Yes, of course!
Take a flat square meter
surface. Tilt it down to the south at an angle of 37 to 39 degrees from horizontal. It then receives
an average of 4 kilowatt hours (kWh) of solar energy each day
-- Caveat!
It has to be an unshaded surface for 4 kWh. Any shading diminishes
the energy. Some shading is tolerable. Too much can make the location unsuitable.
-- Why 37 to 39 degrees? Because that's Kentucky's latitude. Covington is 39
degrees. Bowling Green is 37 degrees. The "optimal
fixed tilt" at any location
in the Northern Hemisphere is usually: 1) tilted down to the south;
2) by an
amount equal to the location's latitude.
-- So we get an average of 4 kWh / day / square meter of raw solar energy on
a south
facing square meter surface at optimal tilt. The 4 kWh comes from historical
observations as shown on the resource map below.
-- Present technologies
convert 9 - 16% or so of this raw energy into usable
electricity (solar PV) and about 30% into usable heat (low temperature (190〫F or
less)
solar thermal).
-- The map below shows that Eastern Kentucky gets about 4 kWh and Western
Kentucky gets about 4.5 kWh or so per day
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| Map courtesy of National Renewable Energy Laboratory. |
One predicts performance of planned photovoltaic
(PV) systems with the help of the above map. PV systems make electricity. Say "solar panel" and
most people think of a PV system on a roof. This map also works with
"solar thermal" systems used to make solar domestic hot water (SDHW) and space heat. Solar thermal systems
use "collectors" to harvest energy. We speak here of "low temperature" (max 180 - 190 degree
F) systems.
The map does not apply to "concentrating solar power" (CSP) systems. CSP systems typically
(but not always) utilize parabolic mirrors and high temperature (300 - 700 degrees F) liquids to make steam to turn turbines.
CSP
does not work well in Kentucky and is more suited to the American Southwest. It requires more sustained intense
sun. The ever-diminishing cost of solar PV is presently (Fall, 2011) bringing a halt to construction of most CSP sytstems. PV
has become cheaper than CSP.
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Isn't Kentucky too cloudy for solar?
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LG&E and KU have in the past distributed materials in essence saying
that solar doesn't work well in Kentucky and making their point with a concentrating solar resource map. This
mis-information may have led to a misperception that Kentucky is "too cloudy for solar."
Kentucky is not too cloudy
for solar. It's just fine for large scale and small scale PV and low temperature solar thermal.
Duke Energy operates in Kentucky. Duke and other large utilities in places like Minnesota and Wisconsin have supported
and encouraged their customers' use of solar energy.
Xcel Energy, a large multistate electrical
utility based in Minnesota, has voluntarily set a goal of 30% renewables by 2020 in Minnesota, with solar playing a
large part in that mix.
Xcel is also a major electrical utility in Colorado. Colorado has set a Renewable Portfolio Standard (RPS) of 30% renewables
by 2020 (after previously setting 10% by 2015 and 20% by 2020 RPS standards). Xcel customers in Colorado presently pay
0.2 cents / kWh to fund the RPS programs in Colorado. That's 2% of their bill.
In large part, Xcel has offered rebates and incentives to customers who install small(technically "distributed
generation") PV systems. So everybody pays (and benefits by new capacity) a little. Purchasers receive some
assistance with their initial up-front costs. The Germans installed
2.24 gigawatts of distributed generation solar PV in 2009. Kentucky can do the same.
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Present Solar Technologies are Mature
Many are Manufactured by Well-Known Companies
Sanyo, GE and Sharp make PV panels. Rheem, Velux, Stiebel-Eltron and
AO Smith make solar thermal systems and components. Other less known but top quality names include AET, Solar Skies,
FirstSolar and Caleffi.
Well designed PV and thermal systems using quality components are
reliable and durable.
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A PV (photovoltaic) system makes electrons from photons
and converts about 9 - 16% of the sun's energy into useful AC or DC electricity.
The wide range is due to possible variants in design and materials.
9% or so would be a thin-film PV system. 16% or so applies to well-designed systems using regular
silicon PV panels. These numbers take into account system inefficiency losses from dust, heat, wiring, etc.
The conversion efficiency of PV panels increases all the
time. The costs are also dropping.
A recent analysis from the Argonne National Laboratory determines a production cost
of 9.7 cents, 9.3 cents and 6.9 cents per kWh for a 20 MW utility-scale PV system in Chicago, Boston and Sacramento,
respectively. These numbers arise after the effect of assumed 30% federal and 8% state tax subsidies. They are
based on a 30-yr projected life.
Presumably, we would be looking at 15 cents or so per kWh without the effect
of subsidies.
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A "solar thermal" system (hot water) converts
30% or so of the sun's daily energy into useful energy for space or water heating purposes.
The cost of solar thermal technology will likely not drop, nor do we see great efficiency improvements coming ahead.
Solar thermal already works really well and is cost-competitive with fossil fuels. If you have an electric hot
water heater, a solar thermal system pays back fairly quickly (7 - 8 years with incentives, 10 to 11 without).
The payback on a gas hot water heater will take a bit longer. Once paid back, you get hot water for 20 years or so at
very low cost!
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Solar energy is not the "do all and end all" of
our energy needs. However, it meets many needs very, very well. Systems can be designed to
perform during power failures, solar thermal especially easily.
What solar can do, it should do.
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