Winter Days Research Articles

Heating and energy performances of a dynamic Trombe wall incorporating phase change materials under different operation modes

Dynamic Trombe wall incorporating PCMs (DTWP) is promising for effectively utilizing solar energy and latent heat storage to achieve building energy saving and different operating modes of the DTWP have different functions corresponding to different thermal and energy performances. However, the suitable operation mode for this system is still unclear. Therefore, in this research, the heating and energy performances of the DTWP system with different operation modes and companion static concrete and PCM Trombe walls under a typical winter day in a cold climate were comprehensively investigated using the corresponding CFD model validated by experimental data. The main results are: (1) The DCNC mode(fully closed vents of the thermal storage wall during daytime and nighttime) showed significant decreases in heat loss and good heating performance for the DTWP system; (2) The DCNC mode could extend the time lag and the thermal comfort duration, and showed significantly improved energy saving by 97.6 %; (3) Compared to the DONO mode (opened vents of the thermal storage wall during daytime and nighttime), the DCNC mode could decrease the indoor temperature stratification by 53.7 % and 67.7 % at noon and midnight, respectively; (4) The air velocity near the outer surface of the energy storage wall and the inner surface of the glazing layer is higher than in the other regions at noon and midnight, respectively. The findings would provide guidance for the application and practical operation optimization of DTWP in cold climate regions.

Enhancing energy efficiency of PCM wall in winter with novel PCM-DLCB coupling design

In order to enhance the thermal performance of the phase change material (PCM) wall during winter, a novel PCM and double-layer capillary bundles (PCM-DLCB) coupling wall is proposed. The PCM-DLCB wall utilizes the capillary bundle near the outer surface to capture solar energy during sunny winter days. The heat is then transferred to the capillary bundle near the inner surface through a circulating pump, promoting the melting of the PCM. Optimization and long-term operation comparison research were conducted using numerical simulation to investigate the potential of the PCM-DLCB wall to improve energy efficiency during winter. Five structural parameters, including the type of PCM, the position of the capillary bundle, the position and thickness of the PCM layer, the spacing of the capillary bundles, and the flow velocity in the capillary bundle, were selected as variables for structural and operation optimization. The optimization target was the accumulated heat gain from the inner surface of the wall. The research results indicate that: (1) The most suitable PCM is RT-18HC; (2) Placing the PCM layer between the double-layer capillary bundle yields better results compared to other arrangements; (3) Optimal energy saving is achieved when the outer capillary bundle is positioned 6 mm away from the outer surface and the inner capillary bundle is positioned 8 mm away from the inner surface; (4) The optimal thickness of the PCM layer is 10 mm; (5) The optimal flow velocity in the capillary bundle is approximately 0.04 m/s. Furthermore, long-term operation results based on a typical hot summer and cold winter climate zone reveal that the optimized PCM-DLCB wall provides a 7.80 % increase in indoor heat gain compared to an ordinary PCM wall during winter, and an 18.4 % increase compared to a wall without PCM.

Influence of Slope Aspect and Vegetation on the Soil Moisture Response to Snowmelt in the German Alps

Snow, especially in mountainous regions, plays a major role acting as a quasi-reservoir, as it gradually releases fresh water during the melting season and thereby fills rivers, lakes, and groundwater aquifers. For vegetation and irrigation, the timing of the snowmelt is crucial. Therefore, it is necessary to understand how snowmelt varies under different local conditions. While differences in slope aspect and vegetation (individually) were linked to differences in snow accumulation and ablation, this study connects the two and describes their influence on the soil moisture response to snowmelt. This research focuses on the catchment of the “Brunnenkopfhütte” (BKH) in Bavaria, southern Germany, where an automatic weather station (AWS) has operated since 2016. In addition, soil temperature and moisture monitoring systems in the surrounding area on a south aspect slope on an open field (SO), on a south aspect slope in the forest (SF), and a north aspect slope in the forest (NF) have operated since 2020. On snow-free days in winter, the soil temperature at the SF site was on average 1 °C lower than on the open site. At the NF site, this soil temperature difference increased to 2.3 °C. At the same time, for a 1 °C increase in the air temperature, the soil temperature increases by 0.35 °C at the NF site. In addition, at this site, snow cover disappeared approximately one week later than on the south aspect slopes. Snow cover at the SF site disappeared even earlier than at the SO site. Finally, a significant difference in the soil moisture response was found between the sites. While the vegetation cover dampens the magnitude of the soil moisture increases, at the NF site, no sharp increases in soil moisture were observed.

A detailed investigation on thermal performance and energy savings of cool roof systems for composite climates of India

ABSTRACT The rising worldwide temperatures leading to a spike in air conditioning to ensure thermal comfort in buildings is the root cause of the increase in energy demand in India's building sector. The roof of a building significantly adds to the heat gained on the top floor, accounting for 50–60% of the total heat gain. One sustainable way to reduce this heat gain is via cool roofing technology. Through examination and dynamic simulations with the Energy-Plus-based Design Builder software tool, this study explores different cool roof solutions. An experimental setup of a Reinforced Cement Concrete (RCC) roof with cement plaster, solar reflective paint, solar reflective tiles, and earthen pots have been created on the institute campus. Recordings were taken during the peak summer days and peak winter days, alongside simulations carried out to determine various factors such as Albedo, Surface Temperatures, Air Temperatures, Diurnal Heat Ingress, and the Building's Thermal Energy Consumption. The experiments have demonstrated that cool roof layers can considerably improve interior thermal comfort by minimizing heat transfer, which maintains a constant temperature over the bottom surface of the roof. By reducing heat gain by 33–71%, they can save energy by 21-26% compared to traditional RCC roof slab.

Performance optimization and evaluation of integrating thermochemical energy storage with low-temperature driven absorption heat pump for building heating: 4E analyses

A heating system achieved by combining thermochemical energy storage and absorption heat pump is proposed and verified. Based on the experimental data, a mathematical model of the zeolite/water reactor is established and verified. By setting up a micro-compressor between the evaporator and absorber, the AHP is driven by low temperature source. Based on typical days in winter, the stable operation of the system is explored, and the influence of main parameters on the charging/discharging and heating processes are analyzed. The results show that the charging and heating efficiency reached 55.11% and 73.52% during the daytime. The discharging efficiency at night reaches 88.27%. The AHP can be driven by a heat source at a minimum of 75 °C, and hot water at 48.3 °C is provided. Parameters influence analysis shows that temperature is an important factor affecting the charging process, and the initial air temperature is recommended to increase. Humidity is the biggest influencing factor in the discharging process and easily changed and controlled. By replacing electric heating, the system can allow the investment to be recovered within 6.23 years. Environmental analysis shows that the proposed system has significant benefits in terms of primary energy savings and pollutant emission reduction

Physiological responses to a changing winter climate in an early spring-breeding amphibian.

Climate change is swiftly altering environmental winter conditions, leading to significant ecological impacts such as phenological shifts in many species. As a result, animals might face physiological mismatches due to longer or earlier activity periods and are at risk of being exposed to late spring freezes. Our study points for the first time to the complex physiological challenges that amphibians face as a result of changing thermal conditions due to winter climate change. We investigated the physiological responses to a period of warmer winter days and sudden spring freeze in the common toad (Bufo bufo) by acclimating them to 4°C or 8°C for 48 h or exposing them to 4°C or -2°C for 6 h, respectively. We assessed the daily energy demands, determined body condition and cold tolerance, explored the molecular responses to freezing through hepatic tissue transcriptome analysis, and measured blood glucose levels. Toads acclimated to higher temperatures showed a higher daily energy expenditure and a reduced cold tolerance suggesting faster depletion of energy stores and the loss of winter acclimation during warmer winters. Blood sugar levels were higher in frozen toads indicating the mobilization of cryoprotective glucose with freezing which was further supported by changed patterns in proteins related to glucose metabolism. Overall, our results emphasize that increased thermal variability incurs physiological costs that may reduce energy reserves and thus affect amphibian health and survival. This might pose a serious threat to breeding adults and may have subsequent effects at the population level.

Performance assessment of the curved-type multi-channel PV roof for space-heating and electricity generation in winter

The curved-type PV roof integrated with flexible PV tiles is a novel attempt to implement the building-integrated photovoltaic/thermal technology into diverse genres of architectural design. To explore its performance in the function of electricity generation and space-heating, different ventilation configurations of the air channels are adopted in the design of the multi-air-channels of the system; two working modes (fresh-air-heating - FAH and recirculated-air-heating - RAH) are applied in the system's operation. The case study is based on a residential building linked with the system in Hefei, China. The performance assessment is conducted on a typical sunny winter day and through the winter of the Typical Meteorological Year. The investigation results indicate that RAH mode has the potential to raise the indoor air temperature to a greater extent. However, the electrical power output shows a disadvantage due to the relatively poor PV cooling effect; increasing the connection air channels could enhance the indoor air heating but add the fan power consumption. The prediction throughout winter manifests that the all-in-parallel connection produces 1827.63 kWh (FAH) and 1574.55 kWh (RAH) of total energy, whereas the 6-in-series connection produces 2085.91 kWh (FAH) and 1618.99 kWh (RAH).

Optimal Scheduling of Source–Load Synergy in Rural Integrated Energy Systems Considering Complementary Biogas–Wind–Solar Utilization

To address the issues of the low usage efficiency and illogical structure in rural regions, this study builds a rural integrated energy system (RIES) that incorporates the complementary use of biogas, wind, and light. For resolving the RIES optimum-low-carbon-economic-dispatch problem, a source–load-cooperative optimal-dispatch strategy is proposed. Firstly, a multi-energy integrated demand response (IDR) model based on time-of-use tariffs and time-varying biogas costs is established on the demand side. Secondly, power-to-gas devices are added on the supply side to optimize the system’s electricity–gas-coupling relationship and increase the wind power output space. Thirdly, an RIES-oriented carbon-trading model is constructed by considering the actual carbon emissions of gas loads and the stepped-carbon-trading mechanism. Finally, an optimal-dispatch model is built with the objective function of reducing the total energy cost, wind abandonment cost, IDR cost, and carbon emission cost, while the problem is transformed into a mixed-integer linear problem and solved using CPLEX 12.9. By setting up four scenarios for example analysis, the results show that on typical days in spring, summer, autumn, and winter, the total operating costs of the stepped-carbon-trading system (Scenario 1), taking into account the source-side power-to-gas (P2G) device and the load-side IDR, are reduced by 12.25%, 11.25%, 12.42%, and 11.56%, respectively, compared to the system without the introduction of the IDR (Scenario 3). In contrast to the system that lacks a P2G device at the source end (Scenario 2), the overall costs are decreased by 4.97%, 3.07%, 5.02%, and 5.36%, but the wind power consumption rates are increased by 11.63%, 7.93%, 11.54%, and 11.65%, respectively. Stepped emission trading (Scenario 1) reduces the total operating costs by 5.12%, 3.15%, 5.21%, and 6.84%, respectively, while reducing the biogas costs by 9.75%, 7.74%, 9.67%, and 9.57%, respectively, in comparison to traditional emission trading (Scenario 4). The example results demonstrate the economics, effectiveness, and reliability of a stepped-carbon-trading system with an integrated P2G load-side energy demand response.

Energy performance of a residential zero energy building energy system – R-CELLS at solar decathlon China 2022

The energy system and its energy performance of R-CELLS, a residential zero energy building from team Tianjin U+ in the Solar Decathlon China 2022, is introduced in this paper. When designing and constructing the R-CELLS energy system, two sets of challenges are encountered. Firstly, from an architectural perspective, the limited construction timeframe (only 21 days) and constrained space for housing the equipment, also ease of maintenance should be taken into account. Secondly, from an operational perspective, a constrained period for tests before the competition, a large number of devices dependent on electricity, heat and hot water supply should be considered. In consideration of the ease of assembly and maintenance of the energy system components and the aesthetic requirements of R-CELLS, an improved “photovoltaics, energy storage, direct current, flexibility” based energy system is utilized in R-CELLS. The R-CELLS energy system integrates various renewable energy sources (building integrated photovoltaics, photovoltaic-thermal, and building integrated wind turbines). Furthermore, it incorporates energy storage systems such as battery energy storage system, hot water tank, and phase change material thermal storage. In order to satisfy user requirements in grid-connected, off-grid and outage scenarios, including electricity, heat and domestic hot water, a tri-period energy management strategy based on optimized scheduling and rule-based control is proposed to achieve weekly, daily, and hourly net zero goals. Furthermore, the energy performance of R-CELLS is simulated for a whole year, including typical days in winter and summer, as well as the competition period. During the Solar Decathlon China 2022 competition, R-CELLS was subjected to testing by the committee. The results demonstrated that R-CELLS can be operated off-grid and with zero energy consumption, while meeting the test requirements for indoor environment, heating and cooling, and home life.

Assessment of the estimation methods of Tmrt in semi-outdoor spaces in humid sub-tropical climates: An empirical study in Wuhan, China

Studies have been conducted on the mean radiant temperature (Tmrt) estimation methods using globe thermometers for measuring outdoor thermal environments in various climate regions. Yet, given the unique thermal environments of semi-outdoor spaces, these Tmrt estimation methods may not be appropriate for the spaces with shading effects. This study aims to assess the thermometric and radiative methods for Tmrt estimation in semi-outdoor spaces in humid sub-tropical climates, taking data from six-directional radiation measurements as validations. During the typical summer and winter days in Wuhan, China, the measurements were carried out in semi-outdoor spaces facing south and west, with an open square for comparison, including air temperature, humidity, wind velocity, black-globe temperature, and long- and short-wavelength radiation fluxes obtained from four-component net radiometers. It was found the maximum mean deviation of diurnal Tmrt values estimated by the black-globe thermometer method in semi-outdoor spaces was 7.1 °C, which exceeded the threshold required by ISO7726, where the shortwave radiation was regarded as the dominant interference factor. To improve the accuracy and cost-effectiveness of Tmrt estimation, we proposed linear empirical equations to calibrate the Tmrt estimated by black-global thermometer method that the root mean square error (RMSE) of the Tmrt deviations can generally vary from 2.22 to 2.72 °C. Contributing to the thermal comfort research, this study proposed an empirical method for estimating Tmrt in semi-outdoor spaces in humid subtropical climates, which can generate satisfactory results in accordance with ISO7726 standards with cost-effective instrumentation.

Energy demand and carbon emission analyses of a solar-driven domestic regional environment mobile robot as household auxiliary heating and cooling method

Under the trend of energy saving and carbon reduction, reducing household energy consumption, which is an important part of social energy consumption, has become a hot topic. In order to solve the problem of mismatch between supply and demand of household environment control systems as well as to better meet the individual needs of users, we innovatively designed a solar-driven domestic regional environment mobile robot as auxiliary heating and cooling method. In this paper, a simplified thermal network analysis of the thermal conditions of a dwelling is utilized to calculate the energy saving and carbon reduction potential on summer and winter reference days in Beijing and Guangzhou, China. The simulation results show that the system has good energy saving potential and carbon reduction effect. In particular, the single-day energy saving potential of the system on winter days in Beijing reaches to 583.6 kWh compared to the traditional method. Under the power supply mode, the single-day carbon reduction can reach 462 kg CO2 on winter days in Guangzhou, and it can reach 333.2 kg CO2 on summer days in Beijing. We also discuss the effect of regional space size and clothing thermal resistance. As the local space size and the clothing thermal resistance increases, the energy saving potential and carbon reduction benefits of the system decrease, but the overall impact is small. The proposed mobile robot following in the vicinity of home inhabitants to help maintain their thermal comfort, can improve the efficiency of dwellings heating and cooling systems and utilize the limited solar energy resources in family area.

Revealing the role of green roof substrate: limitations of simulated substrate temperatures for summer and winter day and night thermal performance in Melbourne, Australia

Revealing the role of green roof substrate: limitations of simulated substrate temperatures for summer and winter day and night thermal performance in Melbourne, Australia

Mapping sedentary behaviour (MAPS-B) in winter and spring using wearable sensors, indoor positioning systems, and diaries in older adults who are pre-frail and frail: A feasibility longitudinal study.

Older adults who are frail are likely to be sedentary. Prior interventions to reduce sedentary time in older adults have not been effective as there is little research about the context of sedentary behaviour (posture, location, purpose, social environment). Moreover, there is limited evidence on feasible measures to assess context of sedentary behaviour in older adults. The aim of our study was to determine the feasibility of measuring context of sedentary behaviour in older adults with pre-frailty or frailty using a combination of objective and self-report measures. We defined "feasibility process" using recruitment (20 participants within two-months), retention (85%), and refusal (20%) rates and "feasibility resource" if the measures capture context and can be linked (e.g., sitting-kitchen-eating-alone) and are all participants willing to use the measures. Context was assessed using a wearable sensor to assess posture, a smart home monitoring system for location, and an electronic or hard-copy diary for purpose and social context over three days in winter and spring. We approached 80 potential individuals, and 58 expressed interest; of the 58 individuals, 37 did not enroll due to lack of interest or medical mistrust (64% refusal). We recruited 21 older adults (72±7.3 years, 13 females, 13 frail) within two months and experienced two dropouts due to medical mistrust or worsening health (90% retention). The wearable sensor, indoor positioning system, and electronic diary accurately captured one domain of context, but the hard copy was often not completed with enough detail, so it was challenging to link it to the other devices. Although not all participants were willing to use the wearable sensor, indoor positioning system, or electronic diary, we were able to triage the measures of those who did. The use of wearable sensors and electronic diaries may be a feasible method to assess context of sedentary behaviour, but more research is needed with device-based measures in diverse groups.

Abstracts of the 11th Anatomy Winter Days 7–9 March 2024, Aydın, Türkiye

Abstracts of the 11th Anatomy Winter Days 7–9 March 2024, Aydın, Türkiye

Analyzing the Energy Usage of a Community and the Benefits of Energy Storage

Understanding the energy usage of a community is crucial for policymaking, energy planning, and achieving sustainable development. The advent of the smart grid has made it feasible to gather fine-grain energy usage data at large-scales, providing us with new opportunities to understand demand patterns at different spatial and temporal scales. In this paper, we conduct a large-scale empirical study of energy usage of 14,849 residential and commercial energy consumers from a small city in the United States. We conduct a wide ranging analysis of energy usage at multiple granularities—citywide, transformer-level, and individual home levels. In doing so, we demonstrate how city-wide smart meter datasets can answer a variety of questions on energy consumption, such as the impact of weather on energy usage. For example, we show that extreme weather events significantly increase energy usage, e.g., by 36% and 11.5% on hot summer and cold winter days, respectively. As another example, we show 19.2% of transformers in the grid get overloaded during peak load periods. Finally, we evaluate the impact of incorporating varying amounts of energy storage within the distribution grid and the impact such deployments will have on the peak demand patterns seen by the grid as well as the ability to reduce overloads seen by distribution transformers during peak periods.

Impact of windbreak design on microclimate in hot regions during cold waves: Numerical investigation

Winter cold wave adaptation strategies in hot climates due to climate change didn’t receive the deserved attention from previous studies. Therefore, this study comprehensively investigates the impact of various windbreak parameters on mitigating winter cold stress in hot steppe-arid climate. A microclimate model for a residential campus was built and validated through on-site measurement on a typical winter day to assess thirty-two scenarios for tree characteristics and spatial configuration windbreak parameters based on PET, wind speed, and Air Temperature (AT). Moreover, four configurations, that had best results on mitigating cold stress in winter, were tested during typical summer conditions to couple the assessment of cold and hot seasons. Additionally, environmental analysis for all scenarios was conducted. The results revealed that the most effective parameters for mitigating cold stress are tree distribution, Leaf Area Density (LAD), row number, spacing, and shape. Double rows of high LAD and medium height trees with small spacing yielded the best cold stress mitigation effect. Furthermore, the windbreak reduced the cold stress in the morning and night by 19.31% and 18.06%, respectively. It reduced AT and wind speed at night by 0.79 °C and 2.56 m/s, respectively. During summer, very hot PET area was reduced by 21.79% and 19.5% at 12:00 and 15:00, respectively.

The Impacts of Changing Winter Warm Spells on Snow Ablation Over Western North America

AbstractAn increase in winter air temperature can amplify snowmelt and sublimation in mountain regions with implications to water resources and ecological systems. Winter Warm Spells (WWS) are defined as a winter period (December to February, DJF) of at least 3 consecutive days with daily maximum temperature anomaly above the 90th percentile (using a moving‐average of 15 days between 2001 and 2013). We calculate WWS for every 4‐km grid cell within an atmospheric model over western North America to characterize WWS and analyze snow ablation and their changes in a warmer climate. We find that days with ablation during WWS represent a small fraction of winter days (0.6 days), however, 49% of total winter ablation (33.4 mm/DJF) occurs during WWS. Greater extreme ablation rates (99th percentile) occur 18% more frequently during WWS than during non‐WWS days. Ablation rates during WWS in humid regions are larger (9 mm d−1) than in dry regions (7 mm d−1) in a warmer climate, which can be explained by differences in the energy balance and the snowpack's cold content. We find that warmer (0.8°C), longer (1.8 days) and more frequent (3.7 more events) WWS increase total winter ablation (on average 109% or 18 mm/DJF) in a warmer climate. Winter melt during WWS in warm and humid places is expected to increase about 3 times more than in the cold and dry region. This study provides a comprehensive description of WWS and their impact on snowpack dynamics, which is relevant to reservoir operations and water security.

Influence of the demand side management on the daily performance of microgrids in smart environments using grey wolf optimizer

PurposeThis study aims to investigate the daily performance of the proposed microgrid (MG) that comprises photovoltaic, wind turbines and is connected to the main grid. The load demand is a residential area that includes 20 houses.Design/methodology/approachThe daily operational strategy of the proposed MG allows to vend and procure utterly between the main grid and MG. The smart metre of every consumer provides the supplier with the daily consumption pattern which is amended by demand side management (DSM). The daily operational cost (DOC) CO2 emission and other measures are utilized to evaluate the system performance. A grey wolf optimizer was employed to minimize DOC including the cost of procuring energy from the main grid, the emission cost and the revenue of sold energy to the main grid.FindingsThe obtained results of winter and summer days revealed that DSM significantly improved the system performance from the economic and environmental perspectives. With DSM, DOC on winter day was −26.93 ($/kWh) and on summer day, DOC was 10.59 ($/kWh). While without considering DSM, DOC on winter day was −25.42 ($/kWh) and on summer day DOC was 14.95 ($/kWh).Originality/valueAs opposed to previous research that predominantly addressed the long-term operation, the value of the proposed research is to investigate the short-term operation (24-hour) of MG that copes with vital contingencies associated with selling and procuring energy with the main grid considering the environmental cost. Outstandingly, the proposed research engaged the consumers by smart meters to apply demand-sideDSM, while the previous studies largely focused on supply side management.

Harnessing fluorescence resonance energy transfer for improved solar still performance with zinc oxide nanoparticles and activated carbon

The Single Slope Corrugated Wick type Solar Distillers (SWS) have attracted significant research funding owing to their simple preparation process and excellent durability against heat and moisture. However, there is a recognized need to enhance their solar energy conversion efficiency. The utilization of ZnO nanoparticles (Z) in SWS is limited by their light absorption capacity, resulting in suboptimal thermal energy conversion and solar energy absorption. In this investigation, we propose an innovative method known as Fluorescence Resonance Energy Transfer (FRET), combining crystallized Z with activated carbon (AC) derived from areca nut shells. This novel approach substantially boosts the thermal efficiency of solar energy utilization in SWS by facilitating efficient energy transfer from ZAC to water.The FRET technique enables the effective transfer of energy from ZAC to water and is comprehensively analyzed. By utilizing Z as donors and AC as acceptors, the photoluminescence emitted by ZAC can be absorbed by both components, thereby increasing the carrier population as of Corrugated Wick-type towards the condenser face within SWS. The evaporation rate from water to the condensing surface is significantly higher in SWS with ZAC compared to conventional wick-type solar stills (CWS), attributed to the efficient heat transfer facilitated through multi-dimensional heterojunctions within ZAC. The energy and charge transfer processes are optimized for both summer and winter operating conditions. The ZAC-based SWS exhibits exceptional resilience in various ambient conditions, resulting in a substantial 33.989 % enhancement in distillation efficiency during summer and a notable 31.199 % improvement in winter. The incorporation of ZAC elevates the production of distillate water to 6.325 liters/m2 per day in summer and 5.840 liters/m2 per day in winter (24 h). The energy distribution among particle components is extensively scrutinized using the FRET mechanism.

Green hydrogen energy source for a residential fuel cell micro-combined heat and power

In this paper, fuel cell micro combined heat and power with green hydrogen production is investigated for a residential house. Solar and wind energy were investigated for green hydrogen production. The performance of the micro-CHP system was evaluated using yearly energy coverage rate as an index, defined by the energy production and need ratio. A dynamic mathematical model of PEM fuel cell combined with the condensing boiler, supplied by local production of green hydrogen was developed. It was validated based on the yearly measurements in the FC micro-CHP unit installed in a French residential house. The key factors in the micro-CHP operating strategy were the fuel cell heat generation, stop phases, and regeneration which control water temperature, fuel cell life cycle, and annual performance. For conventional residential house in Normandy, the fuel cell operates for a short period during a summer day and the stored hot water was sufficient for heat demand. For winter typical day, the fuel cell operates continuously with maximum heat production. Electricity demand is satisfied and the condensing boiler is used to fulfill heat demand. Operating under heat led strategy, the yearly heat coverage rate is of 100% and the electricity coverage rate is usually upper 100% with 20 to 60% of stored electricity. Impact of the heating degree day and solar irradiance were analyzed using climatic zone factor as an index. Micro-CHP minimum hydrogen self-sufficiency of 57% is obtained in the coldest region where the climatic zone factor is 71°Cm2/W. Micro-CHP 100% hydrogen autonomy is achieved in regions where the climatic zone factor is lower than 39°Cm2/W.