State regulators unanimously approved three of four changes Monday to Tampa Electric Co. and Duke Energy Florida customers’ monthly bills for 2019. Still pending when the Florida Public Service Commission hearing resumes Tuesday is fuel costs. Should that item also be approved, Tampa Electric customers’ bills would drop by $8 to an average of $99.53 per 1,000 kilowatt hours — the average monthly household energy use, according to spokeswoman Cherie Jacobs. The fuel accounts for $4 of the $8 reduction for Tampa Electric customers.Overall, the changes mean Duke customers would see a slight increase of 88 cents to $128.78 per month on average, according to spokeswoman Ana Gibbs. Included in the changes are several cost categories, including fuel costs, energy conservation costs, purchased gas agreements, natural gas conservation and environmental costs. In addition to the items approved Monday and improvements made to the grid, Duke customers will pay more next year because they also are funding the second half of construction of the utility’s $1.5 billion natural gas facility in Citrus County, according Gibbs. The first half of 1,640-megawatt combined cycle natural gas plant came online Oct. 26, accounting for 820 megawatts. The second unit is scheduled to come online in December.The latest installment of Duke’s solar project is included in the cost as well. The utility committed to building 700 megawatts of solar power, and will charge customers for its Hamilton Solar Power Plant in Jasper. When completed, it will produce 74.9 megawatts, enough to power 20,000 homes.Tampa Electric customers will be charged for the latest installment of the Tampa utility’s solar project, which aims to create 600 megawatts of solar power by 2021. Despite that charge, they will see an overall reduction in bills in part due to lower fuel costs as well as savings that came from the 2017 tax reform. MORE: Get more business news here Contact Malena Carollo at [email protected] or (727) 892-2249. Follow @malenacarollo.