Solar panels will cover the roofs of four buildings and two parking lots of a New Brunswick hospital in what officials call the largest such project at any healthcare facility in the state. When the project is complete early next year, the Saint Peter's Healthcare System will have nearly 10,000 panels producing more than 2.3 million kilowatt hours of electricity annually, enough to power an estimated 230 homes. Saint Peter's will invest $10 million, half covered by a loan from Public Service Electric & Gas, for the system. The hospital will repay the loan through solar renewable energy certificates, or credits, that will go to PSE&G to sell. In return, the New Brunswick hospital is expected to cut energy costs by $10 million over the next 25 years. Also, PSE&G is paying $4.8 million for energy efficiency improvements at the Saint Peter's University Hospital for additional savings in energy costs, The hospital must pay back 20% of that cost over three years.