As electronic vehicles (EVs) become more popular, there is an increasing need for access to charging stations, also known as ports. To that end, many modern apartment buildings have begun retrofitting their parking garages to include shared charging stations. A charging station is shared if it is accessible by anyone in the building.
But with increasing demand comes competition for these ports — nothing is more frustrating than coming home to find no charging stations available! In this project, you will use a dataset to help apartment building managers better understand their tenants’ EV charging habits.
The data has been loaded into a PostgreSQL database with a table named charging_sessions with the following columns:
charging_sessions
| Column | Definition | Data type |
|---|---|---|
garage_id | Identifier for the garage/building | VARCHAR |
user_id | Identifier for the individual user | VARCHAR |
user_type | Indicating whether the station is Shared or Private | VARCHAR |
start_plugin | The date and time the session started | DATETIME |
start_plugin_hour | The hour (in military time) that the session started | NUMERIC |
end_plugout | The date and time the session ended | DATETIME |
end_plugout_hour | The hour (in military time) that the session ended | NUMERIC |
duration_hours | The length of the session, in hours | NUMERIC |
el_kwh | Amount of electricity used (in Kilowatt hours) | NUMERIC |
month_plugin | The month that the session started | VARCHAR |
weekdays_plugin | The day of the week that the session started | VARCHAR |
Let’s get started!
Sources
Guided question: Find the number of unique users for each garage ID, and then find the shared garage that is the most used.
SELECT garage_id, COUNT(DISTINCT user_id) AS num_unique_users
FROM charging_sessions
WHERE user_type = 'Shared'
GROUP BY garage_id, user_type
ORDER BY num_unique_users DESCGuided question: What is the most popular start time and day for the shared garages?
SELECT weekdays_plugin, start_plugin_hour, COUNT(*) AS num_charging_sessions
FROM charging_sessions
WHERE user_type = 'Shared'
GROUP BY weekdays_plugin, start_plugin_hour
ORDER BY num_charging_sessions DESC
LIMIT 10;
Guided question: What is the average duration for the charges in the shared garages? Only include duration over 10 hours.
SELECT user_id, AVG(duration_hours) as avg_charging_duration
FROM charging_sessions
WHERE user_type = 'Shared'
GROUP BY user_id
HAVING AVG(duration_hours) > 10
ORDER BY AVG(duration_hours) DESC;