ENERGY

Before Industrial Revolution, society made use of SOLAR ENERGY

(direct heating and lighting) including its indirect forms:

• BIOFUELS (photosynthesis)

• WIND ENERGY (ship propulsion, windmills, etc.)

• HYDROPOWER (grindimg waterwheels, etc.)

Extensive use of COAL with the Industrial Revolution, and later other fossil-

fuels: OIL, NATURAL GAS: more concentrated energy forms of easy use

and inexpensive.

Nowadays:

COAL+ OIL + NATURAL GAS: 3/4 of worldwide energy consumption.

First Oil Crisis ( 1972):

• Huge rising of oil price.

• Awareness that fossil fuel reserves are finite.

• Awareness of effect on climate change in medium and long term

(greenhouse effect).

Nuclear energy technology emerged from Second World War as a

promising new source of energy, alternative to fossil fuels, for

electricity production.

Nuclear power has been the subject of controversy since its

inception due to:

• Costs

• Security (Disastrous accidents: Chernobil, Fukushima, etc.)

• Disposal of radioactives wastes

• Concerns about proliferation of nuclear weapons

Renewable energy has been growing rapidly in the last

decade, becoming an important component of energy

supply.

Government intervention in support of renewables has

grown, reflecting efforts to reduce carbon-dioxide

emissions and to diversify energy supplies.

The incentives offered, alongside rising fossil-fuel prices

and the expectation that these will stay high in the future,

have made renewables attractive to many investors.

Job creation through renewables has been another factor

in government support, especially as a contribution to

reducing unemployment following the economic and

financial crisis.

Renewable power investments and contribution

“In 2011, renewable power (excluding large hydro) accounted for 44%

of new generation capacity added worlwide, up from 34% in 2010

and just 10.3% back in 2004.

Total investment in solar power jumped 52% to $147 billion in 2011,

reaching a figure almost twice as high as that in wind energy, at $84

billion, down 12%.

The proportion of power generated by renewables (excluding large

hydro) rose to 6% in 2011 from 5.1% the previous year.”

Source: “Global trends in renewable energy investment 2012”, Frankfurt School of Finance &

Management, UNEP, Bloomberg, 2012.

Costs

“One of the dominat features of the renewable energy landscape in

2011 was falling technology costs. Photovoltaic module prices fell

by close to 50%, and onshore wind turbine prices by between 5%

and 10%. These changes brought these two leading renewable power

technologies closer to competitiveness with fossil-fuel alternatives

such as coal and gas.

The selling prices of Photovoltaic cells fell from $1.50 per Watt in

September 2010, to $1.30 per Watt by January 2011 and only to just

over $0.60 per Watt by the end of the year 2011.”

Source: “Global trends in renewable energy investment 2012”, Frankfurt School of Finance &

Management, UNEP, Bloomberg, 2012.

Grid parity “Based on current cost reduction trends, it is predicted that

the average onshore wind project worldwide will be fully

competitive with combined-cycle gas turbine generation

by 2016. At present, this is true only for a minority of wind

projects, those that use the most efficient turbines in

locations with larger wind resources.

In solar PV, analysis suggests that the cost of producing

power from rooftop panels for domestic use is already

competitive with the retail (but not the wholesale)

electricity price in several countries. Large-scale PV plants

are still at significant distance away from

competitiveness with wholesale power prices.”

Source: “Global trends in renewable energy investment 2012”, Frankfurt School of

Finance & Management, UNEP, Bloomberg, 2012.

Wind production sets records in Spain

“On April 19, 2012, wind production in Spain reached

61.06% of total production during the night, with a peak of

15,338 MW in the afternoon and remaining above 11,500

all day.

Spain’s installed wind farm capacity is 21,674 MW (total

installed power generation is 97,200 MW). At the end of

2011 wind share of total electricity consumption was

15.9%.

Solar rooftops in not super sunny Berlin

Solar PV in Germany Germany set a world record for solar power production

with a peak of 22 GW at midday on Friday 25 and Saturday

26 May 2012. This contributed for a third of the demand at

noon on Friday and half of the demand on Saturday (20%

for the whole day).

Germany has a solar PV installed capacity as of 2011 of

25 GW, of which about 7.5 GW installed in 2011. Solar PV

provided 18 TWh of electricity in 2011, about 3% of total

electricity.

The German government has set a target of 66 GW of

installed solar PV capacity by 2030, to be reached with na

annual increase of 2.5-3.5 GW.

What is special about renewable

intermittent generation ?

• Location is typically widely (but not uniformly)

distributed, since it is determined by the existence of

resources (and often far from important load centers)

• Output has only partly controllable, high time

variability (if without local storage) and partial

unpredictability

• Low variable cost and (sometimes) also dispatch

priority

• Dispersed ownership and control

• Short installation time

• Low or nil mechanical inertia of generators (unless

proper interfaces are used) for system stability purposes

OECD COUNTRIES

Australia, Austria, Belgium, Canada, Czech Republic, Denmark,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,

Japan, Korea, Luxemburg, Mexico, Netherlands, New Zealand,

Norway, Poland, Portugal, Slovak Republic, Spain, Sweden,

Switzerland, Turkey, UK, USA

A SITUAÇÃO ENERGÉTICA MUNDIAL

Consumo mundial de energia primária (2005):

4801018 J/ano ou 11400106 tep/ano

(1 tep 1 tonelada equiv. de petróleo = 42000 MJ = 11700 kWh)

População mundial: 6,4 biliões

Consumo médio por habitante:

Distribuição muito irregular (2002):

EUA 5,0 média mundial

Europa Ocidental 2,3 média mundial

Portugal, Grécia 1,5 média mundial

Brasil 0,6 média mundial

África 0,4 média mundial

Bangladesh 0,1 média mundial

ab.diapetróleo/h de litros 8hab.anoGJ75104,6

10480

9

18

COMBUSTÍVEIS FÓSSEIS: por mais quanto tempo?

Com base em estimativas (2002?) de reservas conhecidas:

• Carvão:

Mais 200 anos

• Petróleo:

Mais 60 anos (mais, se forem descobertas novas reservas)

Produção declinará em 2015-2035

• Gás natural:

Mais 80 anos (mais, se forem descobertas novas reservas)

Produção declinará em 2040

Combustíveis fósseis e alterações climáticas.

Efeito de estufa

Temperatura da superfície da Terra resulta de equilíbrio entre:

1. Energia solar que atinge a superfície

2. Energia radiada pela Terra (radiações infravermelhas)

A atmosfera é muito mais permeável a (1) do que a (2) (tal

como o vidro duma estufa).

Na ausência de atmosfera, a temperatura média da superfície

da Terra seria de cerca de -18C

Efeito de estufa natural: temperatura média de cerca de

+15C

Gases que contribuem para o efeito de estufa:

• Vapor de água

• Dióxido de carbono

• Metano

Desde a Revolução Industrial, o efeito de estufa tem

aumentado, especialmente por CO2 produzido por combustão.

Aumento da temperatura média no Séc. XX: cerca de 0,6C.

A manter-se a taxa de aumento de emissões de CO2: aumento

previsto da temperatura no final do Séc. XXI: 1,4 a 5,8C.

Mesmo parando as emissões, a taxa de redução do CO2 na

atmosfera seria muito lenta.

Energia solar: utilização directa

Aquecimento activo por colectores solares: aquecimento de água,

aquecimento do interior de edifícios

Aquecimento passivo: edifícios como colectores solares

(aquecimento e iluminação)

Aquecimento de alta temperatura com espelhos parabólicos

(produção de energia eléctrica)

Conversão directa em energia eléctrica: paineis fotovoltaicos.

Energia solar: utilização indirecta Evaporação de água condensação chuva rios albufeiras

(energia hídrica) turbinas hidráulicas geradores eléctricos

energia eléctrica.

Desigual aquecimento da superfície da Terra vento (energia

eólica) turbinas eólicas energia eléctrica.

Vento geração de ondas marítimas conversores de energia

das ondas energia eléctrica.

Fotossíntesse biocombustíveis combustão energia útil.

(Nota: os biocombustíveis não contribuem para o efeito de estufa:

ciclo fechado absorção-produção de CO2).

Concrete dam

with turbines

Rock-made

dam Gates

Sea

Basin

Energias "renováveis" não solares

Campo gravítico da Lua (e do Sol) marés turbinas

hidráulicas (com ou sem albufeira) energia eléctrica

Central de la Rance, França

Geração de calor no interior da Terra (radioactividade)

transmissão de calor para camadas superfíciais aquecimento

de águas subterrâneas utilização para aquecimento ou para

produção de energia eléctrica (utilização de energia

geotérmica).

Ilha de S. Miguel, Açores

ENERGIAS RENOVÁVEIS

Enquadramento na Europa e em Portugal:

Meta para 2010 (Directiva 077/CE/2001 da UE)

• 22% da energia eléctrica na União Europeia

produzida por fontes renováveis

• Idem para Portugal: 39%

WORLD ENERGY STATISTICS

Source: Renewables Information 2007,

International Energy Agency, 2007

Fig. 4: 2005 Regional Shares in Renewables Supply

* Asia excludes China

** Excludes pump storage generation

OECD: Australia, Austria, Belgium, Canada, Czech

Republic, Denmark, Finland, France, Germany,

Greece, Hungary, Iceland, Ireland, Italy, Japan,

Korea, Luxemburg, Mexico, Netherlands, New

Zealand, Norway, Poland, Portugal, Slovak

Republic, Spain, Sweden, Switzerland, Turkey, UK,

USA

ENERGY STATISTICS

OECD COUNTRIES

Source: Renewables Information 2007,

International Energy Agency, 2007

Australia, Austria, Belgium, Canada, Czech Republic, Denmark,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,

Japan, Korea, Luxemburg, Mexico, Netherlands, New Zealand,

Norway, Poland, Portugal, Slovak Republic, Spain, Sweden,

Switzerland, Turkey, UK, USA

Energy in 2005 Because of their heavy non-commercial biomass use, non-

OECD regions emerge as the main renewables users,

accounting for 77.4% of world total renewables supply.

On the other hand, OECD countries supply only 22.6% of

world renewables, while consuming 48.5% of world TPES.

OECD has a renewable share of only 5.9%. This share is

19.6% for non-OECD regions, and close to 49% for Africa.

OECD accounts for most of the production of “new

renewables”, producing 87.5% of wind, solar and tidal

energy in 2005.

Renewable Energy in

Europe 1990-2005 Among the different OECD regions (Europe, North America,

Pacific), EUROPE has the highest share of primary energy

supply from renewable sources, with 7.2%.

EUROPE is also the only OECD area that has experienced

an increase in its renewable energy share: from 5.7% in

1990 to 7.2% in 2005.

This increase in EUROPE is the result of strong supporting

policies for renewables in the late 1990s and in the 2000s.

Technology Shares of Government

RD&D Expenditures in IEA Countries

ENERGY STATISTICS

PORTUGAL

Source: Renewables Information 2007,

International Energy Agency, 2007

Contribution of Renewables in 1990

Contribution of Renewables in 2005