Giant heat pumps: A new heating alternative?

As the world continues to work towards adopting cleaner, more sustainable methods of generating electricity, we’ve seen a surge in the development of new technologies. Giant heat pumps are one of the more recent additions to the renewable energy arsenal, providing heat on a huge scale.

So what exactly are giant heat pumps, how do they work, and how can they revolutionise the way we heat our homes? First of all, let’s take a quick look at what a heat pump is.

What is a heat pump?

A heat pump is a device that can heat or cool a space by moving existing heat from one place to another. It works by circulating a refrigerant such as CO₂ or ammonia that absorbs heat from the air, the ground or a water source. This is then pressurised and evaporated into a hot gas, which is used to heat the desired space, or to heat water in a boiler. The refrigerant then passes through an expansion valve, reducing the pressure and temperature so the cycle can start again. This process allows the heat pump to transfer heat from a colder area to a warmer area for heating, or it can be reversed for cooling.

Heat pumps have become increasingly popular with homeowners over recent years, as they are a very efficient method of heating a property. While they do require electricity to operate, a heat pump can generate 3-4 times as much energy as it uses. Domestic units operate on a small scale with a capacity of around 5KW to 15KW, as they only need to generate heat or hot water for a small property.

What are giant heat pumps?

As the name suggests, a giant heat pump is a much larger version of this technology. They are thousands of times more powerful than domestic versions, and often comprise several high-capacity heat pumps connected together. Instead of being measured in kilowatts, the capacity of giant heat pumps is measured in megawatts.

While some giant heat pumps are used for commercial purposes, they are now also being used as district heating systems, providing heat to thousands of homes at once, instead of on an individual basis.

The 'exploding' demand for giant heat pumps https://t.co/bMRjsEBzoX

— BBC News (UK) (@BBCNews) May 30, 2023

How do giant heat pumps work?

Giant heat pumps operate on the same principle as the smaller versions found in domestic applications but on a much larger scale. Water-source giant heat pumps extract thermal energy from seawater, which is used to heat the refrigerant before being pumped back into the sea. The refrigerant is compressed and further heated, reaching temperatures up to 150°C before being transferred to a district heating system, where it can provide heat and hot water for thousands of homes.

Where are they already being used?

Giant heat pump systems are already being used around the world to produce heat and electricity on a large scale, particularly in Europe. For example, Sweden is home to multiple giant heat pump networks. With a maximum capacity of 215MW, the district heating system in the capital city of Stockholm is often referred to as the world’s largest heat pump system, while Gothenburg’s setup generates up to 160MW.

The seaport town of Esbjerg in Denmark is currently working towards their 2030 net zero target by replacing coal-fired heat with carbon-neutral district heating produced from wind and seawater. This involves the introduction of a giant heat pump that will provide water of up to 90°C to a district heating system serving 27,000 households. This system will run on electricity provided by a local wind farm, and is set to come online in autumn 2023. Other cities that are currently planning to introduce giant heat pump developments Vienna, Hamburg and Helsinki.

How could giant heat pumps help in the UK?

One of the biggest challenges with achieving net zero targets is having to meet the current demands of modern consumers and support the existing infrastructure. Simply using less energy is not a viable solution in most instances, so finding cleaner, more efficient ways to generate electricity and heat our homes is essential. With the rising cost of natural gas, more companies are turning to green solutions.

Giant heat pumps are a highly efficient method of providing heat to a lot of homes at once. Embracing this technology would allow the UK to decarbonise thousands of homes rather than relying on individual homeowners to upgrade to carbon-free systems themselves. Heat pumps are also able to store heat and, unlike electrical grids, don’t need to be balanced. Excess electricity can be sold back to the grid, providing cheaper, cleaner energy on a huge scale.