A seemingly impenetrable outer shell makes getting to the heart of the oil giant's greener activities tricky.
At the end of last month, Shell announced that it was raking in profits of about £11.3m a day. But anyone seeing the company's recent adverts could be forgiven for thinking that the oil giant is the greenest of the green. So do those bright fresh images of wind farms imply that the corporation really is putting its money where its mouth is and giving to environmental charities?
Well, you might be surprised to find out that finding out isn't easy.
A Shell spokeswoman said: "We don't give details of how much we give to charity." Discerning what the money is spent on wasn't any easier to discern, either.
The spokeswoman added: "We don't donate to charity in the traditional way." Instead, she said, money is channelled through Shell's Social Investment Programme.
Through this, about £60.5m is shelled out to the 140 countries in which the company works. With profits as they are at the moment, that would take Shell just over five days to make.
Nor would it say which countries get what percentage of this hard-earned cash. "We don't break it down," said the spokeswoman.
The slice the UK gets, whatever that may be, goes to a number of programmes.
These offer support to groups including young entrepreneurs, teenage performing artists, "commercially viable business ideas that tackle climate change" and local communities.
In 2000, the Shell Foundation was set up after the firm realised that incorporating sustainable development into its business practices was "not an option" but "a necessity to survive". It now invests £7m a year through NGOs in the developing world. Funded projects have included encouraging small businesses.