System Sizing Tool

Before sizing a wind/solar powered system you need to calculate your power consumption. Listed below are some common household appliances and their power consumption. These are baseline figures only and should not be used as a true consumption model. Accurate readings can be acquired by using a power consumption meter such as the "Kill a Watt" or "Brand Digital Power Meter". These units give detailed readings of most any 120 volt AC appliance and will find your phantom loads. Phantom loads are appliances such as TV's, VCR's etc. that consume power even when turned off. Your entertainment system may be consuming 30 Watts of electricity 24 hours/day. A simple power bar or unplugging it can save power consumption. Energy efficient appliances will save you money whether you live on the grid or off. Pay back is often only a few short years.

System Sizing Worksheet

Note: right click on the version you require and save to your computer.
Microsoft Excel Version - OpenOffice Version

Your appliance not shown? You can calculate its wattage by multiplying the volts by the amps.

PV array size (Watts) = Daily energy (Watt hrs./day) divided by (Daily Sunlight hrs.*Battery Efficiency*Inverter Efficiency)
Efficiencies range from 70-95%
Battery Capacity (amp hrs.) = Watt hrs./day * days of storage required divided by (battery voltage *battery efficiency * depth of discharge)
Days of storage range from 4-15 days depending on service and location. Depth of discharge depends on type of battery and battery temperature.

Starting wattage is used to size an inverters continuous and surge capacities.

This is a basic sizing formula and many other factors can influence a system design. Use this as a general tool to get a ball park idea on a systems size. Wind turbine only systems have many variables as well, contact us for more accurate designs. The best place to start is to become more efficient and build a smaller system.

Canadian Weather

Province, City Annual average
wind speed m/s Sunlight hrs. Summer Sunlight hrs. Winter Sunlight hrs. Average

Alberta, Edmonton 3.6 4.9 2.2 3.74

Alberta, Calgary 4.4 4.7 1.96 3.58

Alberta, Suffield 5.1 5.19 2.75 4.1

B.C., Kamloops 3.1 4.5 1.5 3.3

B.C., Prince George 2.8 4.1 1.3 3.1

B.C., Vancouver 3.2 4.2 1.3 3.1

Manitoba, The Pas 4.1 5.0 2.0 3.6

Manitoba, Winnipeg 4.9 5.23 2.7 4.0

N.B., Fredericton 3.4 4.24 2.51 3.55

Newfoundland &
Labrador, Goose Bay 4.4 4.6 2.0 3.3

Newfoundland &
Labrador,St. Johns 6.6 3.9 1.8 3.1

N.W.T., Yellowknife 4.1 5.14 0.3 2.58

Nova Scotia, Halifax 4.5 4.0 2.16 3.4

Nunavut, Iqaluit 5.3 4.88 0.3 1.95

Ontario, North Bay 3.8 5.01 1.6 3.6

Ontario, Ottawa 3.9 4.6 2.3 3.7

Ontario, Toronto 4.9 4.0 2.2 3.5

P.E.I., Charlottetown 5.2 4.3 2.3 3.6

Quebec, Montreal 4.0 4.2 2.3 3.5

Quebec, Sept-Isles 4.4 4.3 2.3 3.5

Saskatchewan,
Swift Current 6.0 5.3 2.8 4.2

Yukon, Whitehorse 3.8 4.8 0.7 3.0