Optimal energy supply concepts to minimize Cost and CO2 for a residential neighborhood
The site & The Challenge
The area of study is a residential zone of multi-family buildings with 74 households in the city of Zurich. These buildings are currently using gas boilers and hot water tanks to cover their space heating and domestic hot water demand. The electricity demand for the houses is covered with grid electricity and there are 52 cars using gasoline. The owners of the houses would like to find a new reliable energy system that could supply the energy services at a lower cost and with less CO2 emissions.
The Solution
We used Sympheny optimization algorithms to find for this community the best future scenario in the year 2025 with a higher degree of e-mobility integration (50% of the float of cars will be electric). Sympheny engine will automaticaly find the energy design respect to the targets of minimum Cost and minimum CO2 Emissions.
For the generation of the new optimal energy system design, an energy model with a collection of Technology Candidates both Conversion and Storage was defined in Sympheny software including relevant cost and CO2 data. Different Imports, On-site Resources and Export Candidates with their prices and CO2 intensities were also included in the model of candidates. The Energy Demands for heating, hot water and mobility are fixed and must be satisfied by the optimal supply system that will be calculated.
calculated
In less than 3 minutes Sympheny engine executed more than 10'000 of valid energy system designs and found 3 optimal designs with the minimum Life-cycle Cost and minimum CO2 emissions.
3 Optimal designs found
Sympheny engine found 3 optimal designs that could supply the energy services to the residential area at minimum cost and CO2 emissions possible. For each system solution design different Conversion and Storage Technology sizes were chosen by the optimization engine. In the least cost system the heating and hot water demand was supplied with a combination or Air Source Heat Pump, Wood chips Boiler and Hot Water Storage . In the least CO2 system however the energy demands were covered with a less intensive combination of Air Source Heat Pump, Hot Water Tank and a Ground source Heat Pump connected to a Borehole Storage.
The results compared
The minimum cost solution compared to the current energy system of the residential area reduced the Annual Life-cycle Cost by 29% and the Annual Emissions by 74% compared with the original energy system. Other KPIs as the Annual Operational Cost and Export Revenues were improved.
The minimum Cost Energy System
A closer look into the minimum Life-cycle Cost system solution shows how the operation of the system was also optimized to match the new system design and energy demands. The base heating and hot water demand was covered by the Air Source Heat Pump whereas the peaks of demand were supplied by the Wood Chip Boiler. The Hot Water Storage was charged daily with the free and variable electricity supplied by the PV panels and provided flexibility to the heating system.
Annual Life-Cycle Cost breakdown of the system
Optimal operation of the minimum Cost solution (1st week of March)
