Reported prices for entire PV systems vary widely and depend on a variety of factors including system size, location, customer type, connection to an electricity grid, technical specification and the extent to which end-user prices reflect the real costs of all the components. Photovoltaic modules make up about two-thirds of the lowest achievable grid-connected system prices. Balance of system (BOS) components (the components that are not the PV modules) account for between 20 % (grid-connected) and 70 % (off-grid) of the total PV system installation costs. Accordingly the production of BOS products has become an important sector within the wider PV industry.

On average, system prices for the lowest price off-grid applications are double those for the lowest price grid-connected applications. In 2005 the lowest system prices in the off-grid sector, irrespective of the type of application, ranged from about 10,0 USD to 20,0 USD per watt, with an average of about 13,0 USD per watt. The lowest achievable installed price of grid-connected systems in 2005 varied between countries. The average price of these systems was 6,6 USD per watt and the lower reported prices in 2005 were typically around 5,5 USD to 6,5 USD per watt. Large grid-connected installations can have either lower system prices depending on the economies of scale achieved, or higher system prices where the nature of the building integration and installation, degree of innovation, learning costs in project management and the price of custom-made modules may be significant factors. In 2005 the average price of modules in the reporting countries increased by close to 5 % compared with the corresponding figure for 2004, due to pressures on silicon feedstock supply. Interestingly, a number of countries reported a decrease in module prices from 2004 while other countries reported almost no change. This followed a steady price reduction trend over the previous decade in which the price of PV systems had halved.

A significant milestone will be the achievement of cost-competitiveness of PV with traditional energy sources and other emerging technologies in the various markets. It is expected in some quarters that the continuing development of PV technology will lead to a reduction of the price for solar electricity to lower than the price for peak-load power by 2015. Movements in the retail price of electricity and the way these tariffs are structured in the various countries are also receiving a lot of attention from the PV community. It is difficult to predict cell and module price movements in the near-term as the feedstock supply situation eases. However it appears that the price reduction trend is becoming re-established. Feedstock prices are fixed for a number of years and hedging contracts are in place - sudden drops in price should not be expected from these players. In addition, module production costs comprise about 70 % cost of materials - and these include such things as aluminium, copper and other minerals. However order volumes should go up and consequently costs should go down.