# Solarize Plano Project - Homework Assignment

July 18, 2013

To be prepared for the information meetings (see note (A) below), you will need to do a small amount of preparation.  This preparation will help you determine for your home, three potential PV solar system sizes - we will call them SMALL, MEDIUM, and LARGE.

SMALL means a PV solar system size (measured in kW) that will provide approximately 33% of your total annual energy usage.

MEDIUM means a PV solar system size (measured in kW) that will provide approximately 50% of your total annual energy usage.

LARGE means a PV solar system size (measured in kW) that will provide approximately 67% of your total annual energy usage.

Recall - the estimate for your annual electricity usage is determined by adding up the per month kWh usage for the last 12 months.  This information is available on your electricity bills, or possibly available when you log into your account on your electricity company's website.  (See note B below if you are having trouble locating this information.)

Knowing these three potential systems sizes in kW for your specific home, and with the information to be discussed during the informational meetings, you will be able to calculate estimated system costs.

The basic calculations to perform before the meeting are:

1. for the SMALL system size determination, multiply your total annual energy usage by 33%. Then take this number and divide it by 1400, which is the estimated annual production in kWh from a 1KW south facing PV system in North Texas.  As an example, assuming your annual energy usage is 15,000 kWh:

15,000 * 0.33 = 4,950

4,950 / 1,400 = 3.5 kW PV system

2. for the MEDIUM system size determination, multiply your total annual energy usage by 50%. Using the example from above.

15,000 * 0.50 = 7,500

7,500 / 1,400 = 5.4 kW PV system

3. for the LARGE system size determination, multiply your total annual energy usage by 67%. Using the example from above.

15,000 * 0.67 = 10,050

10,050 / 1,400 = 7.2 kW PV system

Be sure to bring the results from your calculations for SMALL, MEDIUM, and LARGE to the meeting along with a calculator and something to take notes with.

Best Regards & Shine On!

Larry Howe

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Note(s):

A. For a schedule of information meetings, see Schedules and Presentations

REMINDER - Please let us know in which meeting you plan to participate, or if you have conflicts for the scheduled times. Thanks to those who have already responded.

B. If you are having trouble locating the last 12 months of energy consumption, you may also try contacting Oncor's Service Request line at 1.888.313.6862 (see http://www.oncor.com/EN/Pages/I-Need-To.aspx) and asking for consumption or usage history.  If you live in the CoServ service area, try calling the CoServ Customer Service number and inquiring about usage history for your address.

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