H Power

(HPOW)

rose another 19.9% and hit a new intraday high of $33.13 as alternative energy stocks once again soared in the face of high oil and electricity prices. The fuel cell developer's stock nearly doubled between Aug. 16 and yesterday's close. Also showing big gains at midday were

Millennium Cell

TST Recommends

, up 31.3% after setting a new intraday high of $21.88, and

Impco Technologies

(IMCO)

, up 8.3%.