Create an equal area grid over a buffer of points

example.sql

-- 1) Create the desired buffer of 50km around your points, buffs
-- 2) Create a reprojected envelope around your buffs, area
-- 3) Create a rectangular grid inside the envelope, grid
-- 4) Select the centroid of each gridcell and reproject it as a a WGS84 point

-- The equal area Lambert projection for North America is documented here,
-- http://spatialreference.org/ref/sr-org/7314/
-- and is stored in your spatial ref system as, 97314

WITH buffs AS ( --creates a resource called 'area' that will act like any existing table
			SELECT 
				ST_Buffer(
					the_geom::geography, 
					50000)::geometry AS buffers, 
				name 
			FROM uofa_4km_nad83
	),
	area AS ( -- same as buffs, create a second resource
		SELECT 
			ST_Envelope( -- returns a polygon geometry that covers everything included
				ST_Transform( -- changes the porojection
					ST_Union(buffers), -- joins all returned geometries into one geom
					97314 -- the equal-area Lamber projection id for ST_Transform
				)
			) as envelope -- call this column, 'the_geom'
		FROM buffs --using buffs from above as our table
	),
	grid AS (
		SELECT 
			CDB_RectangleGrid( -- A cartodb function to return rect grid polygons
				envelope, --It will return the grid in whatever projection the input geometry is in
				1000, --width
				1000 --height
			) cell --call the column 'cell'
		FROM area 
	)
SELECT 
	ST_Centroid( --Returns the centroid of any geometry as a point
		ST_Transform( -- transform our equal area projection back into WGS84
			cell, 
			4326
		)
	) as the_geom 
FROM grid