NEW YORK (TheStreet) -- The S&P 500 Index has gained 4.9% so far in 2011, while the Dow Jones Utilities Average (XME) advanced 2.2%. Overall, utility stocks are less volatile because of stable cash flows and provide limited upside, or downside, in comparison to other sectors.For instance, upsides for industry majors such as Southern Company ( SO), Exelon ( EXC), Dominion Resources ( D), Duke Energy ( DUK), NextEra Energy ( NEE), PG&E ( PCG), American Electric Power ( AEP) and Spectra Energy ( SE) are expected in the range of -3% to 9% over the next 12 months, according to consensus estimates of analysts surveyed by Bloomberg. Nonetheless, the following 10 utility stocks with an upside range of 14%-65% will likely outperform their peers, according to analysts' estimates of 12-month target prices. Most of these stocks have superior buy and hold ratings, compared to peers. In addition to growth potential, these stocks offer high dividend yields relative to several other sectors. However, rising energy costs will likely moderate dividends of electric utility companies. To sustain profits and for higher dividend yields, utility companies may seek mergers and acquisitions. Last month, Duke Energy announced to buy Progress Energy ( PGN) for $13.7 billion in stock.