Heating with air conditioners – fast and affordable transition towards carbon neutrality?

Panel: 9. Products, appliances, ICT

Authors:
Andrea Roscetti, Politecnico di Milano, Dipartimento di Energia, Italy
Eric Bush, Topten Switzerland, Switzerland
Hélène Rochat, Topten Switzerland, Switzerland
Lorenz Deppler, EKZ - Electrical Utilities of the Canton of Zurich, Switzerland

Abstract

Energy efficiency and renewables are the two main pillars in the Swiss long term energy strategy 2050. A number of policy measures are in place for the building sector: CO2 levy financing incentive schemes for efficiency, obligation for renewable energy, stricter minimum performance standards for appliances and systems.

The building sector accounts for more than 45% of the swiss total final energy consumption and the 30% of the CO2 emissions. The private households’ sector consumed in 2019 about 60 TWh, 66% for the space heating needs and 15% for sanitary hot water. The 65% of the space heating needs are satisfied with gas and oil, only 6% with direct electric heaters. Excluding holiday homes, there are still 23,9 mio. sq.m. of heated surface served by resistance heating: in the last 20 years its consumption – climate corrected - decreased only by 11% at around 2,8 TWh. For hot water preparation three quarters of the 9 TWh consumed are covered by gas, oil and direct electric water heaters.

Despite the incentive programs launched in 2010, the yearly rate of building renovation in Switzerland is less than 1%, in line with the average numbers in the EU countries. Of the 1,7 mio. residential buildings, in 2019 more than 8000 benefitted from incentives for the envelope insulation measures, and more than 4000 substituted the heating systems. The incentive scheme for buildings rewards with additional incentives the combined interventions on envelope and systems, considering the classification in the building energy certificate or in other voluntary certification schemes.

The joint model cantonal provisions in the energy sector (MuKEn) 2014 includes the mandatory substitution of the direct electric heaters and boilers, centralized and not: only few cantons are actually including it in the regulations.

The high investment costs and low energy prices are the main barriers against more efficient heating solutions, despite the level of incentives - that actually excludes air-air heat pumps. Other obstacles are the low building property rate, in average 38%, and the electrical energy tariffs, slightly regressive in all regions. The cost for the installation of a proper hydronic distribution system is not always economically sustainable despite the additional subsidy for its installation.

The reduction of the heating demand is crucial for meeting the decarbonisation and the Swiss Energy Strategy 2050. The heating demand density is already low in many regions. With a higher renovation rate for the building envelope, it will decrease even more: the small scale and decentralized heat generation is still the only cost-effective option in many cases.

In Switzerland the electrification of heating started in the 1970’s with the oil crisis. The higher efficiency of heat pumps in insulated buildings, combined with management systems are an opportunity for the energy utilities: reducing the peak power, managing the supply and the demand reducing the emissions, offering a service without interruption.

The quality of the appliances installed, their consumption levels, installation features and their costs will be presented in more detail for the selected case studies in new and refurbished buildings located in Switzerland, in the alpine or pre-alpine area, that adopt efficient, effective and comfortable air-to-air heat pumps installation for heating.

A quick adoption of highly efficient solutions, typically supported by incentive schemes or obligations, will help in a rapid decrease of the energy consumption and the related CO2 emissions. In order to reach the optimal results in terms of energy, cost and emissions savings, an attentive choice of the right system is always necessary. Initiatives such as the Horizon 2020 HACKS project will aim the households equipped with old and inefficient devices - boilers, water heaters, air conditioners, certain types of boilers and stoves, etc. - to replace them with new super-efficient equipment.

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