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:
As of 2007, the total installed capacity of solar hot water systems is approximately 154 thermal gigawatt (GW th). China is the world leader in their deployment with 70 GW th installed as of 2006 and a long-term goal of 210 GW th by 2020.