Central Versus Semi-Decentralized Solar District Heating for Low Heat Density Housing Areas in Germany
Abstract
Abstract District heating risks to lose competitiveness the lower the linear heat density of a district is. The distribution network needs to be highly efficient in order to ensure economic feasibility. The heat distribution temperatures are crucial to keep distribution heat losses as low as possible. For a new housing area in Germany consisting mainly of single family houses, solar district heating concepts at two different supply temperature levels of 70°C supply and 40°C supply are examined in terms of economic and efficiency aspects. Depending on the required temperature level of the heat supply concept the component’s design differs. A system with 70°C supply temperature is based on a central heat supply with a heat pump and ground-mounted solar collectors , whereas the system with 40°C supply temperature is a semi-decentralized concept with central heat pump for space heating and decentralized solar thermal systems for domestic hot water preparation. Keywords: solar district heating, low heat demand density, ultra-low-temperature district heating