SOLAR TODAY

ISSUE HIGHLIGHTS

PV at the Polar Ice Cap
The Tower of Power’s triangular design means strength to withstand the arctic blasts and maximum solar harvest without mechanical tracking.
By Tracy Dahl

Energy-Positive Homes in Devens, Mass.
Super-efficient construction and declining PV prices mean renewable energy to spare at this community of affordable houses.
By R. Carter Scott

A Day in the Life of a Solar CEO
For OneRoof Energy’s David Field, success in the competitive third-party financing industry depends as much on innovation and risk as on solid investors.
Text and Photos by Mary Beth McCabe, D.B.A.

Renewable Energy to the Rescue
As we seek lessons in Hurricane Sandy, Florida’s SunSmart Emergency Shelter program offers a model for disaster recovery.
By Bill Young

Power Forward at SOLAR 2013
The 42^nd ASES National Solar Conference gets down to business in Baltimore, Md., April 16–20.
ASES staff

Innovators
Making a Market for Solar Financing
By Seth Masia

Investing
Renewable Energy Under Attack
By Rona Fried, Ph.D.

The trade
Small Wind Installation Procedures and Checklists
By Mick Sagrillo

New Products
Mounting and Tracking Systems

System Accomplished
Building Above the Flood
By Seth Masia

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The orientation of installed panels can have a significant impact on energy produced, particularly in winter months. This is illustrated in the map, “Energy Gains with Tilted Panels,” which shows the increase in energy production achieved by tilting solar panels 30 degrees as compared to positioning panels with zero tilt, or horizontally.

As illustrated by the map, tilt-mount PV systems generally have the greatest benefit in northern states, which experience lower sun angles during the winter. This gain is dampened where clouds are prevalent. For the month of November, relatively sunny conditions in the upper Midwest and northeastern United States led to the highest gain in energy production with tilt-mount vs. horizontal-mount PV, with as much as an 80 or 90 percent increase in some locations.

To use the PV Power Map to calculate the generation potential of a PV system in a given location, multiply the power output indicated on the map by a project’s capacity, in kilowatts. The result is the total estimated power output for the month. PV Power Maps can be seen for the entire year at pvpowermap.solartoday.org.

The PV Power Map is created with power output estimates generated by SolarAnywhere services from Clean Power Research; these include simulation capabilities and hourly satellite-derived irradiance data with spatial resolutions from 1 to 10 kilometers. The calculations are based on a PV system with a total 1-kW nameplate rating that is configured as five 200-watt PV panels with a 1.5-kW inverter; fixed, south-facing panels with 30 degree tilt; no shading; panel PVUSA Test Conditions rating of 178 watts; and inverter efficiency of 95.5 percent. Visualization and mapping provided by GeoModel Solar. Access free historical irradiance data at solaranywhere.com.

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ISSUE HIGHLIGHTS

Why a Smart FiT Is Smart Policy
A modified feed-in-tariff would take the best elements of the most effective solar energy compensation system to date but remove some of its weaknesses.

By Richard Perez, Tom Thompson, Thomas E. Hoff, Lyle Rawlings, Ken Zweibel, Pradeep Haldar and Rick Lewandowski

The Solar Perk
A market revolution is spreading into workplaces across the United States, increasing awareness and installations.

By Jason Coughlin

All-Solar in Austin
Texas’ Las Casas Verdes community demonstrates that with knowledge and careful planning, even a small builder can make a big difference in how society uses energy.

By David E. Martin

A Model of Comfort and Efficiency in Japan
Energy savings help this passive solar group home provide high-quality, affordable care to infants and children living apart from their families.

Text and Photos by Richard Crume and Dr. Yoko Crume 

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The PV Power Map is a report of national solar resource availability as illustrated by the monthly energy output of a nominal 1-kilowatt (kW) photovoltaic (PV) system by location. As illustrated by the map, much of the Western United States experienced warm and dry weather conditions, which facilitated average-to-above average solar energy production. The Eastern United States experienced wetter and cloudier conditions for the month, which led to average-to-below solar energy production profiles prevailing throughout much of the region. The Ohio River Valley in particular recorded below average energy production due to an active storm pattern.

To use the PV Power Map to calculate the generation potential of a PV system in a given location, multiply the power output indicated on the map by a project’s capacity, in kilowatts. The result is the total estimated power output for the month. See an archive of monthly PV Power Maps at solartoday.org/pvpowermap.

The PV Power Map is created with power output estimates generated by SolarAnywhere services from Clean Power Research; these include simulation capabilities and hourly satellite-derived irradiance data with spatial resolutions from 1 to 10 kilometers. The calculations are based on a PV system with a total 1-kW nameplate rating that is configured as five 200-watt PV panels with a 1.5-kW inverter; fixed, south-facing panels with 30 degree tilt; no shading; panel PVUSA Test Conditions rating of 178 watts; and inverter efficiency of 95.5 percent. Visualization and mapping provided by GeoModel Solar. Access free historical irradiance data at solaranywhere.com.

The PV Power Map is a report of national solar resource availability as illustrated by the monthly energy output of a nominal 1-kilowatt (kW) photovoltaic (PV) system by location. Summer 2012 showed high solar resource availability across the United States, particularly in July. High irradiance generally also means high temperatures, which drives higher power demand for cooling. One benefit of solar is that it coincides with these peak demand periods, providing substantial value by generating power when it’s needed most.

In areas with tiered electric rates, solar power generation reduces the need to purchase power at the highest rates through peak demand reduction, increasing the financial benefit. For example, in New York, where electricity costs more during peak hours, a homeowner with a 3.5-kW system, with base electricity consumption of 625 to 750 kilowatt-hours per month in July and August, could have saved as much as 70 to 80 percent off their electric bill, even though solar offset would have decreased their utility consumption by 65 to 75 percent. Peak reduction can have benefits at the utility level, as well. For example, as described in the paper “Solar Power Generation in the U.S.: Too Expensive, or a Bargain,” by Richard Perez, Ken Zweibel and Tom Hoff, the August 2003 Northeast blackout could have been averted with as little as 500 megawatts of solar PV installations dispersed throughout the region. (Download at bit.ly/SpAlNY.)

To use the PV Power Map to calculate the generation potential of a PV system in a given location, multiply the power output indicated on the map by a project’s capacity, in kilowatts. The result is the total estimated power output for the month. See an archive of monthly PV Power Maps at solartoday.org/pvpowermap.

The PV Power Map is created with power output estimates generated by SolarAnywhere services from Clean Power Research; these include simulation capabilities and hourly satellite-derived irradiance data with spatial resolutions from 1 to 10 kilometers. The calculations are based on a PV system with a total 1-kW nameplate rating that is configured as five 200-watt PV panels with a 1.5-kW inverter; fixed, south-facing panels with 30 degree tilt; no shading; panel PVUSA Test Conditions rating of 178 watts; and inverter efficiency of 95.5 percent. Visualization and mapping provided by GeoModel Solar. Access free historical irradiance data at solaranywhere.com.

ISSUE HIGHLIGHTS

Southwestern Smarts
This resource-wise house in Santa Fe, N.M., takes vernacular architecture to the next level to achieve near net-zero-energy.
By Mark W. Chalom

Keys to Successful Solar Water-Heating Programs
To encourage adoption, address the big obstacles: high upfront cost and a lack of consumer awareness.
Jordan DiGiorgio, Jeff Curry, Christie Howe and Mark Thornbloom, P.E., with Chip Bircher

5 Insights for Marketing Solar to Hispanics
Green attitudes and behaviors of the nation’s fastest-growing market might surprise you.
By Dr. Mary Beth McCabe, Dr. Ramon Corona, Dr. Richard Weaver

An Angle on Solar and Wind Variability
What is the best match to U.S. loads that could be achieved with wind power and PV? NREL’s load-matching model calculates the answer.
By Victor Diakov

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