Review of potential problems and utility concerns arising from high penetration levels of photovoltaics in distribution systems

Impact of Rooftop Photovoltaics on the Distribution System

“…e opposite is true when the sky shows transitions from cloudy to sunny conditions. e authors have explained this phenomenon by associating it with ambient temperature, i.e., as the sky shows transitions [59, 74-76, 78, 81, 84, 86-88, 94, 96, 99, 100, 107, 109, 110, 122, 123, 128, 129, 153, 155, 168, 171, 174, 176, 183, 187, 188, 200, 213, 214, 230, 235] Effect of system strength (R/X ratio) [155,177,234] Impact of PV on voltage swell/sag [145,169,170,194,211] Effects of cloud movements, cloud pattern, or shading [19,27,59,61,64,67,75,86,96,99,100,107,109,131,146,160,178,215,218,224,240,242,243,258] from sunny to cloudy, both solar irradiance and temperature decrease. A decrease in irradiance decreases the output power of PVs, but temperature drop has an inverse effect.…”

For what it’s worth: My advice to young investigators on preparation of an NSF-CAREER proposal

“…o Studies of a number of aspects of the prevention of unintentional islanding in distributed generators [1][2][3][4][5][6]; o Work on the effects of high penetration levels of distributed generators into utility networks [7], including a set of new computer modeling tools for system-level simulation of high penetration levels of grid-connected PV systems [8]; o A study of the transient overvoltage protection requirements on the PV module side of moduleintegrated PEBBs [9,10]; o A modest improvement to the method normally used when using wind measurements to predict the power output of wind turbines [11]; [12].…”

Power quality improvement utilizing photovoltaic generation connected to a weak grid

“…However, high penetration levels of PV panels could bring significant impacts to the power system. A review of some reports and a survey to utility engineers regarding impacts of PV penetration is presented in [1]. Several concerns about high PV penetration include transient condition during cloud passing, voltage rise in steady state and the need to include voltage regulation in PV inverters.…”