The Solarcoin Foundation are offering 10,000 SLR bonus for First Prize and the Lykke exchange are offering 15,000 SLR split between the winner and runners up, more details here
Disclaimer: I am not officially connected to Lykke or the SolarCoin Foundation, I will have no part in the judging and am not liable for issuing of the rewards and am making no offer of work or reward myself, nothing about this post is intended to create a legal relationship; I am posting this purely as a method to publicise the competition. Please contact Lykke through the link above to enter/ask for clarifications.