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Living Green Today
Step by Step to an Renewable-Energy Powered Home
(assumes you are using an existing home)
Last Updated on:
12/01/2010 05:14 AM
Living Green, is basically
making decisions considering the impact that decision would
have on the environment. Living Green is making choices that are good for the earth.
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| 1. Conserve Energy -
Most people can not afford to buy the additional PV
& solar heating modules to run the average US home. There are many people who
figure they are quite well off just by doing this step alone! |
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| 1A. Insulate as much as you can afford -
Put in double and triple pane windows.
Insulate the roof, walls and maybe floor. Use light colored roofing to reduce your
cooling expenses in hot climates. |
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| 1B. Get energy efficient appliances,
lighting, heating, and cooling - Remember
heating and cooling are your major loads. Solar can replace heating (or even
cooling) depending on your site (and INSULATION). Please see table below for
various heating/cooling methods. Your refrigerator, unless new within the
last 5 years, probably should be replaced with a new one. Check the renewable
energy catalogs for the best efficiency ones. If you can't afford a new one,
consider mounting a couple of muffin fans to blow away the heat generated by the
motor of the refrigerator. A 4 watt muffin fan, left on all the time to cool under
the refrigerator, will save you electricity because it removes most of the heat
that would normally rise up in to the cooling compartments. Washers, the
best efficiency ones are the horizontal axis ones. Lighting, choose fluorescent,
compact fluorescent, or LED.
Cooling/venting your attic reduces the load on
your living space cooling system. Most people use 110vAC fans which use a lot of
electricity. You can use solar, but that is very expensive. A turbine vent or
ridge vent are less expensive, they don't use electricity, don't have a motor to
burn out, and use natural convection currents to cool the attic. Some say ridge
vents work better than turbine vents. However you need to make sure your input/soffit
vents are not blocked, and that you have plenty of them. |
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| 2. Examine your site
- How many hours of sun per day does your site average? Is there any objects
blocking the sun? The clearer the view of the sun's path, the longer you'll get
usable energy out of your solar modules. |
| You can use a single or dual axis tracking mount
to get more usable energy of you pv modules per day. A tracking mount points your
pv's directly towards the sun. The difference between a single and a dual axis
tracking mount is that a single axis one has to be adjusted seasonally. The dual
axis tracker automatically adjusts for seasonal variations. A dual axis tracking
mount usually won't increase your power output enough over a single axis tracking
mount, for most places, to make the dual axis tracking mount worth it. A tracking
mount is more expensive than a fixed mount, but may be more cost efficient than
buying more pv modules. |
| Do you have a stream available? Hydro can give
you surplus electricity if there is enough flow and head. How much flow is the
stream?
How high is the stream (head/vertical fall)? Head
times flow is your hydropower output. 500 Gallons per min. over a 3 foot drop, or
3 gallons per min. over a 500 foot drop give you the same power output. The higher
the head, the lower the gallons per minute you need to make the same power.
Micro-hydro equipment is what is generally sold in renewable energy businesses.
Micro-hydro is usually high head (over 10ft), low flow (less than 120GPM). Please
be considerate of the environment: Ensure that there is plenty of bypass water for
the wildlife all year around. Be careful if there is any fish in the stream about
damming the stream. |
| What is the average miles per hour of the wind
at your site, per year?
The lowest startup wind speed for a wind
generator I've seen is 7mph or 3.0m/s. At that speed not much electricity is
generated, however having a hybrid solar/wind system generates electricity when
the sun is out with the pv's and when it is stormy with the wind generator. For
best performance, mount the wind generator on a tower about 30 or more feet above
any obstacles and for safety's sake, put the tower at least two times the height
away from any building, power line (on poles or towers), and property lines. There
is roof mounts for the Air Modules, performance will not be as good as on it's own
tower due to turbulence from nearby obstacles. |
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| 3. Add up your electrical load -
You need to find the total watt-hours of the load's
you want to put on RE battery system or to compensate for the load usage in a
battery less grid-tied RE system. By using the data plate on your appliances will
give you a quick, but general idea of that appliance's energy usage. A more
accurate, easier, and more expensive way is to use a watt-hour meter. You can also
use your electric bill, which gives you total watts used in kilowatts, or watts
times one thousand. |
| Using the data plate, you might have to convert
to watts. After you have converted to watts, or starting with watts, watts times
the number of hours that appliance is on per week equals watt-hours per week. Then
add up all the watt-hours per week of all the appliances you are going to use on
RE. Divide that by seven to get avg. watt hours per day. |
| Using your electric bills, add up one year's
worth, then times one thousand, divided by 364, or 365 depending on the number of
days that year to get avg. watts per day. |
| Take avg. watts/watt hours per day times 1.2 to
get DC watts per day that you must generate. |
| Divide this by the avg. hours of sun per year or
the avg. hours of sun for the worst month. This gives you how large your PV array
must be. Dividing by the avg. hours of sun per year will undersize the system
during the winter, and either needing a generator, or more grid usage. |
| Using different energy sources complicates the
calculations a bit. |
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| 4. How much money can you spend? -
Due to a lack of money, people will only put
part of their electrical load on an renewable energy system, then spend more later
on when they can afford to buy more. The owner of Real Goods did this a long time
ago! Nice thing about PV's is that they have no moving parts and can last a long
time (some even have warranties for 25 YEARS!) Note PV's don't produce as much in
HOT climates, as they do in COOL climates. Buy NAME BRAND, DEEP CYCLE batteries
for storage (if you decide for any storage at all). A battery bank however has to
be bought all at once. You can't mix old and new batteries because the new
batteries will be brought down to the performance level of the old batteries. |
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