SITUATION:
After the the recent BP Deepwater Horizon oil spill, and the resulting stock market and media fallout, the Exxon Mobil Corporation decided to re-focus its brand image to emphasize it alternative energy efforts.
BRIEF:
Re-design ExxonMobil’s Logo to visually align the company with the emerging “go green” culture.
Make the brand signals more appealing to climate conscious/ environmentally conscious stakeholders.
The logo must, as much as possible, resemble the existing logo.
APPROACH:
Research revealed that the “green” culture advocated alternative and renewable sources of energy. The four main types that were identified were:
Wind Energy
Solar Energy
Hydro Energy
Bio mass Energy
Related imagery was also referenced HERE
The logo features two “windmills” that form the iconic “double X” from the original Exxon Logo and also illustrate the concept of Wind energy.
Alternatively, there are three different color variations that symbolize the other types of alternative energy. HYDRO, BIO and SOLAR
Typographically the logo reads “E” – “on” which as an optional tagline would represent “Energy, On”
P.S – This was just a fantasy / spec re-brand exercise. Please let me know what you think.
Love Mark.
IMPROPER FACTION 
I like the concept of converting the Xs into windmills. With everything else I think you went too far, especially since your brief says the new look should resemble the old logo. This feels like exxon has new logo just for their alt energy divisions. If that were the brief my only critique would be that the Xs seem disproportionately less dense that the rest of the typography.
ExxonMobil is a big serious company, the light colours and light font take it too far away from that. Also, Exxon is a subsidiary of ExxonMobil, i don’t think they would go for removing or reducing the mobil.