Offshore wind turbines and the water depth

At sea, elevation=1 returns the depth of the sea floor as a negative number, from the GEBCO grid. That works for anything mapped offshore: wind turbines, platforms, buoys or wrecks.

This query finds the wind turbines in the German Bight west of Heligoland and lists them from the deepest water.

The query

[out:json][timeout:25];
node["generator:source"="wind"](53.8,5.8,54.6,7.6);
out;

Run it

Live result from overpass.ch, cached for up to 12 hours. Map data © OpenStreetMap contributors (ODbL). Heights produced using Copernicus WorldDEM™-90 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved. Sea depths: GEBCO Compilation Group (2026) GEBCO 2026 Grid.

How it works

1. node["generator:source"="wind"] finds wind turbines, which are mapped as power=generator nodes.
2. The bounding box lies entirely at sea, so no turbines on land are included.
3. With elevation=1 each turbine gets an elevation, here between about −23 and −40 m. A direct call to /elevation also tells you "surface": "sea" and which dataset answered.
4. GEBCO is a grid of about 460 m built from surveys and satellite data. It gives the depth of the surrounding sea floor, not of a single foundation. It is not for navigation.

Variations

• Whole wind farms as areas: nwr["power"="plant"]["plant:source"="wind"] with out center;.
• Land and sea mixed: the same call answers with heights on land and depths at sea, so you don't need to know in advance which one a point is.

Run it from your code

The query is unchanged; elevation=1 in the URL adds the heights. Each height uses one lookup from your elevation allowance.

curl 'https://api.overpass.ch/v1/YOUR_API_KEY/interpreter?elevation=1' \
  --data-urlencode 'data@query.overpassql'

import requests

query = open("query.overpassql").read()
r = requests.post("https://api.overpass.ch/v1/YOUR_API_KEY/interpreter",
                  params={"elevation": 1}, data={"data": query}, timeout=120)
r.raise_for_status()
for el in r.json()["elements"]:
    height = el.get("elevation") or el.get("center", {}).get("elevation")
    print(el.get("tags", {}).get("name"), height)

const res = await fetch("https://api.overpass.ch/v1/YOUR_API_KEY/interpreter?elevation=1", {
  method: "POST",
  body: new URLSearchParams({ data: query }),
});
if (!res.ok) throw new Error(await res.text());
const { elements } = await res.json();
for (const el of elements) console.log(el.tags?.name, el.elevation ?? el.center?.elevation);

Save the query as query.overpassql. It works the same in Overpass Turbo, QGIS and JOSM.