Solar on the Farm (part 1)
Published July 5, 2021
Hello, and thank you for watching this video about solar energy for your farmstead.
My name is Fritz Ebinger and I’m with the Clean Energy Resource Teams, a program of the University of Minnesota Extension.
This video is a joint effort between the MN Farmers Union, the Clean Energy Resource Teams, and the Citizens Utility Board of Minnesota.
Many residents might be surprised to learn solar energy is one of Minnesota’s best homegrown energy resources. Surprisingly, Minnesota receives as much annual sun as parts of Texas and Northern Florida.
Technological advances, declining costs, USDA grants, tax advantages, and utility policies may make solar an attractive investment for your farmstead.
In this video, we will discuss several factors you should consider when evaluating solar energy as an investment. These include:
- Your local solar resource
- Electrical infrastructure needs
- Roof condition and orientation or ground location for solar, and
- Installation goals and selecting a solar installer
Before we dig in, we want to remind you to eat your energy efficiency vegetables first! Please conserve and use efficient technologies where practical. The cheapest and cleanest kilowatt-hours and thermal units are the ones we never consume at all.
Please take a moment to examine any energy efficiency or conservation opportunities that might be available to your farmstead, such as installing efficient lighting, ventilation fans, installing proper levels of insulation, and possibly upgrading any older appliances.
As a rule of thumb, for every dollar we invest in energy efficiency and conservation, we save roughly $3 to $5 in clean energy project costs. Reducing the amount of energy we consume from the start allows us to size a smaller solar array for offsetting our energy needs.
Alright now, back to solar. The following material provides information about grid-tied solar arrays. Grid-tied solar arrays connect to the local distribution grid through your farmstead wiring. This material does not discuss off-the-grid solar installations or battery storage though those resources are available on request.
One of the first factors to consider is the solar resource at your farmstead.
Because Minnesota sits high in the Northern Hemisphere, the surface area you are considering for solar should have a good southern exposure.
A good solar resource will have a good “sun window” from about 9:00 AM to 3:00 PM when the sun’s peak hours are strongest, and there are no shading obstructions.
A “peak sun hour” is an hour in which the intensity of the sun reaches an average of 1,000 watts of energy per square meter.
Minnesota receives a yearly average of about 4.5 peak “sun hours” per day, with a 6.5 sun hour high in the longer days of June and about a 2.5 hour low in the shorter days of January when the sun is low on the horizon.
If you’re interested in detailed information about the solar resource at your farmstead, please check out the University of Minnesota’s Solar Map App, available at solar.maps.umn.edu
The Solar Map App will give you a detailed resolution of the sun’s strength at your farmstead.
Another factor to consider is the electrical infrastructure and wiring on your farmstead.
If your farmhouse and outbuildings have old fuse boxes, meaning panels full of circular colored knobs, then solar will not be viable at your farmstead. Rather, it would be a better investment to rewire your farmstead with a modern wiring system for safety and in preparation to host new, more efficient technologies.
If your farmhouse and outbuilding electric panels hold a series of switches, you likely have circuit breakers and solar is a possibility. If the main circuit breaker on your panel is 200 Amps or more, your farmstead is a good candidate for solar. A 100 amp main circuit breaker can also host solar, though it may limit the size of the solar array.
Ideally, the electric panel into which you tie solar will have at least two vacant circuit breaker spaces to tie solar into your farmstead without needing a larger electrical panel.
Regardless, many solar installers will rewire a larger main panel to host solar that ties in behind the meter for a modest additional cost.
If you wish to place solar on the roof of your farmhouse or an outbuilding, it is important to consider the roof type, condition, orientation, and age. Broadly speaking a newer shingled roof, aged 5 years or under is ready for solar.
Shingled roofs aged 5-10 years may also be ready for solar, depending on their condition.
Shingled roofs 10 years or older are not good candidates because the solar panels will outlast the roof shingles. This means the owner would likely have to remove the solar panels to install a new roof and then reinstall the solar panels at additional cost.
Metal roofs commonly found on agricultural buildings are good candidates for solar because of their durability. Also, raised seam metal roofs lend to straightforward installations because of the ability to clamp the racking system onto the raised seam for hosting the solar panels.
Often, it is easiest for farmsteads to locate a solar array on the ground. This removes any spatial limitations a rooftop might present, allows the owner to set the solar array at the ideal sun angle, makes it easier to maintain the solar array, among other reasons.
Ground-mounted solar installations also avoid the building structural considerations such as wind load and snow load that can risk a building’s integrity.
Following these initial considerations, you are welcome to contact the Clean Energy Resource Teams in the University of Minnesota Extension for more information and resources or contact solar installers directly to obtain project bids.
Much like selecting a contractor for a kitchen remodel or a new roof, the preferred practice is to obtain three quotes from qualified companies to understand costs and options. Solar energy is a long-term investment in your farmstead.
It helps to have a cost budget of several thousand dollars and a solar goal in mind, like offsetting 100% or 50% of your farmstead energy use. Thinking through the project a little will help your conversation with different solar companies.
Thinking through your energy needs and budget will also help you understand how much solar you need.
The preferred practice is to size a solar array to your farmstead’s total annual energy consumption in kilowatt-hours. This is known as sizing to load. Whether the solar array is sized to match the energy needs of the farmhouse, the farm business, or both make a large difference in the solar array size and cost. Generally, residential consumption requires a smaller amount of solar compared to a livestock facility, for example.
The tax advantages, grants available, and utility policies change depending on whether the solar array serves your farm business or your residential energy needs.
As always, consumers should perform their due diligence in selecting a solar installer. Be sure to ask about the installer’s credentials, such as training and certification from the North American Board of Certified Energy Practitioners or NABCEP. Request references to ask about others’ experiences with the company. Also, ensure they are licensed, bonded, and insured.
To find a list of installers, you can check out the Solar Directory on our website, mncerts.org, or members of the MN Solar Energy Industry Association at www.mnseia.org under their “Find an Installer” tab.
The MN Department of Labor and Industry requires the installation of racking, modules, electrical equipment, and wiring to be performed by a licensed electrical contractor or their registered employees. To verify licensure and status, you can go to the DOLI License Lookup tool at www.dli.mn.gov.
Thank you for tuning in! This is part 1 of 3 solar energy for your farmstead. Look for additional segments on the Citizens Utility Board of Minnesota’s YouTube page.