Technology just keeps improving as more consumers are looking for alternatives to traditional sources of electricity. One company is stepping up its efficiency by integrating their vertical wind turbines with solar photovoltaic panels to level out natural peaks and valleys in wind and solar energy.
We spoke with Joel Smith, a business development partner for New York City-based Urban Green Energy. An OEM maker of vertical turbines, Urban Green Energy has developed a workable, quiet, energy alternative that works very well in both urban and rural environments. As part of their development, they’ve found that by integrating a solar photovoltaic grid in addition to the wind turbine, homeowners can maximize the available energy to power domestic energy requirements.
“We started out early on in the design to balance the aesthetic and efficiency while paying close attention to the engineering going into the turbine design,” Smith said. The vertical turbine has blades that each “travel” the same distance from the hub (unlike propeller bladed turbines as explained below). The blades are mounted on bearings at the top and bottom of the turbine hub, which distributes the load evenly along the central axis. The vertical turbines also have a smaller footprint because they capture wind energy in three dimensions rather than the two dimensions that a propeller-type of turbine does.
Some of the issues that residents have had with traditional bladed turbines are noise and light disruption. The industrial-scale wind turbines that feature large propeller blades, create sound because the blade tips travel a longer distance than at the hub. The visual effect is created when the large blades cross between the viewer and the sun, creating a moving shadow visible to close observers.
UGE’s vertical turbine tests out at a 43dB, which is slightly lower than a normal conversation heard from a few feet away (53dB). A vertical turbine casts a much smaller shadow than a propeller type turbine, because its wind gathering aspect is more compact in three dimensions, and as a result produces little visual effect.
Wind and solar assessment
It’s important to have an assessment made of the wind and solar power available to your individual site. As a preliminary assessment, homeowners can look at the average wind speed at their location. The minimum wind speed for power production with a vertical wind turbine is approximately 6.5 mph, though the typical wind speed that Smith looks for at a site is 12 or more mph. “Nonetheless,” he added, “the saying of ‘the more wind the better’ always applies.” Some geographic locations feature “pockets” of more abundant wind that can be tapped by turbines.
Urban Green Energy will provide a free computer assisted wind analysis for the physical location of the building envelope. If this preliminary analysis seems to indicate the feasibility of a wind turbine, UGE will work with a local agent to further assess the site. The costs for this assessment will be deducted from the ultimate equipment and installation costs. Smith says that while most of their projects are retrofitting, having the opportunity to assess the location and construct the infrastructure needed offers some cost savings and can provide a more integrated installation. For example, while doing normal site work for foundation or septic the excavator can be directed to dig the area where the turbine tower footings would be located at no extra cost. Additionally, the site can be optimized through selective cutting to enhance the wind conditions present on the site.
Some municipalities restrict placement and height of wind turbines, and Smith says the local representative can assist in the permitting process. Location of the turbine tower can be near a garage, or mounted on the roof, provided the wind conditions support it. State and federal rebates and grants can also be identified by checking out the dsire.org website for alternative energy programs state by state.
The size of the turbine can also determine whether the power generated will be a supplement to utility power or a complete system that supplies power and can sell it back to the utility. Again, the assessment process of specific household consumption will help in determining the size of the wind turbine. Smith says that a 1KW turbine, the smaller residential size, starts at $14,000. A larger 4KW turbine can provide enough electricity to power a 3,000 square foot home, and starts at about $30,000. This cost can be reduced through state and federal rebates and grants.
If the turbine is supplemented by solar panels, Smith says that understanding what types of panels are appropriate for the location is an important factor. The choice between mono- or polycrystalline panels is dependent on the local climate’s range of temperatures and how the temperature can affect the electrical production of the panel.