Why permaculture: Energy descent, solar case study
This is the second solar electric home we have had. The first was off the grid at 11,300’ in Telluride, Colorado with batteries and a backup propane generator. Restoration Farm in Ashland, Oregon is grid-tied and has three tracking arrays. We are net metered with Pacific Power and pay additional power we need beyond what we generate. The farmhouse is heated with a masonry wood-burning stove and the barn loft apartment with propane. One dwelling cooks with electric and the other with propane. Otherwise we do not have large electric draws beyond lighting, refrigeration and computers. System installation cost was $50,000 of which 92 percent was paid for a collection of grants.
Solar Power Generation Deficit
What I am finding is that a solar electric system, despite having three solar arrays does not cover the energy needs of our farm. The chart below shows this year’s actual power use vs. what we generate. This chart would be more favorable in the southwest four corners area of the U.S. where we used to get 300 sunny days per year. But in the Pacific Northwest and other parts of the country where we have largely cloudy winters, we use up any surplus generated during the summer and the system runs in a deficit. Note how the green kwh generated line only rises above usage for about three plus months. The end of the year is shocking as generation drops off to almost zero and energy use rises just from electric space heat.
Manufacturing Costs Never Recovered
The above discussion even ignores the energy used to manufacture the solar equipment, transport and install it. This indirect energy investments will never be recovered through electric generation surpluses — which is actually a net energy loss. Howard T. Odum, in his book A Prosperous Way Down: Principles and Policies, calls this concept of energy analysis which considers all embedded energy costs Emergy with an “m”.
The photo to the left shows the inverters and breaker box required in additional to the solar arrays themselves. All of these components require a tremendous amount of energy to be manufactured in separate plants around the world, then integrated into one system.
Every alternative energy solution is manufactured with fossil fuels. Without fossil fuels there are no alternatives; renewable power is not renewable once fossil fuels are gone. Look at the alternatives as transitions back to what once worked.
Permaculture – Photosynthesis is the Only Answer
David Holmgren, co-originator of Permaculture, notes in his book Permaculture: Principles and Pathways Beyond Sustainability that, “It may be that the natural conversion of sunlight to electric charge that occurs in all green plant photosynthesis after one billion years of natural selection may already be the highest net Emergy possible.”
That is the point, nature has spent literally three billion years developing life on earth that must rely solely on local sunlight and ecosystems to store and circulate that captured solar energy. Once we burn the last economically recoverable stores of ancient sunlight, we will be back to living off of current local sunlight.
The Transition Generation
This generation is probably the or one of the last fossil fuel generations. Our children or theirs will be the transition generation from stored ancient sunlight back to present local sunlight. Remaining fossil fuel reserves are probably best used for permanent infrastructure projects — use a tractor today to swale your property, build a water farm storage pond or developing and urban gravity water system. We need new energy descent tools — a hand crank flour mill or nut huller is more useful than an electric one when the power is out. You get the idea.
We also need exponentially more small farms, permaculture teachers and a completely re-tooled education system to prepare students for the bright, more sustainable and thriving low-energy future.
Low Energy Permaculture Systems
A well designed permaculture homestead or community can rely largely on local sunlight for food production, fertility renewal, heating, cooling, water, and trombe power tools and refrigeration systems. I have plastic greenhouses that are warmer during the day than my modern house with R-30 insulation. Good design is everything. I got up early this morning to dial in my solstice sunrise and sunset compass which I hope to use for a far more energy efficient dwelling in the future.
Like an ecosystem, integrated or holistic systems take the least energy to maintain because the output of one element is the input of the next element. In permaculture we put energies and resources that enter our systems to as many duties as possible. We can make 10 inches of rain per year do the work of 100 inches. Permaculture designs get out of nature's way and allow succession to continue without holding it back with fossil fuels. We stack functions and thereby increase yields and fertility.
Call this the teaser trailer for permaculture as in permanent-culture. To learn more about low-energy permaculture system design, take a Permaculture Design Certificate (PDC) course at your local independent permaculture institute.
Chuck Burr is the author of Culturequake: The Restoration Revolution. He is a farmer, educator and founder of the Southern Oregon Permaculture Institute (SOPI) and Restoration Farm in Ashland, Oregon. He serves on nonprofit boards, was a software CEO, interned for President Reagan and has an MBA. He has been a traveler, mountaineer, rock and ice climber. [email protected]
1) Chuck Burr argues that because he has not installed enough solar power to meet his needs, he CANNOT install enough power. (His main problem, actually, is that he is using electric space heat, although somehow in the first paragraph he leads the reader to believe that his buildings are all wood heated.) 2) He states "The above discussion even ignores the energy used to manufacture the solar equipment, transport and install it. This indirect energy investments will never be recovered through electric generation surpluses". He states this as if it follows from his experience with solar, but that's completely illogical. He presents no empirical evidence to back up the claim. He fails to even make a simple "price-as-proxy for EROEI" argument. There have been various studies about the EROEI of PV solar, and there is much room for debate, but most estimates are in the range of 3:1 to 8:1. Energy Bulletin has posted articles on these estimates in the past.EB co-editor BA responds:
As Joel points out, a key problem is the use of electricity to produce heat - a very wasteful use of electricity. The article itself is ambiguous in that it says that electricity is mainly used for computers, lighting and refrigeration. However, the article also mentions electric space heating and electric cooking. So, item number one would be an inappropriate use of electricity. Or at least, Burr should not be surprised when electricity usage goes up in winter. About EROEI. This is a sticky one. Early on, I remember claims (by Odum or Holmgren?) that PVs would never pay back the energy used in their manufacture. A researcher wrote and said that this was no longer true for more recent PVs. I think I've seen EROEI figues like the ones Joel mentions. In a way, it is a moot point. EROEIs are hard to calculate, beyond a general order of magnitude, and they really don't enter into the decision of individuals whether to install PVs. More relevant considerations would be cost, payback period, and ease of repair/maintenance. I was surprised that 92% of the cost of the PVs was covered by grants. That rather changes the cost/benefit analysis!-BA
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