Abstract—This paper presents a general overview of photovoltaic power generation technology, the development of associated technologies and components, PV infrastructure, and, why there is now significant attention to PV systems. The paper explores current research and proposed topologies and their similarities and differences are discussed as well as the advantages and limitations of each design topology. A review of current research aims atidentifying where the industry is headed in terms of technological advances in the manufacture of inverter. This paper also shows that PV inverter technology is improving by leaps and bounds and that those improvements are largely based on better design principles and the reduction of needless components such that costs are decreased and efficiencies are increased. Index Terms—Solar energy, Converters, Inverters, Photovoltaic systems, and Energy conversion. I. INTRODUCTION enewable energy is a term for energy sources such as geothermal, wind, marine, and solar energy. Within the last decade, the power being generated by means of solar technology has increased so that as of December 2010, a worldwide combined total of over 40 GW was being generated, 85% of which was being fed into a connecting grid. This is indicative of a meaningful increase in the amount of electricity being generated by solar energy collection when one considers that as recently as the year 2000, there was no notable amount of energy being produced via this method [1- 3]. One of the challenges facing solar power generation is the cost of the components involved. Fortunately, the cost of components has been reduced greatly because of the increase in both public and governmental interest. Economy of scale reduced the costs associated with the production of solar cell panels and inverters. As well, demand, which drove increased production, has also served to drive increased competency and efficiency in the manufacturing of the various components required in order to harness solar energy. Ultimately this has played a part in lowering costs as well [4-7]. S. H. Shehadeh, H. H. Aly, and M. E. El-Hawary are with the Department of Electrical and Computer Engineering, Dalhousie University, Halifax, NS B3J 1Z1, Canada (e-mail: Sh790078@dal.ca; hamed.aly@dal.ca; elhawary@dal.ca). Early inverters were often incompatible with the grid and could not easily be integrated. Inverters also suffered from poor conversion efficiencies. Efficiency was much more critical in the early days of PV, because the cost per Watt of PV power was roughly $15. A 1-2% variation in inverter efficiency could easily translate to upwards of a 10% in overall system cost [8, 9]. Advanced inverter technology was required to bring this renewable energy source into its full potential. The costs associated with silicon semiconductors and other components have come down significantly. Higher efficiency is desirable as a primary goal of research into PV inverter technologies. Reduction of cost is also a major goal. The latter is being made easier to achieve based on volume production due to increased demand in recent years. Such demand, brought on by the realization that the world’s power needs are increasing, and that it is more sustainable to meet these needs via renewable energy sources, has helped to spur research and development with respect to PV systems and as well, increased sponsorship of such R&D [8]. II. PV ENERGY CONVERTERS There are two significant classes of converter in use. The first is the DC-DC converter, which is used to improve the quality of the DC power produced by the PV array. To improve the quality in order to either directly supply most loads which operate on DC power, or to feed a storage implementation such a battery or capacitance bank. The second significant type of converter is the DC-AC variety which is necessary when the PV system is to be connected to the grid network. The DC-AC converter inverts the DC power to AC, and then depending on the parameters specific to the local grid, conditions the voltage and frequency required for integration with that grid. Even off-grid PV implementations require DC-AC power converters as part of their configuration; as such systems can be used to supply AC power to lighting and other larger household appliances [4,10]. The primary function of electronic power converters are is to convert electrical energy of some set of characteristics into energy of a different, more specific set of characteristics. Regardless of the type of power converter, the conversion of the energy takes place as the result of the function of varying switching states. The particular process through which this function is carried out is called modulation. Different types of converters exist; either DC-DC or DC-AC being the primary An Overview of Inverter Topologies for Photovoltaic Electrical Energy Shadi Hazzem Shehadeh, Hamed H. H. Aly, and M. E. El-Hawary R 2013 IEEE Electrical Power & Energy Conferenc (EPEC) 978-1-4799-0106-7/13/$31.00 ©2013 IEEE