A couple in southeast Texas took out a $16,000 personal loan to install solar panels on their home to save on electricity costs.The husband, who is an engineer, handled the installation himself, saving an additional $15,000 in labor costs.After completing the project, they are saving around $500 a month on electricity bills, which amounts to $6,000 a year.The couple plans to pay off the loan early next year to fully enjoy the savings generated by their solar panels.