Efficient Energy Planning

Resiliency and sustainability of design will be gained by use of renewable energy sources. Techniques that harness sun, wind, water and biomass are diverse and small-scale but can be designed to effectively serve the needs of many sites. Efficient energy planning is intended to maximize the use of wild and site-related energies and minimize human and external energy inputs. Energy flow on a site is enhanced by intercepting and recycling the flow across the site. Solar energy is stored in plants and physical mass; water is held by ponds, plants and mulch; wind can be concentrated with building or plant placement. Energy is cycled as kitchen waste is converted to compost, animal manures to biogas production or soil enhancement, greywater to garden irrigation, green cover crops to green manure, and organic matter to mulch. The goal is to catch, store, use and recycle every energy source as it degrades across the site and is finally lost to us forever. 

The sources of wild energy may be determined as a starting point for a design. In doing an analysis of a site the directions from which the wild energies originate can be plotted. Certain slopes are receivers of the most intense solar radiation; winter or tropical storms may originate from predictable directions; prevailing wind directions are known. Simple formulas can be used to determine water volume and runoff under different storm conditions. Permaculture approaches such as zone and sector planning assist in the design of efficient energy systems.

Efficient energy planning is related to use of energy flow. Energy is either in storage or somewhere driving a landscape process. Lyle, in Regenerative Design for Sustainable Development , identifies six basic phases of ecosystem functioning (pg. 26-27). Driven by solar energy, these six connected processes are conversion, distribution, filtration, assimilation, storage and human thought. By understanding these processes we can optimize energy flows.

Energy flow is made usable by intercepting and recycling the flow of energy across the site. While no energy is lost in passage through the site, it is degraded from a concentrated to a more dispersed form. However, techniques can be used to concentrate energy in the short term for more efficient use on the site. There are numerous approaches to making efficient use of solar, wind and water energy.
	•	Solar energy is used by plants that convert light to biomass to be used eventually as compost, mulch or fuel. Water plants may be used to extract nutrients from the water. These plants may, in turn, be used as animal food or composted.

	•	Wind energy can be concentrated with tree or hedge plantings or building placement to increase the speed of the wind as it is forced into a constricted area. Towers can be used to draw wind into a structure for ventilation.

	•	Water running onto, through, then off of our site can be used to advantage. Elevation and water management planning is a well known permaculture technique. Water is stored in ponds or cisterns and its flow across the site is controlled for irrigation or power needs.