Downloadable version of Table 2 in Excel format.

In order to overcome the problem that oil and gas boilers in existing buildings are typically replaced again by fossil fuel boilers, leading cantons in Switzerland have started to implement more targeted decarbonisation policies. The objective of the present paper is to critically discuss the experience made with policy measures for the decarbonisation of building-related heating systems in these cantons. For this purpose, semi-structured interviews were conducted as primary method. Early evidence indicates that the policies are effective by ensuring the transition to renewable heating technologies (primarily heat pumps). The implemented policy packages include coercive elements (mandatory renewable energy shares), subsidies as well as information and communication measures, resulting in a quasi-ban of fossil fuel boilers. Avoiding outright bans of fossil fuel use seems both effective to increase acceptance among building owners and reasonable to account for particularly demanding cases of boiler replacement (for which there is no technically or financially viable, fully renewable solution). Considering the very low carbon footprint of its electricity supply, Switzerland is a particularly convincing case for the transition from fossil fuel boilers to electric heat pumps. This is shown by means of an analysis of the CO2 emissions of heat pumps in comparison to gas and oil boilers across several European countries. We then compare the levelised cost of heat pumps for different subsidy levels. For a typical subsidy for the heat pump (equivalent to 11% of the investment cost), its levelised cost remains in an acceptable range compared to a gas boiler (7% more expensive). A sensitivity analysis shows the importance of high gas to electricity price ratios for financial viability. Evidence from leading cantons in Switzerland indicates that the chosen policy measures are effective, affordable and accepted and that they can be recommended to other countries.为解决既有建筑内的油气锅炉通常仍会被更换为化石燃料锅炉这一痛点，瑞士各州已开始推行更具针对性的脱碳政策。本文旨在批判性探讨上述各州针对建筑供暖系统脱碳所采取的政策措施的实践经验。为此，本研究采用半结构化访谈（semi-structured interviews）作为主要研究方法。初步实证结果表明，相关政策通过推动向可再生能源供暖技术（主要为热泵（heat pumps））转型，已取得良好成效。所推行的政策组合包含强制性要素（如强制性可再生能源占比要求）、补贴政策以及信息宣传与沟通措施，实质上形成了对化石燃料锅炉的准禁令。相较于直接全面禁止化石燃料使用，这种方式既有助于提升建筑业主的接受度，也能合理应对部分锅炉更换难度极高的场景——此类场景暂不存在技术或经济上可行的全可再生解决方案。考虑到瑞士电力供应的碳足迹极低，其从化石燃料锅炉向电动热泵的转型颇具示范意义。我们通过对比欧洲多国热泵与燃气、油气锅炉的二氧化碳排放量，验证了这一点。随后，我们针对不同补贴水平下的热泵平准化成本（levelised cost）展开了对比分析。针对热泵的典型补贴（相当于投资成本的11%）可使热泵的平准化成本处于合理区间，仅比燃气锅炉高出7%。敏感性分析结果显示，燃气与电价的高比值对热泵的经济可行性至关重要。来自瑞士标杆各州的实践证据表明，本次选用的政策措施兼具成效性、可负担性与接受度，可供其他国家借鉴推广。