A majority of the greenhouse operations require electricity.
The electric bill in a greenhouse contributes about 5-10% of the total energy cost.
In this article, we will answer the common questions concerning the use of electricity in greenhouses:
What Do People Use Electricity for in Greenhouses?
The reasons why people use electricity in greenhouses include:
For Heating and Cooling
Appliances such as fans and heaters are essential in greenhouses.
They use electricity which is why most people install electricity in their greenhouses.
To Water Plants
Some growers prefer to use automated sprinklers to water the plants in their greenhouse.
Others prefer using automated drip systems.
To Operate Vents
Some growers prefer to have automated vents that open and close independently.
To Power Greenhouse Grow Lights
For greenhouses located in areas with inadequate sunlight for extended periods, grow lights are the best solution.
Growers use electricity to power these lights, thus enabling the plants to photosynthesize and grow well.
For Visibility
Most growers have fluorescent bulbs in their greenhouses to give visibility when it’s dark. Fluorescent lights can also dabble as grow lights.
To Power Alarm Systems
It isn’t uncommon for growers to have electric alarm systems in their greenhouses.
To Power monitoring Systems
Monitoring systems analyze the conditions in a greenhouse to ensure they are optimal for plants’ growth.
Some growers use these systems, and they require electricity to function.
Do People Normally Run Electricity to Greenhouses?
As we have already seen, electricity has several uses in a greenhouse.
Electricity usage is usually done by having permanent underground electrical lines installed. These lines are connected to the mains power and buried.
This connection means that electricity is always available at the greenhouse should it be needed.
Proper permits are usually required for this kind of work, and it needs to be done by a certified professional.
How Much Electricity Does a Greenhouse Use?
Several factors determine how much electricity is used in a greenhouse.
These include the size of the greenhouse, insulation, the type of plants growing in the greenhouse, and the weather conditions in the area where the warehouse is located.
Despite all these factors, a typical greenhouse uses 1-2 kilowatt-hours of electricity per square foot of floor area per year (KWH/Sq. Ft-Yr.).
If energy conservation measures such as roof and sidewall vents, wall insulation, and energy screens are applied, electric consumption can be cut to a minimum.
Are Electric Fans and Heaters Required?
 Don’t get it wrong, fans and heaters are essential in any greenhouse.
Fans help aid airflow in the greenhouse, while heaters raise the greenhouse temperature when it gets too cold.
Therefore, one question remains: do these two pieces of equipment need to be electric?
No, they do not. This is because you can utilize other forms of energy to power your greenhouse fans and heaters.
It’s a good idea to use solar-powered fans in your greenhouse instead of having electric fans which require electricity to function.
By using solar-powered fans, you can cut down on electric costs in your greenhouse. Solar-powered fans are equally as effective as electric fans.
In the case of greenhouse heaters, you can use a solar-powered one or a gas heater.
To use solar-powered heaters, you’ll need solar panels, some batteries, a solar charger, an inverter.
Gas heaters designed for greenhouses and which are thermostatically controlled can be used to heat your greenhouse. Gas heaters use piezo ignition, so they don’t rely on mains electricity to ignite and heat your greenhouse.
For more information, check out our article: “Should I Leave My Greenhouse Door Open?“.
How To Cool a Greenhouse Without Electricity?
Cooling your greenhouse is of extreme importance, especially if you are growing crops year-round.
The temperatures can become too high, especially during summer and on hot days. This high temperature can cause your crops to wilt or even die.
With the help of electricity, temperature reduction in greenhouses can be relatively easy. The only catch is that it adds to the overall energy cost.
Most of the time, energy conservation in greenhouses is quite desirable, so reducing electric consumption in them makes sense.
Taking away the dependency on electricity when you want to cool your greenhouse can go a long way in helping you reduce electric costs.
Here are several ways you can cool your greenhouse without electricity:
1. Damping down
This is the process of raising the humidity in a greenhouse, and it involves wetting hard surfaces.
You should spray water on woods, blocks, paths, and other surfaces. The water will evaporate and increase the humidity in your greenhouse.
Increasing the air’s moisture level will cool your greenhouse and help your plants deal with high temperatures.
It would be best if you damped down your greenhouse as often as you can. When the temperatures are extremely high, it’s hard to overdo it!
2. Shading
Solar radiation is a common bane among most greenhouse owners.
The good news is that shading can help solve this problem, and the beauty of this method is that one doesn’t need to use electricity.
Shading involves blocking incoming sunlight to keep the temperatures in your greenhouse down. You can use curtains, paint, or cloths for shading your greenhouse against sunlight.
If you choose to use shading cloths, you can place them inside or outside your greenhouse. If the conditions are likely to be windy or rainy, then inside is the best option.
However, in temperate conditions, having shading cloths outside is more effective in reducing your greenhouse temperatures.
If you decide to go with shade paint, you should apply it outside your greenhouse, just like ordinary paint. You may have to do this year for the best effect.
The only downside with this shading method is that you can’t adjust the amount of sunlight you block or let in.
Extreme care should be taken not to completely block out sunlight since your plants need it to grow. Just blocking direct sunlight will be effective in cooling your greenhouse.
3. Ventilation
Ventilation is a very effective way to cool your greenhouse, and the good news is that you don’t have to use electricity.
Ventilation allows good airflow in greenhouses. This airflow is effective in cooling down greenhouses.
You can achieve ventilation in your greenhouse by using roof vents and side vents. These can either be manually operated or solar-power-operated since the aim is not to use electricity.
If the temperatures get too high in your greenhouse, you can open the vents. This will allow airflow in your greenhouse, which will cool the temperatures.
You should take into consideration the size of vents that are appropriate for your greenhouse. Your overall ventilation area should be equal to two-fifths of the floor area of your greenhouse.
So that means one fifth for the roof and one fifth for the walls/side.
4. Misting
Another way of cooling your greenhouse without having to use electricity is by misting.
Misting will raise the humidity in your greenhouse, and this will help reduce the temperatures. The use of misting systems can achieve misting.
The good thing is that these misting systems can use solar-charged batteries to function, so you won’t have to use electricity. The systems won’t have to perform their function all the time, so that you can use a battery-operated timer.
Having electricity in your greenhouse would probably be a more efficient and long-lasting option in the long run.
Sources:
https://gpnmag.com/article/saving-energy-electric-lighting-and-water-systems/#
https://www.greenhousemag.com/article/photovoltaic-solar-electricity-for-greenhouses/
https://www.greenhousetoday.com/how-to-cool-a-greenhouse-without-electricity/