4 RBuildings
The intention here is to make available results on the building stocks at various scale from models that propose configuration of energy systems.
The final goal would be to centralise data and results on buildings so that a quick overlook can be given on any of them in Switzerland.
At the district and building scale, REHO is used to find the optimal energy system according to an objective. REHO is an open-source and well documented tool. Please refer to the REHO documentation for details on its functioning.
To generate results over the whole country, varying the model configuration, we use the district typification explained on Section (district-archetypes?).
Those results can then be stored on a database, where the configuration allows to retrieve them.
4.1 Database
4.1.1 Structure
The data volume that represents the results, even with the clustering, is important. Indeed, REHO computes results with time series. Therefore, the minimum amount of data should be stored on the database: redundancy should be avoided while also minimising the requests to the database to compute a value.
The common variables are stored in the model schema. Everything that is related to the buildings is already in GBuildings. The structure is described in Figure 4.1 and the tables are described in Table 4.1 to Table 4.4.
Table 4.1: Time-related tables fields
| Fields | Comments |
|---|---|
| id | Unique id of each hour represented |
| Period | Representative day |
| Time | Hours of the day from 1 to 24 |
| T_ext | Exterior temperature at the given hour (°C) |
| I_global | Global irradiance at the given hour (W/m2) |
| Fields | Comments |
|---|---|
| hours | Every hour of the year from 1 to 8760 |
| period | The period by which it will be represented |
| a Yellow cells are used to mark Primary Key and blue ones for the Foreign Key, linked to a PK from another table. |
| Fields | Comments |
|---|---|
| Period | ID of the period of the year |
| frequency | How many days in the year are represented by the period |
Table 4.2: REHO model tables fields
| Fields | Comments |
|---|---|
| id | Identifies the unit type |
| name | Name of the unit |
| name_fr | Translation in French |
| name_de | Translation in German |
| lifetime | Lifetime of the unit |
| Cost_inv1 | To compute the investment cost of the unit according to its size |
| Cost_inv2 | |
| GWP_unit1 | To compute the CO2-eq emissions of the unit construction |
| GWP_unit2 | |
| land_use_1 | To compute the investment cost of the unit according to its size |
| land_use_2 | |
| mine_res_1 | To compute the CO2-eq emissions of the unit construction |
| mine_res_2 | |
| water_res_1 | To compute the investment cost of the unit according to its size |
| water_res_2 | |
| energy_res_1 | To compute the CO2-eq emissions of the unit construction |
| energy_res_2 | |
| Human_toxicity_1 | To compute the investment cost of the unit according to its size |
| Human_toxicity_2 | |
| water_pollutants_1 | To compute the CO2-eq emissions of the unit construction |
| water_pollutants_2 | |
| metals_water_1 | To compute the investment cost of the unit according to its size |
| metals_water_2 | |
| pop_water_1 | To compute the CO2-eq emissions of the unit construction |
| pop_water_2 | |
| metals_soil_1 | To compute the investment cost of the unit according to its size |
| metals_soil_2 | |
| pollutants_pm_1 | To compute the CO2-eq emissions of the unit construction |
| polutants_pm_2 | |
| Metal_air_1 | To compute the investment cost of the unit according to its size |
| Metal_air_2 | |
| has_layers | To compute the CO2-eq emissions of the unit construction |
| Fields | Comments |
|---|---|
| id | Identifies the unit type |
| name | Name of the unit |
| name_fr | Translation in French |
| name_de | Translation in German |
| Cost_demand_cst | Pricing of the resource when buying or selling in the model |
| Cost_supply_cst | |
| GWP_demand_cst | Impact of the resource when buying or selling in the model |
| GWP_supply_cst | |
| land_use_demand_cst | To compute the investment cost of the unit according to its size |
| land_use_supply_cst | |
| mine_res_demand_cst | To compute the CO2-eq emissions of the unit construction |
| mine_res_supply_cst | |
| water_res_demand_cst | To compute the investment cost of the unit according to its size |
| water_res_supply_cst | |
| energy_demand_cst | To compute the CO2-eq emissions of the unit construction |
| energy_res_supply_cst | |
| Human_toxicity_demand_cst | To compute the investment cost of the unit according to its size |
| Human_toxicity_supply_cst | |
| water_pollutants_demand_cst | To compute the CO2-eq emissions of the unit construction |
| water_pollutants_supply_cst | |
| metals_water_demand_cst | To compute the investment cost of the unit according to its size |
| metals_water_supply_cst | |
| pop_water_demand_cst | To compute the CO2-eq emissions of the unit construction |
| pop_water_supply_cst | |
| metals_soil_demand_cst | To compute the investment cost of the unit according to its size |
| metals_soil_supply_cst | |
| pollutants_pm_demand_cst | To compute the CO2-eq emissions of the unit construction |
| polutants_pm_supply_cst | |
| Metal_air_demand_cst | To compute the investment cost of the unit according to its size |
| Metal_air_supply_cst |
Table 4.3: District results tables fields
| Fields | Comments |
|---|---|
| id | Unique id for each configuration |
| transformer | id of the transformer on which REHO was run |
| Layer_supply | For each layer in model.layer, the total annual supply and demand are saved (MWh) |
| Layer_demand | |
| Unit_installed_kW | For each unit in model.unit_characteristics, the size installed is saved (kW) |
| a Table used to retrieve a run. Allows to filter results by amount of PV installed or by transformer for instance. |
| Fields | Comments |
|---|---|
| id | Unique id of the hub in the REHO run |
| name | Name of the hub in the REHO run |
| connected_to | |
| id_building | If the hub is a building, id_building in GBuildings, that allows to retrieve data |
| id_config | id of the run configuration from districts.configuration |
| Fields | Comments |
|---|---|
| id | Unique id for the units installation |
| id_config | id of the REHO run configuration, from districts.configuration |
| from_unit_type | id of the unit from model.units_characteristics, allows to retrieve data on unit |
| Hub | id of the hub from districts.hub |
| Units_Mult | Size of the unit installed (kW) |
Table 4.4: District results with timesteps tables fields
| Fields | Comments |
|---|---|
| id | Unique id of the units use at time t for a given run |
| id_period | id of the period to which time t is associated, from model.time_period |
| Hub | id of the hub from districts.hub |
| from_unit_type | id of the unit from model.units_characteristics, allows to retrieve data on unit |
| Units_demand | Amount of demand, supply and curtailement at unit at time t |
| Units_supply | |
| Units_curtailment | |
| id_config | id of the REHO run configuration, from districts.configuration |
| a This table stores the flows at units at each time period. |
| Fields | Comments |
|---|---|
| id | Unique id of the grid data for that period t |
| id_period | id of the time period |
| Layer | id of the layer, allows to retrieve its characteristics from the model schema |
| Hub | id_building, allows to retrieve buildings data from GBuildings |
| Cost_demand | Buying of the layer at time t |
| Cost_supply | Selling of the layer at time t |
| GWP_demand | Impact of buying the layer at time t$ |
| GWP_supply | Impact of selling the layer at time t$ |
| Grid_demand | How much is bought at time t |
| Grid_supply | How much is sold at time t |
| Uncontrollable_load | Part of the demand that is not controllable |
| id_config | To which REHO solving configuration those results correspond |
| a This table stores the layers exchange and their costs and impact at each time period. |
| Fields | Comments |
|---|---|
| id | Unique id of the building data for that period |
| id_period | ID of the time period |
| Hub | Hub id from table districts.hub |
| gains | Heating gains at time t |
| heating | Heating demand at time t |
| a Stores the heating demand and heat gains at each time period |
Because the data have been so compacted in the tables, it is difficult to read one by itself and information from several may be necessary to cross, as they are not self-sufficient. For that reason, the python repository should be used to manipulate the database in a easier way.
4.2 Repository
The repository contains several functions to manipulate the data related to the database. First of all, there is the definition of a class DB_manager that helps for the writing of the results from a pickle to the database format and for the reading of the results back into the pickle format, while selecting a configuration by its id.
The repository also contains functions to retrieve a configuration according to criteria such as the size of PV installed or the electricity consumption.