We had a very full day planned on Wednesday, as you will see below. We started at 8am at the Folkecenter, and rode another chartered bus. Jane and Sunny were again our guides.
We started out at the wave energy test site near Hurup (where we were staying) - I cannot recall the name of the town. Ocean waves are a huge and consistent potential source of energy, and researchers throughout the world are investigating ways to harvest them. Unfortunately, harvesting marine wave energy is fraught with difficulty. Primary among the reasons are a) saltwater is very corrosive and b) waves have tremendous force (1 cubic meter of water weighs over 1 ton!). Many companies have tried many different ways of harvesting waves at the test site. 32 out of 32 have failed at this point. Not a very good record. But indications are that people will still try. The possibilities are too important not to. It was extremely cold and windy that morning, and as you'll see in the images below, the path to the test station was a bit interesting.
After the test site, we headed east to Hurup to visit a wood chip district heating plant. The plant provides all of the heat (except for some supplementary heating) to all but 4 houses in Hurup, which has about 1700 residents. The plant burns wood chips, which it gets from waste wood in the local national park. Though this is a very nice facility, the concept is simple:
For an explanation of hot water-based district heating, see the previous post. The hot water goes through heavily insulated pipes about a foot in diameter. It is a closed loop (like the other district heating facilities). The water goes out at 70 C and comes back at 40 C. The pressure and temperature is strictly regulated. The system is automated, and only requires one person to operate (only for backup if something goes wrong). They have wood pellet and oil backup heat, but the oil heat has not been used for "many years." A couple of additional observations and facts:
We started out at the wave energy test site near Hurup (where we were staying) - I cannot recall the name of the town. Ocean waves are a huge and consistent potential source of energy, and researchers throughout the world are investigating ways to harvest them. Unfortunately, harvesting marine wave energy is fraught with difficulty. Primary among the reasons are a) saltwater is very corrosive and b) waves have tremendous force (1 cubic meter of water weighs over 1 ton!). Many companies have tried many different ways of harvesting waves at the test site. 32 out of 32 have failed at this point. Not a very good record. But indications are that people will still try. The possibilities are too important not to. It was extremely cold and windy that morning, and as you'll see in the images below, the path to the test station was a bit interesting.
After the test site, we headed east to Hurup to visit a wood chip district heating plant. The plant provides all of the heat (except for some supplementary heating) to all but 4 houses in Hurup, which has about 1700 residents. The plant burns wood chips, which it gets from waste wood in the local national park. Though this is a very nice facility, the concept is simple:
- burn wood chips in a giant furnace (about 62,000 cubic meters per year)
- heat water
- distribute hot water to the town for heating the house and hot water.
For an explanation of hot water-based district heating, see the previous post. The hot water goes through heavily insulated pipes about a foot in diameter. It is a closed loop (like the other district heating facilities). The water goes out at 70 C and comes back at 40 C. The pressure and temperature is strictly regulated. The system is automated, and only requires one person to operate (only for backup if something goes wrong). They have wood pellet and oil backup heat, but the oil heat has not been used for "many years." A couple of additional observations and facts:
- The system gathers latent heat from the flue, making it very efficient.
- The combustion gases leave the chimney at 15 C (about 70 F). This is a sign that the system is very efficient. Household furnaces can have stack temperatures in the hundreds of degrees.
- About 18% of the heat is lost in the piping on the way to and back from the town.
- There are about 60-70 tons of ash per year left over after all is said and done. This ash is returned to the national park as organic material/compost.
- Like all heating facilities in Denmark, this is a non-profit operation
After Hurup, we traveled to Hiller Slev, a village near Thisted. This is a single farm owned by one Jens Kirk. He has a very interesting and diverse operation. He has a biodigester that uses the same process as Lemvig (see previous post), but on a much smaller scale. He has a single digester (see below) that produces biogas from manure (pig and cow) and other organic material. He burns the biogas in a combined heat and power (CHP) generator, which just means he gets electricity and heat from the process. He uses the heat for 5 things:
A few interesting facts about this process:
He also has a large wind turbine. He sells about 1.2 million kWh of wind for $0.15/kWh. This makes him a tidy profit after a few years. He sells about 2.5 million kWh of biogas-based electricity to the grid. It is more or less illegal to use your own electricity in Denmark (b/c the government would lose tax dollars if you did).
He also has a very large and impressive garage and collection of farm implements. Among other things, we saw a machine that is used to supply manure to the fields, as an alternative to spraying it (see below).
After the farm, we wnet to Nr. Vorupor to a hybrid biomass/natural gas/wind CHP plant. It generates electricity and provides district heat. (Are you sensing a theme here?) This system is unique for a few reasons:
It also struck me that the plant operator was wearing shorts and sandals. I'm no longer surprised about such things.
- preheat the manure mix (it needs to be 55 C (~130 F) to digest)
- provide heat to his household
- heat his workshop
- provide heat to his neighors (for FREE!)
- to dry crops for feed
A few interesting facts about this process:
- He provides heat to his neighbors for FREE. They do not mind the smell so much after this :)
- The whole process is 92% efficient (heat and power generation)
- He sells the electricity to the grid for 1.05 Danish Kroner (dkk) (about $0.20) per kWh and buys it from the grid for less. This is b/c the government is heavily promoting biomass use, in large part b/c it is illegal to throw organic material in the garbage.
- He generates so much heat that he actually has no use for 30% of it, so it currently goes to waste.
He also has a large wind turbine. He sells about 1.2 million kWh of wind for $0.15/kWh. This makes him a tidy profit after a few years. He sells about 2.5 million kWh of biogas-based electricity to the grid. It is more or less illegal to use your own electricity in Denmark (b/c the government would lose tax dollars if you did).
He also has a very large and impressive garage and collection of farm implements. Among other things, we saw a machine that is used to supply manure to the fields, as an alternative to spraying it (see below).
After the farm, we wnet to Nr. Vorupor to a hybrid biomass/natural gas/wind CHP plant. It generates electricity and provides district heat. (Are you sensing a theme here?) This system is unique for a few reasons:
- It is one of the few facilities gets real-time pricing. The money it gets for electricity is based on hourly prices, which can fluctuate depending on electricity supply and demand. This is very uncommon in DK.
- It uses real-time pricing to increase income by automatically responding to market prices, increasing generation when prices are high and reducing output when prices are low. This is automated and very effective. I'm not sure why they are able to do this.
- It will use wind energy to generate heat (through resistance heating) when extra wind is available. This is uncommon as well, though some places in DK are doing this b/c there is so much wind energy available.
- It provides heat to about 349 households
- It has an electricity capacity of about 700 kW, and a heat capacity of about 1400 kW
It also struck me that the plant operator was wearing shorts and sandals. I'm no longer surprised about such things.
After an hour lunch in Agerr (a nice little beach town on the North Sea), we headed to Hanstholm for one of the more anticipated events of the trip (for some, anyway) - climbing a 40 m wind turbine. The top compartment (the nacelle) is 40 m up a series of ladders, which is about 130 feet high. By the way, there was no safety harness! Most of us enjoyed it, but all of us were happy that we made it. We had a very nice view and took a few pictures at the top.
We then headed to the Danish National Test Site in Aalborg. The site is a few hundred acres, and is operated by Siemen's. They test wind turbines from all over the world. When we were there, they had just taken down the 2nd-largest turbine in the world, a 6 MW behoemoth by Siemen's. The biggest in the world is by Vestas, a Danish company, which is 8 MW. We also saw a 4 MW turbine and a few others. We were a few hundred feet from the 4 MW turbine as it was operating, and I was surprised that it was not louder.
It was neat to see the turbine come to a stop. To do this, the blades pitch (twist, basically) until they are parallel to the wind. When this happens, the forces balance and the turbine stops. This is a "pitch regulated" tubine. We also saw it start up again. It is fascinating to see something as seemingly innocuous as the wind start massive, 60 m (nearly 200 feet) long blades spinning after reaching about 10 mph!
A few interesting things about the site:
Last but not least we headed to Thisted Varmevaerk to see a concentrated solar test site. This site is an experimental site to see if concentrated solar is a viable option in DK. On this site (see pictures below for a clearer visual), curved mirror "troughs" are used to reflect sunlight toward a central tube. The tube contains water and a heat-absorbent material, surrounded by a vacuum-sealed space. The trough is on a single axis tracker, which means it rotates on one axis, following the sun through the day. It has to be within 2 degrees of the sun's angle in order to operate properly. The system also uses geothermal heating (they drill down a few thousand feet) to preheat the water. They also burn straw and run a heat pump to provide heat. The system is used for district heating, which means it is a non-profit operation.
This was a very long, interesting day. We headed back to the Folkecenter to be picked up by our host families. This was our last day of energy adventures in Thy - I was sad to first drop Michael off at the train station (from the bus), and to say goodbye to Jane and Sunny. They are all so wonderful, and were so generous with their time and expertise. We hope to see Michael in Copenhagen on our last day (and hopefully Jane in the near future!).
It was neat to see the turbine come to a stop. To do this, the blades pitch (twist, basically) until they are parallel to the wind. When this happens, the forces balance and the turbine stops. This is a "pitch regulated" tubine. We also saw it start up again. It is fascinating to see something as seemingly innocuous as the wind start massive, 60 m (nearly 200 feet) long blades spinning after reaching about 10 mph!
A few interesting things about the site:
- The entire property is public - you need special permission to drive in, but anyone can walk or ride a bike in.
- They have built a few small cabins for people to hang out and nature watch in. The site has become a de facto wildlife preserve.
- National law in Denmark is that for every acre of forest you remove, you must replace it with 1.6 acres of new forest.
- The research at the site is done by Danish Technical University, which is a very highly regarded University worldwide, especially in terms of engineering and energy. Siemen's provides an essential "supporting" role. Any company is able to test their technology there, including offshore turbines.
- The use is very expensive, but again, the site is well-regarded and very busy. They test new turbines and verify output and reliability claims of other turbines.
- They can fit up to 7 turbines on the site.
Last but not least we headed to Thisted Varmevaerk to see a concentrated solar test site. This site is an experimental site to see if concentrated solar is a viable option in DK. On this site (see pictures below for a clearer visual), curved mirror "troughs" are used to reflect sunlight toward a central tube. The tube contains water and a heat-absorbent material, surrounded by a vacuum-sealed space. The trough is on a single axis tracker, which means it rotates on one axis, following the sun through the day. It has to be within 2 degrees of the sun's angle in order to operate properly. The system also uses geothermal heating (they drill down a few thousand feet) to preheat the water. They also burn straw and run a heat pump to provide heat. The system is used for district heating, which means it is a non-profit operation.
This was a very long, interesting day. We headed back to the Folkecenter to be picked up by our host families. This was our last day of energy adventures in Thy - I was sad to first drop Michael off at the train station (from the bus), and to say goodbye to Jane and Sunny. They are all so wonderful, and were so generous with their time and expertise. We hope to see Michael in Copenhagen on our last day (and hopefully Jane in the near future!).