There is a need to rely on options sustainable heating for buildings, residential and otherwise, to achieve the objectives set by the European Union. The EU has set challenging targets in terms of production from renewable sources, energy efficiency and emissions reduction.
The real balance is and will be the buildings, especially the existing ones. According to the Italian reality, 60% of national cases are characterized by poor energy performance. About 80% of consumption of a home are due to the heating, cooling and hot water production functions.
Regulatory evolution: Green Homes Directive
A few days ago the EPBD was approved. The Green Homes Directive intends to create the conditions for drastically reduce energy consumption by 2030 and greenhouse gas emissions from buildings, aiming for new zero-emission buildings as early as 2030 (anticipating those of the PA to 2028), while existing ones will be discussed in 2050. All this requires huge efforts, in terms of investments to support of the transition.
Furthermore, there is the PNIEC to consider, which calls for a significant commitment to covering consumption with renewable sources.
How is it possible to reverse the trend, above all trying to work to improve the conditions of those already existing? This was discussed at the conference “The scenario for the diffusion of hydrogen in the residential sector: market prospects and legislative evolution”, organized by Anima and H2IT.
More than one reflection has been made in favor of a diversified approach that can still foresee a role for natural gas, taking into account two aspects: Italy’s leading role in the production of numerous “green gas ready” technologies in terms of heating and domestic hot water production and counting on one of the most widespread gas networks in the world. On the gas network it should be considered that it could be used to convey – when it exists – hydrogen, in particular green hydrogen, produced thanks to electricity supplied by renewable sources.
Sustainable heating: Italy’s role
Italy can therefore play an important role in sustainable heating. Not only that: it can play “a role in becoming a European energy hub and a renewable supply corridor for the Mediterranean area,” he said Giuseppe Lorubiopresident of Assothermica, recalling among other things the Italian-German Action Plan for bilateral and European Union strategic cooperation.
Among other things, it includes a promotion of the role of hydrogen and the desire to increase and strengthen cooperation aimed at accelerating the expansion and systemic integration of renewable energy and energy efficiency.
Green hydrogen is the future. But it will take time before significant production occurs. In the meantime, however, we need to work now towards progressive decarbonisation, starting with heating.
Precisely on the possible alternative paths to 2050, there is a study conducted by Guidehouse which outlines two possible lines: one, aimed at a high and rapid diffusion of electrification with heat pumps and extensive redevelopment; the other which provides a balanced mix of technologieswhere electrification is still predominant, but which also includes the gas distribution network and heating systems that need to be redeveloped to be ready to accommodate the entry of mixed hydrogen.
“This technological mix is required because there is also a variety of buildings that entail different technical problemsso we need to think about the best technology for each building to truly achieve decarbonisation”, he noted Stefano Casandrinivice president of Assothermica.
In the case of heat pumps, they prove to be the ideal solution for single-family homes, for buildings undergoing renovations and for new constructions «and there we believe they will continue to grow quickly. Conversely, in multi-family buildings the technological mix is rewarding.”
In Europe, deep retrofitting is proceeding slowly
It must be considered that today, out of 220 million European buildings, 85% of the total residential buildings were built before 2001, therefore with medium-low building standards. The present will also constitute a large part of the future scenario given that 85-95% of the buildings currently existing will also be existing in 2050.
The UK case: incentives do not push retrofitting
The restructuring plans are still very slow in implementation. The case of the United Kingdom is exemplary: Boris Johnson’s government had foreseen it a very challenging plan for retrofitting buildings. To date, less than 1% of the buildings that needed to be renovated to adopt new standards favorable to electrification and heat pumps have been renovated, despite the incentives made available by the Executive.
Netherlands: Heat pumps do not accelerate
Even in the Netherlands, heat pumps have not experienced the expected development. The Dutch case is exemplary: the real estate stock includes 7.5 million houses, for the most part heated by natural gas.
As a study by Delft University of Technology highlights, the Netherlands Ministry of Economic Affairs has introduced a new policy to promote initiatives to support individuals using renewable energy in the heating sector instead of using methane by 2050. Door to 200 thousand zero-emission renovations per year. A large innovation program is under development.
This energy transition implies:
- the abandonment of fossil fuels,
- the electrification of heating,
- raising awareness among residents,
- the adjustment of energy taxes to support renewable energy.
Last but not least, the decision to replace gas boilers with hybrid heat pumps.
“However, several factors, such as low renovation rates, lead to uncertainties in achieving these goals.” The difficulties encountered led the Dutch Ministry of Housing to exempt multi-family and protected buildings from replacement. “The basic principle is that everyone should be able to heat their home comfortably and cost-effectively,” the Ministry of Housing, Hugo de Jonge, wrote in a letter to Parliament.
Heat pumps: advantages and factors to consider
Heat pumps are advocated solutions for the future of sustainable heating. As IEA reports, if powered by low-emission electricity, they are there central technology in the global transition towards safe and sustainable heating. And it reports that “and heat pumps currently available on the market are from three to five times more efficient from an energy point of view compared to natural gas boilers”.
However, they present some elements to consider when replacing a gas boiler. As illustrated by the vice president of Assothermica, they require a storage tank, which has significant dimensions. Furthermore, with the transition to natural refrigerants or refrigerants with very low or zero GWPsolutions characterized by larger dimensions will establish themselves on the market, as in the case of R290 heat pumps, given that from 2026 the use of high-impact refrigerants will be prohibited.
Added to this are the decidedly long replacement times if you decide to replace a boiler with a heat pump.
Casandrini highlighted the outcome of a survey carried out by the European Consumer Organization (BEUC). The average total waiting time for the installation, adding the call to the installer, the first visit, the final offer, taking charge and leaving for the job was 15 weeks, or almost four months, with peaks of over seven months. The long times are also motivated by the shortage of manpower.
“In the world of installation, there is a lack of resources. Therefore, it is not only a problem of training but also of finding young people to start work. Until this is done, electrification probably cannot take place.”
The future of sustainable heating: hydrogen, “more convenient option”
To add perplexity to the sustainable heating scenario, aiming solely at electrification, there is also a study by Imperial College London. It states that: “recent energy scenario models suggest that theElectricity will play a majority role in providing heat and other energy services by 2050. There are, however, potential problems associated with providing a future energy system with such high electricity use.” The main problem is linked to the electricity grid and the need to rely on its stability.
“No one says that in Europe and North America the electricity grids are already old”, noted the vice-president of Assothermica, also posing the question of investments, in particular the role that private investors are called upon to have in supporting the ecological transition .
There Net Zero Roadmap from the International Energy Agency states that limiting global warming to 1.5°C is still possible, but investments in clean energy must reach $4.5 trillion per year by 2030.
However, given the choice, which options will private investors focus on? Casandrini highlighted the value of transmutation of gas networks to hydrogen and/or green gas networks “because the transition to power lines, especially the latest generation, with direct current, has 150% higher costs for the same final energy transported”.
Pipelines vs power grids: two studies promote hydrogen
In support of the thesis, he brought two studies: in the first, by the Oxford Institute for Energy Study, HVDC lines were compared with hydrogen gas pipelines. Considering multiple factors, it is estimated that the investment costs for HVDC overhead lines are likely to be almost double the investment expenditure for above-ground hydrogen pipelines, although the difference for underground and subsea options is less significant.
In the second study, conducted by Deloitte, it emerges that, even if theefficiency of the hydrogen system is reduced by energy losses during conversion, it has advantages over electrification in terms of system cost. Conversion from hydrogen energy to energy/heat leads to energy losses compared to direct electricity, with an efficiency of only 25-40%.
However, the lower system efficiency is offset by the lower system cost of hydrogen compared to electrification. Hydrogen helps decarbonize end uses where electrification has physical limitations. Pipeline transportation of hydrogen can be 8-15 times cheaper than electric cable transportation per unit of energy.
