Design Optimization Of Energy Systems For Zero Energy University Dormitory

In the current world,energy and environmental issues are two of the most difficult challenges in pursuing sustainable development.About 40% of the energy consumption and nearly a third of greenhouse gas emissions are related to the construction industry.Governments are taking the promotion of zero energy buildings as an important strategy to achieve energy conservation and carbon emission reduction targets.In China,university buildings have become part of a variety of high energy buildings,and dormitories have high energy consumption.Therefore,the optimal design of energy systems in zero energy dormitory buildings is critical to the promotion of the zero enegy building.Firstly,this paper analyzes the energy consumption of a university dormitory in a hot summer and cold winter area to determine the annual data of the building.Secondly,two types of renewable energy hybrid systems was designed(wind and solar: PV/WT/BA system;wind,solar and diesel: PV/WT/BA/GE system),so that the building is not connected to the state grid,completely rely on the design of the system to provide electricity to achieve off-grid zero energy buildings.Then this paper considers the renewable energy system to connect to the grid(PV/WT/Grid system)to achieve on-grid zero energy building.And the design and optimization of on-grid renewable energy systems under two different electricity price(single price and time-of-use price)for zero energy dormitory through HOMER.Finally,this paper considers the impact of factors such as component cost and sell-back price in the renewable energy system on system size,economy and environmental friendliness.It provides a reference for users who choose renewable energy systems and governments that have set up tariff and carbon tax policies.The results show that:(1)Among the off-grid renewable energy systems,the PV/WT/BA/GE system has great economic advantages but is not environmentally friendly.The PV/WT/BA system generates more power and wastes more.In PV/WT/BA/GE systems,diesel prices have the greatest impact on system economics.And it is more economical than the PV/WT/BA system when using a high carbon tax scheme.(2)At a single price and time-of-use price,the PV/WT/Grid system is less economical but environmentally friendly than traditional grid-only systems.In the grid-connected renewable energy system,the time-of-use price will make the system more advantageous than the single price in terms of economy and environmental friendliness.Under the time-sharing electricity price,the system adopts a high-carbon tax scheme which is worse than the PV/WT/Grid system.(3)In all renewable energy systems,the economics of the system are better with lower component costs.The order of the cost of each component to the economic impact of the system is basically: BA>PV>WT?inverter.In the time-use-of PV/WT/Grid system,when the cost of other components is constant and the cost of PV modules becomes less than 75% of the original cost,the system is more economical than the grid-only system.(4)The economics of the PV/WT/Grid system deteriorates with the decline in the sell-back price,and the component cost has a greater impact than the sell-back price in the system economy.When the total component cost is reduced to less than 75% of the original cost and the sell-back price is not lower than 87.5% of the original price,the system is more economical than the grid-only system.