GreenMountain.com has agreed to change its advertisements in Pennsylvania and clarify its rates. The deal, with the state's Office of the Attorney General, came after the green energy supplier was found to be advertising its rates as lower, compared with those of incumbent utilities, than they actually are. It had advertised that consumers could save as much as $3.00 monthly on a bill of $100 by buying its cheapest blend, compared with the prices of Peco Energy. But Peco's prices included the gross receipts tax, so the savings would have been more like $1.00. GreenMountain.com, with more than 70,000 residential customers in Pennsylvania, will buy the output of a wind plant being built in the state.