Greenhouses and solar panels have one thing in common: both make use of energy from the sun. The greenhouse uses light and heat from the sun to keep plants warm and growing in cold climates. Solar panels use sunlight to generate electricity. But can you combine the two?
You can put solar panels on a greenhouse. Solar panel installers have developed fasteners, clamps, and other devices to fix panels on a wide range of structures. Many of these can work on the greenhouse frame, as long as the greenhouse is strong enough to bear the extra weight.
This article will tell you more about how greenhouses work, how solar power can make an even better greenhouse, and talk about where you want to put the panels. Sometimes solar panels work just fine on the greenhouse roof; other times you’ll want to put them somewhere else.
How Greenhouses Work
Greenhouses have been around in some form or another since the days of the Roman Empire. The basic idea is pretty straightforward. The greenhouse is a structure made of glass panels held up by a frame, usually made of metal. During the day the glass lets sunlight in, where it warms the air, soil, and plants. But the glass structure also seals off air circulation and slows down the rate at which things cool off overnight.
That creates an artificial zone of warm air. The greenhouse protects plants from the extreme cold of northern winters, allowing you to have thriving plants year-round in places where they wouldn’t survive otherwise because of the cold.
Passive and Active Heating
Capturing and retaining the sun’s warmth like this is called “passive heating.” This can be supplemented with “active heating,” which includes fires, furnaces, hot water, or any other method of raising the temperature.
Both active and passive heating have been used almost as long as there have been greenhouses, and the results can be impressive. For instance, in the 15th century Koreans used underground water pipes to warm greenhouses that they used to grow mandarin oranges during their often harsh winters.
The Solar Powered Greenhouse
From there, it just seems like a natural step to use solar power to operate a modern greenhouse, with the sun powering the whole thing: the glass greenhouse structure capturing the sun’s rays, and solar power operating electrical heaters, as well as thermostats, fans, water pumps, and anything else you would need to create the perfect climate for plants.
This way, solar power provides both passive and active heating. This is a very practical arrangement. There are many solar-powered greenhouses, both small-scale models for hobbyists and large commercial operations.
Are There Solar Panels Specifically Designed for Greenhouses?
The basic principles behind solar power are the same whether you’re powering a home or a greenhouse. You won’t need to look for specialized solar panels or other gear.
The equipment in your greenhouse will likely run on the same current that the appliances in your home use. You will want to set up solar panels that can provide the needed power and an inverter to convert the power to alternating current that your appliances can run. The scale might be smaller, but you can use the same panels as you would on any other solar energy setup.
So Where Do You Put the Panels?
Your solar panels and your greenhouse can make a great team. The question is just how to lay them out to get the best results. Your first thought might be to put the solar panels on the roof of the greenhouse, where they will be away from ground clutter, less likely to fall into the shade, and where they won’t be in the way.
That is one option, but it isn’t always the best one.
Panels on the roof will reduce the amount of passive heating and cut off the sunlight your plants need to thrive.
If Not On The Greenhouse, Where Else?
If you don’t already have solar panels installed on the roof of your home, that might be the first place to consider. While you’re at it, you might consider making your solar panels part of a larger electrical system that includes both your residence and the greenhouse. Otherwise, if your yard is large enough, you can place panels on racks alongside the greenhouse.
There are some situations where it might still make sense to install solar panels on the roof of a greenhouse:
- Larger greenhouses can often afford to turn over some portion of their roof area to solar panels and still receive adequate sunlight.
- If you grow a lot of plants that do best in the shade sacrificing sunlight for electrical power might make sense.
- Finally, if you live in a relatively mild climate you might be less concerned with maximizing heat, and use the electrical power for circulation, irrigation, and monitoring conditions.
These are some of the factors that you might want to consider as you lay out your greenhouse. Just remember that passive solar heating is a crucial factor, and you want to be sure your plants receive adequate sunlight.
Mounting Solar Panels On The Roof Of A Greenhouse
If you decide you do want to install solar panels on the roof of your greenhouse, mounting the panels might present a challenge, but not an impossible one. Drilling through glass to affix solar panels will be impractical, but some of the glass on the roof can probably be replaced by metal since the solar panels will block sunlight anyway.
Metal roofing material is ideal for solar panel installation. You should be able to find metal roofing material with raised seams that can provide ideal anchoring points without creating any risks of leakage. In addition, the metal frame of the greenhouse should also provide anchoring points.
Solar panels can be a great addition to your greenhouse. Your greenhouse relies on the sun for passive heating, but solar-powered electric heat can be very useful as a secondary heating resource, and solar electricity can also power irrigation and climate controls.
Placing solar panels directly on the roof of your greenhouse is not always the best choice. The panels will block light that your plants may need to grow. But there are many ways to provide solar power to a greenhouse, and mounting on the roof is certainly possible.