Large amounts of distributed generation (DG), especially solar, and electric vehicles may cause technical problems related to power quality, safety and reliability on electric distribution circuits. These impacts are not yet well understood. Early evidence suggests that significant infrastructure upgrades and operational changes in utility distribution systems may be required as DG penetration levels reach a critical threshold. New empirical information gathered from the field is needed to better define these requirements and the potential need for new technology developments. Data from distribution circuits must be collected and analyzed at higher resolution and with greater specificity so that the effects of distributed resources can be better understood and mitigated if necessary.