Wind turbines at the Forward Wind Energy Center. Source: Ruth Baranowski/NREL.

President Obama made a recent stop in sun-soaked Nevada to tout solar energy and its importance in America's energy future. Perhaps he should have made a visit to his old stomping grounds in Chicago -- the Windy City would've been more appropriate. A new report from the Department of Energy found that the cost of wind energy is now at an all-time low.

On the level
There are a variety of factors that affect how much a power source costs, so analysts use the levelized cost of electricity, or LCOE, as a way to compare the cost of various sources. In a September 2014 report analyzing the LCOE of various power sources, research from the investment bank Lazard found that wind energy -- at $37 per megawatt hour -- represented the lowest LCOE among both conventional and alternative energy sources. At its most competitive amount, solar power amounted to $60/ MWh. 

From transmission to labor costs, numerous factors affect the LCOE solar and wind on a regional basis. Except for the Southeast, the price of wind power is consistently more competitive than that of solar. As utilities strive to reduce carbon emissions in compliance with the Clean Power Policy, wind will (for the most part) be a more competitive option than that of solar, regardless of where they are located.

As if that wasn't enough positive publicity for the wind industry, it received even more this summer. Basing its estimate on various power purchase agreements, or PPAs, signed in 2014, the Energy Department released its findings that the cost of wind is, in fact, $23.50/MWh -- markedly lower than the almost $70/MWh found in PPAs from 2009. With wind demonstrating how competitive it is to the costs of conventional fuels, it's likely that wind farms will gain a greater presence across the country, and as they do, GE (NYSE:GE) and Siemens AG (OTC:SIEGY) will lead the way.

Top dog
In its 2014 Wind Technologies Market Report, the Energy Department found that the declining cost of wind-generated electricity is due, in part, to the declining cost of turbines. And when it comes to turbines, GE is the perennial winner in supplying the U.S. wind market; the company accounted for 60% of the installation capacity added in 2014. This year has been shaping up to be another success for the company. Booking orders for 1,264 wind turbines through the first two quarters of 2015, GE has improved 11% over the same period last year; year-to-date sales of 1,278 turbines are also an 11% improvement over the 1,156 sold during the same period last year. 

GE's competitive advantage lies not just in its wind turbines, but also in the support services it offers. Bringing the Internet of Things to the wind industry, GE's Digital Wind Farm relies on a network of sensors and software analytics to create an entire ecosystem -- one in which turbines are constantly monitored and modified to operate in the most efficient way based on environmental conditions. According to the company, the system "could boost a wind farm's energy production by as much as 20 percent and create $100 million in extra value over the lifetime of a 100 megawatt farm.".

Player No. 2
Siemens AG also has a substantial presence. Each year, since 2012, Siemens has been the second largest turbine supplier in the United States. Last year, Siemens installed 1,241 MW of capacity -- 26% of the U.S. market. The first two quarters suggest that 2015 may not see Siemens as one of the leaders, though. Through the first two quarters of the year, Siemens' turbines only appeared in 0.01% of utility-scale wind projects that were completed. On the other hand, GE accounted for 43%. It will be interesting to see what sort of presence Siemens has in the remaining two quarters of the year. 

In general, Siemens has seen a decline in its wind-power business. For the third quarter of fiscal year 2015, orders for the wind power and renewables segment is down 65% compared with the same period last year. Revenue, however, has not declined as much -- only 1%. Siemens attributes the drop in revenue to a slowing down in its onshore wind business. The company has succeeded in controlling costs, though; profit improved 26% and the profit margin rose from 2.9% to 3.6%.

A Fool's take
The costs of wind and solar power in the U.S. have been on a steady decline for some time now. According to Lazard, over the past five years, the LCOE of wind power has decreased about 58% while that of solar has come down about 78%. With prices low enough to be cost-competitive with conventional fuels, the adoption of renewable power becomes an increasingly convincing argument, and, in the discourse, GE and Siemens are two prominent names -- companies to keep an eye on as turbines rise across the country.