President Obama last week visited an electric vehicle R&D lab in California where he called on battery developers to step up and innovate. Today, back at the White House, the President once again reached out to cleantech entrepreneurs, this time at an event dubbed “Investing In Our Clean Energy Future.”

Obama met with entrepreneurs and researchers to talk about building an economy that runs on renewable energy and creating green jobs — and to continue promoting his 10-year budget plan, which includes $75 billion to make the Research and Experimentation Tax Credit permanent.

Paul Holland, who focuses on early-stage cleantech investments as a general partner at Foundation Capital and sits on the board of green building materials maker Serious Materials (and will speak at our Green:Net conference tomorrow), kicked off today’s session by telling event attendees about Serious Materials’ plans to reopen shuttered plants and rehire laid-off workers.

As we noted last week, Serious Materials has directly attributed its job openings to the economic stimulus package — so i