PV POWER MAP
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.