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Here is a 4.1kW system we recently installed
in Acton, MA. The panels are Sanyo 195-watt
HIT Power modules and the inverter is a
Solectria PVI-4000. This array will make
about 5,000 kilowatt-hours per year.
The homeowners, Joe and Lucille, were looking
to reduce their dependence on fossil fuels
while helping the
planet. The solar electric system will offset
over 6,000 lbs of Carbon Dioxide annually.
(click on the picture for a larger image)
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A British Thermal Unit (BTU) is a unit of
measure for energy. Specifically, 1 BTU will
raise one pound of water one degree
Fahrenheit.
The BTU (and its metric equivalent the Joule)
provide us a simple way to compare heating
methods. For example, burning a gallon of
heating oil will generate 140,000 BTUs.
Burning a cord of Oak will generate about
21,000,000 BTUs (150 gallons of oil). Running
one kilowatt-hour of electricity through a
space heater or electric water heater will
generate about 3,400 BTUs, and a 4' x 8'
solar hot water panel will collect about
30,000 BTUs on a cool sunny day.
A special note: Each method of generating
heat has different efficiencies. For example,
oil furnaces run at about 85% efficient. That
means that of the 140,000 BTUs generated from
burning a gallon of oil, 21,000 go up the
chimney as waste heat with the carbon
monoxide and carbon dioxide combustion
byproducts. Electric heaters are nearly 100%
efficient when converting electricity to
heat. Gas furnaces usually run about 90%
efficient.
WIth the BTU explained, let me move on to the
"Amish Electric Heater."
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Perhaps you've seen the advertisement
(cleverly disguised as normal content) in the
Sunday Parade Magazine or in the Sunday
comics. If you get past the
oxymoronic
idea of "Amish" and "Electricity",
you'll see that their claims are
dubious at best.
Last Sunday it was the "Amish Electric
Heater." But someone must have called the
company and complained that their ad was
misleading because the heater was not Amish,
just the cabinet was.
This week it's the "Amish Mantle and miracle
invention." The mantle may be Amish in style
but the electric heater should only be a
miracle to someone who lived more than a
hundred years ago. Electric heaters have been
around a long time.
The ad claims that their heater will "help
home heat bills hit rock bottom." But keep
reading and you'll see how. You have to turn
down your thermostat - duh. The only
difference is that if you put one of their
"miracle" devices in the room you spend your
time in, you won't notice that your furnace
or boiler is not heating the room.
If you read their claims (aren't you glad I'm
doing this so you won't have to :-), on
"standard" setting, their "miracle" device
uses 8 cents per hour in electricity. At
typical Massachusetts rates (about 16 cents
per kWh), that means that the device is using
about 500 watts of power on its "standard"
setting. (500 watts X 1 hour
X 16 cents per kWh = 8 cents.
That 8 cents of electricity (0.5 kWh) through
a 100% efficient electric heater will
generate about 1,700 BTUs of heat energy. If
you read further into their ad, you see that
the heater can generate an "amazing 5,119
BTUs on high setting." In other words, their
"miracle" device, on its "high" setting is
a 1,500 watt heater. How do I know? The math
is pretty simple. If a 500 watt heater
generates 1,700 BTUs, how large a heater do I
need to generate 5119 BTUs? 5,119 is almost
exactly (another oxymoron) 3 times 1,700.
Thus, 3 X 500 watts = 1,500 watts.
A quick scan of Amazon.com and I found a
number of 1,500 watt electric heaters. The
most expensive was approximately $60. The
least expensive was $21. The "Amish" heater
is $249. No wonder in this week's ad, they
are "giving" you two free heaters if you buy
one. I'm betting that with their "Amish"
cabinets, you are probably getting $100 of
"stuff" for $249 (plus shipping). What a
bargain.
If you've already bought one, sorry. Try and
get your money back. Worst case, you'll have
lost your shipping costs. If you have not
bought one yet and are thinking about it,
save your money and get a
"non miracle" 1,500-watt electric heater for
under $30.
And as always, be skeptical.
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Here is a little comparison of the cost per
BTU from various sources of energy. To make
the numbers reasonable, I'll use 100,000
useful BTUs. That means that I'll apply the
efficiencies. Without the 100,000
multiplier, the results are tiny and hard to
compare. (By the way, 100,000 BTUs = 1 Therm)
Assumptions:
Cost of Fuel: Electricity: $0.16 per kWh Home heating oil: $3.10 per gallon Natural gas: $1.40 per Therm. Efficiency: Electricity: 99%, Oil: 85% Gas: 90% Electricity: $4.66 per 100,000 useful BTUs
Oil: $2.65 per 100,000 useful BTUs Natural Gas: $1.55 per 100,000 useful BTUs Yes, electricity is the most expensive source
of heat BTUs when compared to Oil and Gas.
Another reason to be skeptical of the "Amish
Electric Heater." Only heat with electricity
when the other options are not practical.
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My son Russell is collecting the solar
collectors from dead calculators and other
non-functioning solar powered devices. If you
have any, let me know and we'll arrange
pickup. And he promises (and I'll hold him to
it) that the parts he does not use will be
recycled properly.
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Turn down your thermostat, disable your doorbell, reduce waste, use a fan instead of an air conditioner, turn off the lights, switch to compact fluorescent bulbs, put computer gear on a power strip and turn it off at night, unplug unnecessary appliances, ventilate your attic, take shorter showers, walk instead of drive, ride a bike, group your errands, inflate your tires, grow your own food, eat locally-produced food, recycle, use your most efficient vehicle, get a hybrid vehicle, wash your clothes in cold water, buy less packaging, use a clothesline instead of the dryer, drink tap water, print with narrower margins, use both sides of the page, buy less, compost, install a renewable energy system...
Thanks for Reading the Energy Miser,
 Mark Durrenberger
New England Breeze, LLC
phone:
978-567-WIND (9463)
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