How Does Permaculture Use Renewable Energy For Heating?

“Hey there! I’m in the process of setting up a small permaculture garden in my backyard and I’ve heard a lot about using renewable energy for heating. I’m from Guelph, Ontario, and winters here can get pretty cold. I’m curious about what options might be suitable for keeping my greenhouse warm or even for keeping my home cozy using renewable energy in a permaculture framework. Any advice on how to make it work in an environment like mine would be really helpful!” Warm regards, Patrick, Guelph, Ontario, Canada.

A Cozy Greenhouse with Passive Solar Heating

Patrick, when it comes to renewable energy in permaculture, one of the most straightforward and cost-effective methods for maintaining heat in your greenhouse during those harsh Canadian winters is passive solar heating. This approach doesn’t require complex machinery, just a bit of thoughtful design.

Think of your greenhouse as a solar collector. The idea is to trap as much sunlight as possible during the day and then prevent that heat from escaping at night. To do this:

• Orientation: Position your greenhouse so the longest side faces south. This maximizes sunlight exposure during daylight hours.
• Thermal Mass: Use materials that can absorb, store, and slowly release solar energy, such as rocks, water barrels, or even packed earth, to help maintain warmth during the chilly night hours.
• Insulation: Double glazing or thermal curtains can make a huge difference in keeping heat inside.

If you really want to amp up that passive heat, consider installing a ‘solar wall’ on the north side of the greenhouse. Basically, it’s a dark, thermally massive wall that soaks up the sun’s rays and slowly releases it into the space over time. It could be as simple as painting some cinder blocks black and stacking them in a way that they get good sun exposure.

Active Solar Heating Options

If your space needs a bit more warmth than passive methods can provide, active solar heating systems can help. These systems are still within the ‘renewable’ scope and allow you to harness solar energy more intensively. Here’s how this could work in a permaculture setting:

• Solar Air Heaters: These are simple panels that can be attached to your greenhouse or even your home. They circulate air through collectors that are heated by the sun, warming the air and then circulating it back into the space.
• Solar Water Heaters: Water is great at storing heat. You could install a solar water heating system to heat a network of piping under your greenhouse beds. This is known as a ‘hydronic heating’ system and it’s particularly good for keeping the roots of your plants cozy, which helps them survive the frost.

Maintaining Active Systems Through Permaculture Lenses

One thing to keep in mind, Patrick, is that with active solar systems, you still want to stay true to the low-input, self-sustaining ethos of permaculture. To maintain these systems, consider technologies that are durable and require minimal maintenance. Look for ways to use gravity-fed systems or thermosiphoning to circulate water without relying on electric pumps if possible. And make sure to build in redundancy—like adding a simple wood stove or rocket mass heater as a backup (more on that later).

Extending Permaculture Principles to Your Home

Your home, as part of your permaculture setup, should also benefit from renewable energy to keep you toasty! Good news, the strategies here aren’t too different from what you’d use in the greenhouse.

Passive Solar Home Design

Let’s start with passive solar design for your home. If you’re building a new place or are able to do some retrofitting, you can incorporate elements like:

• South-Facing Windows: Just like the greenhouse, orienting your home to face the south and using large, double-glazed windows provides maximum solar gain in the winter.
• Thermal Mass Flooring: Concrete, brick, or stone floors can absorb the heat during the day and release it at night, helping to moderate temperatures.
• Insulation and Earth Berming: Insulating your home well and even partially burying it (berming) into a slope or positioning it against a hill can reduce heat loss.

The great thing about these techniques is they utilize renewable energy provided by the sun, reduce your need for external resources, and create a comfortable living environment.

Integrated Wood Heating Systems

Now, Patrick, let’s talk about another excellent option that’s often overlooked: rocket mass heaters. These work wonders for heating a home or even a greenhouse—just the sort of system you might find in a Wisconsin or Minnesota homestead, similar to those tough Ontario winters you face.

• Efficient Burning: Rocket mass heaters are super efficient, burning small amounts of wood that release a lot of heat.
• Thermal Mass Bench: The heat created by the burning wood is stored in a thermal mass bench—often made out of cob (a mix of clay, sand, and straw)—that releases the heat slowly over time.
• Renewable Energy Source: Since they can burn small sticks and even scrap wood, you’re using a renewable resource without a lot of external energy input.

If you’re the kind of person who likes to have their cake and eat it too, a rocket mass heater is perfect because it provides heat while also being an inherent part of the permaculture closed-loop system. You can harvest wood from your own property, managing your woodlot sustainably, and it fits the permaculture ‘zones’ model where you place perennials and food forests closer to home—making the whole system naturally regenerative.

Harnessing Biogas for Heating

Moving on to biogas, an option that’s become increasingly popular in permaculture circles and brings a bit of science into play. Now, I know this might sound a bit “out there,” but stick with me!

Biogas is created by anaerobic digestion—microorganisms breaking down organic matter in the absence of oxygen—which produces a mixture of methane and carbon dioxide. This biogas can be used to fire a stove, heat water, or even run a small generator.

You can create a small biogas digester using kitchen scraps, animal manure, or even plant cuttings. Install a small burner in your greenhouse or home as a backup heating source. What’s nice about biogas is that, again, it fits right into your permaculture setup by reusing waste. Plus, the byproduct (digestate) can be used as a high-quality fertilizer for your plants.

Troubleshooting Biogas Systems

However, success with biogas can require some trial and error. Here are a few tips:

• Temperature Control: The digestion process works best in warmer conditions, so in those freezing Ontario winters, insulate your digester well and consider how you’ll keep it warm using a bit of external heating if necessary.
• Feedstock Consistency: Make sure you’re consistent with what you’re feeding into the digester (not too much of one type of material), and don’t overload it—gradual feeding is key.
• Airtight Seal: Check that your system is airtight. The anaerobic process doesn’t like oxygen, so fixing any leaks will increase your gas production.

Patrick, biogas might not be your first choice, but it’s worth considering if you’re already diving deep into the permaculture world and have the space and resources to give it a go. It can be particularly useful if you’re raising small livestock, creating a self-sustaining cycle!

Geothermal Heating Options for Permaculture

For those who are eyeing something even more efficient and renewable, let’s talk about geothermal heating. Although the upfront costs may be higher, it’s a fantastic long-term solution, especially if you’re thinking of building a new home or considerably renovating.

Geothermal systems rely on the earth’s stable temperatures below the surface. During winter, you can harness this relatively constant heat to warm your home, while in the summer, it can be reversed to cool your space.

Options for Installing a Geothermal System

Here are a few ways geothermal might work for you:

• Horizontal Loops: If you have a large piece of land and don’t want to dig too deep, horizontal pipe loops laid below the frost line are one option. This system is ideal for a rural setting where space is plentiful.
• Vertical Loops: When land is at a premium, vertical loops are the solution as they require several deep boreholes, making them more space-efficient but a bit pricier.
• Pond/Lake Loops: If you have a large body of water nearby, it can be used to place coils or loops, utilizing the water’s stable temperature as a heat source or sink.

A geothermal system doesn’t need a lot of energy to run, just enough to circulate the water through the pipes and into your home. While the system is powered by electricity, the amount required is minimal compared to conventional heating options, making it a renewable and efficient choice.

Integrating geothermal into a permaculture design can significantly reduce your energy footprint, fitting in perfectly with the long-term, sustainable outlook you’re building.

Utilizing Wind Power in Permaculture Heating

Now, if you’re in an area like Guelph that experiences good wind conditions, you might want to consider adding wind power to your heating strategy.

Small wind turbines are a great way to generate electricity that can be used to power an electric heating system or even help pump water in a hydronic heating setup. It could also be stored in batteries to provide a backup on calm, windless days.

Locating Wind Turbines

When planning out your setup, you’ll want to consider:

• Site Selection: Wind turbines need a clear, open space to function efficiently. Install them where they won’t be blocked by trees or buildings.
• Height: Higher is typically better. The higher up they are, the more consistently they’ll tap into the wind resource.
• Hybrid Systems: Wind can work well alongside other renewable options like solar panels, creating a hybrid system that covers your needs more comprehensively.

You could even look into using your wind turbine to help power vertical axis wind turbines, which are particularly good if you don’t have a lot of space but still want to harness wind energy on a smaller scale.

Final Thoughts…

Patrick, thank you for your awesome question! Exploring the various renewable energy options for heating within a permaculture framework really shows how much potential there is to keep your home and greenhouse toasty without relying on fossil fuels.

To summarize, solar energy in both passive and active forms offers a lot of accessibility. For those really harsh days, wood-fired systems like rocket mass heaters coupled with biomass backups can provide reliable warmth. Geothermal and wind power, while being a larger investment, pay off in the long run with minimal environmental impact and low operational costs.

Incorporating renewable energy into your permaculture design isn’t just about warmth—it’s about creating a system that works in harmony with nature. Remember, start small, experiment, and find what works best for your specific circumstances. Keep cozy, and have fun with your permaculture journey!