At its 60-acre site on Bogue Road in Harwinton, O&G has invested more than $800,000 over the past year in equipment and system upgrades that should significantly reduce the amount of energy its asphalt and concrete plants use. Paul Balavender, O&G’s general counsel, said the upgrades are projected to reduce annual electric use by 12% and natural gas consumption by 30%. He said the upgrades are not mandated by state or federal regulations. Balavender said he was notified by Lauriero Engineering a couple of years ago of a presentation that Eversource was putting on regarding energy efficiency. But he said it is too soon to know whether O&G’s customers will benefit long-term from lower costs due to O&G’s reduced energy consumption. O&G plant manager Tony Blanchard said further savings are expected from upgrading exhaust fans, switching over from electricity to natural gas and repairing air leaks.