curl --request GET \
  --url https://api.voltview.co.uk/v1/sites/{siteId}/siteSpecificEnergyIntensity \
  --header 'x-api-key: <api-key>'

{
  "siteId": "<string>",
  "intensity": 123,
  "period": "<string>",
  "benchmark": 123,
  "rating": "<string>"
}