The Solar Resource

Overview Overview of the solar resource in the U.S. Features impacting solar irradiance »Latitude, cloud cover, seasonality Converting power to energy Tools to measure solar energy and shading An overview of solar energy systems 3/30/2009http://retc.morrisville.edu2

Solar PV 3/30/2009http://retc.morrisville.edu3 Solarbuzz LLC.

So Germany must be sunny, right? 3/30/2009http://retc.morrisville.edu4

Measuring the solar resource Magnetic declination Solar pathways Solar math (power to energy) Latitude and curvature Air currents 3/30/2009http://retc.morrisville.edu5

What impacts solar gain each day? Latitude (winter solstice) 3/30/2009http://retc.morrisville.edu6

Sun Path – New York 3/30/2009http://retc.morrisville.edu7 N E W S Winter Solstice Equinox Summer Solstice This angle should be equal to your latitude

Magnetic Declination 3/30/2009http://retc.morrisville.edu8

True south and declination 3/30/2009http://retc.morrisville.edu9

Declination corrections 4/3/2009http://retc.morrisville.edu10 Magnetic North True North True South 12°48’ W

Solar Angles by month in Morrisville 3/30/2009http://retc.morrisville.edu11

What impacts solar gain each day? Latitude 3/30/2009http://retc.morrisville.edu12

Morrisville’s Solar Resource 3/30/2009http://retc.morrisville.edu13 MonthMean W/m 2 /daykWh/m 2 /day January 63.8 February 98.8 March April May June July August September October November 59.3 December 44.7

Morrisville’s Solar Resource 3/30/2009http://retc.morrisville.edu14 kWh/m 2 /day = MonthMean W/m 2 /daykWh/m 2 /day January 63.8 February 98.8 March April May June July August September October November 59.3 December 44.7

Morrisville’s Solar Resource 3/30/2009http://retc.morrisville.edu15 MonthMean W/m 2 /daykWh/m 2 /day January February March April May June July August September October November December kWh/m 2 /day = Yearly mean power? W/m 2 /day Yearly mean energy? 3.5 kWh/m 2 /day

Solar energy throughout the year 3/30/2009http://retc.morrisville.edu16 MSC weather station data

How does central NY compare? Average of solar energy throughout the year is 3.5 kWh/m 2 /day. »This is kWh/m 2 /year (365 days * 3.5 per day) »Albany has a daily average of 4.3 kWh/m 2 /day ( kWh/m 2 /year) »San Diego has 7.3 kWh/m 2 /day ( kWh/m 2 /year) 3/30/2009http://retc.morrisville.edu17

Solar energy 3/30/2009http://retc.morrisville.edu18

Cloud cover 3/30/2009http://retc.morrisville.edu19

Air Cells 3/30/2009http://retc.morrisville.edu20 Low pressure High pressure Deserts (sunny) Rain Forests (cloudy)

Global Solar Energy 3/30/2009http://retc.morrisville.edu21

Solar energy systems If you assume that systems costs are comparable in NY and southern California, which location has more expensive solar energy? 3/30/2009http://retc.morrisville.edu22

Estimating the Solar Resource 3/30/2009http://retc.morrisville.edu23

3/30/2009http://retc.morrisville.edu24 Estimating the Solar Resource

3/30/2009http://retc.morrisville.edu25 S E W

Estimating the Solar Resource 3/30/2009http://retc.morrisville.edu26 June (lowest line): = 9% July (next up): = 10% May: = 10% August: = 9% April: = 8% September: = 5% October: 1%

3/30/2009http://retc.morrisville.edu27 Estimating the Solar Resource

Solar energy systems 3/30/2009http://retc.morrisville.edu28

Photovoltaics 3/30/2009http://retc.morrisville.edu29

Solar Thermal Electricity 3/30/2009http://retc.morrisville.edu30 Parabolic mirrors

Solar Hot Water 3/30/2009http://retc.morrisville.edu31 Domestic solar hot water system Flat plate collector (low temp) Evacuated tubes (higher temp) Solar hot water tank with heat exchanger Images courtesy of John Siegenthaler

Passive Solar Heating 3/30/2009http://retc.morrisville.edu32 Large windows facing south Conifers to the north Small windows to north Thermal mass

Summary 3/30/2009http://retc.morrisville.edu33 New York has an adequate solar resource for solar PV, solar hot water, and passive solar homes Solar power can be easily converted to solar energy (and we can account for shading) Incoming solar energy is affected by many factors such as latitude, cloud cover, and time of year Many systems can take advantage of solar energy

Phil Hofmeyer, Ph.D. Assistant Professor Ph: Web: Ben Ballard, Ph.D. Director, RETC Assistant Professor Ph: Web: Contact Information