Remote Power, Communication, and Living Systems

Home ] Email PS ]

Up ]

Wind Generator Case Study

The following case study & pictures are from an Air-X 400 watt wind generator installation designed & installed by Pioneer Systems for a remote, wilderness cottage which is off-grid.

Historical Situation

The owner's cottage is located on Manitoulin Island, Ontario, Canada.  Manitoulin Island is the largest freshwater island in the world.  The public utility wanted $60,000 to install hydro poles & string wire for connecting the cottage to the grid; economically impossible for the owners.  Therefore the owners have generated their own electricity for the past 20 years using a 4 kW, gasoline powered,  110/220 VAC generator.  While the generator was cheaper than the grid tie, it was still expensive, noisy, and environmentally unfriendly.

The owners wanted a reliable, scaleable, ecologically sound, and economically feasible power supply for their cottage lights. The owners needed to explore alternatives, but didn't have the expertise to achieve their goal for cost reduction, greener living, and minimizing their ecological footprint.

Pioneer Systems Assigned Task
Pioneer Systems was asked to investigate alternatives that were ecologically and economically sound & feasible for the owners to have lights in their cottage each evening.

Pioneer Systems Actions
Upon interviewing the owners, and other investigations, Pioneer Systems learned that the cottage owners were located on the South Shore of Manitoulin Island.  Being on the waterfront of Lake Huron, the unobstructed wind and solar energy represented two excellent sources of energy.

Historically, the owners ran a 4 kW gasoline generator to power about 0.4 kW of electrical lighting each evening for about 4 hrs. on average.  At other times, the generator was used to run the well pump, and power tools. The electric lights each evening for 4 hrs. represented over 95% of the historical generator run-time for this cottage. The 4 kW gasoline generator is estimated to have an operating cost of  $2.00 /hr just for the gasoline.  For oil, maintenance, & depreciation, the total cost of operating the generator is estimated to be $4.00 per hour operated. When the generator is only loaded at 10% load (0.4 kW used when 4 kW generator is operated), this idling is very hard on the gasoline engine; resulting in engine fouling, higher maintenance costs, and shorter life expectancy.  The owners agreed that this had occurred numerous times over the past 20 years.

Since the cost of wind power is cheaper that photovoltaics (PV), it was decided to investigate wind power first.  The winds off Lake Huron are estimated to be as high as Class 5 (700 kW-hr/yr per sq. meter of swept area of wind generator's rotor, with an annual average wind speed of 14 mph).  The 24 VDC battery bank and DC-AC inverter should provide sufficient electricity to provide 4 hrs. of lighting for the cottage every evening on a continuous basis.  For periods with little or no wind, the battery bank will supply up to 3 days of power.  This assumed there would be no input from the wind generator for 3 days, while discharging the batteries from 100% full to 50% full.

Based on conservative design estimates, conservation, and high efficiency lighting inside the cottage, the owners were pleased with Pioneer Systems recommendations for design, cost, reliability, risk, upkeep/invisibility, and required lifestyle changes (energy efficient compact fluorescent bulbs instead of the incandescent bulbs used historically by the owners).

The system design depends on having at least Class 3 winds (605 kW-hr/yr per sq. meter of swept area, with an annual average wind speed of 12 mph) which should be exceeded over 90% of the time.  When exceptionally calm days occur, the generator can be run for a short duration during one evening to charge the battery bank while supplying lights for the cottage.

The beach area at the cottage site was rock & boulder glacial moraine of  0 ft to 3 ft. deep on top of the dolomite-limestone bedrock.  This represents a severe grounding and lightning protection challenge, as bedrock has a soil resistivity 10,000 times greater than damp organic loam.  A special design for grounding, static, and lightning protection was developed by Pioneer Systems.

Large sheets of ice, up to one foot in thickness can come off the lake and up over the beach area during winter storms.  Anything that is close to the beach must be massive (resisting the forces of the ice), or otherwise protected from the dangerous ice.  Pioneer Systems proposal was cheap & effective; and readily accepted by the owners.

Based on the Pioneer Systems' estimate of the owner's installed cost for the wind generator, it was estimated that the wind generator will pay for itself after 312 days of not operating the generator for 4 hrs. each evening just for cottage lights. For sites operating year round, this is less than 1 year payback on the investment in wind power.  The generator will still be run for the heavy electrical loads which occur less frequently, and represent the other 5% of the generator run time. 

Pioneer Systems had the role of doing the needs assessment, survey of electrical usage patterns, site selection, wind generator selection, detailed return on investment calculations to economically justify the system, and detailed system design.

The owners approved the design proposal of Pioneer Systems.  Pioneer Systems proceede to buy the required materials, the wind generator, tower sections, and equipment; all of which were delivered on-site.  The rock drilling was sub-contracted to a local driller for the anchors and ground rods.  Installation was done Pioneer Systems working hand-in-hand with the cottage owner over a 4 day period.

Day 1 was site survey for location of tower base, ground rods, and guy wire anchor placement; and excavation to the bedrock (where necessary).

Day 2 was rock drilling and installation of anchors, tower base rebar & cement, and grounding rods.

Day 3 was assembly of tower, guy wires, wind generator, electrical cabling from the wind generator to the tower base, and lightning protection.  Due to the high winds in the area, it was necessary to hoist at either dusk or dawn.  To ensure adequate lighting, we decided to hoist the tower early the next morning when it would be more calm.

On Day 4 at 07:00 AM, the hoist began.  The tower was secured to the anchors within the hour.  Guy tensioning, grounding, backfill of holes, and electrical connections were completed before the end of the day.  The generator was cycled through its operating modes to ensure it was operating properly.

Results Achieved

The owners are pleased with the installation overall,  how it looks, and the power that is generating.  Adequacy of the design and the elimination of excessive & expensive generator run time will only be proven over time.  Pioneer Systems will monitor the installation after 1 week, 1 month, 3 months, 6 months, and end of the first year to ensure all is operating properly, and the owners satisfaction continues.

Completed wind turbine installation on Manitoulin Island
The installed wind generator on the 45 ft. tower, with the proud owner at the base.
Looking up the 45 ft. wind generator tower
Looking up the 45 ft tower, we can see the electrical box at the base, and the two sets of guy wires at 24 ft. and 42 ft elevation
Base of tower with lightning protection & generator output
The tower base showing the electrical junction box and lightning protection system.
Wind turbine tower, guy wires, lightning protection, & generator
A close-up view of the top end of the 45 ft. tower, the guy wires, lightning protection, and the wind generator on top.
© 2001 Pioneer Systems       Original Version: May 17, 2001       Current version: 27       Sept. 14, 2003

2001-2009   Pioneer Systems   All rights reserved.  All other material owned by their respective copyright holders
Page Last Modified:   04-May-2009 05:45:36 PM -0500