NEW YORK ( TheStreet) -- Applied Materials ( AMAT), First Solar ( FSLR), MEMC ( WFR), GT Solar International ( SOLR), Woodward ( WWD), Amtech Systems ( ASYS), Satcon Technology ( SATC) and SunPower ( SPWRA) are alternative energy stocks with upside potential of up to 138%, based on analysts' consensus estimates of 12-month price targets.

We recommend these eight alternative energy stocks as they have outperformed the broader indices to gain an average 21% during the last year. These stocks, riding on firm crude prices, could deliver earnings of 15% to 20% over the next year, analysts say.

The stocks have average buy ratings of 54% and mean upside value of around 51%, according to analysts polled by Bloomberg.

The stocks are stacked in terms of percentage upside, from great to greatest. 8. First Solar ( FSLR) manufactures solar modules with an advanced semiconductor technology, and is a provider of comprehensive photovoltaic system solutions.

Higher selling costs and research and development expenses pressured profitability in the first quarter of 2011. Net income reported was $115 million versus $172 million in the same quarter last year. For 2011 first quarter, total revenue came in flat year-over-year at $567 million.

Summarizing the business environment, Rob Gillette, CEO of First Solar, said, "Despite European market uncertainties, First Solar has good visibility into our demand for 2011." He added, "We continue to execute our cost roadmaps, invest in new module capacity, build our project pipeline, and develop promising new markets around the world."

The company has updated its 2011 guidance with net sales estimated between $3.7 billion and $3.8 billion for the full year. Operating income is pegged at $900 million to $970 million, while 2011 earnings per share is estimated between $9.25 and $9.7.

The stock has analysts' buy ratings of 49% and is expected to deliver 22% return over the next one year. The stock is trading at 12.4 times its estimated 2011 earnings.

7. Woodward ( WWD) is a designer, manufacturer, and provider of energy control and optimization solutions. The company designs, produces, and services components and integrated systems that manage and control the energy of fluid movement, motion, combustion and electricity.

Net sales for the second quarter of fiscal 2011 were $419 million, increasing 20% from $349 million during the second quarter of the prior year. Net earnings were $32.1 million compared with $24.1 million in the same quarter of the earlier year.

Operating profit was $53 million as against $43 million during the second quarter of 2010 due to increased volumes, although partially offset by higher R&D costs and variable compensation.

The company expects fiscal 2011 sales to come in line with the original guidance of $1.55 billion to $1.65 billion, and earnings per share between $1.75 and $1.90.

The stock has 70% buy ratings and is expected to deliver 26% over the next year. The stock trades at 17.3 times its estimated 2011 earnings.

6. Applied Materials ( AMAT) provides innovative equipment, services and software for the manufacture of solar photovoltaic products, advanced semiconductors and flat panel displays.

Net income reported for the first quarter of fiscal 2011 was $506 million as against $83 million in the same quarter last year. Net revenue rose to $2.69 billion from $1.89 billion in the first quarter of 2010.

The backlog for orders increased by $292 million to $3.54 billion at the end of the first quarter. Gross margin was 42.3%, marginally higher than 42.2% reported in the fourth quarter of fiscal 2010.

Looking ahead, Mike Splinter, CEO of Applied, said, "We see momentum building in our end markets and expect our company's fiscal year revenue to be more than $11 billion, exceeding our previous record by over a billion dollars. We now expect wafer fab equipment spending to be up 10% to 15% from approximately $31 billion in calendar 2010, with crystalline silicon solar equipment spending rising by more than 30% year over year."

Cash and cash equivalents increased to $4.1 billion at the end of the quarter. Analysts have 36% buy ratings and expect the stock to deliver 30% over the next year. The stock is trading at 8.8 times its estimated 2011 earnings.

5. GT Solar International ( SOLR) provides polysilicon production equipment and sapphire and silicon crystalline growth systems and materials for the solar, LED and other specialty markets.

For the fourth quarter of 2011, the company reported revenue of $271.6 million from $194.7 million in the fourth quarter of the prior year. Sales were 40% higher than the previous year, while actual earnings per share zoomed 78% to $0.41 per share.

Gross profit for the quarter came in at $117 million, up from $73.1 million reported in the year-ago quarter. Operating margin was 30.5% as opposed to 28.4% in the fourth quarter of the previous year. Net income rose 56% to $51.9 million from $33.3 million during the same quarter last year.

Cash and cash equivalents at the end of the third quarter were $362.4 million with an order backlog of $1.19 billion. Based on the company's guidance for fiscal 2012, revenue is expected between $1 billion and $1.1 billion, higher than the company's earlier estimate of $850 million to $1 billion.

The stock has analysts' buy ratings of 73% and is expected to deliver 30% over the next one year. The stock is trading at 7.4 times its estimated 2011 earnings.

4. SunPower ( SPWRA) designs, manufactures and sells solar electric power technologies.

For the first quarter of 2011, the company reported lower-than-expected revenue, driven by changing market dynamics in Europe. Revenue increased to $451.4 million from $347.3 million in the same quarter of 2010. Gross margin stood at 19.6% vs. 20.7% in the prior year's same quarter.

Reviewing the company's performance, Tom Werner, SunPower CEO, said in a press statement, "We met our margin and bottom line financial goals in the first quarter by adjusting our downstream channels and operating expenses." Besides, SunPower has reduced its manufacturing costs for the quarter, and is likely to achieve the efficiency-adjusted panel cost per watt target of $1.08 in the fourth quarter of 2011.

The stock delivered 32% returns during 2011 and is trading at 13 times its estimated 2011 earnings.

3. Amtech Systems ( ASYS) manufactures capital equipment, including silicon wafer handling automation, thermal processing equipment and related consumables used in fabricating solar cells, LED and semiconductor devices.

Net revenue for the second quarter of fiscal 2011 was $61.3 million, up 281% from $16.1 million for the second quarter of the earlier year, primarily driven by higher solar shipments. Total order value for the quarter was $73 million, with $60 million solar. At the end of March 2011, the company's order backlog was $195 million.

Gross margin improved to 40% from 29% in the second quarter of fiscal 2010, driven by efficient capacity utilization from higher shipment volumes. Net income for the second quarter of fiscal 2011 was $7.5 million as against $206,000 during the second quarter of the prior year.

Amtech has revised its financial guidance for the full year 2011 upward with revenue seen exceeding $240 million, up 100% from fiscal 2010. For the third quarter of 2011, Amtech pegs revenue to range from $63 million to $66 million.

The stock has analysts' buy ratings of 67% and is expected to deliver 61% over the next one year. The stock is trading at 7.2 times its estimated 2011 earnings.

2. MEMC ( WFR), a global leader in semiconductor and solar technology, engages in the design and development of silicon wafer technologies. With R&D and manufacturing facilities in the U.S., Europe, and Asia, MEMC provides services useful in the manufacture of next generation semiconductor devices and solar cells.

For the first quarter, the company's Solar Materials and SunEdison segments posted strong sales. Net sales at the end of March 2011 were $735.9 million, increasing 68% from $437.7 million in the first quarter of 2010.

Capital expenditure during the quarter was $205.4 million, primarily related to investment in solar wafer capacity, semiconductor 300 mm wafer production, and polysilicon capacity expansion.

Cash and cash equivalents for the quarter stood at $684.1 million. Analysts polled by Bloomberg are positive on the stock and expect it to deliver around 76% within a year's time. The stock is trading at 8 times its estimated 2011 earnings.

1. Satcon Technology ( SATC) is a supplier of utility grade power solutions for the renewable and distributed energy markets.

Revenue reported for the first quarter of 2011 was $62 million, up 321% from the same period last year. North America contributed 76% of total sales, Asia factored in 22%, while Europe had only a 2% share.

During the quarter, the company shipped 276.5 megawatt industry-leading solutions. Satcon's utility scale solutions were over 240 megawatts, representing 87% of total units shipped during the quarter.

Bookings for Satcon's solutions during 2011 first quarter totaled $35.5 million, or 132 megawatts, with North America generating 77% of the demand.

Looking ahead, Steve Rhoades, Satcon's CEO, said, "For the second quarter of 2011 we believe the markets in North America and Asia will remain strong and that Germany and Italy will define their long-term FIT strategies. We expect Q2 revenue to be in the range of $50 to $60 million."

The stock has 77% buy ratings and is expected to deliver 138% returns over the next one year. The stock trades at 7.8 times its estimated 2012 earnings.

>>To see these stocks in action, visit the 8 Alternative Energy Stocks With Upside portfolio on Stockpickr.