The plan is simple: draw lots of cards, send big fire tornadoes at your opponent, and boost your damage with Biting Sun.

Early game: use Sunflower Fields to tutor Biting Sun, and draw cards to find some solar spells, at least one Solar Wind and one Solar Invocation. Keep your mana as much as you can while you wait to play a big combo.

Mid game: at Zenith, set up Biting Sun, then play and activate Solar Wind (which will allow you to draw a card in addition to dealing damage). Put Solar Wind as a component with Solar Invocation (which will also deal damage), allowing you to play Tornado, which in addition to hitting quite hard, will reactivate Solar Wind and return it to your deck.

Total combo if everything is done in one turn: 15 damage for 11 mana.
All you have to do is finish off your opponent with a simple Solar Burn.

Late game: there is no late game with this deck.