A Maine official who is responsible for representing the interests of utility consumers has voiced concerns that an offshore wind electricity supply contract could add to residents’ power bills. The developers of the offshore wind research array want Maine to approve a 20-year electricity supply contract. Backers of the proposal have described it as integral to Maine’s renewable energy goals. Public Advocate William Harwood said this week that it’s possible the contract could increase bills if the proposed price is far above wholesale market rates, the Portland Press Herald reported. Details of the contract are not publicly available yet.