The Clean Energy Revolution is Bigger Than You Think

Rooftop solar is without question the poster child of the clean energy revolution, with good reason: it’s visible, increasingly affordable, and growing explosively. Dubbed “power to the people” by leading environmental author and activist Bill McKibben, rooftop solar now symbolizes green commitment for the left and bootstrap self-reliance for the right. It would be hard to blame anyone for concluding that the shiny panels dotting communities everywhere were the principal drivers of America’s transition to clean energy.

Except that they’re not.

The truth is that the vast majority of America’s wind and solar electricity – more than 85 percent – comes from large scale facilities. Virtually all wind power comes from utility-scale installations in places so remote that they’re rarely seen by anyone who is not operating them. More than half of all solar panels in the U.S. are in vast arrays capable of powering tens of thousands of homes. Solar on residential rooftops is growing rapidly, but accounts for just 20 percent of total U.S. solar electric capacity, a proportion that will fall further as large scale installations grow.

Bigger is Cheaper

Economies of scale – the principle that the cost of making a unit of something falls as you produce more of them – applies to renewable energy just as it has to countless other products, from Henry Ford’s Model T’s to flat screen TVs. Large wind turbines produce energy for pennies on the dollar compared to small turbines suitable for commercial or residential settings. Taller towers reach stronger and more consistent winds at higher elevations, and longer blades capture more of the wind’s energy in each sweep. Despite using identical photovoltaic (PV) technology, large scale solar arrays generate electricity at less than half the cost of panels on a typical home (installed costs per watt dc: $1.38 for utility scale vs. $3.55 for residential[1]). Superior resource quality is a big driver of lower costs: utility-scale developers target very windy and sunny places far from where most people live. Large solar arrays save even more money by cutting unit installation costs and by ensuring that each panel sits at the optimal angle to the sun (not an option for most residential rooftops).

Bigger Networks Connect More Renewables – and Improve Their Performance

Moving power hundreds of miles from remote wind and solar facilities to customers is much more efficient than widely believed. In 2013, just 5% of the power generated on the U.S. grid was lost on wires[2], and most of that “line loss” occurred at the distribution level. Transmission is the smallest part of the average electric bill, only 9% compared with more than 65% for generation[3]. Generation cost savings from large scale wind and solar facilities are so large that they recoup the cost of transmission lines needed to connect them rapidly. Regional transmission investments in Texas, California, the Southwest Power Pool, and the Midcontinent Independent System Operator are delivering enormous amounts of large scale wind at net savings to customers. Benefits to electricity customers typically exceed costs by factors of 3 to 1 or more, and include reduced energy costs, congestion relief, improved reliability, reduced capacity costs, improved market liquidity and competition, and emissions reductions.

Robust regional transmission grids squeeze more kilowatts out of every wind and solar facility by finding demand whenever the wind is blowing or the sun is shining. When the grid is constrained, excess wind and solar generation are “curtailed,” i.e. wasted or dumped to avoid dangerously overloading the grid. Transmission expansions eliminate these losses, making wind and solar generators even more efficient and valuable. Texas wind curtailments plummeted from 17% in 2009 to 0.5% in 2014 – even as total wind generation nearly doubled – thanks primarily to well-planned transmission expansions and upgrades completed in 2013[4].

Big Solutions for a Huge Challenge

Small may be beautiful, but the global climate challenge is anything but small. The landmark agreement negotiated in Paris last year provided another stark reminder of its staggering magnitude. Avoiding catastrophic climate change impacts means reducing global carbon emissions 80 percent by 2050, with even steeper cuts in the electric sector. Big, cheap, and abundant wind and solar, enabled by expanded and upgraded regional transmission networks, are quietly leading the transition away from aging fossil power plants and toward an affordable, reliable, and universally accessible clean energy future. America has more than enough wind and solar to power everything – including transportation – dozens of times over. The key to capturing this potential is doubling down on the big solutions that are working better, cheaper, and faster than anything else.

[1] Solar Energy Industries Association, Solar Market Insight 2015 Q3, Executive Summary, December 9, 2015.

[2] U.S. Energy Information Administration (EIA), State Electricity Profiles, Table 10: Supply and Disposition of Electricity, July 10, 2015 update.

[3] U.S. EIA, Annual Energy Outlook 2015, Reference Case, Table 8: Electrical supply, disposition, prices, and emissions.

[4] Department of Energy, 2014 Wind Technologies Market Report, Ryan Wiser and Mark Bollinger, August, 2015.

Zond wind turbines rise up among a young corn crop at the Buffalo Ridge wind farm in SW Minnesota.

The main reason wind energy output appears lower in 2015? 2014 was a record high wind year

This article was originally published on September 2, 2015 on the AWEA Blog and written by Michael Googin

2014 saw record high wind output in the U.S., most notably when wind energy provided large amounts of extremely valuable power that helped keep the lights on during extreme cold in January 2014. However, the downside of 2014’s record high output is that it makes 2015 wind output appear to be drastically lower. Several recent news articles have used the comparison against 2014 output to build the narrative that 2015 wind output has been concerningly low.

While the first half of 2015 has seen below average wind speeds, a more meaningful comparison against a longer-term average shows 2015 wind output to be within the normal bounds of inter-annual wind output variation. Moreover, several months of below average wind output are not a reason for concern, as they fall within the band that grid operators and power plant investors expect because many sources of energy experience variability in fuel supply.

The EIA data in the table below show that the first six months of 2014 and 2015 both depart from the more typical wind output in 2013, with 2014 being a few percentage points higher and 2015 a few percentage points lower. Moreover, each datapoint covers only a narrow six month period, and the anomalies seen during those periods were offset by more normal levels of wind output during the latter six months of the year, as shown in the chart further below and as one would expect due to the statistical principle of regression toward the mean.

Time Period First Half 2013 1H 2014 1H 2015
Wind fleet capacity factor 36% 38% 33%

With that full context provided, it is clear that a few percentage point difference in wind output over a few months is not a reason for concern. However, if one focuses solely on the change from 1H 2014 to 1H 2015, as several recent articles have done, then one can get the mistaken impression that the wind output seen during the first few months of 2015 is a cause for concern.

The green line in the chart below shows that the wind resource was extremely high in 2014, significantly higher than any other year in the last 15 years. Even 2013 fell in the top four wind resource years over the last 15 years, so 2015’s wind output would look even less unusual if it were compared to a more typical year than 2013 in the table above.

sample-wide capacity

The following chart shows that the average capacity factor for the first half of 2015 is still higher than that seen in the first halves of 2007, 2009, and 2010, based on an estimate calculated from EIA capacity and January-June generation data for all U.S. wind projects. In addition, total wind energy production in the first half of 2015 is higher than that seen in the first half of any year except 2014.


Inter-annual variations in wind output are not a concern, as variability in fuel supply affects nearly all sources of energy. Last year one-third of Midwest coal plants had their fuel supplies curtailed due to railroad constraints, while natural gas pipelines experience congestion or even supply shortages. Natural gas prices have varied by a factor of five over the last 10 years due to fluctuations in supply and demand, resulting in large fluctuations in electricity prices and consumer costs. In contrast, wind plants have no fuel costs, so utilities that diversify their fuel mix with stably-priced wind protect their consumers from electricity price volatility. In addition, all power plants experience failures from time to time, which are a far larger cost for grid operators than the gradual and predictable changes in wind energy output. As another example, the hydropower resource varies more from year to year than the wind resource, yet the Pacific Northwest has successfully relied on hydropower to provide the majority of its electricity for several generations.

The main reason why the United States built an interstate power system 100 years ago was so that a large number of power plants and sources of electricity demand, each of which is inherently unreliable, could be combined to make a reliable power system.

A strong transmission system plays a key role in accommodating the fluctuations in the availability and price of all fuels. For example, transmission lines like the Pacific DC Intertie in the Western U.S. allow wind and hydropower to be delivered from the Pacific Northwest to California when output is high in the Northwest, while the line can flow in reverse when hydropower, wind, and solar generation is high in California and total generation supply is low in the Pacific Northwest.

AWEA Manager of Industry Data and Analysis John Hensley contributed to the analysis included in this post.


The Clean Energy Case for Transmission Has Never Been Stronger

This article was written by Bill White and John Jimison and was originally published on Greentech Media.

In the two years since we outlined how smarter transmission policy could accelerate and reduce clean energy costs in America’s Power Plan, evidence continues to mount that robust high-voltage transmission networks are indispensable to a clean energy future.

Smart transmission planning has enabled most of the wind and solar now operating in the United States and has done so while generating large net economic benefits; one study estimated that co-optimizing generation and transmission planning could save an incredible $90 billion.

But transmission expansion isn’t happening fast enough. Scientists say avoiding catastrophic climate impacts requires slashing global carbon emissions 80 percent or more by 2050. While wind and sunlight can power our nation’s homes and businesses, they can’t be moved in pipelines or rail cars — electric transmission lines are essential, and inadequate transmission remains the principal barrier to potentially explosive renewable energy growth.

So how do we clear this hurdle to our clean energy future?

The Lone Star State shines

Texas provides the best example of how new transmission facilitates renewable energy development. The state’s 2005 Renewable Energy Program directed the Public Utilities Commission (PUC) to identify Competitive Renewable Energy Zones (CREZ), geographic areas where wind generation facilities would be constructed. In 2008, the PUC unveiled a plan to build 3,600 circuit miles of new and upgraded high-voltage lines to deliver 18,500 megawatts of wind energy to Texas consumers.

Completed in 2013, the CREZ lines had connected 14,098 megawatts of wind generating capacity by the end of 2014 — more than one-fifth of all U.S. wind power. Texas added 1,800 megawatts of wind in 2014 alone, more than the installed wind capacity in 39 states. By the end of 2016, Texas installed wind capacity will reach 21,200 megawatts — surpassing the CREZ target by almost 3,000 megawatts.

But wind isn’t the only beneficiary of CREZ transmission. Utility-scale solar photovoltaic facilities — not even part of the original plan — are rushing to connect to the CREZ lines. The Electric Reliability Council of Texas predicts 6,000 megawatts of solar PV generation will come on-line by 2017, catapulting Texas to second in the nation in solar capacity, behind only California.

The economics of Texas’ CREZ make this remarkable story even better. CREZ cost $6.8 billion, but the transmission lines and renewable energy they enable are saving ratepayers $1.7 billion a year in electricity production costs, creating more than $5 billion in economic development benefits and cutting electric-sector carbon emissions 16 percent.

Bottom line: CREZ transmission lines are rapidly paying for themselves and will deliver huge net economic and environmental benefits for decades.

Smart transmission planning benefits across America

Texas isn’t the only place where transmission lines are unlocking renewable resources. California’s Renewable Energy Transmission Initiative identified transmission projects needed to meet the state’s aggressive 33 percent by 2020 renewable energy standard. San Diego Gas & Electric’s Sunrise Powerlinkwas energized in 2012, and in just two years added more than 1,000 megawatts of renewable energy to the utility’s portfolio, increasing its renewable share from 12 percent to 30 percent.

The Midwest Independent System Operator approved seventeen 345-kV transmission lines across nine states at a cost of $5.2 billion to help cost-effectively meet regional renewable energy goals. MISO estimates the so-called “MVP” projects will enable 43 million megawatt-hours of wind energy, reduce carbon emissions between 9 million and 15 million tons per year, improve system reliability, and generate up to $49.6 billion in net economic benefits over the next 20 to 40 years.

Solving the transmission-renewables mismatch

Successes like these prove renewables can grow rapidly at low cost — if transmission is built to connect them. However, the seven- to 10-year lead times for planning and building transmission and one- to two-year lead times for building renewable generation continue to intimidate wind and solar development across the country, despite welcome policy reforms like FERC Order 1000. Developers can’t build large new wind or solar resources unless new transmission capacity needed to deliver their power to customers has been planned years in advance.

Lack of transmission infrastructure also prevents resource-rich states like New Mexico (11th in wind potential, 2nd in solar potential) from exporting huge amounts of high-quality, low-cost wind and solar. Senator Martin Heinrich (D-NM) recently introduced legislation to restore federal backstop authority to site transmission lines, noting similar federal authority has expedited siting of thousands of miles of natural gas pipelines in recent years. From the Dakotas to Arizona, wind and solar resources capable of powering everything in the country dozens of times over remain untapped due to insufficient transmission.

A 2014 update to NREL’s 2012 Renewable Electricity Futures Study found if today’s cost trends continue, an 80 percent renewable energy future is technically feasible and may cost no more than business as usual, not to mention the multi-trillion-dollar public health and environmental benefits. And the cheapest generation, by far, is utility-scale.

The transmission imperative is clear. Now let’s help every region of the country embrace what forward-looking regions have shown: if they take proactive steps to permit and finance transmission infrastructure, the low-cost renewable resources will come.


Bill White is president at Norton White Energy and Senior Advisor to Americans for a Clean Energy Grid (ACEG) and John Jimison is managing director of the Energy Future Coalition, which hosts the campaign for ACEG. Both are contributing authors to America’s Power Plan.




Rooftop Solar is Great, But the Grid is the Real Key to Giving Everyone Clean Power

Bill McKibben (“Solar Power for Everyone,” June 29th) is right that cheap solar energy is hopeful news for the climate, but no one should conclude that it will render our integrated electric grid or the utilities that own and operate it obsolete.  Energy efficiency and rooftop solar are essential, but expanding the grid to tap remote but rich wind and solar resources is the fastest and cheapest way to remove carbon from electricity.

Nearly all of America’s solar and wind power is purchased today by utilities from large scale facilities connected to the grid, with good reason: utility-scale solar farms produce electricity at half the cost of small rooftop systems.  Wind economics are only compelling at large scale and with large groups of turbines, not as distributed resources.   Almost every household in America with solar panels – including the Borkowskis – still gets most of its electricity from large regional power grids.

Transmission networks are also much more efficient than batteries at smoothing out the natural variability of wind turbines and solar panels.  Grid engineers now blend wind and solar from sources scattered over thousands of square miles into steady and reliable power.  It turns out that the sun is shining or the wind blowing someplace almost every hour of every day – the key is having a network capable of collecting that energy and delivering to where it’s needed.

The ability of transmission to accelerate renewable energy deployment is a fact supported by a mountain of real world evidence, not speculation about future breakthroughs.  Texas built transmission to develop its immense wind resources and is now home to one fifth of the nation’s wind energy.  Large scale wind and solar facilities connected by California’s Renewable Energy Transmission Initiative are much more important than rooftop solar to achieving the state’s 33% by 2030 renewable energy target.  In both cases, transmission investments are paying for themselves quickly by delivering renewable energy to customers at net savings.  Mark Jacobson at Stanford University recently showed 100 percent renewable energy by 2050 to be technically and economically feasible in all 50 states; more than ninety percent of the energy he would have us call on is grid-connected wind, solar, and hydropower.

We share Mr. McKibben’s optimism that we can provide everyone, everywhere with affordable carbon free energy in time to avert a global climate catastrophe; but only if we use ALL of the resources at our disposal, especially the grid.