Visiting villages throughout Germany, especially Freiburg, has been inspirational to say the least. I lived in Europe for a month each year (September) in 2006, 2007 and 2008, and had a good chance to study what the Germans and Danes are doing regarding solar, geothermal, hydro power, and wind energy. Driving all through Bavaria in particular blew my mind on our first trip. I have been a renewable energy advocate since the mid-1970s. Moving to northern Michigan in 1976 and living off the land taught me a lot about sustainability, but I still had a lot to learn. These trips provided that education for me.
Solar HW Heliodyne collectors
I built our home in 1980 and with the Carter Administration tax credits, immediately added solar hot water from Enerdyne in Suttons Bay, Michigan, which qualified for tax incentives. Because of our finances at the time, we had to finance our home through the government which put restrictions on the house we could build. However a lot of reading of books by architects that were building passive solar homes put me in the right direction (also, Mother Earth News as well). My home was designed with the "Passivhaus" principles to the degree that the Farmers Home Administration allowed - that meant 6" walls, triple glazed windows and 12" of ceiling insulation. A later addition included a passive solar dining room with large triple glazed (Anderson) windows to the south. This will heat my house to 70f on a cold day when the sun is shining.
South facing passive solar windows
In 1980, it was a good design and has worked well when we have cold weather and the sun. However, we live in northern Michigan just off of Lake Michigan where we get tons of "lake effect" snow and cloudy skies. From mid-November until mid-March we live in the "dark zone"......solar is not too helpful during those times.
At first, to compensate for the loss of sun, I had a Ashley/Jensen wood burning furnace with a "Fire Plate" installed for heating our solar hot water tank. Because I had a heat exchanger in the cold air return of my furnace, I heated the home with both wood forced air and also with the heat exchanger off the solar tank when I was not burning wood. That has worked well over the almost 30 years of installation.
The "solar room" looking west - no windows because of summertime over heating
This summer, I tore out the old propane furnace, sold the wood burning furnace and installed a new 16 SEER heat pump (tax credits are in effect again). This is coupled with a new LPG 95% furnace. The old duct work has been increased to match the new system with a re-engineered solar tank interface in the cold air return (much larger and more free breathing). I love to share good news when it happens and I have been extremely impressed with the numbers I am getting on energy use. Since the heat pump is electric, it is monitored by a peak interrupter and subtractive meter for a discount rate on my electricity. Within a month, I am adding a new Seisco tankless boiler to heat the solar hot water tank when the sun is not shining. Insulation in the attic will increase to 16" and other energy savings will be implemented. I have already added thick new double cellular blinds that are tight fitting in all my windows, which is helping as well. The old Ashley/Jensen 2AF will be replaced with a high efficiency Danish Morso 2B wood stove in spring to take advantage of the woodlot that I live on. Hopefully a wind turbine will be added this coming summer to offset my electric bill. We have a newly structured electric rate that makes it now a feasible addition.
The passive "solar room" looking east
Through an accident by a heating guy working on my furnace years ago, my solar controller was shorted out. Also I had a failure of one of my Taco pumps (the one that pumps water to my solar collectors). The solar controller was sent in for repair to the company that made it and upon returning it, I realized that all of the internal dip switches were set to the 0 position. Going through the manual was totally confusing because they created a large number of the controllers for different uses. With the help of a neighbor who is a great electrical person, I reset the 16 dip switches, but still had issues with the performance of the solar system. It was complex because of the heat exchanger for home heating, and the loop that went to the wood furnace for heating the solar tank during the cold months. Finally I got a hold of Jon Klima of Conifer Solar Consulting. Jon worked with me for a week with back and forth e-mails and he got my system totally straightened out! He is a great guy and you can visit his website at: http://www.conifer-solar-consulting.com/ Jon helped me last year and we have now become good friends writing to each other weekly. Here is a Colorado site that has home tours. Jon's home is #2. He is totally off the grid. http://www.coseia.org/newsite/home.html Look for: Solar Homes V-Tour.
My new high efficiency heat pump and furnace - the "Big Blue" solar HW storage tank is to the right.
The second bit of good luck came by meeting a Mechanical Contractor in our town, a young man by the name of Matt Oliver. Matt has a 2 year technical degree as well as working on heating systems during his stint in the military. I told Matt that he had to integrate the new furnace and heat-pump with my solar system as I still wanted that in the equation. He completely rebuilt my heat exchanger in the cold air return of my furnace making it much more efficient. At the same time, he increased the size of my duct work for the proper fit to the new system. He integrated both controllers so that my system automatically chooses solar first, when the solar HW tank is depleted, it switches to the heat pump and then when temps dip below 15f, the system switches last to propane. Everything is seamless and I am very pleased with the results.
This is the integration of the solar HW heat exchanger that heats my home - The solar HW tank has a preheat coil that preheats my domestic hot water. All heat ducts have been expanded to handle the new air flow of the system.
A torn rotator cuff last year made it impossible for me to split wood and use my wood burning furnace. My propane heating bill was huge! That is when I decided to change out the old system and install something more modern and up to date. My old system was pretty much state of the art for circa 1980, but times have changed with heating systems. With no wood being used at present, my heating bills per month during the cold months is running about $55.00/mo. That is about the same price as 1 face cord of wood bought here locally. When I used my Ashley/Jensen wood furnace in the past, a typical cold month burning would be about 4 face cords!!! My new system will pay for itself in a short amount of time!
Here is a block diagram of my solar HW and heat pump heating system. The drawing shows pipes entering the side of the solar storage tank when in fact they all enter or exit at the top of the tank. I drew it that way for clarity.