| dc.description.abstract | Net zero energy building is becoming one of the most interesting concept to design new residential and commercial buildings where natural energy sources are able to supply the energy demand. Solar energy is a recent innovative technology to meet the energy demand in order to achieve the vision of net zero energy building. There are several attributes which have effects on solar energy production such as geographical site conditions, building area and shape of the roof. In addition, there are some factors that influence on energy consumption such as number of offices, number of equipment and climatic condition. Several solar energy simulators can estimate the solar energy production rate per hour (KWh) and multiply hourly energy production rate by average number of producing hours per each month in order to predict the maximum solar energy production rate (KW) over the whole year. These simulators estimate the energy production rate based on design factors. These factors are including tilt angle, pitch, azimuth, racking type and weather conditions. For example, if a specific solar panel’s design (specific tilt angle, pitch, azimuth and racking type) produces 40 KW energy per hour in April (30 days) and the expected number of producing hours in this month is 5 hours per day, the expected total solar energy production in April is 6000 KW. However, there are three issues that have been taken into account in such energy estimations: (1) Considering the expected monthly production overlooks daily and weekly production rate which decrease our understanding of hourly production behavior within a day and during the week. (2) The utilization of energy production is dependent on energy consumption which means there are some time intervals when solar energy is produced but there is no consumption. Therefore, the produced energy in these time intervals is wasted, if storage is not installed. In order to have an efficient system, we need to understand hourly energy production rate and hourly energy consumption rate. It is hard to have an efficient system in monthly base. (3) In order to conduct revision for the building and solar energy design, we should understand the impact of each design factor on both energy production and energy consumption. Different design factors may have contradictory effect or systemic impact on whole system. For instance, reduction in building area can decrease the consumption in one hand and reduce the solar energy production in the other hand. Hence, we need to understand the dynamic behavior of energy production and energy consumption per hour which can lead to revise the conceptual design in a more effective manner i.e. to have effective operational energy management and to avoid economical risk.
Thus, the objective of this thesis is to develop a cost-oriented model to estimate the hourly solar energy production rate and hourly energy consumption rate for specific office building and solar energy design over a whole year.
In order to develop this model, a case study has been selected to extract the real solar energy production and energy consumption profiles which have been mimicked by simulation model and to be used as a reference for testing the model i.e. comparing the simulated results with the measured data (real data).
The work first has been started with system analysis for office building design (architecture data) and potential alternatives in solar energy designs. Second, the optimal solar energy design has been determined which has been used in simulation model to estimate its potential energy production rate. Third, the building design concept has been simulated to estimate the energy consumption. Then, the energy production model and energy consumption model have been integrated together in order to specify the systemic energy building profile which includes the utilized energy profile, purchased energy from the grid, stored energy. Fourth, the economic risk analysis has been conducted to identify the aspects of systemic risk.
The system analysis for the building design has shown that the building roof area and its shape (flat roof or tilted/sloped roof) play a crucial role for solar energy production i.e. tilt angle is the most important design factor which affects the solar energy production system. It is significant to mention that tilted solar panels with different angles (10° to 45°) need spacing between the panels (pitch) to minimize the total shade losses. Thus, tilted (slopped) roof can provide an option to use the entire roof without spacing between the solar panels (pitch).
The system analysis for solar energy design has illustrated that the most significant design factors which influence the solar energy production are tilt angle, pitch, racking type and site climatic conditions (sunlight, clouds). However, the most critical factor is tilt angle which is 10° in our system due to site location.
The simulation model for solar energy production has indicated that there are a lot of fluctuations in estimation of hourly energy production over the month. However, the monthly accumulated energy production rate is almost similar to monthly estimation. Hence, the energy production model underlines that there is a difference between energy utilization rate and the production rate.
The simulation model for energy consumption has shown that there are not considerable fluctuations in hourly estimation and accumulated seasonal consumption rate proves it since the seasonal accumulated energy consumption rate is almost similar to the seasonal real energy consumption rate. In addition, it is worth to highlight that the minimum hourly energy consumption rate is approximately the same over the year (60 KWh to 75 KWh) and also there is no big gap between maximum hourly energy consumption rate during the year (220 KWh to 245 KWh).
The proposed systemic energy building is including the utilized energy profile, purchased energy from the grid and stored energy which have illustrated that if the minimum energy consumption rate over the day is higher than maximum solar energy production rate, then the design needs to be revised and/or the energy consumption needs to be minimized.
The utilized energy profile has shown that the utilization rate is high in office building. It is obvious that high energy demand with limited flat roof area cannot achieve the zero energy building vision and it will be dependent on grid supply.
The systemic risk analysis has demonstrated that in calculation of energy consumption and energy production, there are several uncertain factors which need to be taken into more consideration to reduce the risk. However, amongst all uncertain factors, tilt angle in energy production and number of offices in energy consumption are the most uncertain ones. That is why, the uncertainty assessment has been carried out for these selected factors to evaluate the possibility to have a cost-effective system and results show that number of offices needs to be considered for more treatment and evaluation, if time, budget and resources permits.
The developed simulator is an effective and simple model to estimate the expected solar energy production, energy consumption, storage and grid dependencies in monetary terms. | nb_NO |
