Energy presentation for the Ecology week of Ecovillage Design Education course taught at Stellenbosch, Cape Town, South Africa, in 2012

1. Day 3: INFRASTRUCTURE, WATER
and ENERGY

2. 3.1 INTRO
• Permaculture Bingo
• Appropriate technology
• Energy

3. Appropriate technology
• Low cost
• Long lasting
• Locally produced
• Low embodied energy
• Low maintenence

4. Low embodied energy
• Solutions found and implemented at lowest
possible energy-use levels
• This means “don’t use a sledgehammer to
crack a nut!”

5. Low maintenence
• Maintenance = work that WE have to do (or
pay someone else to do).
• As much as possible, we should design
maintenance OUT of the system.

6. Energy: Summary
• What is energy? What is energy power?
• What is the status of the technology?
Comparison
• Can we store energy?
• Reduce, conserve, design!
• Village-scale energy potentials and solutions
• Energy and mobility
• Measuring ecological footprint and design for
carbon neutrality

7. What is energy? What is energy
power?
Forms of energy that we use:
•Mechanical
•Chemical
•Electricity
•Heat
•Light
They are all interchangeable
LOSSES: Energy is lost when we convert from one form to another (usually as
heat). All energy comes indirectly from the sun.
POWER is the ability to do work: a measure of energy. The more power, the
more work can be done.

8. Mechanical
• Direct drive water wheel (e.g. corn mill or
sawmill)
• Brick press (human provides the energy, but
the lever provides a mechanical advantage)
• Direct drive wind powered water pump
Less losses than if we generate electricity and
use electric pumps or grinders.

9. Chemical
Usually an energy store that is released when
we use it.
•A battery (used to generate electricity)
•Wood in a tree (burned in a fire – heat+light)
•Food! (Perhaps this is the most important and
fundamental form of energy of all, from our
point of view)

10. Electricity
• Can be generated from many of the other
forms.
• Is a very useful and versatile form of energy to
have, but often is gained through an
inefficient process (lots of losses)
– Coal power station is only 35% efficient at transferring the
chemical energy in coal to electricity.
– Solar panel is <20% efficient at transforming solar
radiation (but that’s OK because sunlight is abundant).

11. Heat
• Cooking
• Space heating
• Hot water
• Increasing crop growth (greenhouse or
nursery)
• Generating other forms of energy (e.g. steam
to drive a turbine)

12. Solar water heater made from recycle milk
cartons and plastic bottles

15. Aluminiu coated “tetrapak” milk cartons are painted black and put
around water pipes passing through tubes made from staked plastic
bottles. No pump is required as the hot water rises to an inlet in the
top of the roof-mounted HW tank, drawing in cold water from the
bottom of the tank to the inlet at the bottom of the solar collector

16. Light
• Use natural daylight in buildings as much as possible instead
of electric light
• Separate solar-powered low energy LED lighting systems
(using daytime sunlight at night)
• A key element for plant growth (chemical energy production
in biomass).

17. Solar Bottle Lights
• Youtube video links:
• https://www.youtube.com/watch?v=bLg-K97sWxA
• https://www.youtube.com/watch?v=kHTD_RX3J2I
• https://www.youtube.com/watch?v=SBWi3NtND6
• https://www.youtube.com/watch?v=p3ccUgbTPIc

18. What is the status of the technology?
Comparison
• Fossil fuels
• Solar
• Wind
• Biofuel
• Gas
• Hydro

19. Fossil fuels
• Peak oil
• Climate change
• Fossil Fuel Dependency
10 calories oil used to produce 1 calorie of food (from
industrial system). This is a MASSIVE energy DEFECIT.
In economic terms, this is the road to bankruptcy.
We must design systems that create an energy
SURPLUS.

20. Peak oil

21. Peak oil
As well as increasing fuel and transport costs,
this will have a direct effect on products with
high embodied fossil fuel energy.

22. Climate change
• Increasing instability
• Unpredictability
• Every year local extreme records are broken
(hottest, wettest, driest, coldest…)
• We MUST design more flexible, resilient
systems that can survive weather extremes
and adapt to rapid change.

23. Solar
• Photovoltaic (PV) for electric
– Expensive, but price is coming down as global production volume
increases and technology and efficiency improves (average global cost
per W of PV power installed is decreasing). Good investment if you
have the capital.
• Solar hot water
– One of the most cost-effective and useful
renewable technologies.

24. Solar cooking
• Can be simple and low tech…

25. Solar Cooking
• Or high performance low-tech

29. Wind
• Small turbines can be good, but YOU MUST
HAVE THE RIGHT LOCATION!
• The power in wind increases with the square
of the speed. >7 meters per second is
minimum to be worthwhile.
• Larger turbines more efficient.
• Balance out well with solar in a hybrid system
– Use same batteries and charge controller etc
– Often windy when no sun

31. Biofuel
• Very bad from industrial monoculture (e.g.
palm oil plantations)
• Can be good from permaculture systems
– Co-product that does not compete with fuel
– Grown on waste
– Not using a food crop to make fuel
– Using a multifunctional element, such as…

32. • Bulrushes: Typha sp.
• More that 30 times higher potential fuel
alcohol yield per hectare than sugar cane!
• Can be grown in our community sewage
treatment system as it also cleans the water.

33. Design for a
“Biorefinery”
cosmetics
factory in Brazil

34. • Simple core
process (in
this case
“Biorefinery”
is the
cosmetics
factory)

35. Gas
• Highly convenient, but fossil gas becoming
more expensive (see peak oil)
• We can MAKE our own – biogas digester.
• This can be beneficially connected to many
other elements.

36. Hydro
• Can be done at the small scale.
• Can be used to generate constant electricity
with no batteries needed (if flow is steady).
This saves money and energy.
• Water PV pumped to high dams can be used
to generate electricity when no sun.
• You can generate as you irrigate your crops
below the dam.

37. Dams… Development?
Poverty alleviation?

39. Reduce, conserve, design!
• First we must design to reduce energy
consumption. This is more efficient than ANY
form of generation. (Passive Design!)
• Second we must use the simplest and most
appropriate form of generation.

40. ROCKET STOVE
• Haiti Rocket Stove Design Website

42. • Principles the same but design
can be very different and
versatile, according to available
materials.

43. Rocket Stoves in Malawi
• https://www.youtube.com/watch?
v=sh5EYVuKFEg

44. Rocket Stove Kitchen
• https://www.youtube.com/watch?
v=VypiS5X31aA

45. Village-scale energy potentials and
solutions
• Biogas
• Managed fuelwood forest
• Ethanol/ biodiesel
• ENERGY CAPTURE AND CYCLING

46. Biogas
• Many different types of systems, to suit
different climates, feedstocks and other
requirements.
• Excellent for centralised community-scale
energy production.
• Vehicles can be run on biogas. You can power
your car on poo!

47. Managed fuelwood forest
• Wood is a very sustainable fuel if it is
managed correctly and not overharvested
• Cook on smallwood/fallen branches, coppice,
not timber from cut trees. Don’t burn your
building materials!
• Nitrogen-fixing pioneers (improve soil for
main crop)
• Grown in waste stream (sewage treatment)
e.g. wattles (Salix sp.) or bullrushes (Typha
sp.).

48. ENERGY CAPTURE AND CYCLING
• Source to sink diagram
• Constructed wetland sewage system
producing biomass fuel and building materials

49. We aim to catch and store energy
Source
Hold all energy flows on the site for as long as
possible and make them do work for you.
(When they reach the sink, we can’t use them any more).
Sink

50. We can make them take a longer,
Source
slower path, touching more
elements, doing work and creating
stores on the way through
“Sink”

51. Constructed wetland sewage system
producing biomass fuel

52. Energy and mobility
• Reduce dependency on fossil fuels where
possible
• Bike and animal transport (more feasible
within community on car-free roads).
• Alternative vehicle fuels – biogas, biodiesel,
bioethanol.

53. Measuring ecological footprint and
design for carbon neutrality

54. Measuring ecological footprint and
design for carbon neutrality
• Consumption of...
– energy
– biomass (food, fiber)
– water
– other resources
– and processing of waste
• Converted to global hectares (gha)
• Online calculators
• In 2006 biologically active area of earth available per person was 1.8 gha
• Shows that some lifestyles are unsustainable, living past carrying capacity
• Methodology and assumptions based on mainstream society:
overconsumption and industrial production of goods and services
• Permaculture changes these assumptions (resources produced for less
gha)

55. Online calculator for S.A.
• http://www.footprintnetwork.org/en/index.php/g
• You can go online and calculate your
ecological footprint by answering a
questionnaire

56. In 2006 biologically active area of
earth available per person was 1.8 gha
• American EF was 9.0 gha per peson
• Switzerland was 5.6 gha
• China was 1.8 gha
Shows that some lifestyles are unsustainable,
living past carrying capacity

57. But…methodology has
assumptions
It is a good place to start, but assumes…
•Business as usual Monoculture etc
•Permaculture = Doing more with less, so we can reduce our
footprint further by increasing efficient design of our supply
systems, not just reducing consumption.
•This is how everyone on the planet can have a dignified and
developed standard of living. But we need to get back within
limits (more of a concern for the over-developed, energy-obese
west, but also for fast developing countries).

58. Past the point of “enough”, consumption does
not improve welfare