxide.

Therefore, the source of the hydrogen determines how carbon-neutral it is.

For example, grey hydrogen is produced from natural gas and can have even more emissions than the natural gas itself. Green hydrogen, on the other hand, is basically carbon-neutral. Blue hydrogen is produced from gas and produces carbon dioxide.

So, although the boilers themselves do not release any carbon dioxide or greenhouse gases, the production of hydrogen must be considered when it comes to carbon emissions.

Heat pumps

Heat pumps use electricity to generate heat and don’t burn any kind of fuel. Therefore, their carbon emissions will depend on the source of the electricity.

If renewable energy is used in the grid, then heat pumps can be low- or carbon-neutral to use. If fossil fuels are used for grid electricity generation, then the carbon emissions involved in powering the pump increase since burning a fossil fuel releases greenhouse gases.

Generally speaking, though, heat pumps are considered to be an environmentally friendly option, especially when powered by renewable energy.

heat pump

Should Scotland Focus On Hydrogen Boilers Or Heat Pumps?

A heat pump that is powered by electricity uses one-fifth of the electricity required to power a green hydrogen boiler. A pump is also very efficient and can heat the property with warm air or water in radiators.

However, hydrogen boilers also have their place.

With both these heating systems having the potential to push Scotland towards a carbon-zero future, both need to be considered. Hydrogen-ready boilers are still being tested while hydrogen-blended boilers are slowly increasing in popularity.

But even so, when you consider the workings, efficiency and sustainability of these systems, it seems that heat pumps are coming out on top in the fight against climate change.

That does not mean Scotland should completely disregard hydrogen boilers, though. As they develop more, their efficiency will improve. And as more renewable energy initiatives are adopted, there will be more energy available to produce green hydrogen.

Heat pumps and hydrogen boilers are expensive to install, but hopefully, with the increased demand, prices will start to drop.

How Many Homes Have Hydrogen Boilers In Scotland?

Currently, there isn’t a 100% hydrogen-ready boiler on the market, although Baxi, Worcester Bosch and Viessman are working on prototypes.

In a world first, it was announced that 300 Scottish homes were going to be fitted with a green hydrogen gas boiler in 2024. The National Grid is planned to use 100% hydrogen in the network through the H100 Fife scheme to address the need for alternative energy sources.

Currently, the scheme has hit some delays, and only time will tell how successful it will be.

How Many Homes Have Heat Pumps In Scotland?

18,072 Scottish homes had heat pumps installed by the end of 2022. This is a significant step towards the Scottish government’s goal of fitting 40% of homes with low-carbon heating by 2030.

It is expected that gas boilers will no longer see the light of day (but no, there is no gas boiler ban – just no new builds with gas boilers) and that heat pumps will increasingly be adopted.

Envirohomes Renewables can help you get financial support through the ECO4 scheme to get a heat pump installed in your home.

FAQs

Yes, schemes like ECO4 offer financial incentives to help homeowners source and install heat pumps on their properties.

Installing a heat pump generally has a lower environmental impact due to its higher energy efficiency.

Both heat pumps and hydrogen-ready boilers seem to be the future (if the gas infrastructure supports it).

Switching away from natural gas to hydrogen seems easy on paper, but the costs involved can cause the prices of these systems to skyrocket, making it impossible for environmentally conscious homeowners to make the change.

Until hydrogen can be produced more efficiently, it seems that heat pumps will become the primary way to heat Scottish homes for the foreseeable future.