Is cleaner clean?

And no area is more ripe for such innovation than energy. …But to create more of these clean energy jobs, we need more production, more efficiency, more incentives. And that means building a new generation of safe, clean nuclear power plants in this country. It means making tough decisions about opening new offshore areas for oil and gas development. It means continued investment in advanced biofuels and clean coal technologies. And, yes, it means passing a comprehensive energy and climate bill with incentives that will finally make clean energy the profitable kind of energy in America. (State of the Union Address 2010)

A comparative, followed by than, expresses that an entity has a property or quality greater or less in extent than an other. One person might be sillier than an other and a speech more carefully drafted this time than last. The comparative here indicates an increase or improvement. Sillier is – oh well – even less reasonable than silly, hence indicates an increase in folly, while something more carefully prepared has – one might hope – improved.
However, that something is better does not necessarily mean that it is good. That Timothy Dalton was a better James Bond than Pierce Brosman does not mean that Timothy Dalton was good; it simply means that Pierce Brosman was even worse. Ergo, that something is cleaner does certainly not mean it is clean.
The definition of clean is not only that something is not dirty. Especially in reference to air, water, or power, clean means that something does not contain or produce anything that is dirty or harmful. In a similar vein, clean can also refer to the degree of honesty and fairness of actions or statements. Clean delivery is “without anything omitted or left; without any exception that may vitiate the statement. This sense arose from the consideration that when a substance is taken entirely out of any vessel, etc., without leaving a particle behind, the vessel is left clean, and its cleanness is a measure of the completeness of the removal. Hence clean was used with all verbs of taking, driving, going away, losing, and thence of finishing up, completing, or performing any action” (OED).
The time, therefore, is ripe for coming clean about “clean energy” and no topic riper for clean statements that do not omit anything and for a clean break with misleading phraseology than clean energy.

Comparatives are formed by adding the ending -er to adjectives that either have only one syllable (short/shorter) or end in -y (pretty/prettier) or -le (simple/simpler). One syllable adverbs form the comparative in the same way (fast/faster).
Longer adjectives and adverbs ending in -ly require the use of more (more intelligent, more carefully).
A combination of more and the -er form is not possible (He cooks more better than she).
The most common adjectives and adverbs that form an irregular comparative are:
good/better
well/better
bad/worse
badly/worse
much/more
many/more
little/less
far/farther (distance) or further (degree)