Warren Jenson, Chief Operating Officer at smart grid player and IPO aspirant Silver Spring Networks, has left the company, according to VentureWire.

Why would a COO leave one of the more successful and potentially lucrative greentech companies? Since the firm will not comment, a smart grid expert colleague offers these potential reasons: he's being forced out for a more IPO-ready COO; he's ditching a leaky ship; he's got personal problems; or,he found a higher paying job. No new COO has yet been announced on the company website.

Last week, we reported that EcoFactor was replacing its CEO and that founder and now-former CEO John Steinberg would likely take another role at the firm. This week we learned that Roy Johnson is coming to EcoFactor as CEO. Johnson comes to EcoFactor after four years as CEO at Calisolar, a manufacturer ofsolarsilicon. Terry Jester, former EIR at Hudson Clean Energy and Director at Sunpower, is now the CEO at CaliSolar.

Terry Jester, former EIR at Hudson Clean Energy and Director at Sunpower, is now the CEO at Calisolar. Calisolar has been working on UMG solar cells for some time, raising $102 million in 2008 to build a factory in California, back when UMG silicon was about one-sixth the price of the higher-grade polysilicon going into the solar industry.

Lunera Lighting, a maker of LED-based fluorescent light replacements, recently collected a new funding round and a new CEO, Michael Keddington.

Sunlogics, a solar developer, appointed Charles Bryant, former EVP of Finance, as Interim Chief Executive Officer. Sunlogics is working with General Motors on a variety of solar projects. GM Ventures is an investor in the firm.

Brice Koch was appointed head of ABB’s Power Systems.