Heat is a great challenge in the fight against climate change, making up half the world’s total energy consumption and contributing more than 40% of global energy-related carbon dioxide (CO2) emissions.
1. Decarbonising heating systems
In the race to reduce carbon emissions, it is vital to decarbonize the heating system, both in households and in the industry sector, with the latter accounting for half of all heating and requiring new innovations for the sector to be able to decarbonize. Heat comprises half of the world’s total energy consumption – which is significantly more than electricity (20%) and transportation (30%), according to the sustainable heat and power tech company Modern Electron.
Most climate efforts have been focused on decarbonizing electricity and cars, but European policymakers have recognized the urgency in addressing emissions caused by heating systems too, under its ongoing legislation to regulate energy efficiency in buildings. While curbing emissions from heat might be the hardest battle, it may be the biggest untapped opportunity in the climate fight.
For example, modern district heating systems are offering promising results as they can integrate other emission-neutral energy sources, especially in urban settings where neighbourhood solutions can work well, states a policy brief from the European Environment Agency (EEA). However, the advantages and disadvantages of investing in such systems need to be carefully assessed in each case and in relation with other potentially more cost-effective and sustainable local solutions, the EEA added.
2. Household vs industry heating
On average, about 60% of home energy demand in the United States is used for heating, with that number reaching approximately 80% in Europe, according to Eurostat. Since households usually require low temperature heat, electric heat pumps and renewable electricity are making headway towards reducing emissions.
Heating in a professional setting, however, is the biggest challenge to address when thinking of slashing CO2 emissions. Specific industries dealing with manufacturing, often critical for human civilizations, including ammonia, cement, steel, plastics, refining raw materials, melting metals and producing chemicals, account for 50% of all heat in their production.
3. Biofuels, hydrogen, carbon capture, thermal storage
A possible solution to address the emissions caused by industrial heating is to relocate businesses and factories to an area with a consistent and cheap supply of zero-carbon electricity 24/7. Iceland, for example, is a leader in the export of aluminium due to the volcanic country’s abundant and affordable geothermal power. Moreover, electric arc furnaces can use renewable electricity to reach high temperatures, but they have limitations, such as the being only able to heat conductive materials like metals.
Biofuels and hydrogen are other options. Organic fuel sources such as wood chips, sawdust and agricultural waste can be burned in boilers or furnaces, while hydrogen can burn at around 2,000°C, it can provide a low retrofit solution to commercial and industrial heating equipment. However, traditional production of hydrogen emits plenty of CO2, the industry must be sure that its hydrogen is coming from renewable sources, produced via water electrolysis, or from natural gas and biogas with pre-or-post-combustion carbon capture, resulting in turquoise or blue hydrogen.
Finally, thermal storage is being touted as a means of storing excess renewable electricity produced during periods of high generation, such as solar at noon. Among the several technical challenges, it’s hard to find a low-cost storage medium with fantastic insulation able to keep the heat hot enough over hours and days.
