The purpose of this paper is to study the development of photovoltaic (PV) systems in some countries of the European Union (EU). We establish the stage of development of each country, their short- and long-term degree of compliance and the trends of international investors favouring one market or another. EU countries employ four major types of programs to encourage PV use: (1) feed in tariffs (FIT), (2) green certificates with a quota system, (3) investment and tax incentives, and (4) bids on the quota system. The FIT is the most widely used program to create incentives for the use of PV systems. During the past two years, PV tariffs have been reduced in many European countries. Investments in PV are still attractive, in some cases even overly generous with respect to the financial landscape in the world. This paper shows, for each country, the type of incentive and the trends in and forecast for installed capacity and calculates the internal rate of return (IRR) for investment in grid-connected PV systems.