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This is the most important page on this web site because it will
determine the cost and capabilities of your energy system. If you haven't
been to the System Planning page, now
would be a good time to check it out. It has great information and many
energy saving tips.
Until we can get this page interactive, we are more than willing
to do all of your calculations over the phone. It takes about 30 minuets
to an hour and will generate the cost of the system as well. You can reach
us at 208-267-6409 between the hours of 9 am to 4 pm pacific time. Prior
to talking with us we suggest that you walk through your home and take
inventory of all of your electrical loads. Every appliance has a power
consumption tag that you should write down as part of the inventory list.
You are looking for either a wattage or amperage (amps) rating. If your
appliance is rated in amps use this formula to convert it to watts. AMPS x
VOLTS = WATTS. Be sure to use the voltage shown on the tag.
- Generic Power Consumption Table, This table lists many appliances and there average power consumption. If your appliances are newer then the consumption will probably be much lower than that listed in the table, if they are older then the table is close.
- A Power Consumption
Worksheet, This sheet allows you to enter each appliance and their energy usage as indicated by the "tag or stamp" attached to each appliance.
- Solar Array Sizing
Worksheet, This worksheet allows you to calculate the amount of solar modules needed for your energy consumption at your location.
- Battery Sizing Worksheet, This worksheet calculates the needed battery storage required to sustain your
system.
| Appliance |
Watts/Hour |
Appliance |
Watts/Hour |
| Coffee
Pot |
200 |
Ceiling
Fan |
10-75 |
| Coffee
Maker |
800-1200 |
Table
Fan |
1-25 |
| Toaster |
800-1500 |
Computer |
80-150 |
| Popcorn
Popper |
250 |
Laptop |
20-50 |
| Blender |
300 |
Printer
Laser |
300-475 |
| Microwave |
600-1500 |
Printer
Ink Jet |
60-75 |
| Waffle
Iron |
1200 |
30"
Color TV |
288 |
| Frying
Pan |
1200 |
25"
Color TV |
150 |
| Dishwasher |
1200-1500 |
19"
Color TV |
70 |
| Garbage
Disposal |
450 |
12"
B&W TV |
20 |
| Washing
Machine |
500 |
VCR |
40 |
| Gas
Clothes |
300-400 |
Stereo |
30-100 |
| Vacuum
Cleaner |
500-1200 |
18"
Satellite Dish |
30 |
| Sewing
Machine |
100-500 |
20
cf. Conventional Refrigerator/Freezer |
540
(15 hrs.) |
| Iron |
900-1200 |
16
cf. Conventional Refrigerator/Freezer |
475
(13 hrs.) |
| Blow
Dryer |
900-1500 |
Sunfrost
19 cf. Freezer |
112
(10 hrs.) |
| Electric
Shaver |
15 |
Vestfrost
Freezer |
1200/day |
| Garage
Door |
350 |
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Your appliances may use much more or less energy than those listed to the right. To come to the most accurate estimate of your energy needs you must use the energy consumption ratings of the actual appliances you intend to use.
To get exact data for your appliances purchase or secure with a credit card the
Brand 4-1850 meter.
Back to top
How to fill out this
worksheet:
From left to right.
- Add the
Quantities of appliances. (column A)
- Multiply them times the Rated Wattage.
(column B)
- Multiply this number times the Hours Of Use Per Day (column C)
- Multiply this number times
Days Of Use Per Week. (column D)
- Divide this number by 7. (column E)
- This is the Average Watt-Hours Per Day for each appliance. (column F).
- Add together all the average watt-hours per day in (column F) and multiply the results by the
Load Correction Multiplier (1.3). This is your average power consumption Per Day.
|
A |
B |
C |
D |
E |
F |
| Appliance |
QTY. |
Rated
Wattage |
Hrs.
Used/Day |
Days
Used/Wk. |
Divide
by 7 |
Avg.
Watts-Hrs./Day |
| Example
TV |
1 |
x
90 |
x 4 |
x
5 |
÷
7 |
257 |
| TV |
|
x |
x |
x |
÷ |
|
| VCR |
|
x |
x |
x |
÷ |
|
| Coffee
Maker |
|
x |
x |
x |
÷ |
|
| Toaster |
|
x |
x |
x |
÷ |
|
| Microwave |
|
x |
x |
x |
÷ |
|
| Computer |
|
x |
x |
x |
÷ |
|
| Lights |
|
x |
x |
x |
÷ |
|
| Water
Pumps |
|
x |
x |
x |
÷ |
|
| Blow
Dryer |
|
x |
x |
x |
÷ |
|
| Refrigerator |
|
x |
x |
x |
÷ |
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x |
x |
x |
÷ |
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x |
x |
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÷ |
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÷ |
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Please use additional sheets of paper to list
all of you planned electrical uses.
|
Largest Load In
Watts: |
___________ |
| Total Wattage Used At One
Time: |
___________ |
| Total Watt-Hours Per day: |
___________ |
| Load Correction Multiplier |
x 1.3 |
| Corrected Watt-Hours Per Day |
___________ |
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Annual Average
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Winter
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| 1. Locate your site on the Winter and
Average yearly insolation map and list the nearest figures. |
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| 2. Enter the corrected watt hours
from your load evaluation form. |
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| 3. Divide line 2 by line 1. This is
the number of watts you need to generate per full hour of sun. |
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| 4. Enter the “real world” wattage
for the solar modules you have chosen for your system. Note: This
is generally 10% to 15% less than manufacturer's ratings. |
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| 5. Divide line 3 by line 4. The
result is the number of modules required for your system. |
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| In many northern climates
almost twice the modules are required, this fact is also
amplified in winter due to the increased loads from lighting, TV
time etc. In the interest of cost effectiveness we generally size
the solar array to supply 100% of the annual average requirements.
The shortfall in the winter can be made up by a generator. |
Insolation Maps
Annual
Average
Winter
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1. Enter the corrected watt hours per day from your load calculation
sheet |
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2. Determine days of storage required. This approximates the expected greatest number
of cloudy days in a row (2-4 days is normal 5 days
max.) |
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3. Multiply line 1 by line
2. |
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4. Determine the depth of discharge: 80% is the maximum for deep cycle lead acid
batteries, 50% depth of discharge (DOD) can increase
battery
life by approximately 25%. Divide line 3 by .80 for a 80% DOD
or .50 for a 50% DOD respectively. |
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| 5. De-rate the battery for low temperatures
by multiplying line 4 by the factors in the table below to arrive at watt/hour capacity of the battery
needed. |
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| To convert watt hours into amp hours (A/H) multiply the battery A/H x the
system voltage. |
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