In this article, you will learn about greenhouse solar panels including what you can run, installation, and the top products.
Using solar panels in a greenhouse is an excellent way to add electricity to a building that is not connected to the main grid. Not only does it provide off-grid power but it’s an eco-friendly and free way to generate electricity.
It can be tricky to get right if this is your first time using solar. But with the correct equipment and setup, you can run ventilation, lighting, and even heat your greenhouse during the winter.
We will discuss all of this and more to make your greenhouse the most efficient in your neighborhood.
Can You Heat a Greenhouse with Solar Panels?
The first question you might have is about heating your greenhouse with solar.
The good news is that it is possible to do this, although you need to understand the requirements and restrictions. There are huge benefits to solar power but it has limitations. Firstly, you will be reliant on weather conditions. Secondly, you need a lot of panels and space to generate a decent amount of electricity.
If you want to run a ‘normal’ electric heater or a greenhouse specific one you’ll need over 1000 watts power output. For example, the Bio Green Pal draws 1500 watts!
A solar panel will generate around 100 to 200 watts. So to run a heater like this directly you’d need over 10 solar panels. And that’s a lot of money and space which is not practical.
To use a solar panel efficiently you’ll need to add a battery to store energy generated during the day to use when you need heating, like during the night. In addition, you should look to use a low wattage heater which will put less strain on your power supply.
Here’s what you’ll need to create solar panel heating for a greenhouse:
- Solar panels and Charge controller (can be bought as a kit)
- Deep cycle battery
- Power Inverter
- Low Wattage heater
Don’t worry, further down we will go through the components and installation in detail.
What Can You Run with Greenhouse Solar Panels?
We’ve discussed heaters but what else could you power with solar panels in a greenhouse?
In my experience, most other electronics should be very easy to run, including LED lighting, fans/ventilation, heat mats, water pumps, and UV lights.
When working out what you want to run it is a good idea to find out what your daily energy usage will be. Then you can install solar panels and batteries that can produce and store enough energy each day.
Installing Solar Panels for a Greenhouse
If you’re looking to install a complete solar panel system in your greenhouse then you need to understand all the components and how they work together.
As we discussed above you’ll need a solar panel, charge controller, battery, and inverter to get this working correctly. Let’s take a look at the solar panel diagram and how to hook everything up.
Solar Panel for Greenhouse Diagram
Take the time to study the following diagram to gain an understanding of where the components sit in the circuit.
Step by Step Greenhouse Solar Panel Installation
- Connect Charge Controller to Battery
Always start by connecting the charge controller to the battery before the solar panel.
To do this wire the positive battery output on the controller to the positive battery terminal. Repeat this with the negative side.
- Place/Mount Solar Panel in Direct Sun
You want to find a spot that gets direct sunlight to your solar panels. This might be on the roof of the greenhouse, the wall, or another location not too far from your charge controller.
Solar panels need direct sunlight during peak sun hours (11am to 3pm). Otherwise, they will not work efficiently and electricity production will be severely reduced!
- Connect Solar Panel to Charge Controller
Now you can wire the solar panel to the charge controller. If you have a starter kit it should arrive with adaptor cables. These will have MC4 connectors on one end and stripped wires on the other.
Connect the MC4 connectors on the adaptors and solar panels together. (Positive to positive and negative to negative). Then wire the stripped end to the charge controller input. Once again, positive to positive and negative to negative.
You should now be charging your battery from solar power! A voltage and charge reading will show on the controller LCD screen.
- Connect Inverter to Battery
Finally, we can hook up our power inverter. This device is used to convert DC electricity from solar panels and batteries into AC power needed to run appliances. (AC is what you get from the main utility grid)
You can wire your inverter directly to your battery terminal in a positive to positive and negative to negative fashion.
N.B You don’t need an inverter if you only run DC devices.
- Plug-in Electronics
When everything is wired up and working correctly you can plug your electronics into your power inverter just like you would into a wall socket.
See it in action here:
Tips to Keep Your Greenhouse Warm in Winter
When it comes to heating a greenhouse it’s only natural to think you need electricity and technology to solve the problem. You should look to add a couple of other ways to increase efficiency. When investing in solar panels, you should also incorporate passive solar energy and insulation to achieve the best outcome. This will mean you need less electricity to maintain a stable temperature.
Passive Solar Energy
We’ve only discussed active solar energy so far but you should also learn about passive solar energy.
It’s a simple low tech solution. Passive solar energy is when the sun heats up an object. This object retains heat in direct sunlight then when the sun disappears it slowly dissipates its heat into the surrounding air.
Think about a tarmac road or big rock during the summer. They can get very hot and stay warm for hours after the sun goes down. These objects don’t just keep themselves warm, the heat will slowly pass into the air over a number of hours. This is passive solar energy. We can use this in a greenhouse to create a stable temperature at night.
You can add barrels of water or large concrete blocks to create this effect for yourself.
Just like this:
Insulation
Good insulation is always the key to maintaining stable temperatures, especially if you want to use passive solar energy. It stops the heat leaving your structure! You can insulate the walls of the building and plants individually.
Many people like to use large bubble wrap to insulate greenhouses as it allows light to pass through while retaining warm air inside.
Plus polystyrene and raising beds off the ground is an ideal way to keep plant roots and seedlings nice and toasty during colder months.
Greenhouse Solar Panels Summary
I hope this article has given you an in-depth insight into solar panels for your greenhouse.
Adding this equipment is a useful way to produce electricity for all sorts of uses in your backyard. If you want to run a heater, ensure you check the power requirements and check your system will be up to the task. For low energy items like lighting and fans, there are off-the-shelf options available. And don’t forget to make everything as efficient as possible with passive solar energy and insulation.
Thanks for reading and happy growing.
