Low Carbon Power Generation
Copenhagen is well on its way to reaching its goal of carbon neutrality by 2025. It's achieving this by using renewable energy technologies such as wind
— all of which lessen the burden of CO2 pumped into the atmosphere. There are a number of other technologies that are also being investigated.
A wide range of alternative power-generation and application technologies is under development around the world. Here we look at a few that are relevant to Denmark — wave power generation, fuel cell technology, hydrogen as a fuel and electric vehicles.
Wave power generation
Producing electricity using wave power is a technology in development, and Denmark is one of the top five countries in the world working on projects in this field. There are several pilot schemes around the Danish coast, though none near Copenhagen.
At Hanstholm, off the north Jutland peninsula, is a full-scale working wave power scheme set up by Wave Star
. It has been generating 500kW since September 2009 and is anticipated to produce some 6MW when complete.
Fuel cell technology
A fuel cell converts chemical energy into electrical energy. A battery is a simple type of fuel cell but there are several kinds (see right hand column). It's not a new idea — Sir William Grove invented a gas voltaic battery in 1839 that produced electricity and water, and the term has been in use since the 1880s.
One current attraction is that fuel cells don't produce pollution as a by-product, just water and heat. And they are efficient at converting energy input into work output. Taking the car as an example, a typical petrol engine is only 20% efficient. A battery-powered electric car is between 26% and 65% efficient, while a car using a hydrogen-powered fuel cell has the potential to be 64% efficient.
Suitable fuels for fuel cells include natural gas, biomass, methane, ammonia and hydrogen. Recently, Risø DTU
, the Danish National Laboratory for Sustainable Energy, has been working with Topsøe Fuel Cell (Copenhagen) to develop a ceramic solid oxide version. These could be used in vehicles and ships.
On the 4th January 2010, the 5,900 tonne Norwegian Viking Lady docked in Copenhagen. It's the world's first ship to be powered by a fuel cell — a 320kW molten carbonate cell, running on liquefied natural gas.
Hydrogen as a fuel
Hydrogen is the most common element and one of the most combustible substances — the Sun consists mostly of hydrogen. But how do you harvest it? You can use power to split water molecules into hydrogen and oxygen, but you need a power source to do it. And how do you store hydrogen safely?
In Denmark, on the island of Lolland, they have been using wind-generated electrical current to electrolyse water (separating the hydrogen and oxygen). The wind-hydrogen plant has been in operation since May 2007, one of the first in Europe. The hydrogen they produce is used in fuel cells that run a combined heat and power (CHP) scheme.
has been developing an electrolytic cell that produces synthetic gas (hydrogen and carbon oxide) from water and CO2. The input power can come from wind or solar sources and the CO2 from industrial emissions.
On 12th November 2009, in time for the United Nations climate change summit COP15
, Copenhagen opened its first hydrogen refuelling station. It served six hydrogen cars and two vans to begin with but the city fleet is set to increase to 33. Some vehicles used to ferry COP15 delegates ran on hydrogen fuel cells, though they used batteries for short trips.
Electric vehicles can be powered by conventional batteries or fuel cells. There are also hybrid vehicles that can combine the reliability of the combustion engine with the environmentally-friendly benefits of electric power.
Copenhagen is expected to have the infrastructure for plug-in charging stations and battery exchanges by 2011. DONG Energy
has been testing the feasibility of wind-powered charging stations. The Danish Energy Agency
has awarded grants to 19 pilot projects, totalling some 7m Kroner, to get more electric cars onto Danish streets.
The Copenhagen Climate Plan
(pdf download) sets out the following initiatives:
— free parking in Copenhagen for electric and hydrogen cars
— bus CO2 emissions to reduce by 25% through use of electricity and hydrogen
— all new municipal car procurement to be electric and hydrogen from 2011
— 85% of all municipality cars to electric or hydrogen in 2015 (600 cars)
Renewable Energy Focus www.renewableenergyfocus.com
Denmark continues its renewable tradition
— article on all kinds of renewable enery in Denmark
Copenhagen X www.cphx.dk
Danish Architecture Centre site on urban development and innovation in Copenhagen
Risø: DTU : National Laboratory for Sustainable Energy www.risoe.dk
Technical University of Denmark : includes info fuel cell research
European Hydrogen Association www.h2euro.org
Pan-national organization that promotes hydrogen as an energy source in Europe
Danish internet portal for energy- and climate-related solutions