Performance Study of External Wall Insulation and a Hybrid Energy Supply System for a Rural Residential Building

Residential building energy consumption in rural areas of China is changing from noncommercial energy to commercial energy, which is detrimental to sustainable development. In order to utilize renewable energy to satisfy the energy demands of farmers in cold regions of China, a hybrid energy supply system of heat, electricity, and biogas and external wall insulation were developed and constructed for a typical rural residential building, and an experimental study and analysis has been conducted to evaluate their performance. The results showed that (1)the accumulated heat energy supplied from solar energy was 11,619MJ, and the corresponding proportion was 64.6%; (2)the total biogas yield satisfied the cooking fuel demands of the residents; (3)the electricity generated was sufficient for the hybrid system, but the excess was wasted due to a mismatch between the time of electricity generation and utilization; and (4)the annual energy saving rate was 85% and the static payback period was 7years. Also, some crucial issues are discussed for the improvement of room temperature and utilization efficiency of solar energy.