If you are using the word costs as a noun, then it is plural. You would say the costs are..., never the costs is.... If you are using it as a verb, then it refers to a singular object: It costs a lot of money They cost a lot of money.
The average solar water heating system can cost between $6,300 and $7,200 depending on the tank size and need.We help to make getting a solar water heating system installed in your home both easy and affordable.We provide two rebates to help you offset costs:he Cost of a Solar Water Heating System. The average solar water heating system can cost between $6,300 and $7,200 depending on the tank size and need. We help to make getting a solar water heating system installed in your home both easy and affordable. We provide two rebates to help you offset costs:
To estimate the annual operating cost of a solar water heating system, you need the following: 1  The system's solar energy factor (SEF). 2  The auxiliary tank fuel type (gas or electric) and costs (your local utility can provide current rates).ow much money you save depends on the following: 1  The amount of hot water you use. 2  Your system's performance. 3  Your geographic location and solar resource. 4  Available financing and incentives. 5  The cost of conventional fuels (natural gas, oil, and electricity).