For maps the EEA uses the ETRS_1989_LAEA_52N_10E coordinate system. This example shows how to get a similair projection with lat-lon data. The key parameters to get the right projection are:
The transverse Mercator projection
d3.geoTransverseMercator()
The center of the projection is on 10E 52N
projection.center([10,52])
A rotation around the normal axis to align the center meridian north
projection.rotate([-10,0,0])
Modified http://d3js.org/topojson.v1.min.js to a secure url
https://d3js.org/d3.v4.min.js
https://d3js.org/topojson.v1.min.js