energy and renewable energy
DESCRIPTION
Renewable energy has been growing rapidly in the last decade, becoming an important component of energy supply.TRANSCRIPT
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