This is part learning, part experiencing, part designing + Building a lo-cost, no op-cost, close-the-loop Eco Home owner built + designed in the Sierra Mountains.
After taking my first deep forest walk since the start of the winter season, it is time to reflect. The winter of 2010-11 started and ended with very strong and intense storms. More intense than I have seen in 30 years.
~November 15, 2010 saw over 5 feet of snow dumped in one storm at 7L. It was great for skiing at Thanksgiving, but made life difficult for several weeks. There were more broken trees and blocked roads that are still being cleaned up 6 months later. Then in March 2011 (I was in europe) there were even more intense storms that had more high winds and a lot of snow. This broke more large trees and blocked more roads.
In January 2011 we have 5 weeks of very warm and sunny weather. It was 60F here (at 4200ft) in January! A lot of the trees started to blossom and then had to retreat. This sudden warmth did not fool too many trees tho. Most trees blossomed more in early April and hopefully there will not be another snow storm. (Last year it snowed on May 1st).
I consider these extreme weather patterns to be part of climate change: global weirding. This is great for providing California with a lot of water. Everything goes in cycles, and there will come the opposite cycle of NO WATER - and that is when WinSol3 will shine, because it was designed with this in mind. The only issue will be that I need to be here during each small winter rainstorm and make sure that all the systems capture and store the little rainwater/snow that will be available. A small price to pay for 'free' rainwater.
As summer draws closer, the last remaining challenge at Winsol3 rises up again: providing energy for food refrigeration. Summers here can get up to 90F in July and August.
Over the years my biggest nemesis in balancing a comfortable lifestyle with net-zero energy remains food refrigeration. This is a long blog on a very important issue for all net-zero and off-grid dwellers.
Let me start by reviewing common food storage techniques and then relate my attempts at solving this challenge over the last few years at WinSol3.
Food Storage:
In the old days (60% of households in the US owned a refrigerator by the 1930s, it was not until 40 years later that the refrigerator achieved a similar % in the UK) there were no refrigerators in most households. Mothers (usually) did summer and fall canning of foods, some people dried or salted their foods for winter storage. Nearly every household had some type of root cellar, and consumed seasonal and local foods only.
With the advent of cheap electricity, transportation and then cheaper labor, the green (agricultural) revolution bought food from faraway places to every ‘super’market in the world through a complex global supply chain. In the USA every one calorie of food requires 7 calories of fossil fuel to get it there! After 30+ years of this fossil-fuel driven supply chain, we are accustomed to having any food at any time - and we feel entitled to it.
Bigger is better?
Gone are root cellars, cold boxes, ice houses/ponds and seasonal/local consumption habits.
Instead we have twenty+ cu.ft. double-door 'french' refrigerators that defrost automatically with an endless array of temperature and humidity controlled compartments. Additionally, American suburban homes have at least one big chest freezer (usually in the garage) where endless cold meats are stored endlessly. Some buy a whole or half of a cow and keep it in those freezers for consumption months later. One of the sad facts is that over 50% of the food pushed to the back of refrigerators usually ends up in the garbage can.
The rest of the world is slowly catching up to the USA. Even though most European and Asian households have small 2-4 cu.ft. refrigerators, I've noticed many of these new households having bigger and bigger refrigerators.
We have grapes from Chile available in all USA/Europe/Asia supermarkets in January. We can have any food available to us from anywhere in the world 24/7/365. With peak oil in the past, and rising prices and shrinking supplies inevitable, what will the future of this food supply chain look like? One can only imagine its slow demise. Are we going to go back to root cellars, canning, and ice ponds? Probably not.
So what are the solutions? That is where eco-village and local off-grid visionaries may provide some possible solutions.
Added note: Off-grid homes usually have a propane powered Sun Frost Refrigerator. These units cost well over $1,200. and use a substantial amount of propane gas each year. They are 80% more efficient than off-the-shelf electrical refrigerators.
Now, back to WinSol3’s food refrigeration history. Here's the story of my food storage journey over the past 5 years, summarized into four main areas: (Note: I had a digital thermometer inside each cold box.)
#1 Try= small fridge
My first attempt 5 years ago, was to use a small ‘bar’ refrigerator. These small refrigerators provide ~two cu.ft. of cold storage with a tiny freezer. Their compressors draw about 3.5 LRA (locked rotor amps) as opposed to 20+ LRA for big fridges.
Since there is an inductive load presented to an inverter, fridges have a high amperage surge as they startup. My 3,000 watt inverter usually beeped (draws more than it’s rated amps) for a few seconds while the compressor surges on startup. As long as I have bright sunlight (no problem in California summers) the small fridge worked fine. After sunset, each time the compressor cycled on, the inverter load was exceeded and eventually the battery voltage went below 12.1 VDC (my low voltage setpoint). I tried putting frozen water bottles in and keeping the fridge off overnight, but could not continuously freeze enough water bottles during the day for the small freezer.
#2 Try = two cu.ft. cooler inside a cold box
My next try was keeping the food cold in the fridge during daylight hours and transfering critical foods like chicken, seafood, etc into a cooler overnite. That lasted one week before I realized that doing this every summer day was going to be labor intensive. I tried transferring frozen water bottles into the cooler and eventually transitioned totally to the cooler using the fridge to occasionally freeze water bottles. Several people on the internet commented this was their preferred method. Again, after a few weeks I also gave up on this, because it was still too labor intensive.
I purchased a new, bigger, more insulated cooler. I made a cold box under the kitchen counter (the bottom of the cooler was in direct contact with the cold basement) and put in extra 4”of XPS insulation all around it – except for the bottom; and placed the cooler into the box. This ‘cold box’ is still used to this day with #3 ice added.
#3 Try = Success! Cold Box + purchased Ice
Every time I went to the local grocery store I started buying ice blocks to put into the cold box cooler. This worked great – the cooler inside the cold box would stay below 40F for over 7 days with the ice block. Eventually tho this was tiresome, as spending money and transporting ice blocks from a store was not my idea of sustainable living. So I purchased an electric ice maker.
#4 Try = Cold Box + PV produced ice.
My thoughts turned to what other mainstream consumer products were available that could make things cold without upsetting my solar powered inverter. I researched various portable ice makers and purchased one for $99.
It works great, and I can make about 3 pounds of ice each summer day in bright sunlight with my PV panels. I use the ice for my cold drinks and put the rest into the cooler inside the cold box. It’s still a bit labor intensive, but it works.
(Note: from November to April at WinSol3 there is no issue since snow is readily available)
Changing lifestyle cooling practices
The real issue in food cooling is having the convenience of cold storage at our finger tips with minimal efforts. As RMI + Avory Lovins recently have stated: 'We don’t use energy, we use energy services.'
The energy service I wanted was to keep certain foods cold.
I started researching how others had done it before compressors and cheap electricity were available. There’s a lake off Hwy 50 between Placerville and Tahoe called ‘Ice House’ named appropriately because here pioneers of the 1800’s skimmed ice from the top of large ponds specifically designed for this use – and delivered the ice via heavily insulated cold boxes to the supermarkets in the hot summer California Valleys. Image the embodied energy of human labor on each ton of delivered ice!
But the real solution to refrigeration lies much deeper: our lifestyle of eating and preparing food and basic physics. Language is also important: instead of calling it refrigeration, I like saying ‘cold food storage’ – which is really the energy service we want.
The key questions are:
(a)which foods need which temperatures for how long?
(b)Which foods do we need for nutrition? And how long from harvest to eating?
The latter is all about choice. As in any lifestyle choice, this is a personal question and no science or debate can convince someone to do with or without a certain food. But once I had the answer to (a),which can be found through siteslike this one from Virginia Tech:
"For optimal quality and safety, dairy products should be stored at refrigerated temperatures between 34°F and 38°F, meats between 33°F and 36°F, and eggs 33°F to 37°F. Fresh vegetables and ripe fresh fruits should be stored between 35°F and 40°F. Always store refrigerated foods at temperatures less than 40°F."
It was really easy to change my lifestyle choices with some knowledge of the refrigeration energy it takes to cool foods and to change a little bit of lifestyle.
My keys to net zero energy Food cooling
The first step to reducing an energy profile for cold food storage is to inventory your households eating habits (especially during hot summer months):
My personal food habits include:
Eating ice cream in the summer
Seafood once a week.
Papayas, pineapple, yogurt, eggs,
Given these personal food habits, I had to adjust my life style a bit. Instead of ice cream, I make smoothies with fresh berries and ice cubes from the icemaker. I only store seafood about once a week and use the local grocery store as my 'outsourced' freezer supplier - its free! (cold storage only :-)
A personal note:
I don’t freak out about having 'perfect' food - I don't understand why a little blemish on a strawberry or apple make some people throw the whole thing away. I am a firm believer that farm kids are much healthier than city kids because of their exposure to all kinds of bacteria at a young age. I also believe we need to continue this throughout our adult lives keeping our immune and other systems tuned-up. So, I do not abhor eating a little 'dirt' every now and then. Since all my vegetable beds are biodynamic (no chemical fertilizer or spray, +++), a little bit of dirt on the lettuce or radishes is no biggie!
If it wasn’t for my experimenting through steps #1-4 above, I don’t think I can go into step #5 below.
Step #5 – my ultimate solution for cold food storage
It’s a five step process:
First, and foremost are WinSol3’s gardens, greenhouse and hotbox. These three places can provide me with green leaf veggies and more, year round. Nothing, and I do mean – nothing! – beats freshly picked produce from a garden where biodynamic principles are practiced along with local rainwater.
Second, are my de-hydrators and canning processes. This takes either my, or a local neighbor’s excess harvest and prepares it for long term storage. I like to store dried herbs and mushrooms this way.
Third, is the root cellar which is currently under construction in the basement of WinSol3.
Fourth, is the cooler within a cold box and summertime PV driven Icemaker (#4 above). Right now that is located below the kitchen counter, and is a bit awkward to access. I wish I had built an upright vertical cold box. I am still contemplating on doing this – the added convenience of not having to stoop down to access cold food as I get older (20" is the lower limit).
Fifth, are for special occasions for parties, tours, weekend visitors, etc. This is outsourced to the local grocery store and perhaps an ice block.
I wonder what will happen first: Changes to our food supply and habits, or new hi-tech, appropriate + balanced solutions?
Personally, I’m not waiting for the promise of hi-tech. Changing my cold food habits has been a long journey, and I still have a ways to go. Change is difficult, if it’s not – you’re not changing. Try putting your sweater or coat on with the opposite arm – see how weird it feels? That’s change.
Adsorption refigeration is making big inroads in the cooling industry. This proven technology has been used by industry for decades. With the advent of affordable solar thermal systems and California’s sunny summers, solar hot water with adsorption chilling is a huge promising industry. Stay tuned.
With my new found passion for energy commons, I was most curious about how Sieben Linden (eco-village in Germany - see previous post) balanced their energy needs.
This picture says it all: Current solar income with biomass. This picture shows the storage area for Sieben Linden's wood heating supply. Cool to put solar PV (current solar income) on top of it.
Biomass in Europe usually implies wood (biofuels is everything else). Europeans are VERY sensitive to biofuels due to their tremendous influence on global food prices and how biofuels are sacrificing rain forests in 3rd world countries (palm oil, soybeans, etc.). Here's a summary of their energy systems from the web site:
The average resident uses about 500kwh per year (compared to the average USA residential usage of 11,000Kwh per year.) which 1/3 of what the average German uses. There is no electrical energy used for heating water or space. There are multiple solar PV and thermal arrays around the community. A total of 47KW PV with about 4m ² (40 ft ²) of solar PV panels per resident which supplies 85% of their annual needs. Sieben Linden's solar PV arrays are grid-connected [Germany is on a feed-through tariff system (USA uses net-metering)]. Since there are strict rules of no toxic materials allowed on site, there is no battery storage.
Heating is done mainly through biomass = wood. There are very large, multiple storage areas for cut wood logs ready to be consumed by fireplaces. Each fireplace's exhaust extends over 20ft above the roof. It appears this is more to get the emissions higher up and airborne, than for fire prevention.
Hot water appears to be 100% from solar thermal panels. There are a LOT of solar HW panels. They have a biomass gasification generator (turns wood to heat + ?steam?) which appeared to me to be a simple boiler. The unit is hooked up to three of the large buildings in a central district type configuration. This is also VERY commonplace in Europe. It's easy to interconnect multiple dwellings to one central heating system and far cheaper than having individual heating units in each building.
Propane appears to be used only in the common kitchen areas. I don't know if it was piped to other homes.
----------------------------------- My view on this:
An eco-community's priority should be for a long-range smart energy plan that focuses on self sufficiency and micro-grid power. By tying into a main grid (no matter where you are - even in California) there is a direct connection and support of coal, nuclear, etc. utility mega-corporations; even though one is investing in green power RECs.
I don't quite understand Sieben Linden's reluctance for battery or other electrical on-site storage. There are benefits of using new battery technologies that would avoid lead acids and toxic-plated batteries on-site. There are also alternative storage mechanisms such as compressed air, hydrogen, pumped water storage,fuel cells, or even cutting edge technology such as the 'cube'.
I was really surprised to see all the wood. I always thought that burning wood was eco-uncool. But after Austria and Sieben Linden, I have changed my mind. I will start harvesting and burning more wood at 7L. I hope to eventually find a small gasificaiton generator to make electricity (co-gen + tri-gen) from wood. I'll probably have to import if from Europe or Asia.
One of the guiding principles in permaculture and cradle-to-cradle is to celebrate diversity. That has always been they key to any system = especially energy. Sieben Linden does a good job at this. It has wood, grid electric, solar PV, solar thermal, and propane. I thought for sure I would see a wind generator - which has a nice parity balance to solar systems. But, alas - none to be found. Seems that the wind speeds are just not high enough. Bullocks, I say. For mere hundreds of euros a small wind generator can be erected, not very high up and supplement the solar PV panels.
The biggie at Sieben Linden is solar thermal. I am always surprised in the USA and especially in California, that we don't have more solar thermal. It is so much more efficient, so much easier and much lower cost to construct. But with freezing temperatures, and shady contractors, the USA has a history of bad experiences. Once freeze-proof silicone neoprene piping comes out of NSA's labs though that will change.
I wasn't able to find out if their solar thermal panels use food-grade glycol - which is a toxin.
I reluctantly left Sieben Linden in Northern Germany one week ago. It was my first experience at a 'real' eco-village - my first glimpse at a working community that really walks its talk. You can read the English overview of Sieben Linden (Seven Elms) here.
Similar to my own experience with WinSol3 - albeit on a much larger scale, Sieben Linden proves that any thing is possible with vision and determination. It also has room for improvement which is continuously taking place.
What I saw in my very short stay, was truly amazing and heartening!
Before I arrived at Sieben Linden, I wondered if I would encounter an Amish-like village, an extended hippie-like village, or a modern uber-permaculture village. Yes, all of that and more! Anyone that thinks this is a modern 'hippie' community making a statement is mistaken: Sieben Linden embodies cutting-edge building technologies along with proven low-tech and ancient methodologies, while encompassing a learning center, profitable businesses, connections to surrounding communities, a working vision of what is possible within a super low carbon footprint, + + +
Putting my penchant for technical eco-building + energy systems aside; it was the synergy of the community of people, the ambience and spirit of the place that impacted me most. Maybe it had something to do with my meditative walk in the woods: It just felt right.
Sieben Linden is a living example of what a persistent and loving, enlightened group of people can do. They sure had a difficult road to hoe getting where they are now. It seems that persistence with all the mainstream barriers is the key in developing all these communities.
I don't even know where to begin explaining all the things that I observed at Sieben Linden. I'll start with a couple things here and expand on them later. Here's a picture of one of the multi-unit buildings complete with snow-shedding solar PV and SHW panels, on-site straw-bale and massive timber construction, note the south facing window/atrium areas:
Permaculture with resultant synergies is prevalent in throughout Sieben Linden. Everything has multiple purposes and all parts are integrated within the whole. A sense of community togetherness, flexibility, tolerance, give and take, along with privacy was evident. Everyone had specific responsibilities to the community and to each other, to doing daily tasks, and yet were free to be on their own if they wished so. This is common in most co-housing communities, but here it seemed more free-flowing.
Here's a picture of the contrasts at Sieben Linden. In the foreground is a funky living wagon and in the background is a state of the art multi-unit 'PassivHaus' with multi-channel broadband-monitored control system and hi-tech heat recovery HVAC system.
Community within Community
The vetting process at Sieben Linden intrigued me. I'll talk how one gets to be a member within Sieben Linden later. Once you are accepted you need to establish your own community within the community. There was an entire area of 'living wagons' that appeared almost like our western cliche of 'circling the covered wagons'. Residents of these wagons are encouraged to mingle and find like-minded people to devise a development plan to build a larger community house. Again this appears confusing until one is there. To back up, Sieben Linden consists basically of about ~7 very large multi-residential units, NO middle sized units, ~20+ tiny to small homes, and ~15 living wagons. There is also one very large central building and a connected common building. This is for about 85 people (35 kids). These are all on an area no larger than 15+ acres with an adjoining 50+ acre forest that cannot be developed.
So the concept of temporary living wagons is quite organic on many dimensions. It allows individuals and couples to be part of the community while at the same time they are coalescing (collaborating) within as much time as they need, to find kindred spirits they can co-habitate together with and to build one large multi-unit housing together. There is no rush, no deadline. It needs to work for the long term. These small living wagons can be easily moved around, and 'adjusted' based on members' and community needs. This temporary community within a community grows, shrinks, moves, as needed. Very much like a natural eco-system transition zone.
Construction of the buildings appears to be a community effort - mostly on-site community members along with the general public. While I didn't get to observe this on my short visit, there was a small public workshop for a new building going on. It appears to be a combination of old fashioned barn raising with a little help from industrial strength cranes:
Short version of Sieben Linden's vetting process: You can look over their web site and get the specific details, but my memory in listening to their process is: One first joins a workshop, then an extended workshop/project. Then one (applies for?) is accepted for a 3 month stay. After this stay 66% of the residents need to be positive about wanting this person to continue the process. The person then makes an application and a presentation for a 1 year living on-site committment. Again, after a 66% acceptance, and after the 1 year period, the person can then apply for full-time residence. The final approval is again done with an application, presentation and 66% approval. Whew! (i hope i got this right). There are only about 10 people accepted each year to live at Sieben Linden, and I understand there is a VERY long waiting list.
btw: there's even a connection to Sieben Linden with WinSol3! While I was showing my pictures + the operational plans for WinSol3 and showing it's location within the 7L pioneer ranching area - Nicoletta commented that 7L stood for Sieben Linden (SevenL)! My heart skipped a beat at that realization.
I cannot conclude this first Sieben Linden blog without extending a heartfelt thanks to Michael and Julia for allowing me to visit, and to Nicoletta for being my wonderful host, putting up with my endless questions and curiosity, and made some wonderful second-chance recycled momentos for me; and to Ole who has an inspiring viewpoint on all things eco, green building and is actually doing it with his rocket stove, PAHS (Passive Annual Heat Storage) house concept and much more!
