Two types of crystalline silicon (c-Si) photovoltaic (PV) modules have been tested in the cold-dry climate of the Gobi Desert of Mongolia, from 2002 to 2012, to verify the preliminary estimation of PV power generation. This study mainly focuses on the analysis of the long-term performance of the PV modules using indices such as energy yield, reference yield, performance ratio (PR), and characterization indices of the main electrical parameters as well as degradation rate. Average annual energy yields were 1880 h for Module 1 and 1789 h for Module 2. Thus, PRs were 0.85 and 0.80, while the average annual reference yield was 2223 h. On the other hand, degradation rates of Modules 1 and 2 were −1.28 and −0.86%/year, respectively. The electrical degradation observed in both modules was due to the loss of short-circuit current as open-circuit voltage reduction was not considered in this field test.

There are approximately 200,000 households living in detached houses and gers (yurts) with small coal stoves that burn raw coal in Ulaanbaatar city. A proper heating system and improvement of the energy efficiency of residential dwellings are vitally important for Ulaanbaatar city to reduce air pollution as well as for the operation of the current central energy system. This study shows the experimental results for two gers with two different heating systems and different thermal insulation, for investigating the merits of each. The technical feasibility of the system consisting of an electric thermal storage (ETS) heater with a daytime charging schedule and areal photovoltaic (PV) system was also examined by using a simulation with software developed in MATLAB (R2020a, MathWorks, USA). As a result of the experiment, the indoor comfort level and energy efficiency of the ger with added insulation and an ETS heater with nighttime charging were shown to be enhanced compared with those of the reference ger. The ger with added insulation and the ETS heater consumed 3169 kWh for electric appliances and 5989 kWh for the heating season. The simulation showed that the PV self-consumption rate is 76% for the Ger 2 with the ETS heater because of the daytime charging schedule of the ETS heater. The PV system supplied 31% of the total energy consumed, with the remaining 69% from the main grid.