Building My Carbon-Free Library

Challenges and Opportunities

Photo by Aida Geraeva on Unsplash

I am nuts about books. I'm so nuts about books that one time about thirty years ago, I bought an out-of-print bookstore. Yeah… the whole thing. It didn’t go so well. Turns out that if you love books, owning a bookstore is kind of awful. You have to keep selling the books you love to stay alive! So I sold the store and reverted to being a book buyer.

I have a library of about 2,000 books, and I have a new homestead I purchased in June of 2022. It is a small cabin on ten mostly wooded acres. If I stay here, the intention is to build it into a totally off-the-grid, no-carbon place.

Now, I know that construction has carbon costs. There will be concrete, lumber, windows, and other building materials. No doubt, all those have carbon implications. There is little I can do about that without resigning myself to a grass hut, and that’s just not going to happen. But what I can control, and hope to demonstrate, is how easy it is to build to modern standards and have a home and life operation that generates little or no carbon from the operation. We’ll see how it goes.

The First Building—My Library

The reason I mention books is that my first building is going to be something a bit unusual. Many people undertaking a project like this would start with a garage so they can house their tools, and have a place to work. I’m starting with the library. It is far more important to me than the garage because books are what sustain my life. They are integral to my creativity, my livelihood, my curiosity, and my energy. I just can't live without them. Plus, the current cost of housing them in a storage locker is fairly high, at $120 per month, and they are not in a climate-controlled situation. My books are deteriorating. They are also fairly inaccessible.

So, what does this library need? First, I need a climate-controlled place to hold the books and a place to read, write, and study. Not an office, per se, but a writing studio. Every artist needs a place of their own. This means that the building must be constructed with heat, electricity, and daylight. Water and a bathroom will be present in the home rather than in the library, so I am not dealing with that here.

I calculated the average number of books per shelf (30) and average shelf size (36 inches), and divided it out by 2,000 books. It looks like I need about fifty feet of wall space to house what I have. I am figuring 70 feet to allow for expansion. That could mean 30 feet along a back wall and 20 feet deep, so about 600 square feet. The front will be all glass. As life goes on, I am sure to keep buying books, so I must also allow for the possibility of an addition to the original building. There will always be more books!

Solar and Heat Pumps

Electricity and heat will be best supplied via solar energy. The first option for solar is to maximize passive solar gain—i.e, capturing heat through the windows. I've been thinking of a large southern exposure with really good heat-holding windows to collect sunlight and warm the place during the day. Of course, the challenge is that the sun damages books, so I would also have to install shades. These shades, however, would not cover the windows. Rather, I would mount them over the bookcases deep into the building so that the windows can collect sunlight warmth and the blinds can protect the books. I would not use the blinds for privacy—only for shading the books and protecting them from the sun. This way, I can protect the books but still take advantage of that large solar gain available.

Because the building is small, it is also an excellent application for a mini split heat pump. These units do a great job of heating and cooling, and they are far more efficient than either electric heaters or air conditioners. That efficiency is important if I am running on solar. Efficiency shrinks the size and cost of the solar system I will need to install, and since this will be off-grid, the smaller the better.

Also, I want to mount all the panels needed on the rooftop, and that produces a limit on the size of the solar system. Being off the grid, I cannot send extra production back to the grid, nor can I store overproduction in summer for use in winter. That overproduction is substantial. According to NREL and other solar organizations, summer production in my area is on average 3-4X winter production. So if I build a system big enough to cover all of my winter needs, I will generate 3-4 times too much in the summer, thereby having incurred far more expense to build the system than most of the year requires. That means I over-invested and built too large of a system.

This comes into play in a big way. My preliminary calculations showed that I might need as much as 1,030 square feet of space covered with solar panels to generate the electricity I need. However, I am building the roof on a footprint of 600-700 square feet. The tilt of the roof will add some space, but not that much. So the roof becomes a limiting factor, unless I am willing to install a ground mount system at a substantial additional cost.

Because I can build the structure specifically to accommodate solar energy, the south-facing roof slope and size will be determined by the needs of a solar system. In northern Wisconsin where I live, the lowest sun radiation we receive is on the winter solstice when the sun is at about 22-degree angle to horizontal. To maximize production at the solstice, therefore, I would want my panels at 22 degrees tilt. My first thought is that if I can design the roof to be at that tilt, I can mount the panels flush with a minimum of racking, and protect my roof from the weather.

Pluses and Minuses of This Plan

The ultimate idea is to run everything on solar year-round, but this may not be possible for two reasons. First, I could be limited in the size of my solar array, therefore limiting the electricity available to run the system during the winter months. No electricity, no heat. Second, mini split heat pumps don't work as well as advertised in sub-freezing temperatures. I know because I have one in my current cabin. It is excellent in the fall and spring when temperatures are in the chilly thirties and forties, but the deep freeze of winter makes it divert to automatic defrost mode and it stops heating the place. When the temperatures plunge into the sub-zero range (Fahrenheit), it's just not up to the job at all.

How to Supplement?

The biggest questions with this plan are: First, what happens if we get extended cloudy days and I don’t have enough electricity to power the heating system or, quite possibly, run the air conditioning? And second, what happens if it is too cold outside for the mini split heat pump to work effectively? There are only two reasonable options—propane and wood.

The Problem with Wood

While heating a home with wood as a backup isn't workable due to the requirement to be there all the time, it could work in the library. I would only need to heat the building when I am there (since there are no pipes or water). Even if I was gone for a month and the temperature went below freezing, the only things to freeze would be the books themselves.

Besides the need to be there to feed the fire, and take the time to heat the place up if you were gone for a while, burning wood for heat creates carbon emissions, particulate matter, and ash. Burning wood also tends to get smoke inside the building despite best efforts, and it doesn’t take much smoke to deposit a filthy soot onto the books. Not good for a library.

Finally, wood burning does not produce electricity, and without a backup, I would be relegated to over-building the solar system the way I described or using a gasoline-powered generator to recharge the batteries. The other option would be to just accept the limitation that, sometimes, the library might not have electricity.

Propane—Concerns and Benefits

Propane has different concerns. It is a fossil fuel and has all the drawbacks of fossil fuels in a climate-changing world. Propane is refined from crude oil, delivered by truck, and releases carbon emissions when burned. It also has the advantages that made fossil fuels so dominant—it can be burned on demand, appliances like furnaces that use it a relatively inexpensive, the heat is immediate, and you can run it on a thermostat whether you are there or not. In other words, as a writer, propane would allow me to reliably plan that the place is warm when I arrive in the morning to write. With wood, I’d need to start the fire first, and then warm it up.

It is easy to install a propane backup for heat. If the temperatures drop to where the heat pump can’t handle the job, a thermostat can turn on a wall-mounted propane heater. Propane can power the heater, but it can also power a generator.

One tank for two gas lines—one to the electric generator and one to a wall-mounted propane heater. The generator can turn on automatically if there isn’t enough electricity in the batteries due to low recharge rates on cloudy days. That would provide the electricity to run the heat pump(if it is not too cold) and the lights.

These considerations are quite a bit simpler for this library project than they would be for a home because I don't have or need running water in the library. Hence, "backup heat" is really just to make it comfortable for me. If the heating system suddenly stopped working it would not be a terrible disaster—no frozen pipes, no broken pipes, no frozen liquids, shampoos, food, or people. I would just have a building full of cold books—much as I do now in storage.

What to Do?

As I write this in my homestead cabin, I am locked into a multi-day overcast and foggy weather pattern. It is January and we've been in it for three days. The ten-day forecast shows zero sunny days ahead. Heat and electricity are still needed to operate, and while a solar array will produce some electricity in conditions like this, it will produce far less than it will on a sunny day. If I were attached to the grid, I could just pull the needed energy from the grid—energy that would be produced from a mix of fossil fuels, nuclear, or renewable sources. Since I will not have the grid, I need a second source for reliable backup, and it seems that propane is the only alternative to just being cold. Although I could likely get by with that on this library project, being cold in a home just doesn't cut it. I'm leaning toward a solar-propane mix as my optimal solution.

What disappoints me is this: While I would have a nice library for my books and my work, I would fail on the goal of being 100% carbon-free. I can get to a nearly carbon-free library with plenty of daylight, a good opportunity to concentrate, and my old books all around me, but I will still need to burn something for heat or electricity and thereby emit carbon. I’m guessing it would be 90% less than with grid electricity and propane heat, and the building could operate at nearly zero cost for decades to come. I think it is worth it. Unless readers comment with an approach I didn’t consider, this is the path I am likely to take.

—Anthony Signorelli

Note: Please consider upgrading your subscription to a paid level to support this work. We all have to figure out how we are going to live with climate change and determine what we are going to do about it. That’s what Intertwine is dedicated to. Please, join me and support the project as we think this through together.

See Anthony's Most Read Stories on Climate Change--on Medium