The Solar and Energy Loan Fund of St. Lucie County Inc. is a personal loan from Solar and Energy Loan Fund of St. Lucie County Inc.. Loan terms: Fixed 10-year on-bill payment plan. Sign up for Martin County Utilities (MCU) Septic-to-Sewer (S2S) Conversion Program today and receive an automatic $1000 incentive and the option to apply for a fixed 10 year, $92/month payment plan through SELF!