Thinking about using a solar heater for your greenhouse? It’s a great idea, but often you’ll need to use it alongside other heating methods.

Here’s a straightforward guide to help you navigate the options.

Why You Can’t Rely On A Solar Heater For Your Greenhouse

A solar heater for a greenhouse sounds great in theory, but here’s the catch: the sun isn’t always shining, especially when you need the heat the most—like on cloudy days or at night.

This means you can’t rely solely on solar power (1) to keep your greenhouse warm all the time.

Here are a few reasons why a true solar heater for a greenhouse doesn’t really exist:

1. Sunlight Dependency: Solar heaters depend on sunlight to generate heat. When the sun isn’t out, they can’t produce the warmth your greenhouse needs.
   
   
2. Energy Storage: To keep your greenhouse warm when the sun isn’t shining, you’d need to store solar energy in batteries. Batteries are expensive, have limited storage capacity, and can be complicated to set up.
   
   
3. Supplementary Systems: Because of these limitations, solar heating systems are usually used to supplement other heating methods, not replace them. They can reduce your overall energy costs, but they can’t do the whole job on their own.
   
   
4. Standalone Products: There are some products that claim to be solar greenhouse heaters, but they generally combine solar panels with electric space heaters. These work well for small spaces but aren’t enough for larger greenhouses.
   

So, while solar power can help heat a greenhouse, you’ll still need other heating methods to keep it warm consistently.

That’s why, in this article I’m going to be showing you a few options that you can use to combine solar and traditional heating methods in your greenhouse.

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Best Solar Greenhouse Heater Setups In 2024

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Details:

For a top-performance solution to heat your greenhouse, combine the BLUETTI Solar Generator AC300&B300 with the Bio Green Palma Greenhouse Heater. The BLUETTI system includes a 3072Wh modular power station and a 350W foldable solar panel, providing reliable off-grid power. It features 16 versatile ports to meet various needs.

The Bio Green Palma Heater delivers rapid warmth with a 5118 BTU/1500 W output, ideal for greenhouses up to 120 square feet. It has a digital thermostat for precise temperature control and is designed for humid environments with durable stainless steel housing.

Using the BLUETTI solar generator to power this heater ensures your greenhouse stays warm efficiently and sustainably, making it an excellent investment for top greenhouse performance.

#1: Bluetti Solar Generator Set

PROS	CONS
– This system has a large capacity, and you can add more batteries to make it even bigger. – The included solar panel can recharge the power station quickly, in about 7-14 hours. – You get everything you need to start, including the power station, battery, solar panels, and charging cables. – The 3000W inverter can run multiple heavy appliances at once	– The initial cost is high, especially if you want to add more batteries. – You’ll need to keep an eye on it and do some regular maintenance to keep it running smoothly. – It’s heavy and a bit bulky, which might be a hassle for some people

What’s Included:

• AC300 power station
• B300 expansion battery
• PV350 Solar panels
• AC/Solar/Car charging cable
• User manual

Check Best Price ➡️ Amazon

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#2: Palma Greenhouse Heater

PROS	CONS
– Compact and lightweight so you can move it around where you want it. – It’s easy to use – High quality with a durable stainless steel casing – It isn’t energy hungry. You can get powerful heating with efficient consumption	– It runs on electricity so you’ll need the solar panels and other items to make it work on solar.

What’s Included:

• Greenhouse heater
• Thermostat
• 2 user manuals for a hassle-free setup.

This is one of the best solar heaters for small greenhouses so I can strongly recommend this. Its also a smart way to heat a greenhouse with solar power in cold climates.

Check Best Price ➡️ Amazon

Details

For an affordable and effective way to heat your greenhouse, consider combining the Renogy 200 Watt Solar Panel with the Bio Green Palma Greenhouse Heater. The Renogy solar panel, made from durable aluminum, has a high efficiency rate of 19.2% and is built to last, withstanding harsh weather conditions like high winds and heavy snow. It’s easy to install with pre-drilled holes and is compatible with various mounting systems.

The Bio Green Palma Heater offers 5118 BTU/1500 W of heat, perfect for greenhouses up to 120 square feet. It features a digital thermostat for precise temperature control, is energy-efficient, and designed to handle humid environments with its robust stainless steel housing.

Using the solar panel to power this heater can keep your greenhouse warm and your energy costs low, making it an economical and eco-friendly solution.

Products Included:

#1: Renogy Solar Panel

Check Best Price ➡️ Amazon

PROS	CONS
– It has a high efficiency rate of 19.2% – Great price – Easy to install with pre-drilled holes for mounting and securing. – Designed for extended outdoor use, it comes with a 10-year workmanship warranty and maintains over 80% output after 25 years	– It is quite heavy at 26.5 lbs so it can be a hassle to set up and move around initially. – You need quite a bit of space for this because its big (58.7″L x 27.5″W x 1.38″H)

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#2: Palma Greenhouse Heater

💡 Look above for the pros and cons of this heater system

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Solar Heating Systems for Greenhouses: Buyers Guide

Here is all the information that you need to know about solar heating systems.

Types of Solar Heating Systems

Solar heating for greenhouses uses both active (with pumps or fans) and passive (using natural airflow) systems. They both work to circulate the sun’s heat throughout the greenhouse.

Solar Air Heaters

Solar air heaters capture the sun’s energy to heat the air inside your greenhouse. They use fans to move this warm air around, giving your plants a cozy breeze even in the winter. These heaters are very efficient and are considered active solar heating systems.

Solar Water Heaters

Similar to air heaters, solar water heaters use the sun’s energy to heat water instead. This warm water is then circulated through the greenhouse, providing a gentle heat. Like air heaters, these are active systems because they use pumps to move the water.

Thermal Mass

Thermal mass is a passive heating method, meaning it doesn’t use pumps or fans. Objects like water containers or stones inside the greenhouse absorb heat from the sun during the day and release it at night, helping to maintain a stable temperature when there’s no sunlight.

What to Consider When Installing A Solar Heater For Your Greenhouse

Installing solar heating in your greenhouse is essential for consistent plant growth. Here are some things to keep in mind:

Size of Your Greenhouse

The size of your greenhouse will determine the type and number of solar systems you need. Smaller greenhouses might need just one system, while larger ones will require more powerful or multiple systems.

Location and Climate

Where your greenhouse is located and the local climate are crucial factors. You need to assess how much sunlight your location gets and choose a system that works well in those conditions. For colder climates, you’ll need systems designed to operate efficiently in low temperatures.

Insulation

Good insulation is key. Even the best solar heaters won’t be effective if the heat escapes easily. Make sure your greenhouse is well-insulated to retain the warmth generated by your solar system.

Here’s what you need to know about insulation: 16 Genius Ways To Insulate Your Greenhouse For Year-Round Growth

Budget

Solar heating systems can be expensive upfront, but they save money in the long run. Set a budget that you’re comfortable with, keeping in mind that the initial investment will pay off over time with reduced heating costs.

Pros and Cons of Solar Greenhouse Heaters

Pros

Eco-friendly:	Solar heaters don’t emit harmful gases, making them environmentally friendly.
Cost-effective:	While the initial cost is high, maintenance is low and you save money on energy bills over time.
Sustainable:	Solar energy is renewable, so you’re not depleting resources.

Cons

High initial cost:	The upfront investment can be significant.
Weather dependent:	Solar heaters need sunlight, so they’re less effective on cloudy days and at night.
Space requirements:	Solar systems need enough space for installation.

Designing Your Solar Heating System

When designing a solar heating system for your greenhouse, consider these elements:

Orientation

Place your solar panels where they will get the most sunlight. This ensures they capture the maximum amount of energy.

The roof is always a great spot to place your solar panels

Storage Mechanism

Consider adding a storage system, like batteries, to store excess energy for use when there’s no sunlight. A popular choice is the BLUETTI AC300 Home Battery Backup, which can also be used for greenhouses.

Integration

Connect your solar system to fans or pumps to effectively distribute the heat throughout the greenhouse.

Seasonal Heating Strategies

Winter Heating

Winter can be tough on your greenhouse, but you can maximize your solar heating with a few smart tips:

1. Maximize Sunlight Exposure: Make sure your solar panels are positioned to get the most sunlight during the shorter winter days. Clean off any snow or debris that might block the sun.
2. Insulate Your Greenhouse: Good insulation keeps the warmth in. Use bubble wrap on the inside of your greenhouse windows and check for any drafts that need sealing.
3. Use Thermal Mass: Place water barrels or large stones in your greenhouse. These will absorb heat during the day and release it at night, helping to maintain a stable temperature.
4. Cover Plants at Night: Use frost cloths or row covers to provide an extra layer of warmth for your plants when temperatures drop.
5. Optimize Ventilation: Make sure vents are properly adjusted to maintain airflow without losing too much heat. You can use automated vent openers that respond to temperature changes.

Summer Cooling

In the summer, you can use your solar system to help cool your greenhouse and keep your plants from overheating:

1. Install Shade Cloths: Use shade cloths to reduce the amount of direct sunlight entering your greenhouse. This helps keep temperatures down.
2. Use Solar-Powered Fans: Set up solar-powered fans to improve air circulation. These fans can help move hot air out and bring cooler air in, keeping the temperature more comfortable for your plants.
3. Ventilation: Keep vents and windows open during the day to allow hot air to escape. Automated vent openers can be a big help here as well.
4. Misting Systems: A misting system can cool the air through evaporation. Solar-powered misters can be an efficient way to keep your greenhouse cool without using extra electricity.
5. Water Plants in the Morning: Watering early in the day helps keep the soil moist and cool, which can reduce the overall temperature inside the greenhouse.

By adjusting your strategies based on the season, you can maintain a healthy environment for your plants year-round using your solar heating system effectively.

Conclusion

Heating your greenhouse with solar power is a great way to be eco-friendly and save on energy costs. While you can’t rely solely on solar heaters due to weather and sunlight limitations, combining solar systems with traditional heaters can keep your plants warm and thriving.

Whether you go for a high-performance setup like the BLUETTI Solar Generator and Bio Green Palma Heater, or a more budget-friendly option like the Renogy Solar Panel with the Palma Heater, you’ll be making a smart investment for your greenhouse. Remember to consider the size of your greenhouse, local climate, and insulation to get the best results. With the right setup, you can enjoy year-round growth and a more sustainable gardening experience.

FAQ

Can you heat a greenhouse with solar?

Yes, you can heat a greenhouse with solar power, but it’s usually best to use it alongside other heating methods. Solar heaters depend on sunlight, so they might not provide enough heat on cloudy days or at night. Combining solar power with traditional heaters can give you a more consistent warmth.

Are solar greenhouse heaters any good?

Solar greenhouse heaters can be very effective, especially when used as part of a hybrid system with traditional heaters. They help reduce energy costs and are environmentally friendly. However, since they rely on sunlight, they can’t be the sole heating source for your greenhouse.

How do you heat a greenhouse without electricity?

You can heat a greenhouse without electricity using methods like thermal mass (e.g., water barrels or stones that store heat during the day and release it at night), composting (which generates heat), and cold frames or cloches to protect individual plants.

How do you heat a greenhouse at night?

To heat a greenhouse at night, you can use thermal mass to release stored heat, or a battery-powered heater if you’ve stored solar energy during the day. Additionally, insulating your greenhouse well can help retain the warmth generated during the day.

Can I run a heater from a solar battery?

Yes, you can run a heater from a solar battery. During the day, solar panels can charge the battery, which then powers the heater at night or during cloudy periods. Just make sure the battery capacity is sufficient to meet your heating needs.

References:
1 – Lee Wallender, How to Heat a Greenhouse: 8 Ways, taken from: https://www.thespruce.com/how-to-heat-a-greenhouse-7371811