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All about Solar Energy

May 15, 2013
Paul Gipe

Penetration of Renewable Energy in Selected Markets

Inter-annual Wind Variability Less than that of Hydro

Steady Growth of Non-Hydro Renewable Penetration in European Markets

US Renewable Energy Penetration: Little Progress Since 1983

The penetration of renewable energy into the electricity supply mix has been much in the news recently. During the first quarter, Portugal generated three-quarters of its electricity with renewable energy. Meanwhile, in Germany, one-fifth of all electricity was generated with renewables, most of that from new sources of renewable energy, such as wind and solar. And recently, at a conference in San Francisco, attendees heard calls for generating not just 100 percent of electricity supply with renewable energy, but far more—200% to 300% of generation--in order to meet the need for heating, cooling, and transportation as well.

It’s always a good idea to take stock of where you are before you can determine how to get where you want to go. Below is a brief survey of the penetration of renewable energy in selected countries.

Penetration refers to the percentage of electricity generated by a particular resource. It can refer to the percentage relative to the total amount of electricity generated, or the amount consumed.

Often the penetration of renewable energy is compared to the amount of electricity consumed, because most new sources of renewable generation are close to the load--that is, close to where the electricity is consumed. Thus, there is less electricity lost in transmission as comparied with that from a large, central-station, conventional power plant.

Data collected by various nations on electricity generation and consumption is inconsistent in whether penetration reported for renewable energy is based on generation or consumption.

The data used in this analysis was collected by the Energy Information Administration (EIA) of the US Department of Energy: International Energy Statistics of Electricity Generation. EIA compiled the data from countries worldwide.

While EIA’s data may not correspond exactly to that published by various sources in other countries, the data is presented in a consistent manner, and in a user-friendly format.

For the most part, EIA’s data is complete from 1980 through 2011, though there are some exceptions. In some cases, other public sources of data have been included to extend the analysis to 2012.

The objective here is to present the broad sweep—the panorama—of the role renewable sources of generation play in electricity systems and how that has varied during the past three decades. It’s important not to get bogged down by superfluous detail. In some countries, renewables play a small role; in others, they provide all the electricity—today, not in some distant future.

Generally, “new sources” of renewable energy refer to the addition of wind, solar, and biomass. However, some “new” sources of hydroelectric generation have also been added during the past 30 years. The EIA sorts data for geothermal, wind, solar, and biomass and lumps all hydroelectric generation together. Thus, this analysis considers total renewable penetration and the penetration for all non-hydro sources. Where appropriate, specific renewables are singled out.

Let’s start at the top with two Scandinavian countries that already generate 100%--or nearly 100%--of their electricity from renewables: Norway and Iceland.


For the past 30 years, Norway has consistently harnessed its abundant hydroelectricity to generate nearly all of its generation for the nation of 5 million.

Since the turn of the century, Norway has been adding an increasing amount of new renewable generation from wind and biomass. Today, non-hydro sources of generation account for nearly 1.5% of Norway’s total generation.

Norway uses fossil fuels for only 3% of its supply.


Iceland has produced 100% of its supply from renewables since 1980. Though a much smaller country than Norway—there are only 320,000 inhabitants—the country has gone beyond Norway in adding new renewables to a system dominated by large hydro.

Since the late 1990s, Iceland has added a growing percentage of its generation from geothermal. In 2010, geothermal provided 26% of the country’s electricity.


Portugal has been in the news, for good reason. In 2010 and 2011 Portugal produced  a higher percentage of their supply from renewables than even Denmark.

The contribution of renewables to the Portuguese electricity mix varies dramatically from one year to the next, however, because of its dependence on large hydro.

The country has long relied on hydro for a high percentage of its generation. In 1988, large hydro generated 58% of supply; in 1997, 40%; and as late as 2010, as much as 38%.

Because of its Mediterranean climate, Portugal—like neighboring Spain—is subject to periodic droughts. These play havoc with hydroelectricity. For example, during the drought year of 2005, hydro dams in Portugal generated only 4.6 TWh. Whereas in the rainy year of 2010, hydro generated nearly 16 TWh—or three times as much as a dry year.

While critics of wind and solar are quick to point out the variability of wind and solar generation, they seldom mention the variability of other sources of electricity, such as nuclear, fossil fuels, or large hydro.

However, the generation from both wind and solar, while variable, is predictable. What is apparent from the data is that generation from hydro is much more highly variable from year to year than that from non-hydro renewables, with wind energy providing the bulk of the new generation.

The development of wind energy in Portugal is one of the often-overlooked renewable energy success stories. The 10.6 million Portuguese have made remarkable strides in developing their wind resource. Wind provided less than 1% of supply in 2002, but within only one decade wind generated nearly one-fifth of Portuguese electricity.

Biomass generated slightly more than 5% of supply in 2012. Solar contributed less than 1%.


In contrast to Portugal, Denmark has nearly zero hydroelectric resources. Renewable generation in Denmark is due solely to wind energy and biomass.

Danish renewable generation demonstrates even more clearly than Portugal that while inter-annual variability exists, it’s much less dramatic than that in countries with a high penetration of hydro.

In 2012, renewable sources of energy provided 45% of the electricity generated by 5.6 million Danes. Wind accounted for 30% of generation and biomass accounted for nearly 15%.

This data—again--refutes a perennial myth among anti-renewables ideologues that, somehow, Denmark really doesn’t produce a significant amount of wind energy. It’s as if they believe the entire nation of Denmark, right and left, windmill companies and utilities, have all conspired to “cook the books” to show that wind turbines generate more electricity than they actually do.

The majority of new wind generating capacity in Denmark has been added in the past 16 years. Despite the dominance of conservative parties in Denmark during the decade of the 2000s, Danish commitment to wind energy and biomass has not faltered.


Italy is the world’s tenth-largest industrial economy with 60 million inhabitants. It consumes 285 TWh of electricity annually—as much as California.

In 1980, hydro provided as much as a quarter of Italy’s electricity generation. By 2012, hydro’s portion of generation had dropped to 15% of supply, as consumption and generation continued to grow with limited expansion of new dams.

Italy has been producing as much as 2% of its generation from geothermal since the 1960s and 1970s.

However, the penetration from all renewables have been declining steadily from the 1980s until the mid-2000s when more wind, biomass, and especially solar photovoltaics (solar PV) began to be added to the system.

Wind and biomass have been growing steadily since the beginning of the 2000s. In 2012, wind contributed nearly 5% of supply, while biomass provided 4%.

But it’s been the meteoric increase in the amount of solar PV that has surprised energy analysts. As late as 2007, the generation from solar PV has rocketed from nothing to more than 6% in 2012, exceeding the percentage of supply from wind, biomass, and geothermal.

Altogether, new renewables provided more than 17% of total generation.


As an industrial power, Spain’s population, land area, domestic product, and climate are roughly comparable to those of California. The country of 47 million people has been on a trajectory of ever-greater penetration from non-hydro renewables since the mid-1990s.

Prior to the 1990s, hydro was the sole source of renewable energy in Spain’s electricity mix. As late as 1996, hydro provided nearly one quarter of Spain’s generation. As in nearby Portugal, annual generation from hydro varies dramatically from wet to dry years.

Since 2002, the penetration of non-hydro renewables in supply have increased from only 2% to 22% in 2012.

The bulk of generation from new renewables, as in Portugal, is from wind energy. In 2011, wind energy contributed more than 15% of supply; solar more than 3%; and biomass nearly 2%.


Germany has justifiably received the most of the attention of energy analysts and critics alike. The world’s fifth-largest industrial economy with a population of 80 million, Germany generates 575 TWh of electricity per year.

And, surprisingly, Germany is not a major producer of hydroelectricity. Germany generates only 20 TWh per year from hydro in contrast to Norway’s 120 TWh per year.

Thus, all the growth in the penetration of renewables in Germany’s supply is from non-hydro resources, such as wind, solar, biogas, and biomass.

Germany now generates more renewable energy than Norway.

In 2011, Germany generated 19%--or nearly one-fifth--of its supply with renewables. Hydro provided only 3% of generation; wind, 8%; biomass, 8%; and solar, 3%.

(Note: Germany provides more up-to-date data than EIA, however, it is not in the same format as that recorded by EIA; thus, it is not reflected here. The EIA data is also discontinuous because of German reunification in 1989.)


In the three decades since 1980, the contribution from renewables in France has steadily declined as its electricity consumption has more than doubled.

In 1980, hydro accounted for 27% of supply. By the late 2000s, hydro’s contribution to the French electricity supply had fallen to 10-12%.

The increase in renewable penetration since 2005 has been solely due to the addition of wind and a modest amount of solar PV and biomass.

In the 1970s, France made a political commitment to develop nuclear energy and undertook a massive construction program. As the reactors came on line, France launched what now seem foolhardy programs to encourage consumption of electricity. These consumption patterns are now integrated into France’s building stock and are playing havoc with the country’s energy policy.

Unlike the development of renewables in Denmark and Germany, France’s approach can best be characterized as schizophrenic. It has made commitments to its European Union (EU) partners to develop a certain percentage of its supply with renewables by 2020. Yet, France’s ruling elite is not yet ready to give up dreams of further nuclear expansion.

At the current pace, France will not meet its EU renewables obligation—and doesn’t seem too concerned about it either.

While the current government came to power with a call for reducing France’s reliance on nuclear power, there has been no concerted effort to do so.

In 2012, the penetration of wind in French supply was only about 3%, that from solar PV, less than 1%. Biomass contributed 1% of total generation.


The US generated a higher percentage of electricity with renewables in 1983, 14.1%, than it has anytime since in the past 30 years.

In 2012, renewables provided 12.7% of total generation. Existing large hydro accounted for three-quarters of total renewables generation, wind contributed the bulk of the remainder.

In 2011, wind generated nearly 4% of supply in the US.

The total penetration of renewables in 2011, despite news reports about the growth of wind and solar in absolute terms, only reached the same level of renewables in supply as was first achieved in 1980!

Though total renewable generation has increased to more than 500 TWh in 2012 from less than 300 TWh in 1980, total generation has nearly doubled since then, increasing from 2,300 TWh to 4,100 TWh last year. Thus, until the growth of wind energy in 2009, the percentage of renewables in supply had been steadily decreasing since 1983.

Great Britain

Among European countries, Great Britain is clearly the laggard. The total renewable contribution to its supply is less than 10%. Even France, with its development of hydro resources in the French Alps, generates a higher percentage of its supply, 16%, with renewables than Great Britain.

Britain’s poor track record is not for lack of resources. All analysts agree that while Britain may not be as sunny as Spain or Italy, it does have the best wind resource in Europe—far better than that in Germany, and better even than that in Denmark.

Nor is it for lack of experience or technology. Britain has been developing wind energy much longer than France.

Britain’s first significant foray into renewable energy was the introduction of the Non-Fossil Fuel Obligation (NFFO) in 1990. Designed originally as a way to fund “clean”, that is non-fossil fuel-fired nuclear power, the Thatcher government was shocked to learn that sloppy legislative language opened the door to other “clean” technologies, such as wind and hydro.

This was the same time period when Germany introduced its feed-in law—the Stromeinspeisungsgesetz. In contrast to Germany’s consistent policy support for renewables through its feed-in tariff mechanism, Britain stumbled badly with its quota model and has never recovered. Today, Britain has few renewables in comparison to other European countries, and an aging nuclear fleet as well.

In 2011, Britain generated nearly 5% of its supply with wind, and about 4% of its supply with biomass. Hydro contributed less than 2% of total generation.

Even the US generates a higher percentage of its electricity with renewables than Britain does.


Some countries generate 100% of their electricity with renewable energy today. Norway produces nearly all its electricity with hydro. Iceland generates three-quarters of its electricity with hydro and one-quarter with geothermal.

Both Denmark and Portugal produce nearly one-half their electricity with renewable energy. Portugal generates one-fifth of its electricity with wind energy alone, while Denmark produces nearly one-third of its electricity with wind.

Italy and Spain both generate about one-third of their electricity with renewables. Italy produces 17% of its electricity, or half of its total renewable generation from non-hydro resources. Non-hydro resources, such as wind, solar, and biomass, contributes two-thirds of Spain’s total renewable generation.

Germany provides about one-quarter of their generation from renewables. Nearly one-fifth of Germany’s electricity is produced by non-hydro resources.

New, or non-hydro resources provide less than 5% of generation in France and the US. The penetration of renewable generation in the US has yet to reach levels seen thirty years ago. The total renewable penetration in France remains substantially less than that seen three decades ago.

Great Britain generates one-tenth of its electricity with renewables, 90% of that from non-hydro resources, mostly wind.

Clearly, countries can, when they choose to do so, generate a very high percentage--if not 100%--of their electricity with renewables. The challenge has never been technical. The problem has always been the political desire for a high percentage of renewable energy in a nation's generating mix--and the consistent implementation of policies that work.

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