The price of PV components varies depending on the size of the system (generating capacity), type and quality of the components purchased, and complexity of the system selected. The good news for consumers is that the cost of PV has declined dramatically, while the technology has improved, equally dramatically. Installation costs depend on the size and complexity of the system, but also on the home layout and construction. For example, a simple, south-facing roof allows for an easier install than a roof with hips and valleys. In addition, some homes require structural or wiring upgrades. An average 4 kW system may cost between $10,000 and $20,000, before credits and incentives. This is based on a typical installed cost of $2.50 to $5 per Watt of distributed generation capacity. To determine your costs, look for online calculators to help you estimate your pricing, and also get bids from reputable installers.