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    Q&a on re Q&a on re Document Transcript

    • O NS T I U ES & Q WE RS A NS le w ab Re ne on rgy E newww.solargeneration.org
    • QUESTIONS === & ANSWERS ON RENEWABLE ENERGY 1. WHAT IS RENEWABLE ENERGY? 3 2. WHAT ARE THE MOST COMMON RENEWABLE ENERGY SOURCES? 3 Wind 3 Solar 3 Biomass 4 Geothermal 4 Hydropower 4 3. IS RENEWABLE ENERGY MORE EXPENSIVE? 5 4. CAN RENEWABLE ENERGY AND ENERGY EFFICIENCY MEET THE GROWING ENERGY DEMAND? 5 5. WHAT ABOUT RELIABILITY – WHAT IF THE WIND DOES NOT BLOW? 6 6. WHAT ABOUT DEVELOPING COUNTRIES? WHAT USE IS IT TO INVEST IN RENEWABLE ENERGY IF CHINA AND INDIA AND OTHER RAPIDLY INDUSTRIALISING COUNTRIES BUILD A NEW COAL-FIRED POWER STATION EVERY WEEK? 7 7. ISN’T NUCLEAR “ZERO CARBON” AND MORE RELIABLE? 8 8. WHAT ABOUT “CLEAN COAL” AND CARBON CAPTURE AND STORAGE? 8 9. WHERE CAN I FIND MORE INFORMATION? 9
    • 1. WHAT IS RENEWABLE ENERGY?Renewable energy is electricity that is produced from sources that replenishthemselves naturally. There are five sources of renewable energy: wind, sun-light (solar), landfill and agricultural waste (biomass), the heat of the earth(geothermal) and water (hydropower). These renewable sources of electricityhave less impact on the environment than traditional methods of electricitygeneration, which include burning fossil fuels such as coal, oil and naturalgas. Natural gas and coal, for example, are not renewables becausetheir use consumes gas and coal reserves at a much quicker ratethan they are replenished.2. WHAT ARE THE MOST COMMON RENEWABLE ENERGY SOURCES?Wind, the world’s fastest growing energy sector with an averageannual growth rate of 28%, could provide 12% of the worlds energyby 2020. The industry is expected to generate two million jobs and f naked ssave more than 10 billion tons of carbon dioxide emissions. Hundreds os symbolife er t volunte erabilityroSolar energy comes from the sun, and has the potential to provide the valners unde u iseveral times the current world energy consumption if it can be he gl tc change, kproperly exploited. Solar thermal and photovoltaic are the two basic ima e cer Tunic cl entypes of solar power. by SpSolar photovoltaic (Solar PV) generates electricity from sunlight by usingsemi-conductor materials. Silicon, an element most commonly found in sand,is the most common material used in photovoltaic cells. All photovoltaic cellshave at least two layers of such semi-conductors, one positively charged andone negatively charged. When light shines on the semi-conductor, the electricfield across the junction between these two layers causes electricity to flow in,generating DC current. Therefore, the photovoltaic system does not needbright sunlight in order to operate. It also generates electricity on cloudy days,with its energy output proportionate to the density of the clouds. Due to the
    • reflection of sunlight from clouds, days with a few clouds can even result inhigher energy yields than days with a completely clear blue sky.Solar thermal is based on a simple principle: the sun heats up watercontained in a dark vessel, using the heat of the sun directly. Large mirrorsconcentrate sunlight into a single line or point. The heat created there is usedto generate steam. The hot, highly pressurised steam is used to power tur-bines, which generate electricity. In sun-drenched regions, solar thermalpower plants can guarantee a large share of electricity production.Biomass refers to the utilisation of organic matter (plants, etc.) as fuel usingtechnologies such as gas collection, gasification (converting solid material togas), combustion, and digestion (for wet wastes). Potential problems such asfuel from unsustainable sources, and releasing greenhouse gases while burn-ing, are fundamental to biomass technology, and they can be avoided withproper implementation. Furthermore, in areas with plentiful farmland, bio-mass can play a major role in supplying heat and electricity.Geothermal comes from the heat inside the Earth. According to estimates,the Earths core is incredibly hot - 5,500° Celsius (9,932° F). Power genera-tion from geothermal causes virtually no pollution or greenhouse gas emis-sions. Its also quiet and extremely reliable. Geothermal power plants produceelectricity about 90% of the time, compared to 65-75% for fossil fuel powerplants.Hydropower, energy from water, running rivers or waves in the ocean, can beharnessed and converted into electricity without producing greenhouse gasemissions. It is a renewable energy resource because water is constantlyreplenished through the earths hydrological cycle.Estimated by the World Energy Council, wave power could produce two ter-awatts of energy each year, which is twice the world’s current electricity pro-duction. The total renewable energy within the world’s ocean, if all harnessed,could satisfy the present world demand for energy more than 5,000 timesover. Yet, the technology of wave power is still under development.For river power, harnessing the energy of water going from a higher to a lowerlevel, the greater the drop in elevation, the faster the water flows, the moreelectricity can be produced.Large scale hydropower, such as big dams, can drown ecosystems. They cancause shortages in the water needs of downstream communities, farmers andecosystems, and be unreliable during prolonged droughts and dry seasonswhen rivers dry up or reduce in volume. Small-scale hydro systems, classifiedas “small”, “mini” or “micro” by the amount of electricity production, capture theriver’s energy without diverting too much water away from its natural flow.
    • 3. IS RENEWABLE ENERGY MORE EXPENSIVE?As the market for renewable energy grows rapidly, renewable energybecomes more competitive. For instance, wind power has shown up to a 50%drop in production costs over the past 15 years. Now, at optimum sites windcan be competitive with new coal-fired plants and in some locations can chal-lenge gas. Thanks to continuing improvements in the average turbine size andcapacity, by 2020 the cost of wind power on good sites is expected to drop to2.45 euro cents/kWh (per kilowatt hour) – 36% less than its 3.79 eurocents/kWh cost in 2003. In addition, this does not even take ‘external costs’(polluting costs) into account. If external costs were added to traditional fossilfuel powered electricity, renewable energy would easily take up the competi-tion. Since costs of CO2 emissions are now starting to be integrated into elec-tricity prices (as in Europe), it won’t take long until renewable energy willbecome competitive.4. CAN RENEWABLE ENERGY AND ENERGY EFFICIENCY MEET THE GROWING ENERGY DEMAND?Energy [R]evolution, the latest report released by Greenpeace, addressesdetails of how to halve global CO2 emissions by 2050 by using existing tech-nology and still providing affordable energy and economic growth. How? Theanswer to this is two-fold:1. By sustaining the current double-digit growth rate of the global renewable energy industry over the next two decades (approx. 30% per annum for wind and 40% per annum for solar photovoltaic - both figures represent the average of the last 10 years).2. By introducing high technical efficiency standards for all energy-consuming appliances such as computer systems, heating and cooling equipment, and other high energy users such as road vehicles.This combined approach will ensure that there is sufficient energy for a glob-ally growing economy, equating broadly with the projection of the InternationalEnergy Agency.
    • 5. WHAT ABOUT RELIABILITY – WHAT IF THE WIND DOES NOT BLOW? Most renewable technologies are not ‘inter- mittent’. In fact only two of the five renew- able energy technologies are: wind and solar photovoltaic. All other renewable energy technologies are reliable and predictable, such as geothermal, bio- mass energy and hydro-electric power. In the heating and cooling sector, fluctuating energy sources (in this case solar collectors only) are not an issue, as it is no problem to store heat. And for wind: Actually, the wind always blows somewhere (particularly off-shore and at heights), so this issue is largely irrelevant with a proper electrical grid tomove power from one place to another. Modern power grids already transmitelectricity over hundreds of kilometres, and cope with significant fluctuationsin both demand and supply.Of course, it is also a good idea to have a mix of power solutions - includingsolar, bio-energy, and hydropower - to balance the strengths and weaknessesof each source against the others.
    • 6. WHAT ABOUT DEVELOPING COUNTRIES?What use is it to invest in renewableenergy if China and India and otherrapidly industrialising countries builda new coal-fired power stationevery week?China currently builds a lot of new coal-fired power plants – but it shuts downa lot of older, more inefficient ones as well. The Greenpeace energy scenarioassumes that all coal power plants currently under construction will come online. This explains why this alternative scenario (which includes an increase inthe use of coal up to the years 2010 – 2015) is close to the “business as usual”scenario. It does take a few years to change policy and switch to renewables.The same is true for the development of the energy supply in India.The alternative scenario assumes the same GDP growth as the IEA(International Energy Agency) energy scenario does. In fact renewableenergy can “follow” the growing demand much better, as the planning & con-struction time of renewable energy is a lot faster than conventional centralisedpower plants.
    • 7. ISN’T NUCLEAR “ZERO CARBON” AND MORE RELIABLE?No. Nuclear energy also generates CO2, if we take uranium mining intoaccount. Besides that, uranium is also a finite and limited resource. It is esti-mated that the economically viable uranium will last approximately only 65years for the existing nuclear power plants around the world. Besides beingnon-renewable, nuclear power remains dangerous, polluting and expensive.More nuclear power means more radioactive waste, more nuclear weaponsproliferation, more nuclear-armed states, more potential "dirty bombs" andmore targets for terrorists.8. WHAT ABOUT “CLEAN COAL” AND CARBON CAPTURE AND STORAGE? There is no such thing as clean coal. New coal power plants are more efficient than old ones – but this has been achieved through technology developments over the years because of hard competition with gas power plants! Compared to gas, coal still emits roughly twice as much CO2 per kWh than a gas power plant – and due to technical rea- sons, coal will never be as CO2-efficient as gas. Proposed “CO2-free” coal power plants are not CO2-free, they just remove the CO2 from the emissions – which wipes outapproximately 20% of the energy generated. So those power plants are lessfuel-efficient than “conventional” ones.
    • Carbon capture and storage, is complicated and only possible (if ever) for asmall number of power plants. This is because the areas that have a suitablegeology for carbon capture and storage are limited and unevenly distributedglobally. Clean coal is a “Trojan horse” to build coal power plants, and a sur-vival strategy for mining companies. It will not be cost-competitive with renew-able energy.9. WHERE CAN I FIND MORE INFORMATION?http://www.energyblueprint.info/http://www.greenpeace.org/international/solargen/about-solar-energyhttp://www.yes2wind.com
    • NOTES
    • TESTIMONY A PERSONAL IMPRESSION OF THE ‘RESTRAINT, EFFICIENCY, & RENEWABLE ENERGY’ GUIDE BY SÉBASTIEN, « When I started working on the ‘Sustainable Campus’ project at my university, Euromed Marseille, dealing with the energy theme, I must con- fess that I was completely lost... I had no idea how to approach things or where to start. The association had already set up a feasibility study for the installation of solar panels, but this did not necessarily seem to be the logical first step. I made some enquiries, particularly by talking to Solar Generation, and I found out about an approach that had instant appeal because of its clarity and logic: this was the ‘negaWatt’ initiative. This association advocates the following energy-saving approach: Restraint = consume less; Efficiency = consume better; Renewable energy = ‘clean’ production systems. We therefore tried to follow this initiative as best we could. First of all, we tried to reduce consumption in our school by teaching people on campus to become bet- Greenpeace International Ottho Heldringstraat 5 1066 AZ Amsterdam Netherlands ter eco-citizens. Then we put pressure on our administration to carry out an energy diagnosis on its installations with a view to making them more efficient. This study was carried out over a month and a half, and certain measures were selected and should be put in place over time. I feel that the first two steps in the ‘negaWatt’ initiative are quite easy to put into practice and negotiate with management. Indeed, in both of these steps, the finan- cial argument is a powerful factor. Quite clearly, we are saving our establishmentsPrinted on 100% post consumer recycled chlorine-free paper money, so how can they resist? The projects for the installation of renewable energy are more complex and time- consuming, but they can be done. They require a financial investment which can often be substantial – at least if we wish to achieve a significant reduction in our campus’s impact. And persuading a School or University to invest is a major oper- ation... The administrative procedures are complicated and technical aspects are pre-eminent. Having said that, don’t hesitate to get involved, be ambitious, www.solargeneration.org because once you’re in there you can’t do without it, it’s a fascinating area to work in, with some brilliant projects! Also, working on these themes as a team within the Solar Generation network is a real pleasure. Finally, as regards the ‘negaWatt’ initiative, I would advise everybody, if they have the motivation and the means, to undertake the maximum number of measures at the same time. But most of all, do yourself a favour and remember that Solar Generation is there for you!