Embed Size (px)
Citation preview
In June of 2008, a group of students from HCC and several other US community colleges traveled to Denmark to examine first-hand that country’s energy strategies.
Denmark is a small country of only 5.9 million people with a land area of 16,640 km2. It has 7,314 km of coastline. No point in the country is further than 52 km from the coast.
US/Denmark Comparisons
US DenmarkPopulation 309 M 5.9 M
Area 9,158,960 km2 16,640 km2
Annual Energy Use 99,214 kWHr 42,682 kWHr
per capita
GDP per capita 45,800 USD 39,617 USD
US/Denmark Comparisons
US DenmarkNet Energy Imports 27.5% -44.6%
Average Gasoline Tax ~$0.46/Gal ~$5.00/Gal
Average Electricity Cost ~$0.09/KWHR ~$0.46/KWHR
Minimum Wage $15,080/yr $22,713/yr
Maximum Federal Tax Rate 35% (>$373,650) 59% (>$70,000)
State/Sales/VAT Rates up to 10% 25%
US/Denmark Energy Fuels
US DenmarkOil 39% 39%
Coal 23% 21%
Natural Gas 23% 22%
Nuclear 8% 0%
Renewables* 6% 18%
*Hydro/Wind/Biomass/Geothermal/Solar
Wind Power
Denmark is perhaps best known for its wind turbines. Wind power provides over 3500 MW or nearly 20% of all electricity produced in the country. The US is the world leader in wind capacity, however, with over 35,000 MW of installed capacity.
Especially in the North of the country, wind turbines are a ubiquitous sight, both on land and offshore.
Windmill CooperativesSpecial tax exemptions and feed-in tariffs are designed to encourage private individuals and groups of individuals to invest in renewable energy. Typically, several dozen to several hundred individuals will pool their assets and invest in one or more wind turbines. The feed-in tariffs guarantee a fixed price for energy fed into the grid for a period of time, usually 20 years.
Time until payoff on these investments (when the turbine is paid off and all additional revenue is free and clear) is typically 8 – 12 years.
CHP - Combined Heat and Power
Conventional power plants are typically about 40% efficient due to Second Law of Thermodynamics restrictions. They vent excess heat to the atmosphere or to local water bodies using cooling towers of cooling canals. Here in Tampa Bay, the Big Bend power plant near Apollo Beach becomes a manatee attraction during the winter due to the warm water ejected by the plant. This thermal pollution has been suspected of causing unhealthy changes in the ecosystem of Tampa Bay. Capturing and using this waste heat can more than double the efficiency of a power plant to 80% – 90%.
Cooling Towers
Cooling Canals
The Turkey Point Reactor Site has 168 miles of canals.
CHP - Combined Heat and Power
CHP plants use the waste heat from electricity generation for other purposes, including domestic and industrial heating. The condensed steam from the power plant is passed through a heat exchanger, where it gives off heat to a separate water circuit which is then distributed through underground pipes to nearby homes and businesses. In Denmark, 60% of households have district heating. The Average cost to the consumer per Btu is approximately 30% of electric or oil heating cost. The large infrastructure costs for these projects are largely subsidized by the federal government, using funds collected via the various energy taxes.
District Heating Pipes - Strudstrupvaerket
This 265 MW coal-fired electric plant provides district heating to 285,000 consumers using over 124 km of hot water distribution pipes throughout the city of Arhus.
Home Heating Distribution Pipes
These pipes carry the hot water from larger pipes installed underneath the street into and out of homes and buildings.
Instruments in each home measure flow rate, incoming and outgoing temperature to calculate household energy usage.
This small building contains a natural gas fired generator which produces 1.4 MW of electricity and 2.2 MW of heat for a small town of 350 homes. The system circulates 40 m3/hr of water through 4 km of 150 mm pipes.
Here is the generator that provides the power. For small, rural communities, right-sized units like this are more efficient than bringing in power and hot water from a distant plant.
Lemvig Biogas Facility
The Lemvig Biogas facility transforms manure, fish, slaughterhouse, feed and other agricultural waste into biogas (75% Methane, 25% CO2) for electricity and district heat serving 14,000 households. The Lemvig facility processes over 90,000 tons of animal manure and nearly 80,000 tons of industrial waste annually.
Lemvig Biogas Facility
Fermentation Vessels
Biogas Storage Tanks
Brave, handsome, intelligent gentlemen often climb to the top of the storage tanks to get a better view of the surrounding landscape.
A small 1.2 MW generator provides all the power to run the plant and provides district heating for the citizens of Lemvig.
Denmark is the world’s leading exporter of pork products, with 25 million pigs, or about 5 for every Danish citizen, so there is no shortage of manure.
This pork farmer got together with two of his fellow farmers and constructed a small methane digestion plant. Generous government subsidies helped him with the $1.3 Million cost of the plant.
This small methane-fired generator produces 750 kW of electricity and about one megawatt of heat.
The entire operation is monitored and run by a single personal computer.
He expects a pay-back time of 8 years. He was so enthusiastic about his success that he decided to expand his operation to triple its current size.
Electricity from Solid Waste
Most domestic solid waste in Denmark is burned in special power plants. The garbage is first dumped in a giant pit and mixed by a crane operator to increase the homogeneity. This plant burns 41 tons per hour of garbage at full capacity.
The scale of the power plant is impressive. It burns approximately 240,000 tons per year of domestic waste and produces 236,000 MWh of electricity and 500,000 MWh of heat for district heating.
All operations are controlled via a sophisticated network of computers and sensors which monitor the smokestack and adjust various parameters to maximize power output and minimized emissions.
Look familiar? Yes, it’s LabVIEW! (Danish version)
The Nordic Folkecenter for Renewable Energy is a think tank where researchers from all over the world come to work on designing next-generation renewable energy technologies, from new oil seeds to optimized turbine blade shapes.
The first hydrogen refueling station in Denmark was installed for cars that are being tested at the Folkecenter.
Solar panels old and new being tested for efficiency and aging characteristics.
This dome contains a small scale, closed-ecosystem, food production facility.
The two swimming pools contain fish that are harvested to feed the visiting researchers. Water from the pools is circulated to the balcony above where vegetables are grown year round.
Here, Preben Maegaard, founder of the Folkecenter and an internationally respected advocate of renewable energy technologies, speaks to the students about his vision for the future.
Recycling
Garbage pickup is very expensive so most Danes make regular trips to the expansive recycling centers. Appliances, electronics and building materials are all accepted and reused.
Bicycles
Bicycles are everywhere in Denmark. Specially marked lanes crisscross all major cities.In Copenhagen, 37% of all people commute to work by bicycle.
Parking bicycles is convenient because nearly all businesses and government buildings have ample parking areas specifically designated for bicycles.
Like most European countries, Denmark has an extensive public transit system of buses and rail lines that makes car ownership optional for most Danes. This bus in Copenhagen is fueled by biodiesel.
Public Transit
Conclusion Denmark is a very small country that is culturally, socially
and politically very cohesive and homogeneous. I believe that the primary lesson to be learned from Denmark’s approach to energy policy is that regional solutions are best. In a country like the United States, with our very wide cultural, social and political heterogeneity, as well as our vast geographical diversity, solutions to the energy challenges we face will best be handled on a regional basis. Where we have wind, build windmills. Where we have sun, install solar panels. Public transit will probably have the greatest impact in areas where the population density is greatest, like on our two coasts. While we do need a national energy policy that promotes renewable energy sources, regionally appropriate technologies will be the key to our success.
