Using high tunnels and hybrid renewable energy systems to reduce energy costs and fossil fuel use on the farm

Sustainable living, now more than ever, requires a commitment to reducing energy use. Quiet Creek Herb Farm and School of Country Living in Jefferson County has long been a leader in teaching others about sustainable production, and reducing the use of fossil fuels. Clare and Rusty Orner showed PA-WAgN and Pennsylvania Association of Sustainable Agriculture (PASA) members how high tunnels and new hybrid renewable energy systems can help reduce energy consumption on the farm.


High Tunnels

The two high tunnels on the farm--30' by 30' and 30' by 65'--have been in use for Hoopseveral years now. A high tunnel is, by definition, an unheated greenhouse. Its plastic skin collects passive solar heat during the day, allowing farmers to extend their growing time by a month or more at the beginning and end of the season.

Quiet Creek's high tunnels are covered with a high-quality 6 mm. plastic. "We paid more for this 3-layer film than we would have for thinner plastic, but that actually saved us money in the end," Rusty said. "The life of this plastic may be 8 years or more." The high tunnels are vented at the peak above the doors and at the top. The sides roll up six feet high to regulate the inside temperature.

Inside the tunnels are growing strawberries, raspberries, tomatoes, and--in winter--salad greens. To save energy and water usage, Rusty uses drip irrigation. An innovation he made was to install the tunnels on a box channel so that they can be moved over raised beds. For example, if he wants to "freeze out" any insect pests in his vegetable beds in late winter and give his strawberries a warmer start, he pulls the tunnel away from the vegetable bed and over the strawberry bed. His tunnels are moved on a pulley system, and can be moved with a tractor and come-along.


Renewable Energy

Quiet Creek's hybrid renewable energy system--which includes both solar and wind power--was installed to provide supplemental energy for the farm, and the project has provided a substantial reduction in utility bills. With Quiet Creek's mission of environmental education, though, other goals of the project were to reduce the use of fossil fuel energy and provide education about renewable energy. Since they created Quiet Creek, Clair and Rusty have dreamed of generating electricity using renewable resources that minimize impact on the environment.


The system reduces energy dependence by reducing the amount of electricity drawn from the utility grid. (However, it does not provide protection in case of a power outage because the system inverters must go off-line in order to protect both the system and utility line-workers from voltage in the lines.)

Before building the system, the Orners calculated that a hybrid system could generate 7,043 kWh per year--enough energy to cover 100% of the non-profit's electrical usage and have excess to sell back to the grid. Now that it is finished, they find that it does cover 100 percent of their electric usage--about 20kw/h per day. On its best day it has produced 40kw/h.

The solar system ( 2.4kW Photo Voltaic array) and the wind system (5.1kw DC system with a 127-foot 2.5kw turbine with tilt-up SkyStream wind tower) each generate about 50 percent of the energy produced. However, the Orners recommend solar power over wind because of the maintenance costs involved in wind power .As Claire noted, fewer moving parts equal fewer mechanical failures. The wind tower has already been lowered once for repairs and it has been struck by lightning as well.

As a non-profit, 501c3, charitable organization, Quiet Creek was awarded a Pennsylvania Department of Environmental Protection Energy Harvest Grant grant. The grant covered the $72,000 cost of the system, with a $5,000 contribution from Quiet Creek. As a result of the project, every year 5,000 school students, teachers, and visitors at the farm's workshops can learn about renewable energy through hands-on learning and real-time data tracking (take a look at http://siteapp.fatspaniel.net/siteapp/simpleView.jsf?eid=363998 to see this data).

Claire recommends getting an energy assessment to see if if alternative energy is feasible for your needs. And if you plan to stay on grid and sell back power to the electric company you must get their input and an interconnection agreement.

Other Resources:

Quiet Creek Herb Farm and School of Country Living

Renewable Energy Project details from Pathway to Green Schools (PDF) and Turf Magazine

High Tunnel Information from Penn State's Center for Plasticulture

Pennsylvania Women's Agricultural Network

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