35 kv 2 kv oil spills essential components businesses typically 120240 businesses opens glamorous technology reliable electricity vital part contaminate soil humming noise small amount day 365 days operation 24 hours typically cooled aboveground installations concrete pad small groups utility poles low voltage high voltage primary function delivering electricity crucial role top supplier distribution transformer highefficiency transformers air tank underground vaults highvoltage winding serve individual homes efficiency distribution transformers common type typically isolation distribution transformers underground distribution systems highvoltage distribution system customers padmounted transformers steel tank importance lowvoltage winding insulation highvoltage transmission lines electrical grid ensuring residential areas manufacturers laminated silicon steel serve larger commercial provide electrical isolation electrical grid playing