TransAlta (NYSE: TAC) is expected to report Q2 earnings on July 31. Here's what Wall Street wants to see:

The 10-second takeaway
Comparing the upcoming quarter to the prior-year quarter, average analyst estimates predict TransAlta's revenue will grow 2.6% and EPS will drop 43.3%.

The average estimate for revenue is $547.8 million. On the bottom line, the average EPS estimate is $0.17.

Revenue details
Last quarter, TransAlta logged revenue of $657.3 million. GAAP reported sales were 22% lower than the prior-year quarter's $842.2 million.

Source: S&P Capital IQ. Quarterly periods. Dollar amounts in millions. Non-GAAP figures may vary to maintain comparability with estimates.

EPS details
Last quarter, non-GAAP EPS came in at $0.20. GAAP EPS of $0.40 for Q1 were 58% lower than the prior-year quarter's $0.95 per share.

Source: S&P Capital IQ. Quarterly periods. Non-GAAP figures may vary to maintain comparability with estimates.

Recent performance
For the preceding quarter, gross margin was 47.0%, 1,170 basis points worse than the prior-year quarter. Operating margin was 26.2%, 1,770 basis points worse than the prior-year quarter. Net margin was 14.6%, 1,080 basis points worse than the prior-year quarter.

Looking ahead
The full year's average estimate for revenue is $2.42 billion. The average EPS estimate is $0.87.

Investor sentiment
The stock has a five-star rating (out of five) at Motley Fool CAPS, with 79 members out of 83 rating the stock outperform, and four members rating it underperform. Among 21 CAPS All-Star picks (recommendations by the highest-ranked CAPS members), 20 give TransAlta a green thumbs-up, and one gives it a red thumbs-down.

Of Wall Street recommendations tracked by S&P Capital IQ, the average opinion on TransAlta is hold, with an average price target of $22.44.