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This article explores how a city like Hannover can become climate neutral by 2050 and achieve 100% renewable energy. It examines the potential of solar, wind, biomass, and geothermal energy sources, as well as the need for regional collaboration and local storage solutions.
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(How) Can a city become climate neutral in 2050? Hannover 2050 Are 100% renewable energy in industrial conurbations possible?
Challenges • By 2022 Germany will have phased out nuclear power. • To protect the climate, we will have to opt out of coal- based power generation in the mid term. • Due to the worldwide demand for energy, oil and gas reserves will have (virtually) run out by 2050 at the latest. • The conclusion: we need a plan for 100% renewables
Issues • How much renewable energy is Hannover sustainably likely to have (i.e. without creating new ecological problems and without exploitation at the cost of other regions) in 2050? • Does the expected supply meet the expected demand and what challenges are anticipated? • Key info:for the first time in a local study, a detailed analysis that factors in electricity and heat and traffic (normally renewable energy studies deal only with electricity)
1. • Renewable energy potential in/for Hannover in 2050
Solar energy in Hannover • There are about 32 million m² of roofs in Hannover • Goal:to use all suitable roofs in the city • Approx.22% (approx. 7 million m²) of the roofs are suitable for solar power (minus areas for dormer windows, shade etc) • In residential properties, solar thermal energy is used to generate hot water, all other roofs for photovoltaics • Result for 2050: • 6.5 million m² photovoltaic areas = 1,150 GWh/a • + approx. 0.5 million m² hot water collectors = 210 GWh/a
Regional thinking in wind and bio mass • Only a regional perspective makes sense when considering bio mass and wind renewable potentials • In the cramped confines of the city there are no relevant potentials for wind and bio mass. • Compared with the surrounding area, Hannover’s energy consumption is defined by trade and industry (53% of consumption today).1/3 of people employed in Hannover live in the surrounding area.In the future, they will have to “contribute” their own share of energy.
Hannover region plus 20 surrounding towns 2,3 km² 1,1 Mio. inhabitants
Regional bio gas • Usage of residues (organic wast of househoulds, green waste, straw, beet leaves, potato leaves) and liquid manure 340 GWh/a • Energy crop cultivation on 17% of arable land • Proportion Hannover 2050: • (divided up according to consumption [electricity 61%; heat 51%]) • 130 GWh/a electricity + 700 GWh/a bio gas
Regional Windpower • In the Hannover region, 240 wind farms are already available (biggest number in inland Germany) • The figure is not to be increased, but consistent re-powering with 3 MW plants (140 m hub height, 100 m rotor blade diameters) Proportion of electricity (61%) distributed to Hannover population • 2050: 850 GWh/a from the region
Further regional renewable sources • Water • Local potential from the River Leine fully exploited with three hydro power stations = 10 GWh/a • Timber: • Waste wood from forests and industry in the region • Proportion of heat consumption (51%) distributed to Hannover population • 25 GWh/a • Waste incineration: • Assumption:waste at today’s level • (ecologically doubtful; priority given to recycling!) • Electricity generation 25 GWh/a, • Connection to the district heating grid => 160 GWh/a heat
Partizipation of national sources • wind power offshore: • Germany 2050 = 45 GW • proportional to the population of Germany – calculated for Hannover • 1,100 GWh/a Wind offshore • National hydro power: • bigger hydraulic power stations • proportional to the population of Germany – calculated for Hannover • = 130 GWh/a
Local deep geothermal energy • Hannover has considerable heat reserves at vast depths (drilling about 3.000 m deep • Trial drilling to use heat for electricity and heating • Assumption:in the city 25 drills à 2 MW connected to the district heating network • Producing a potential of 30 MW of electricity and 270 MW heat • Feasibility and efficiency are currently being checked and are not yet certain
Summary of the renewable energy in 2050 according to Siepe/von Krosigk’s study • Total supply of renewable energy • 4,500 GWh/a
Possible scenario for a distribution of renewable energy potentials for electricity, heat and fuels Primary energy supply of renewable energies (incl.pipe and storage losses) Biogas Waste Geothermalenergy 3% 2% 1% Hydropower Photovoltaics Biogas Germany 24% 3% 8% Heat, Water Waste fuels 4% Region Windoffshore 23% 0.2% Geothermal energy 24% 6% Timber Windregion 1% Solar thermal power 5% 19% 23%heat+ fuels 77% electricity
the storage issue • If about 80% of the total renewable energy is distributed as electricity via cables, the storage issue is entirely different from before: • In addition to expanding the European grid and more pumped storage plants, local solutions are increasing in importance.This could be the sign for public utilities to act: • Smart Grid; intelligent energy networks • Underground cavern compressed air storage • Car batteries as temporary storage
Analysis of national wide studies • The basis of the needs assessment is analysing and extrapolating information from the following three studies • [1] Greenpeace Germany:Climate Protection Plan B 2050 • [2] WWF Germany:German Model:Climate protection till 2050 • [3] German Environment Agency:Energy objective 2050: 100% of electricity from renewable sources
Results of the national studies to the situation in Hannover:
In 2050, how much energy will be required and what for (in GWh/a)
3. How does the renewable energy supply and demand in Hannover correlate
Results • In Hannover 14,500 GWh/a are consumed today • The national studies se a max. reduction to 5.600 GWh/a • Only 4,500 GWh/a of renewable energy will probably be available sustainably • We need an reduction of about 70% compared by 2005
But… • 70% reduction is a massive challenge!It will require a substantial change in the mindsets of consumers, more intelligent planning on the part of architects (less resistance to insulation), more intensive regulation from the EU and German government and a whole range of other aspects.
But a huge opportunity for the economy too • People living in Hannover, trade and industry spend about 1.5 billion euros a year on electricity, heat and fuel. • This figure includes approx. 440 million euros in purchasing costs for gas, oil and coal, the majority of which today goes to Russia, the Middle East and Australia. • In the case of a full renewable energy concept most of the €440 million (amount set to rise heavily in the future with increasing energy costs)will be available to put back into regional business.
Thank you for listening. Internet: www.sustainable-hannover.de