hnzinformation

Climate change

Scientists have observed that increasing amounts of greenhouse gases (especially carbon dioxide) in our atmosphere has led to some unusual recent changes in the earth’s climate. While there are natural fluctuations in the earth’s temperature, scientists are telling us that temperatures are rising faster than at any other point in history.

This is linked to the greenhouse effect. Our atmosphere traps heat from the sun. Increasing amounts of greenhouse gases means there is more heat from the sun trapped in our atmosphere. This is warming our planet. This process is called climate change.

The impacts of climate change will be significant and felt globally. The UK Climate Impacts Programme (UKCIP) predict that in the UK we will see:

• Average temperature rise, with warmer, wetter winters and drier, hotter and longer summers.
• An increase in severe weather events like flooding, droughts, heat waves and severe gales.
• A 40cm increase in sea levels by 2100, leading to further coastal erosion and flood risks.
• Changes to UK farming in terms of where and what crops are grown and available.
• UK wildlife under threat as their environment changes due to temperature changes.

What does this mean for you?

In 2019, the UK government became the first major economy in the world to pass laws to end its contribution to climate change by 2050. This means that the UK needs to bring all greenhouse gas emissions to net zero by 2050.

To achieve this, we will all need to make changes to limit our greenhouse gas emissions. This could be changes to your home or where you work and how you travel. Actions to tackle climate change can have benefits for you and wider society. For example:

• Making improvements to the buildings we live and work in can make them more comfortable to be in and more affordable to run.
• New jobs creation – recent research suggests that the UK construction industry will need another 350,000 working in the sector in the next decade.

Decarbonisation

Carbon dioxide is present in the Earth’s atmosphere and acts as a greenhouse gas. The UK has made great progress in reducing the amount of carbon dioxide we release into the atmosphere when generating electricity. There is now less power generated from coal and more from renewable technologies such as wind and solar. This activity is called decarbonisation.

One of the big challenges for the UK now is reducing the amount of carbon dioxide we release when we heat our buildings – the decarbonisation of heat. The government are considering lots of options for replacing heating systems that release carbon dioxide, such as gas boilers, with lower carbon producing alternatives.

One option they are considering is increasing the number of heat networks in operation in the UK.

What are heat networks

A heat network is a system of insulated pipes, often laid underground, which transport heat to more than one end user. While many heat networks are powered by natural gas, there are lots of different technologies and fuels that can be used to generate heat. This includes biomass (wood) and electric heat pumps. Heat networks have been used successfully for decades to provide both heating and cooling for buildings.

The UK government has stated that heat networks will be used more widely to heat our homes and businesses. They can supply heat at lower cost, at lower carbon and at scale. They can also use waste heat from other buildings, such as waste incinerators. They currently supply around 2% of UK heat demand – the UK Climate Change Committee thinks this should increase to over 17% by 2050.

There are two types of heat network:

• Communal heat networks: systems that heat lots of properties within one building, such as a block of flats.
• District heat networks: systems that involve a local energy centre that supplies heat and hot water to customers in more than one building. They can range in size from a few hundred metres supplying just a few homes to several kilometres of pipe supplying heat and hot water to multiple buildings in a development.

Heat networks are operated by one company. This means that buildings connected to heat networks are unable to switch their heating and/or hot water supplier in the same way as they can for other utilities such as gas or electricity. This will be a familiar arrangement for many and is very common in the water sector.

Heat network zoning

Heat networks can’t be introduced everywhere. In order to work effectively, we need to look at areas where there are lots of buildings with lots of heat or cooling demand.

The UK Government is considering the introduction of policies to create heat network zones. These zones would be areas where it would be cost effective and technically feasible to decarbonise heating in buildings through a heat network. In these areas, there would be plans to improve the energy performance of buildings, by adding insulation, and then heating those buildings through a district heat network.

There are current trials to look at heat network zoning in six English cities. These are Bristol, Birmingham, Greater Manchester, Leeds, Newcastle and Nottingham.

What does this mean for you?

If the government decides to implement heat network zones, your building may be eligible to connect to a heat network in the future.

This would require some changes to your home or workplace. For example, a heat interface unit (HIU) would need to be installed be installed. This unit – which looks like a boiler – brings hot water and heat from the main heat network into the property.