Business Green: For years developers have wondered how to make better use of landfill sites, but now a Spanish company may have come up with an answer that promises to redevelop existing landfill sites while bolstering the UK’s renewable energy capacity. Engineering firm Fomento de Construcciones y Contratas (FCC) this week announced plans to invest £100m through its subsidiaries FCC Energy (FCCE) and Waste Recycling Group (WRG) to install up to 80MW of wind energy capacity at its landfill sites in …