Retail energy supply marketplace Choose Energy is offering $300 in Visa Rewards Cards to a lucky Texan each week through Sept. 13

Judges will pick one winner a week from submissions of 100 words or fewer for the following topic: "I'm #TexasCool and this is why ChooseEnergy.com should help me with my electricity costs this summer."

Submissions can be made by one of the following methods:

• Twitter or Instagram using the #TexasCool hashtag

• Facebook, in comments on our posts and/or

• Email

The contest is part of Choose Energy's #TexasCool campaign -- recognizing the state's great food and music, diverse cities, top-notch academic institutions, technology giants, other important businesses, great beverages, and more.

In addition to the giveaway, the site will publish daily #TexasCool Top 5s. Today's kickoff is the Top 5 things you didn't know about Texas. Future Top 5 lists will include such topics as: Top 5 ways to keep your pets cool; Top 5 coolest roadside attractions; Top 5 cool things created in Texas.

Some Top 5s will be determined by reader votes, and others will come from Choose Energy researchers.