Solar Energy

The rapid decline in solar equipment prices has created difficult times for solar vendors, yet plenty of opportunities for innovation in this industry remain. Additional costs can be taken out of solar systems, in part by tailoring solutions and services to individual market segments. Jay Holman, Principal of VtM, has carried out in-depth studies of the needs of attitudes of the North American PV Installer community, and has authored numerous papers on this industry for utility clients. These papers covered topics ranging from the risk of fire in rooftop PV systems to the latest developments in large scale concentrating solar power technologies.

Published Articles and Reports on Solar Energy

Grid Codes for Interconnection of Inverter-Based Distributed Energy Resources by Country: Recent Trends and Developments

Published by EPRI in November 2014

Author: Jay Holman

This report outlines the latest developments in local, regional, and national grid codes that define interconnection requirements for distributed photovoltaic systems and battery energy storage systems. The term grid codes refers to the set of rules and regulations that utilities, installers, and project developers must follow when connecting inverter-based distributed generation to the grid, and that relate to the electrical behavior of inverters. Specifically, this report focuses on a set of inverter parameters that directly impact grid stability, reliability, and safety, including voltage limits, voltage regulation, frequency limits, frequency regulation, anti-islanding behavior, reactive power settings, real power ramp rates, and remote control of inverters by local utilities.

Brief descriptions of these requirements are provided for 11 countries and the European Union, as are the sources of the requirements, whether they be laws, technical standards, or distribution utility rules. Countries covered include the United States, Germany, Italy, France, Spain, United Kingdom, Belgium, Czech Republic, Greece, Australia, and India. The goal of these descriptions is to provide general insight into the grid codes of various countries where a significant amount of solar photovoltaic has been installed, including summaries of recent developments and potential upcoming changes to interconnection requirements.

Smart Inverter Field Experiences: A State of the Industry Overview

Published by EPRI in December 2013

Author: Jay Holman

The inverters that connect solar photovoltaic, battery, and other distributed resources to the power grid have the potential to provide a number of services or functions that may be useful to utilities. Inverter manufacturers have been designing and implementing these capabilities into their products for many years. During the past few years, significant industry effort has been expended in the identification of a common set of such functions that may be supported by open standards and implemented in many different types, sizes, and brands of inverters.

As these smart inverter capabilities have become available, many utilities have been experimenting with devices in the field in limited or widespread deployments.

This report provides a summary of these activities worldwide. It identifies the specific grid-supportive functions used in each case and investigates the outcome, including benefits observed and any unintended side effects noted.

IDC MarketScape: North American Residential Solar Inverter 2011 Vendor Assessment

Published by IDC in October 2011

Authors: Jay Holman, Casey Talon

This IDC Energy Insights report uses the IDC MarketScape model to provide a detailed, quantitative assessment of the top vendors participating in the North American residential solar inverter market.

Best Practices: Finding the Sweet Spot for Micro CSP — The Holaniku at Keahole Point Case Study

Published by IDC in March 2011

Authors: Jay Holman, Casey Talon

This IDC Energy Insights report provides an in-depth look at the micro concentrating solar power (CSP) plant Holaniku at Keahole Point, located in Kailua-Kona on the Big Island of Hawaii. The pilot plant produces 2MW of thermal energy that can be used to generate up to 500kW of electricity through an organic rankine cycle (ORC) power block, and the site includes up to two hours of thermal energy storage.