The windmill will produce energy for the household, powering things like their TV and computers. To take advantage of the excess electricity it will produce, it is  tied to the electrical grid of their utility company (Platte-Clay Electric). When more power is generated than the family can use, they will sell the electricity back to the utility company (this is  referred to as net-metering). 

While they love the idea of selling electricity back to the utility company, reducing their reliance on traditional fossil fuels is very  important to this family. They will do both, in addition to reducing their electric bills.

The Evance 5 kW windmill is on an impressive 60 foot pole (mono-pole). We placed it about 250 feet from the home.

2.4kW Skystream wind turbine from Southwest Windpower

Wind energy has been used for thousands of years to pump water, mill grains, and move ships across lakes and seas.  Windmills became a fairly standard fixture on farms across rural America during the 20^th century.  Eventually, the windmill was used to generate electricity, and ultimately gave birth to more modern wind turbines in the 1980's.  Since then, dramatic advances in the efficiency of wind power production have created tremendous opportunity for use in residential and commercial applications.

The United States initially took a lead in the development of wind turbines, but the wind power industry in Europe established much higher gains in terms of the percentage of power provided by wind.  According to the 2008 World Wind Energy Report, the US has reclaimed its position to boast the largest installed windpower capacity (25,170 megawatts), but the energy produced from wind represents only about 1.3% of our total consumption.  This remains tiny in comparison to Denmark, with 19%, Spain and Portugal with 11% each, and Germany and Ireland with 7% each.  In the US, it is estimated that three states alone, Texas, Kansas and North Dakota, have enough wind power potential to supply the entire country's current demand. 

 While the wind may come and go, it is by and large very predictable and reliable.  The American Wind Energy Association provides wind maps that show general trends.  Another source, FirstLook, provides more detail readings for specific areas.  You can select a point on the map to get an estimate of the average wind speeds for that area.

To get reasonably good power production, you should have a minimum of 10 mph average winds, though 12 mph winds produce a substantial increase in power production.  Within a given area, a flatter topography with fewer obstructions (like a river valley) posess higher winds than hilly or forested lands.  The Griggs-Putnam Index can be used to look for prevailing winds by observing deformities in vegetation.  In windier areas, you'll see an imbalance in the growth of tree branches, with a greater proportion of branches leaning downwind.

Another consideration is turbulence.  Obstructions that redirect the wind flow will create a spinning effect, which adversely affects the performance of the wind turbine.  With this in mind, a rule of thumb is to mount the turbine on a tower 20 feet higher than any obstruction within 250 feet.  The picture below illustrates wind flow, turbulence, and how different tower heights fit into the flow.

It's important to minimize turbulence when selecting a site

The Skystream 3.7 wind turbine (pictured above) is a very popular turbine due to its all-inclusive design.  The unit is intended to be used as a grid-tied solution - supplementing existing electric power from the local utility.  The inverter, which converts DC power to the AC power that most appliances use, is housed in the turbine itself so the output is easily streamed into the existing electrical system.  The turbine has a power* rating of 2.4KW, which means it is capable of producing 2.4kW of power at its peak performance, with 29 mph winds.  In typical 12 mph winds, the system will produce roughly a third of the average home's electric needs. The installed price, without financial incentives, starts at about $15,000.  Read about sample Skystream installations>>

For smaller off-grid applications, such as in cabins, trailers and boats, a battery-based system is ideal.  The Air-X wind turbine is a 400W turbine, designed to charge one or more batteries to run lights and other DC-based appliances.  The battery power can also be converted to AC using an inverter.  This turbine will produce 38kWh per month with sustained winds of 12 mph.  The installed price without incentives starts at about $2,500.  Read about sample Air-X installations>>

In urban settings where the built environment results in increased turbulence, vertical-axis wind turbines can be more effective.  Traditional wind turbines spin on a horizontal axis, parallel to the ground.  Vertical axis turbines, on the other hand, spin around the tower itself, and are less susceptible to turbulence.  The Mariah Windspire is a 1.2kW wind turbine that can be easily incorporated into a residential or commercial setting.  The turbine produces approximately 166kWh of power per month in 12 mph winds.  The installed price before incentives are applied starts at $10,000.  Read about sample Windspire installations>>

Wind is a rich, clean, abundant source of energy, and if you are blessed with sufficient resources to benefit from this gift, please be sure to consider the worthwhile investment.  In the past, people have been quick to curse the wind, but now many are smiling upon their newfound fortune!

4.8kW solar PV system and 1.2kW vertical-axis wind turbine are sole energy source in off-grid home

In a modest neighborhood near the Kansas University Medical Center, a new trend-setting home is generating almost all of its energy from solar and the wind.  The home was designed and built by Dan Rockhill and his students from the University of Kansas.  Studio 804, the university's sustainable architecture program, is known for forward-thinking designs with emphasis on energy efficiency and sustainability.  Students worked tirelessly since January to complete the construction of this eco-friendly home, and are seeking the coveted LEED Platinum for Homes certification for their efforts.

The 2600 square foot house, located at 3716 Springfield in Kansas City, Kansas, includes a plethora of energy-saving features.   The home starts with thicker walls filled with recycled newspaper to form a tight building envelope.  The argon-filled windows complement the structure by minimizing heat transfer and maximizing natural daylight.  To further reduce heating and cooling costs, which are by far the biggest guzzlers of power in a typical home, a geothermal heating and cooling system was installed.  This system uses the constant 58 degree temperature of the earth to cool the home in the summer with no air conditioning, and requires minimal energy to heat the home.  The concrete ground floor absorbs the warmth of the sun in the winter afternoons and stays warm into the evening.  Inside the concrete floor are a series of pipes that carry hot water to provide additional heat when needed.   In addition, the home makes extensive use of other energy misers, including LED lighting and Energy Star appliances.

With all these energy-saving features, the home uses very little electricity compared to a typical home, and generates most of its own power.  The 4.8kW solar PV system produces the majority of the electricity, with 24 Canadian Solar photovoltaic panels built into the rain screen that forms a pressure buffer between the home's interior and exterior.  An additional 1.2kW of power is generated by a 24' Mariah Windspire vertical-axis wind turbine located in the backyard.  Studio 804 is pushing the public utility to adopt net-metering, which would enable the home to provide clean, renewable energy onto the grid.  All of the work on the renewable energy systems was done by the students with guidance from The Energy Savings Store.

The home has many additional features which may help it achieve the LEED certification.  Faucets and toilets minimize water use, and low VOC finishes were used to provide a clean and healthy living environment.  The interior framing was salvaged from a building slated for demolition, and the exterior wood used in the rain screen was made from Brazilian hardwood that was certified as coming from a sustainably harvested forest.  The driveway is made of a porous concrete that absorbs rainwater, and runoff from the roof is collected in an underground cistern to water a garden.  The rest of the home's landscape, which was built on an empty lot in an existing neighborhood rather than a new suburban lot, features native plants that don't require anything more than rain.

Studio 804 staked a major claim to fame by building the first LEED Platinum building in Kansas last year.  The 5.4.7 Arts Center in Greensburg, Kansas was built as part of the town's restoration on the first anniversary of the tornado that devastated the town in 2007.  The 22 students on this year's team were empowered by Rockhill to make important design and building decisions in a democratic manner. Grants and donations pay for materials, but students provided free labor.  If the home were commercially built, it would likely sell for $500,000, but is listed at a very attractive $349,000.

The students have demonstrated remarkable prowess in designing and building this model for sustainability.  Undoubtedly this will inspire others to adopt similar building fundamentals and techniques.  For more information on all of the features of this eco-friendly home, check out additional stories in InkKC or KansasCity.com.

Solar and wind systems provide significant returns when rising rates are taken into consideration

While many people love the idea of using clean, renewable energy from the sun and wind, they find the investment significant enough to think twice about the purchase.  The installed cost of a mid-sized wind turbine or solar photovoltaic (PV) system is about $20,000, and does not provide the same visibility or utility as a new kitchen.  However, while a new kitchen provides a great new space to cook and congregate, and will bring back nearly every dollar invested if the house is sold soon after, it loses its value over time. The renewable energy systems, on the other hand, become cash cows that actually increase in value as energy prices rise.

A simple payback will show you that the money you initially invest in the system is offset by the value of the energy produced over time.  This becomes a little tricky, because we know that energy prices will rise, but can't predict actual rate increases without a crystal ball. Historical rate increases over the past 10 years or so have been about 4.5% per year, although this varies widely across the country.  Over the next 20 years, we expect rates to increase 6-9 percent per year, given supply pressures on fossil fuels and imminent carbon taxes.  Just like the miracle of compounding interest, the compounding effect of rising electric rates results in the system returning 1.5 to 3 times its initial cost.

While the life expectancy of a solar PV system is generally 40-50 years, we typically look at 30-years of operation to calculate expected returns on both solar and wind.  (Wind turbines require maintenance, and the turbine itself can be replaced with a more efficient unit at a fraction of the cost of the original installation.)  The chart below shows the value of the electricity produced over a thirty year period.

Estimated value of power produced by 2.4kW solar array*

*Assumes $0.09 p/kWh with 7.5% annual inflation on electric rates for 2.4kW solar PV system

Our February newsletter summarized the highlights of the American Recovery and Reinvestment Act of 2009.  With this legislation, the 30 percent tax credit for commercial and residential renewable energy investments was extended through 2016, and the $2000 cap was eliminated.  This tax credit effectively creates a 30% discount on all solar and wind installations, reducing your investment accordingly.  (For commercial projects, you can apply for a grant up front in lieu of the tax credit.)  Additionally, the state of Illinois offers a 30% state tax credit for solar, and is considering extending this to wind power also.  Historic tax credits of up to 25% are also widely available, depending on the area.

Finally, the recently passed Proposition C in Missouri will require that utilities produce 15% of their total demand with renewable energy.  The Public Service Commission is currently finalizing the rules, but at this point it is agreed that the investor-owned utilities (including AmerenUE, KCP&L, and possibly Empire)will  provide a taxable rebate of $2 per installed watt (up to 25kW).  In addition, they may buy Renewable Energy Credits (RECs) based on the amount of electricity produced by your system.  It is anticipated that the value of this taxable income would be similar to the rebate ($1.80-$2.20 p/watt) but this will likely be paid out over time as the energy is produced.

So the 2.4kW system described above might look like this:

* Actual figures are contingent upon the finalization of rules. Prop C rebates will go into effect January 1, 2010.

Using the assumptions above, the system will have produced a total of $4,400 in electricity in its 12th year of service, thus paying for itself.  However, in the 18 years after it's paid off, it will produce an additional $23,500 worth of power, yielding an internal rate of return of 11.7%.  Businesses will achieve even greater returns by depreciating equipment.

In spite of this return on the investment, for some people, this long of a payback is troubling because they may not intend to live in the house that long. The truth is, that, just like the kitchen, an investment in a solar or wind energy system will add to the value of the home, with a higher return than a kitchen or bathroom renovation.

While the return on your investment may not match some of the historic returns of the market, you can be sure that it will be much less volatile.  Probably more important than anything, you must place intrinsic value on producing your own clean, renewable energy.   As one of our customers put it, "No one ever expects to catch enough fish to pay for their new bass boat!"

Farm house has solar PV on the upper roof, and solar thermal (for water heating) on the lower roof

The Green Dirt Farm, located just north of Kansas City in Weston, Missouri, is a small community-based farm dedicated to producing healthy food in a sustainable environment.  The entire farm complex was designed to be a net-zero energy farmstead, producing 100 percent of the energy for the operation using a combination of solar and wind.  Chris DeVolder, the home's architect, calls it "the greenest house in the Midwest, possibly in the country."

From the ground up, this farm was built with sustainability in mind.  Most of the materials used in the construction were salvaged from local demolished buildings (including a reclaimed church railing as the rail in the loft of the barn!)  The designers largely limited themselves to these materials, and any new materials used in the home were considered environmentally-friendly.   It was a true collaboration between owner, architect and builder.

The house uses only 25 percent of energy required in a typical home of its size, and uses no fossil fuels to heat or cool. This is accomplished in part using a passive solar design that shades the home from the sun in the summer but absorbs the solar heat in the winter.  Complementing this is a geothermal heat pump, with radiant heating system in the floor.  In addition, the home uses a small word-burning masonry heater as a back-up heating source, and doubles as a Swedish oven for bread-baking.

2.4kW Skystream wind turbine provides half of the power used on the farm

The Energy Savings Store was selected to design, engineer and install the renewable energy systems used on the Green Dirt Farm in 2005.  The electricity used in the home and barn comes from a 2.4kW Skystream wind turbine, perched atop a 70' tower.  Complementing this is a 2.4kW Uni-Solar PV laminate system on the home's metal roof.  These two energy sources, coupled with the efficiencies designed into the home, enable the owners to live and operate their farm with a "net-zero" energy requirement.  The home is actually connected to the utility grid, so that in the event that more power is consumed than produced at any given point in time, the system can draw additional power from the grid.  On the other hand, when more power is being produced than consumed, the utility meter spins backward, pushing the excess electricity out onto the grid.  The home also contains a battery backup system, so that in the event of power outages, they can run safely on their own backup power.

Solar thermal energy is also used to heat the potable water in the home.  A 5kW SunEarth glazed panel solar water heating system was installed by The Energy Savings Store to heat water in a 120 gallon tank, enabling the owners to use very little energy to heat water used both personally and in the farm operations.  Solar water heating systems typically reduce energy use by up to 80 percent.

Finally, solar energy is used for space heating in another small building on the farm.  Several years after the home was built, a small cabin was built on the property to house the farm's manager, and the owners came back to The Energy Savings Store for guidance.   The house was designed with a south-facing wall, on which a 1.5kW SolarSheat solar air heating system was installed.  This glazed panel system is self-powered, using a small photovoltaic (PV) panel to power a fan that draws air from the bottom of a room up through a heated-duct and back out the top into the room.  The panels are ideal for a south-facing wall on a great room, but can be installed on a south-facing roof as well.

The Green Dirt Farm owner's commitment to healthy, organic food and a sustainable living gives us a great model for home development.  Everyone involved in the project shared and realized the same vision, and now the path has been cleared for others who wish to create a sustainable, environmentally friendly living space.

Skystream wind turbine captures clean, renewable energy near New Town farmhouse

New Town, a mixed development of residential, retail and commercial, is a planned community with an emphasis on green living.  The entire 750-acre tract of prairie land was optimized to promote a five-minute walk anywhere within five neighborhood centers.  Homes are all built near lakes and canals, specifically designed to capture stormwater runoff from the entire development.

The community includes neighborhood parks, restaurants and markets, where you can walk or bike rather than drive.  Food is locally produced on an organic farm, powered by a wind turbine installed by The Energy Savings Store. The 2.4kW Skystream wind turbine sits atop a sleek 45' tower, generates about a third of the farmhouse's energy requirements.

Be sure to check out New Town for a look at clean, renewable energy in a decidedly green community!

New Town is located about 40 minutes from St. Louis, Missouri. The Energy Savings Store provides solar energy and wind power solutions throughout Missouri, Kansas and Illinois.