A journey into hybrid solar power

         Welcome Back! Last week we talked about one of my favorite forms of food production, aquaponics, and we talked about why it won't revolutionize our waning agriculture industry. Specifically we covered the root cause of the ills of agriculture, many industries for that matter, and how globally we suffer from a cultural mentality that must dramatically change in order to revolutionize or change our food production and distribution systems in a positive and meaningful way.

         This week we are going to talk about hybrid photovoltaic/thermal (PV/T) power and some of the applications of these systems. Specifically I am centering this article around the EarthShip inspired greenhouse I am building this year and how I intend on using hybrid PV/T power to heat and cool the greenhouse for a year round tropical environment. I will briefly cover PV and thermal panels and how they work, along with some of their drawbacks and how hybridizing them can turn some of those drawbacks into net positives. My intent with the real world design example is to provide a more practical application explanation of theory based off of a design that I have experience and knowledge of instead of a theory alone explanation. As well, it gives you a bit of a look into my goals, my nerdy passions, my mind and life.

My intro and adventure with solar energy. 

         I became interested in solar, wind, geothermal, and bio-fuel power somewhere around age 19 or 20 and like anything I develop an interest in, I researched and read every article, book, and company I could find. I don't remember what or who in particular got me started, only that I became an overnight fanatic of all clean, renewable, and non-conventional forms of energy and I have been ever since. After some research I realized our energy industry, like so many others, is teetering on the cliff of oblivion just waiting for the right factor to send it over the edge. This is probably where my passion for Environmental Science and Sociology began. I thought it was ridiculous that we rely so heavily on centralized power from pollution generating, exceedingly hard to extract, and finite fossil fuels like coal and natural gas when there are billions of acres of rooftops worldwide that could act as a decentralized solar electrical infrastructure. I found it mind blowingly stupid of our nation to ignore the possibilities of feed in tariffs for solar, small scale wind, and geothermal when countries like the UK, Germany, and Spain were prime examples for successful implementation of such systems. Also considering the latitude of Germany and the UK make them poor candidates for mass implementation of solar energy production as compared to the solar resources and latitude of the US, how could they be beating the pants off of us in an industry we by all means should be a world leader in.

         While I still hold the same beliefs and convictions, my decade of experience and education since then has allowed me to recognize that entrenched ideologies, corporate law, and the bureaucratic process make initiatives like feed in tariffs, decentralized energy production, and switching to renewables exceedingly difficult to accomplish on any meaningful scale. At least with food production we have farmers markets to help in the whole decentralizing process, whereas energy production is a far way off from allowing the individual to capitalize on and stake their claim to a small part of the industry. However, even with food production, we face many obstacles from our legislature and ingrained cultural beliefs. The tide does seem to be changing for energy production however, the price per watt of solar energy has dropped significantly over the past decade. I remember when it was almost $2.50 per watt and now the price hovers around $1.35 per watt and may be below $1.00 per watt by 2020. This in combination with more investment into increased efficiency of solar and more home owners installing solar on their homes, is laying the groundwork for decentralized energy production and a significant decrease in our dependence on fossil fuels. Just not fast enough by carbon emission and sustainability standards.

So how does Solar PV work and how will I use it?

         Photovoltaic or electricity producing solar panels are generally made of silicon wafers (solar cells) that have been chemically treated to have a positive or negative charge, a process called doping, and they operate off the principle of the photoelectric effect. there are other types of non-silicon solar cells, however they are special application for things like satellites in space or low energy metallic plates and you are not likely to see them in any home or commercial scale electricity production. The basic design is a negative and a positive charged cell are sandwiched together with the negative cell being the one that faces the sun and the space between the two cells is called the P/N (or positive/negative) junction. Again there are variations on this, this is just the most common. As a light photon strikes the negative cell, it frees an electron which then travels to the positive cell and as it crosses the P/N junction it generates an electrical charge. Think of the negative cell as the emitter in the video and the positive cell as the collector in the video. The tiny silver bars you see inside solar cells are a collection grid for the free floating electrons to travel down and be harvested for use in generating electricity. Usually a cell can produce between .5 to 1.5 volts, so it takes quite a few to produce any significant energy. Hence why a rooftop array may only provide half a homes needs, depending on the roof size and home electricity consumption. On the flip side of that coin, with responsible energy usage and a well situated and large enough rooftop, one home could provide enough power for four or five. I know with my houses roof space resource and home energy usage of 500-600Kw/month, we could provide energy for just shy of three homes with comparable usage.

Great visual of how a solar cell works, and the link gives a good explanation of how solar yard lights work. Just think of a panel or array as a very large scale version of the yard light.

          For the greenhouse system, I plan on utilizing solar PV to run all of the electrical components in the greenhouse and aquaponics. This includes lights (both regular lights for working at night and seasonal florescent grow lights for starting sprouts under 24 hour light), water and air pumps, fans, the system controller, a battery bank, and anything else that may pop up over time. All the excess electricity will be used by my family in the house and will offset our already low energy usage and bill. Considering the electrical usage of an average aquaponics system (20-30 watts for a single bilge pump, 20 watts for an air pump, maybe a 1Kw heater (though it'd be more efficient to insulate and heat the room and let the water act as a thermal battery), then extrapolating for my planned system size (not likely using heaters) and adding in several 50 to 60 watt canister fans or air moving fans, I believe I'd be using no more than 400Kw per month. And that's with a rather liberal usage of electricity. The 2100w PV system in my initial design will be more than the greenhouse will need.

PV drawbacks and how I intend on addressing them.

         Like anything, solar PV has a few drawbacks. The most significant being that they only work when the sun is out and they are not being shaded. So if you have no other form of energy, as in the grid or a generator, you need battery backup or you will go without electricity at night and on cloudy days. The sunlight part is obvious enough given solar panels harvest sunlight to make electricity, so how does this shading thing work? Well, because of the way the panels operate, if even one cell is more than 40% shaded, it will not produce any energy and will draw down the energy production of the rest of the panel possibly damaging the cell or the whole panel. Likewise, if a solar array is connected to a single inverter, like most are, then a single panel being only 25% shaded will be enough to drop the entire array output by 50% or more. Now think about things like snow, dust, airborne soot particulate, and the like. This is in addition to the shadow arcs of trees, chimneys, pipes, swamp coolers (Ive been asked "whats that" many times before, it's a dry climate form of energy efficient air conditioning), etc... that may shade a panel in part or full for part of the day. Personally I believe that micro-inverters should be used for the grand majority of home and business arrays because any shading on one panel will only affect the performance of that one panel and not of the array. The cost is about 10% to 20% higher than a single inverter system, however added electrical output and lower line losses will pay back the additional cost in a couple of years. Commercial arrays are another story, one where single inverters are a more economically driven factor due to the sheer size of the array making micro inverters cost prohibitive while the sites themselves are almost guaranteed to have no trees or buildings shading them.

         For my system, I plan on using micro-inverters however I have many other factors to consider. In front of the greenhouse I plan on planting a polyculture centered around taproot and heartroot habit mulberry, persimmon, and chestnut trees to keep the water table low in this low part of my yard, stabilize the soil in that area, and shade the south face of the greenhouse in high summer when it would be subject to extremely high temperatures. As an added benefit I get pretty trees with delicious and healthy fruits and my ducks get a woodland meadow habitat when it's all completed. The average temperature at my location for the past eight years has been between 95 and 105 degrees Fahrenheit from roughly June to August and anthropogenic climate destabilization seems to be making those numbers climb. In those conditions, even with good ventilation, the greenhouse may overheat. In winter when the sun is low in the sky and the trees are bare, the glazing should get almost maximum insolation (large tree branches on espalier will block some sunlight, its unavoidable) while the earthen walls, roof, and floor will insulate the interior from the cold. The espalier trees could be problematic for the solar panels if not maintained at the proper height for shading the greenhouse but not the panels. As well, I plan on having a backup battery bank in addition to running the proper cabling to tie the greenhouse to my home and therefore the grid. When considering that the greenhouse will have live fish largely dependent on constant water flow and aeration, I'd rather have the grid as my primary backup and the batteries as a secondary than try to go grid free and have my system go down for whatever reason while I'm not home.

East facing cutaway of my initial plan showing solar panel location at the highest point of the 15 foot tall greenhouse and the general location of the expected mature size espalier trees. Ive still not settled on a design for the aquaponics system, the system depicted is just to see what I do and don't like.

North facing view of greenhouse showing eight solar panels, expected to be 250 watts each for an array size of 2350 watts. For the cost, I might run five panels at 285 watts for a 1710 watt system, still more than I'd need.

Heat, a solar PV killer and waste byproduct or untapped resource?

         Another factor is heat, heat is the enemy of solar PV panels. As an industry standard panels are rated at 25 degrees Celsius (77F) and for every degree above 25C, the electrical output drops by .4% to .5%. This doesn't sound like much until we consider that rooftop PV panels operate at roughly 55C-75C (130F-167F). Do the math, .4x25 to 50 = 10% to 20%, and .5x25 to 50 = 12.5% to 25%. That's anywhere from  10% to 25% reduction in electrical output, or for my estimated 2100 watt system (2.1Kw) those percentages mean it is only an 1890w (1.89Kw) to 1575w (1.57Kw) system before calculating shading, DC/AC conversion, load and line losses, or any other variables. Ouch!

         Where does the heat come from? Only the visible light spectrum is utilized in solar energy production. Infrared light passes right through the panels as if they didn't exist, and ultraviolet light is primarily converted into heat energy and only partly into electrical energy. This has to do with the voltage and amperage potentials of the different light spectra and their photon energy. Infrared light, though the most abundant, produces such little energy that the resources for collection are not justifiable. While ultraviolet light, though the highest in energy potential, has the lowest working potential and is harder to effectively harness.  The excess heat energy from the ultraviolet photons pools behind the panel while the infrared light is absorbed by the roof and panel backing material and slowly radiates back out as more heat. Another factor of heat with solar PV is that heat degrades the silicon cells and shortens their effective lifespan. So it's well worth the effort and costs to cool the panels, however cooling fans and the sort consume roughly equal the amount of energy they save in reducing temperatures thus making them only marginally beneficial. This is where hybridizing with solar thermal comes into play as it only adds roughly 25% to the cost of the panel and harnesses 2x to 4x more energy than a PV panel alone.

SolarWall example of how hybrid solar PV/T systems work. I intend on modifying this to meet my needs and putting my own unique spin on it to avoid any patent infringment.

Solar thermal and how I intend on using it.

         For the sake of simplicity, were going to focus on home scale air heating and will only touch on water heating. We will not be discussing electricity producing thermal systems or commercial concentrator systems. Those are fascinating topics for another article on another day. 

         Solar thermal collectors are very simple and don't have as much to them as solar PV, unless were talking about concentrator arrays and computer controlled or evacuated tube water heating. The panels rely on infrared light and as a result are not affected by cloudy days, moderate shade, or the like. They however do require daylight to work, that is to say they don't work very well at night. Though there are several designs from many manufacturers, my favorite designs are the DIY home built ones for both air and water heating. What I like the most about solar thermal is you can build your own for low to no cost using new or salvaged components. Though you can build your own PV panels, for the cost and carbon footprint in doing so you are better off buying them wholesale from a reputable manufacture. Really the only downsides thermal panels have are they don't work at night, as mentioned above, and in summer air units need to have their heat load dumped to avoid internal damage. For water heat, cold climates are problematic in that systems can freeze and suffer internal damage from expanding ice in the pipes and hot climates or summer heat can damage a system that does not have a large enough reservoir to dissipate its heat load. However there are many options to avoid damage while running the systems in extreme temperatures and climates.

          I intend on keeping the greenhouse a tropical environment year round, which in Colorado zone 5a is no small task. However Ive seen it done with a barn converted into a greenhouse in Colorado zone 4b and it's exposed on four sides plus the roof, my greenhouse will be earth bermed and have a living roof, leaving only the south glazing and the east entry door exposed. With all that thermal mass, not including the water in the aquaponics system as thermal batteries, I believe I can do it and keep the system for the most part passive. I plan on drawing the excess heat away from the PV panels with a home built thermal hybrid air system that will pump the excess heat into the ground below the greenhouse and into the ambient air in the greenhouse in winter. In summer the panels will draw cool air from a shaded area on the north side of the greenhouse through the ground below the greenhouse and through the panels which will evacuate out the roof of the greenhouse. I believe this will all be possible by thrermosiphon action alone, however I plan on using high velocity canister fans to increase airflow in the greenhouse in general, so combining them with the panels will stack functions. I contemplated using thermal water to heat the fish stock tanks in winter, however that would require somewhere to dump the heat load in summer when the greenhouse would be too hot to need water heating. With the earthen insulation and under floor air heating, there should be more than enough heat to warm the water in the stock tanks during the day while the water and thermal mass of the floor will heat the greenhouse at night.

 

The initial schematic with view of preliminary ducting concept for HVAC. This version has been modified for more accurate portrayal of the attached shed housing the chicken and duck coops, and rabbit hutch.

         Hopefully you are already seeing the benefits of combining solar PV with solar thermal. Not only would the thermal component capture the lost infrared light that passes through the PV portion, it also collects the excess heat and removes it from behind the PV panel helping keep the whole system cooler thus increasing electrical output and overall energy extraction. Using no extra space, the hybrid panels turn a waste product into a resource. This is stacking functions in true permaculture fashion. Whats more is this not just an ideal, its a reality already being utilized commercially.

         If this has piqued your interest and you want to learn more or maybe want to design and build your own system for whatever your purposes may be, I recommend checking out BuildItSolar.com and OtherPower.com. What I like most about them is that of all the text books and online resources Ive read, these websites have given me the best information for practical application of that amassed knowledge. You will find all kinds of projects where others have experimented, tinkered, designed, and built all kinds of different and innovative renewable energy systems.

         Ive not settled on a topic for next week, though I'm thinking seed starting since Ive got some already going and many more scheduled for the next month. If you have any suggestions, definitely send them my way. This diversion from my normal daily topics of conversation has been really fun and refreshing, I'm thinking I might do one of these more technology geared or non-Environment and Society geared articles per month to mix it up a bit. In any event, have a wonderful week and look for ways to make the world we inhabit a better place.

Why aquaponics is not a revolution in agriculture

         Welcome back! Last week we talked about water and drought, some of the problems we face, and most importantly, some easy solutions we can all implement to help regenerate local and regional water cycles. I go so far as to say with enough effort the world over, we can positively affect the world's water, carbon, and climatic cycles while reversing climate destabilization. If we can destabilize the whole planet, then we can repair the damage and reverse course, it's not too late to take meaningful action.

         This week, in response to an article I read and questions from friends, I want to get into dealing a dose of reality about aquaponics, or rather our global westernized mentality and how aquaponics, though revolutionary in itself, is not a revolution in thought and will not revolutionize agriculture. Only a systemic change in how we think about, interact with, and treat the world around us will accomplish that. Lets start with a basic description of what aquaponics is, how it's revolutionary in food production, and some of its applications. From there I will be able to describe how aquaponics fails to address mentality. I will end on the changes in mentality and actions that must happen before any agricultural revolution can take place.

My Experience

         You already know my story and progression with outdoor conventional and organic soil farming. I've also grown vegetables indoors for three years. I grew organically in soil and with both synthetic and organic hydroponics using deep water culture (DWC), nutrient film technique (NFT), and aeroponics. I've found that with a lot of labor input and energy, indoor soil can be competitive in both yield and growth rate with hydroponics, however that extra input mitigates those benefits as compared to the labor involved in hydroponics. On the flip side, I've never had a great tasting crop of anything come out of my hydroponics systems, they weren't bad they just weren't any better than what you get at the grocery. My soil systems, whether indoor or outdoor, have always produced phenomenally flavorful foods.

         I've seen and may attempt a hybrid system with cloth bags that are sub irrigated with what looks like an NFT setup, however I've stopped and do not recommend indoor growing of anything because of the resources consumed and the carbon footprint in powering the lights necessary for good crop yields. I do make exception for seed starting under florescent light to guarantee a long enough season for some crops , however the mercury vapor in florescent bulbs is a dangerous poison and the spent bulbs need to be taken to a reputable recycler for disposal. If I do build a setup to try the hybrid system, it'll have to be outdoors and seasonal only or, possibly year round in my greenhouse if it proves to be highly productive with low labor and few inputs. I'm concerned about how the soil media could affect my aquaponics nutrient levels and pH, I've read wood chips make a great hydroponics media and from experience growing outdoors in wood chip piles, I totally agree. However the varying chemicals in the wood could be toxic to the fish in an aquaponics system, this is where some of my concern for soil bags in aquaponics comes from. As well, I have concerns about mineral salinization of the soil since the bags promote growth and massive roots by means of evaporative capillary action. Time and experimentation will tell, now to the the bulk of the article.

 Aquaponics in a nutshell

         Aquaponics is the net positive combination of fish farming (aquaculture) and hydroponics, two very resource intensive and environmentally damaging forms of food production. Aquaculture produces high amounts of concentrated fish waste that needs to be disposed of regularly. If the aquaculture system is set up in natural bodies of water, the wastes pollute the local watershed and kill off most of the native species while contributing to large algae blooms. If the aquaculture system is in a sealed system, the wastes must be removed regularly, which requires more labor or mechanical input. The systems are poorly regulated and more often than not the wastes wind up in local watersheds or going down the drain, which overloads water treatment and increases the use of toxic chemicals for denaturing nitrogen and phosphorus and increases resource consumption while damaging local ecosystems. Some of the wastes end up in landfills, contributing to methane greenhouse gas production and not being used for beneficial agricultural uses while a very small percentage ends up being used as fertilizers for the home garden or industrial agricultural uses. All in all its horrible system that causes more damage than benefit. Aquaculture is short sighted and has far reaching implications that endanger the stability of ecosystems, dramatically affect climate, and contribute to lowering planetary habitability for all species including humans. Frankly it should be illegal in open water and strict regulations implemented for sealed and dry land fish farms.

Aquaculture illustration

         Hydroponics is growing plants, namely but not limited to vegetables and leafy greens in a water and nutrient solution, with or without an aggregate media. With hydroponics, you get significantly more root contact with nutrients, and significantly better yields than soil alone. As well, by comparison hydroponics requires significantly less maintenance and labor than gardening or farming in soil. I'm an advocate for deep organic soil, and though some soil techniques can compete with hydroponics, the scales are heavily weighted in favor of hydroponics for yield and speed of production. In addition, the recirculating water guarantees that about 1/10th of the water is used in hydroponics than in conventional gardening or farming, though drip irrigation gets soil gardening really close to being competitive with hydroponics on water usage.

Nice example of an easy to make diy NFT hydroponics system

         So where is the downside to hydroponics? Hydroponics is capital intensive and relies on chemical (organic or synthetic) inputs for its nutrient source and if you trace the products back to their source you'll find the deferred costs in fuel used, generated pollution, resources consumed, and ecological damage in the manufacturing and distribution of organic and synthetic chemical nutrients far outweighs the benefits of increased yields. To carry this further, synthetic nutrients noticeably taint the flavor the foods at best, and at worst remain in the foods and are toxic to human health and the environment. Organic nutrients, though generally not harmful to human health or the local ecosystem (in highly concentrated doses they can be however), tend to foul up hydroponic systems because they promote system colonization by beneficial bacteria that make the nutrients more readily available to the plants. This then creates considerably more labor and higher costs, mitigating the maintenance and labor benefits of hydroponics while producing a concentrated and potentially toxic waste product similar to the fish wastes in aquaculture.

         So if both systems are so bad in practice, how would combining them be any better? Simply put, aquaponics uses the fish wastes as the organic nutrient source for plant growth thus making use of an otherwise concentrated toxic sludge waste while closing the manufacturing and distribution loop of the nutrient source for hydroponics. In aquaponics, a healthy and vibrant biological community is necessary for proper nitrification of the fish wastes, thus reducing maintenance and labor by creating a need for bacterial communities that would be problematic in hydroponic systems. Aquaponics is an almost closed loop system with few inputs and low capital requirements, however the inputs must be considered in order to gain a complete picture of both the benefits and drawbacks to aquaponics.

  Illustration of simple aquaponics system and the nitrogen cycle

         One input and potential drawback is feed. Though you can produce supplementary feed on site such as duckweed in the aquaponics system or compost worms, meal worms, crickets, and black soldier fly larvae from food scraps, the reality is you will need to bring in feed from an outside source and must consider the carbon and ecological footprint (deferred costs) of that feed source. Another drawback is that aquaponics systems tend to run deficient in iron and can run deficient in potassium and other nutrients, thus requiring outside inputs and consideration of the deferred environmental costs of those inputs.

         As well, Aquaponics produces a small amount of potentially toxic or polluting undissolved waste solids that need to be purged from the system. However, the amount is small enough that they can be diluted and used as a nutrient rich and biologically active soil additive for home garden soils. Commercial producers should consider packaging and resale as a concentrated soil amending garden product. As well a bumper crop of prawns or crayfish can be used as biological water filters that eat a considerable amount of the solid wastes and convert them into more soluble nutrient forms. All things considered, aquaponics is a revolutionary shift in thought for both aquaculture and hydroponics with a net positive output as compared to its inputs.

          Aquaponics has both home and commercial scale applications on more of a continuum than a dividing line. That is, home scale systems can be a supplemental food source thus lowering living expenses and environmental impact per individual, or they can be large enough to produce all home food needs and a modest side income. Commercial systems can be small farm to mega plantation in size and scale. I believe every home and commercial rooftop (warehouses, office buildings, grocery stores, etc...) should house aquaponics outdoors or in greenhouses while mega farms should not exist as they are allergic to biodiversity and flexibility by design. This is a logical viewpoint for sustainable solutions to part of our food production system. However that's the ideal, what looks good on paper, not necessarily representative of western thought, industry practice, or general reality.

         Home scale production is a possibility for the majority of urban and suburban houses everywhere. As aquaponics becomes more mainstream and industry standards more prevalent, I believe this part of 'the ideal' could become reality. Year round rooftop greenhouse production of food is being proven by several companies in Canada and the U.S., and seems to be gaining momentum as the millennial generation is demanding more local and ethically run businesses. However, intensive decentralized production across urban environments is less likely due to varying degrees of bureaucracy and regulation in just these two countries alone. Bummer!

 Image: Great IBC aquaponics setup I plan on mimicing for my setup

You can download the IBC of Aquaponics from Backyard Aquaponics here.

The Backyard Aquaponics homepage is here. 

The revolution

         So now we have a quick snapshot of what aquaponics is, where it came from, and its applications. I've let my bias slip, I love aquaponics and I think it's a phenomenal low tech way of producing lots of healthy food in a small space with a low to neutral environmental impact. So how could it fail to revolutionize our waning agriculture industry? This is where were going to shift gears and take a look at our cultural mentality and industry practices when it comes to technology in food production and how they prevent any revolution from taking place. Were going to take a look into the history of our thought process and what it will take to revolutionize the way we approach food production and the world.

         Throughout the history of agriculture, reaching all the way back to the first seeds sewn in ancient Mesopotamia, population growth has always outpaced food production in agricultural societies. Check out David Mongomery and Jared Diamond for an in depth look into this subject. It basically breaks down to more food production or better technology allowing for higher yields will lead to population increases and not to greater food abundance. The addiction then begins when societies choose to either innovate new technologies or move to more fertile lands, causing the whole cycle of overtaxing land resources and population outpacing production to start over. It's a positive feedback loop that will always end in failure to thrive and demand new resources or technologies. This is not a natural state of being however, this is a mentality and thought process that negates critical thought about itself and fails to recognize the need to change thought and action in order to fix the problems it caused. It's a form of collective mental illness, insanity. As Albert Einstein put it, Insanity - doing the same thing over and over again and expecting different results.

         Enter scene: aquaponics, a revolutionary technology that has serious potential for producing more food with significantly lower inputs than current systems. Just like plowing was a technological revolution, and synthesized atmospheric nitrogen, and mined organic and mineral phosphorus, and deeper plowing, and mechanization, and so on. I hope you're getting the point, technological advancements have come to the rescue time and again while the prevailing beliefs in infinite resources and uncontrolled over-consumption have not been addressed. As we've covered, aquaponics is not without its downsides and not without its inputs. Simply replacing current technology with another without consideration to things like exponential population growth; resource depletion; linear lines of production, distribution, consumption, and waste; and so on, will only serve to perpetuate the systems and problems as they exist today. We have to be careful not to mistake the revolution in technology for a revolution thought, they are no synonymous.

         This all runs deep in the cultural mentality of Western societies and we are on the cusp of environmental and societal collapse worldwide. Change has to come by necessity, either revolution or collapse and natural systems don't care which. This is not to say we are destined for collapse or that our mentality about the world and everything in it is the sole cause, only that the path we are on as dictated by our collective mentality is headed in that general direction. However, there are many other factors that could exacerbate or mitigate this. One possibility is Bill Mollison's permaculture as an ethic and a life governing philosophy. We must think of everything as a cyclical system, every waste as a production for something else; every resource consumed has to be reusable or replaceable; in order to maintain planetary homeostasis (the ability to support life, including our species), we have to actively keep the world's systems in balance. It's a naturalist fallacy of logic to argue that natural systems innately balance themselves when disturbed, therefore non-action would be the best action. As a species we have cognitively separated ourselves from those natural systems and have actively damaged, destroyed, and destabilized them. The responsibility then falls to us, not the damaged natural systems, to repair and balance out what we have done.

         As much as I love aquaponics, it is not and will not be a revolution in agriculture because the revolution has to come in the form of the philosophy we keep and actions we take. Don't take my word for it, look at the world around you and question if it sustainable long term and what effect we are having on everything we touch. The science and research has been there for nearly a century now and the time for hiding behind our own cognitive dissonance is over. The time to take positive and meaningful action is now, really it was 40 to 50 years ago however there's never a better time for anything than the present.

         I've been talking a lot about environmental conditions, both here and in my daily activities. They're very important and have immense consequences for our futures no matter what course of action we take. However I want to get off this broken record train for a while. With that in mind, next week I want to switch things up and talk about solar power, specifically hybrid PV/T systems, as I plan on running my greenhouse aquaponics system on solar power and heating/cooling the greenhouse itself with passive systems or very low input from active systems like fans. I've been considering several setups and options, and this is where I think I'll settle myself when that time comes this winter to next summer. Have a wonderful week and look for ways to take daily action to improve the world we inhabit.