Sister Janet Ryan, of the Sister Servants of the Immaculate Heart of Mary, shows Lee Patrick Sullivan the pipes for her convent's geothermal heating system. It's connected to 239 wells on the convent's property. Ryan says the system has saved the convent about $139,000 a year in heating and cooling costs, enough to pay for itself in just five years. That savings has also helped the convent pay for a new heating and cooling system.