Sale of a house with solar, federal tax accounting

[Drindin]

Let's say I purchase a house for 100000. I install solar for 10000 on it. I live in the house for 3  years immediately after the purchase, and sell the house for 200000. How is the solar system treated upon sale? Is it treated as part of the house like a water heater? So we add the cost of the solar system to the basis, and eventually substract the basis from the sale of the house, to get the long term capital gains, or there is another way to account for the solar system separately. 

[Critter-3]

How is the solar system treated upon sale? Is it treated as part of the house like a water heater?   YES ... total improvements + purchase price + cost to buy + cost to sell  =  cost basis

Sales price -  cost basis =  profit or loss

[Mike9241]

the solar cost net of the solar tax credit would be added to the tax basis of the property.