25 years off the grid, a retrospective. (Alternative energy).
Many articles have been written on how to choose were you live: Climate, soil, neighbors, etc. We, being the intrepid trail blazers we were, ignored all this good advice and bought the land 'cause it was pretty, and, in the end, things worked out. Armed with Ed Mazrias' new book on passive solar, we built a saltbox post and beam with what would become called Saskatchewan Framing. It had insulated drapes to keep the heat in (Kathy always joked that with passive solar you're active, and with active solar you are passive), a compost toilet built from McGill University's Stop the 5 Gallon Flush, a grey water system, A Whirlwind Mdl A windmill and a drilled well with a hand pump. House "mostly" finished, without a mortgage, waving goodbye to our city friends and income from my mechanical contracting business, we loaded up our belongings in a semi owned by a casket company, our personal belongings in our 10 year old VW van and moved up. On the way up, baby in the back, $500 in our pockets, having burnt our bridges behind us, I turned to Kathy and said, "What are we doing?"
The first winter had 10 days where the temperature never got above zero, the windmill self-destructed after a month, our refrigeration was a large "walk out cooler," and the water line from the pump to the second floor cistern froze. I made a pedal powered washing machine to do two loads of diapers per day for our first daughter, Emily. Fortunately we had put up enough wood, our "Mama Bear" Fisher stove glowed in the living room surrounded by the "bar M" corral, a pun I still laugh at.
With no electricity we did get a lot of sleep that winter and dreamt about how things would be ...
In the spring we dug the water line deeper, motorized the pump, installed a new 2Kw Whirlwind (which is up to this day), purchased a 50-year-old Delco light plant as a back-up, moved the wood stove into the basement, installed a direct thermosyphon solar direct hot water (DHW) system (yes, in northern Wisconsin), planted a huge garden, and I went to town and got a job designing energy saving retrofits for seniors on SSI for a year. Over the years we added a small PV array, added a room for daughter number two, Kate, and a second-generation solar green house. We got the land certified organic and tried growing vegetables, in the end the bedding plants we grew were what we stuck with. We tried organizing a farmers market group (farmers also adhere to Groucho's philosophy).
As the girls grew we knew we had chosen a good place for them, they had the freedom to roam, get dirty, use their imaginations. I have read that we can't define ourselves by ourselves, that you need to be with other people to truly find out who you are. At a young age children take so many things to heart, I'm not sure that the best socializing skills are learned from a class of seven-year-olds, so I'm glad they had some time to themselves in what we call "the literal years." When we'd go visiting outside our circle of back-to-the-land friends the girls would often ask us in a quiet voice, "Where is their windmill and why is there water in their toilet?" When Emily went to kindergarten we tried introducing whole vegetarian foods to the school, seat belts in the bus, and explaining the Pledge of Allegiance. Our contributions went unappreciated for some unknown reason, and we decided to give homeschooling a whirl, a whirl that ended with Kate going off to a boarding high school and both girls going to college. To this day, of all the things we did different that our relatives disapproved of, homeschooling was viewed as the most aberrant. Homeschooling allowed us to be a family. During this time we worked together both on home activities and the alternate energy (AE) business, which grew out of our own experiences and actually used part of my schooling!
We sold that house in 1988 and have built another off grid home. Let me try to summarize what we've learned: Unless you are so inclined, you need not recreate the wheel. When we got interested in AE info was hard to find and the equipment untried. Energy systems are so much more dependable now but keep this in mind: The more you are willing to change your lifestyle the simpler and less expensive your system will be. One of the biggest advantages AE systems have is that they can be tailored to meet your needs. Rather than talk to sales people when you are trying to figure out what is right for you, talk to someone who is product neutral. If you are starting from scratch (new home) it is easier to integrate all sorts of energy efficiencies and comforts. If can be done with an existing home, it's just more difficult. For the adventuresome: Try going cold turkey with energy, live without all the gizmos that have become a necessity, you'll really appreciate even a small system. Will your dream be someone else's? Even if you never plan on selling, it does happen, so build it right. This does not necessarily mean a contractor doing everything; I've seen awful work by both contractors and homeowners.
1) Space heating and water heating
I'll start with this one because of all the AE systems out there, these two have the best payback. Passive solar space heating can be as simple as putting most of your windows on the south side, having an overhang to reduce summertime overheating, some form of moveable insulation to keep the heat in and a bit of mass to "soak up" the heat and gradually release it. We have tried both angled and vertical glazing. The thought with angled glazing is that lowering the angle of incidence to 90 degrees allows more sunlight to pass through your glazing and that yields more heat. Problem is angled glass loses much more heat due to night sky radiation. We've tried all sorts of moveable insulation schemes on the angled glazing. Last year we removed the upper south side of our house and went to vertical glazing with excellent results. The big problem with passive solar is control: How do you regulate heat gain ? How much mass? Too little and you overheat, too much and you won't be able to heat it during a short winter day. Passive can be the least expensive way to gain heat. If you don't mind putzing with the insulation and having the temperature swings it's a good idea.
Active solar is more complicated and has more up front costs, but it allows you control. To make active solar work in a northern climate you'll need to have the system work at the lowest possible temperatures. We always joked the active systems installed in the late 70s would last forever because they never came on, the distribution needed high temperatures to work. If you need 160[degrees]F out of a collector and it's -20[degrees]F, the system won't come on much even in full sun. Find a system that fits your needs. If the advertising glossies have palm trees in the background the system probably won't work in the north woods! We have tried solar forced air with rock storage, with brick storage, with an air to water heat exchanger and floor on storage. Air carries a fraction of the amount of heat water can, takes a lot more electrical energy to move and generally requires higher temps than water to operate. It is much easier for the do-it-yourselfer as there isn't any plumbing and a small air leak won't kill you like a small water leak will. We converted our slab on a solar hot air system to hydronics years ago.
Solar hot water with a low mass radiant panel is what we have settled on, both for our own home (for the past 20 years) and is what we recommend to our customers. (See diagram on page 35.) The diagram shows how we set up the system. The valve below the back up boiler (which can be wood, gas, oil, etc.) allows the system to utilize solar generated warm water as long as the solar tank is warm enough. When the solar is too cool to do the job, the valve isolates the solar from the heating loop and the back-up provides the supplemental heat. It is important not to have your back-up heat source go into the solar portion as it reduces the solar contribution (if the storage medium is already heated by the back-up source, the solar panels have to get much warmer to come on). This is why we stopped using a method that has both heat sources going into the same floor. This method had a large sand bed where the solar generated warm water went into hydronic tubing imbedded in the sand. Above the sand bed was a slab where backup heat went into another set of hydronic tubing when the solar wasn't keeping up. While this is an elegantly simple system the drawback is twofold: when the slab becomes warm from the back-up heat source the heat travels downward into the sand, lessening the solar contribution.
Secondly, having all this mass creates a "thermal flywheel": When do you stop putting heat into the sand to prevent overheating? When do you start putting heat into the sand so you'll be warm? Whatever space heating system you go with you want to reduce the amount of heat needed as much as possible. It is important to note that a well weatherized home is more comfortable, and, using less heat means a smaller, more affordable solar system. Our system consists of 6-4'x10' panels which on a normal house wouldn't help much in the way of heating, but because our home is super insulated (uses three Btu/sq./ft/ 100 degrees delta T) it, along with the passive solar gain, contributes between 60-90% of our heating and domestic hot water (DHW) needs. There are flat plate collectors and evacuated tube collectors. If you live in an area where solar is marginal, evacuated tube collectors may be the ticket for getting enough heat from a cloudy sky. They are more expensive and in the past have been prone to losing their vacuum and fogging up. Flat plate collectors were the only used equipment we ever dealt with because (properly maintained and built right) they last a long time. We have flat plate systems that are 27 years old and work fine.
We have tried batch heaters (with six layers of glazing), thermosysphon (where the water circulates directly from the panel into a storage tank), and tracking evacuated tube collectors (which worked great for one to four years ...). Batch heaters and thermosyphon work fine in more temperate climates, but here up north, we have settled on flat plate collectors with a nontoxic antifreeze solution which gets circulated through a heat exchanger mounted on a storage tank (see diagram on page 34). We have found that instantaneous modulating water heaters are a great back-up as they only come on as need be and eliminate a second tank in the system. This is important because there is nothing as frustrating as having a storage tank full of solar generated hot water sitting next to the back-up tank and having the back-up come on. If you are going to do anything with AE, do this system first.
2) Solar/wind electric
Our first house was a mile away from the nearest power line and the land was cheaper because of it. This was fine with us as we weren't going to hook up anyway, but knowing it would cost us 10 grand to have the umbilical cord stretched to our house made the decision all the easier. We started out with a 2Kw windmill that generated about 200 Kwh/month average, a modest amount of juice to say the least. Our refrigerator (after a year of using the "walk out") was a little gas refrigerator out of a motor home, and we had a root cellar. I mention refrigeration first because it is generally the single largest electric user in a home. Our heating system was a passive solar and a wood stove, so no electric consumption there. We had a double set of golf cart batteries and a rotary inverter to make AC from the DC battery bank. While rotary (a DC motor coupled to a AC alternator) inverters were the only dependable inverter back then, it wasn't very efficient and it was noisy. We went with a 36VDC system because we could use regular gauge wire for smaller loads and there was a lot of 36-volt stuff from the 30s and 40s (motors, lights, etc.) I built a freezer with a remote compressor and a 36 volt motor. It worked great except that we always didn't have enough power, so we got the Delco. This single cylinder air-cooled engine sounded like an old John Deere and taught me the value of running things slow. We have tried every imaginable combination of engines and generator/alternators over the years and finally settled on a diesel with a low speed alternator, the whole thing runs at 600 RPM. It'll be around long after I'm gone. I have reclaimed most of the exhaust heat so it's a cogenerator, charging our batteries and our floors with heat. By the way, we purchased our diesel by selling our last four cylinder "copper cooled" Delco to a collector. This was not the first time we found ourselves using things that had become collector items.
At the old house we installed 240 watts of PV's the second year and our back-up needs fell off so much that we didn't use the back-up for eight months, which I found out was way too long to have the Delco sit. It locked up on us!
The system at the first house showed us a number of things: It's hard to spend too much on a good set of batteries and efficiency of electric use was very important in an off grid house. Golf cart batteries can be good for a few years if you take care of them, and since most people's electrical needs grow (and you can't add new batteries to an old string), they may make a good first set. There is an old joke that until the periodic table of elements is recreated you won't find much change in batteries (these are the sort of jokes you tell when you've been in AE too long). Batteries are nasty. I have seen many DIY systems fail because of used batteries and/or batteries that were not meant for deep cycling. Our present electrical system has a 3 Kw Whisper, 1.5Kw of PV's, a single string (to eliminate series-parallel aging problems), 1300-amp/hr SBS batteries and two of the original Trace inverters. The 450 Kwh/month average is still a modest amount of juice, but combined with efficient equipment and being frugal, our back-up diesel cost $15 last year. We still use 36VDC because I'm stubborn, and at my age, stubbornness is an asset.
RELATED ARTICLE: Macadamia power.
A new renewable energy source has emerged in Australia with the development of the world's first power station to be fueled by waste macadamia-nut shells.
Construction began in June on the A$3 million ($2 million) power plant in the northern state of Queensland, which will use 5,000 tons of shells annually from Australia's native macadamia nuts as fuel for the 1.5 megawatt generator.
The biomass co-generation plant, which is a joint venture between Queensland state-owned Ergon Energy and macadamia nut producer Suncoast Gold Macadamias, will generate 9.5 gigawatt hours of electricity annually to supply more than 1,200 homes.
Ergon Energy's retail general manager, Kate Skilleter, said the macadamia power plant was expected to be operating by August and would reduce greenhouse gases by around 9,500 tons a year--the equivalent of taking more than 2,000 cars off the roads.
"This project ... could be replicated across a range of other industries, including peanut, timber, meat, wheat and grain processing, where waste streams could generate heat, electricity and revenue," Skilleter said.
The joint venture said it aimed to double the power plant's output by 2005, when the shell waste from Suncoast Gold Macadamias was expected to have increased to 10,000 tons.
Suncoast Gold Macadamias plans to use 1.4 gigawatt hours annually while the rest will be exported and traded in the national electricity market.
NEST STEP ENERGY SYSTEMS
NEW AUBURN, WI
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|Publication:||Countryside & Small Stock Journal|
|Date:||Sep 1, 2003|
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