PennEnvironment Research & Policy Center
Clean energy is sweeping across America and
is poised for further dramatic growth in the
Wind turbines and solar panels were novelties 10
years ago; today, they are everyday parts of America’s
energy landscape. Energy-saving LED light bulbs cost
$40 apiece as recently as 2010; today, they cost a few
dollars at the local hardware store.
Electric cars and the use of batteries to store excess electricity on the
grid seemed like far-off solutions just a few years ago;
now, they are breaking through into the mass market.
Virtually every day, there are new developments that
increase our ability to produce renewable energy, use
energy more efficiently, and use clean energy tech-
nologies to meet a wider range of energy needs –
bringing us closer to a future in which we can power
our economy with clean, renewable energy.
America produces nearly six times as much renew-
able electricity from the sun and the wind as it did in
2008, and in March 2017, for the first time ever, wind
and solar produced 10 percent of America’s electric-ity.
At the same time, the average American uses
nearly 8 percent less energy than a decade ago, due
in great part to improvements in energy efficiency.
The last decade has proven that clean energy tech-
nology can power American homes, businesses and
industry – and has left America poised to accelerate
its shift away from fossil fuels. With renewable energy
prices falling and new energy-saving technologies
coming on line every day, America should work
to obtain 100 percent of our energy from clean, renewable resources.
The last decade has seen explosive growth in the
key technologies needed to power America with
clean, renewable energy.
•Solar energy: In 2017, America produced 39
times as much solar power as it did in 2008, and
by the end of the first quarter of 2018, America
had enough solar capacity to power more than 10
In 2008, on-site and rooftop solar
combined with utility-scale solar power plants
produced 0.05 percent of U.S. electricity; in 2017,
they produced 2.1 percent of America’s power.
•Wind energy: America produces 4.6 times as much
wind power as it did in 2008, enough to power 24
million homes. In 2008, wind turbines produced
1.5 percent of the nation’s electricity; in 2017, they
produced 6.9 percent of America’s power.
•Energy efficiency: Despite a population that
has grown by more than 20 million, America
uses 1.1 percent less energy than in 2008, in
great part due to more energy efficient lighting,
appliances and cars.
The average American uses
7.7 percent less energy than in 2008, and the
nation’s energy consumption per unit of GDP
has fallen by 14 percent.
•Electric vehicles: Building an economy reliant on
clean, renewable energy means ending the use of
fossil fuels for all activities, including transporta-
tion. Over the last decade, 395,000 electric vehicles
(EVs) have been sold, passing 100,000 annual sales
for the first time in 2017.
Electric vehicle sales surged by 24 percent in 2017, fueled by lower
prices, better performance and a range of attr tive and affordable new vehicle models.
In the first three months of 2018, electric vehicle sales
were up an additional 35 percent over 2017.
•Battery storage: Expanding the ability to store
electricity can help the nation take full advantage
of its vast potential for clean, renewable energy.
Utility-scale battery energy storage capacity
in the U.S. grew 17-fold from 2008 to 2017 (in
megawatts), adding half of its total capacity in
2016 and 2017.
The recent introduction of home
electricity storage systems produced by compa-
nies like Tesla and LG Chem could set the stage for
further growth in the years to come.
Clean energy leadership is not concentrated in
one part of the country. Rather, it is distributed
across the United States, in states with different
economic and demographic makeups, driven in
part by the adoption of strong public policies.
•Solar energy: California, Arizona, North Carolina,
Nevada and Texas saw the greatest total increases
in solar energy generation from 2008 to 2017.
California’s landmark “Million Solar Roofs” program,
which accelerated the state’s solar industry in
the mid-2000s, along with its strong renewable
electricity standard and other policies, helped to
trigger the dramatic rise of solar power there
•Wind energy: Texas, Oklahoma, Kansas, Iowa and
North Dakota saw the greatest total increases in
wind energy generation from 2008 to 2017. Texas’
policies to upgrade its grid to accommodate
more wind power from rural west Texas played an
important role in the boom.
•Energy efficiency: Massachusetts, Rhode Island,
Illinois, Michigan and Washington saw the great-
est increases in the share of electricity saved
through efficiency measures, according to the
American Council for an Energy-Efficient Econo-
my. In 2016, Massachusetts and Rhode Island
implemented efficiency measures that saved the
equivalent of 3 percent of statewide electricity
consumption over the previous year.
•Electric vehicles: California, Hawaii, Washington,
Georgia and Oregon have seen the most battery
electric vehicles sold since 2008, as a percentage
of in-state vehicles.
Four of the top 10 states for EV sales require that a certain percentage of
each automakers’ sales be zero-emission vehicles,
including California, which is home to nearly half
of the nation’s electric vehicles.
•Battery storage: California, Illinois, Texas, West
Virginia and Ohio led the nation in additions to
utility-scale battery energy storage since 2008.
Nine of the 10 states that added the most battery
storage capacity had zero utility-scale battery
capacity in 2008.
Rapid improvements in technology and plum-
meting prices for clean energy suggest that
America has only begun to tap its vast clean
•Nearly every segment of the clean energy market
is seeing rapid price declines, and the unsubsi-
dized costs of utility-scale wind and solar energy
have fallen to levels that are “cost-competitive with
conventional generation technologies under some
scenarios” even before accounting for environmen-
tal and social benefits, according to the financial
firm Lazard’s most recent levelized cost of energy
From 2009 to 2017, the levelized cost of
energy from wind and utility-scale solar fell by 67
percent and 86 percent, respectively.
•Experts predict that prices will continue to fall. A
2016 survey of wind energy experts by the Nation-
al Renewable Energy Laboratory found that the
global price of wind power is expected to fall 24-30
percent by 2030 and 35-41 percent by 2050.
Bloomberg New Energy Finance predicts that “[b]
y 2025, solar may be cheaper than using coal on
average globally,” even excluding the costs coal use
imposes on public health and the environment.
Technology advances are also making renewable
energy technologies more efficient and effective.
In 2007, the highest-capacity wind turbine in the
world was 6 MW, with only one such test proto-
type actually in operation.
Today, an entire wind farm of 8 MW turbines is generating electricity off
the coast of England. According to Ørsted, that
company that led the project, a single revolu-
tion of the blades on just one turbine can power
a home for 29 hours.
The average rooftop solar
panel installed in 2016 was 25 percent more
efficient than in 2008.
•Advanced new products are also helping to
reduce energy consumption. Smart, internet-
connected appliances and climate control
systems, for example, can reduce energy
consumption and peak grid demand by enabling
users to control equipment remotely or shift its
operation to off-peak hours. U.S. smart appliance
revenue grew more than eight-fold from 2011 to
2016, from $105 million to $887 million.
The U.S. should work toward meeting all of its
energy needs – for electricity, transportation and
industry – with clean, renewable energy.
•Repowering America with clean, renewable
energy is a key strategy in phasing out carbon
pollution by 2050 – a necessary step to prevent
the worst impacts of global warming. Transition-
ing to clean, renewable energy will also improve
our health by preventing hazardous air pollution
and eliminating the hazards of extracting, trans-
porting and processing fossil fuels.
•America’s renewable energy resources are suffi-
cient to power the nation several times over. The
technologies needed to harness and apply renew-
able energy are advancing rapidly. And research-
ers from a wide variety of academic and govern-
mental institutions have developed a variety of
scenarios suggesting renewable energy can meet
all or nearly all of our society’s needs.
•Between 2008 and 2017, U.S. wind and solar
generation grew at an annual rate of 22 percent.
If generation were to grow by 14 percent per year,
or about two thirds of the past decade’s growth
rate, wind and solar would produce enough
electricity to meet all of our current electricity
needs by 2035.
•To accelerate progress, a growing number of
businesses, institutions of higher learning, local
governments and states are adopting 100 percent
renewable energy targets and goals. In 2015,
Hawaii became the first state in the country to set
a 100 percent renewable energy requirement for
its electricity sector, doing so through its renew-
able energy standard.
According to the Sierra Club, 65 cities have committed to 100 percent
renewable energy, and another six cities have
already achieved it.
The organization RE100
has chronicled 100 percent renewable energy
commitments from 131 companies, including
Bank of America, Google and Anheuser-Busch
And many college and university campus-
es already get 100 percent of their electricity from
clean energy sources.
America has already made incredible progress toward
getting its energy from clean, renewable sources.
Policymakers at all levels should adopt policies aimed
at repowering America with clean, renewable energy.