Hmm .. this little snippet put into question Ms Birch's claims that the 30 percent is a 'world record':

At the conference, NREL announced a new record efficiency of 37.9 percent at 10 suns, a measure of concentrated sunlight. Soon thereafter Boeing-Spectrolab, under contract to NREL and the Department of Energy, surpassed the NREL record with 39.0 percent at 236 suns announced at the European photovoltaic conference in Barcelona, Spain.

Apart from that quibble yes it's all looking good, although I still can't imagine how this tech would service a large metropolis - it would need to be on an absolutely huge scale. Maybe it could be miniaturized to fit on individual rooftops, like today's solar heaters. But anyway I suppose in regions with lesser sunlight it couldn't be more than a supplementary power source at most ..?