Guest blog post, by Margy Lutz
Finally this winter, our thermoelectric wood stove generator is fully operational. Following our test runs, we placed the pump to recycle cold water down in the lake water under the cabin. In winter, it gets about 5 degrees C (41 F). That’s plenty cold for a good differential between the 300 degrees C on the hot side.
Most system owners don’t live in a float cabin four feet with a constant cold water source under the floor. The typical user has to use a recycled liquid (usually including a water/antifreeze mixture) that runs through a radiator for cooling.
In addition, a charge regulator/controller is used to protect the batteries and prevent overcharging. The model that came with our system has lights to let you know the status of the charging process.
Wayne likes to know more about the charge we are getting. He installed an ammeter and a volt meter. The switch in the middle controls the water pump down below the cabin. To maximize the charge to our cabin battery bank, we’ve installed a separate solar panel and two six volt batteries wired in a series to run the pump.
Living off the grid has its challenges, but having an alternative power sources has made our winters much brighter (pun intended). Do you generate power? What are some of the solutions that have worked for you? — Margy
Postscript by Ken Adler, AGH Technical Advisor:
Congratulations to Wayne and Margy on their thermoelectric wood stove. In a follow-up communication with Wayne, he reported that they are no longer using the system because the thermoelectric modules failed. Wayne doesn’t know why they failed, however, the most common reason for failure is overheating. The modules can also fail if Bellville washers are not used to allow the module to expand and contract during heating and cooling. Wayne also reports,
Even when I was partially (marginally) operational, I produced less than 2 amps at 12V DC (23 watts) to recharge my cabin battery bank. This would have been enough to put a top-off charge on my cabin batteries (normally recharged via my solar system), particularly valuable in the winter when solar power is minimal and my wood stove is operating nearly 24-7. The primary reason for the low amperage was the need for a 1,8 amp 12V (21.6 watts) water pump to feed the cold side of the modules. In many ways, I reside in the perfect test location for this thermoelectric system, since
I have a nearly infinite supply of very cold water 4 feet below my wood stove. I live in a floating cabin on Powell Lake BC, and the lake is extremely deep and very cold in all seasons. What an opportunity to serve as a source of cold water through the cooling system! The pump only needed to pump the cold water up 4 feet and then outflow back into the lake. Even with this tremendous advantage, I couldn’t get everything fully operational.
Does this make me a non-believer in thermoelectric from a wood stove? Absolutely not — I still believe this is an important future source of electrical power in my cabin, since even a top-off voltage during the solar-depraved Canadian winter would be worth the price. I’d be one of the first in line if a recreational property thermoelectric system was available, and I’d be quick to try again. Thus, I wish you all of the best with your preparation for the 2018 conference. I’ll be following the results closely.
In an earlier post, Wayne reports that he is using three 25 watt thermoelectric generators for a total rated power of 75 watts of output, however, he’s only getting 23 watts of power for his battery. Part of this is due to his pump, which is drawing almost 22 watts of power. If you are interested in building your own thermoelectric wood stove, there are a few improvements that you may want to consider. First, TEG suppliers (see our resourcespage) now sell more efficient lower wattage pumps. Second, consider starting with a thermoelectric generator rated for 100 to 200-watts. While this is more expensive, if you go with a smaller system much of your power will be consumed by the pumps and/or fans you need to cool the modules. Third, Bellville washers are critical for allowing the modules to expand and contract.
If you are interested in designing a thermoelectric wood stove for our 2018 Wood Stove Design Challenge, please visit our web sitefor more information. For more information on Wayne and Margy’s life on a floating cabin, please visit their blog at Powell River Books Blog.
For an overview of the potential of thermoelectric wood stoves, click here.
One of the loopholes in the new EPA regulations about to close
|The cleanest and most efficient
forced air furnace is the Maine
Energy System Auto Pellet Air.
It delivers 89% efficiency.
One of the big loopholes in the new EPA wood and pellet heater regulations is closing this month.
Small forced air furnaces were required to meet new emission regulations in May 2016, but many very small furnaces declared themselves to be large furnaces, giving them until May 2017 to meet the new standards
As of May 16, 2016, all forced air furnaces, large and small, must emit no more than 0.93 lbs per mmBTU of heat output regardless of whether they are wood or pellet units.
Currently, there are six forced air furnaces that are certified, four of which use wood and two of which use pellets.
The average emissions rate ranges between 0.06 to 0.84 lbs, with the average at 0.411 lbs, less than half the current standard.
However, as of 2020, this class of heaters must meet a far stricter standard of 0.15 lbs/mmBTU.
(This is the subject of litigation by the HPBA.)
Only one of the current six models, the Maine Energy System Auto Pellet Air
emits less than 0.15 lbs, but it has to be retested using a different test method to comply with the 2020 standards.
Of the six currently on the market, there is a huge efficiency range, from 48% to 89%. Both ends of the spectrum are listed as pellet heaters. At the top end is the Maine Energy System’s Auto Pellet Air, which was developed by OkoFEN
, a leading pellet boiler company in Austria. At the bottom end is US Stove’s 8500 multi-fuel furnace
(US Stove also has a certified cordwood furnace that has lower emissions and higher efficiency than this pellet model.) The average efficiency of the six
|The US Stove 8500 pellet
furnace is the least efficient
certified furnace at 48%, but sells
for less then $ 3,000.
furnaces is 66%.
At the end of May 2017, it will be clear how which forced air furnaces did not get certified.
There are many more coal furnaces on the market today, compared with 3 or 4 years ago, as some companies have added grates and other slight modifications to outdoor wood boilers and furnaces in order to keep them on the market as coal units.
Coal heaters are still not covered by EPA emission regulations, so renaming a wood boiler or furnace a coal boiler or furnace is still a loophole used by some companies.
Massachusetts has developed the first wood stove change out program in the country that recognizes the value of automated stoves and stoves that disclose their verified efficiency to consumers. The 2017 program offers Massachusetts residents between $ 500 and $ 3,000 for upgrades, depending on the stove and income level of the family. The Commonwealth […]
Today, the Alliance for Green Heat announced the fourth Wood Stove Design Challenge, returning to the National Mall in Washington, DC in November 2018. The 2018 event will be free and open to the public and includes rigorous testing of the next generation of technology that can make wood stoves consistently cleaner, more efficient, easier […]
Posted by Earth Stove on February 15, 2017 with No Comments
The EPA’s new wooden heater regulations has left far more than ten states with outside boiler restrictions that now want updating. Most point out rules refer to Stage 1 and Stage 2 boilers, a voluntary plan that has now been superseded by certified boilers in new EPA rules.  At the moment, at the very least New […]
This site contains excerpts from a very crucial and readable report released by the Planet Health Organization (WHO) in 2015.  It is mainly from a wellness and policy perspective and is extremely useful for North American as it provides more of a European point of view and is balanced in its technique. The complete 58-page […]
Posted by Earth Stove on December 9, 2016 with No Comments
Wood heating has created a comeback in the United States and has been the quickest expanding heating gasoline for most several years given that 2005, according to US Census figures. Currently, 2.36 million houses in the United States use wood as a primary heating gas (ACS, 2015, 1-year estimates). And 8.eight U.S. million houses use […]
Online Useful resource Center released to aid software professionals & buyers States and counties are progressively seeking to wood stove adjust out applications to inspire people to give up previous, polluting wooden stoves for cleaner options.  In 2016, there ended up 34 stove adjust-out programs. The average incentive was about $ 900 to change and […]
Posted by Earth Stove on February 20, 2016 with No Comments
When it comes to listing accurate efficiency and BTU output on their websites, there are only a handful of companies that you can trust. The Enviro EF2 pelletstove is one exampleof misleading advertising. If a consumer calculates the pay back period of am Enviro EF2 pellet stove based on the 87% efficiency listed on the Enviro […]
Posted by Earth Stove on January 12, 2016 with No Comments
The Internet is full of opinions and reviews of wood pellet brands. However, data of actual properties of various wood pellet brands is hard to locate. It cost under $ 100 for a lab to test ash, moisture and BTU content of a pellet. We tested 4 popular brands, along with corn kernels, to see […]