Keith Wagstaff


On a recent trip down to Durham, North Carolina, I was lucky enough to stay with Stephen and Rebekah Hren, authors of The Carbon-Free Home. Their beautiful two-story house produces enough energy to fill all of their energy needs and is outfitted with all kinds of ingenious projects straight from their book. In front, a garden grows everything from artichokes to pomegranates, while chickens roam around in the backyard. They were gracious enough to talk to me about how we can become a more sustainable society.

What's the simplest home project people can do to start towards having a carbon-free home?

Two biggies are phantom loads and hanging up clothes to dry instead of using an electric dryer. Phantom loads are things like TVs and computers and also battery chargers that often are on standby and therefore partially on at all times. Using a power strip or motion-activated outlet to turn these things on or off when not in use can often reduce their power consumption by three-quarters. By one estimate, if people in the US were more conscientious about not having phantom loads, that would save enough electricy to power the continent of Australia. Folks often say that solar power is expensive and only for the wealthy, but much of our book is focused on things that both renters and homeowners can do that gives them access to renewable energy and also saves them money. Probably our favorite is hanging up clothes to dry on a solar clothes dryer instead of using a fossil-fuel powered dryer. For a typical household, installing one of these solar devices is roughly equivalent to installing $8-10,000 of solar electric panels.

What is the biggest energy waster in most people's homes and what can they do to mitigate its effects?

Well, there's the two above that we already mentioned. Lighting and refrigeration are two other biggies. Refrigerators have made huge strides over the last decade or two, and are often three to five times as efficient as they once were. Incandescent lights put 95% of their energy into heat and only 5% into making light, so they are basically just heaters that accidentally put out light. Fine in winter, but in summer, that just means you're heating up your apartment and either being uncomfortable or having to use more AC. Phase those puppies out with CFLs.

I, like most people who live in New York, live in a small apartment without much room for home renovation projects. What are some ways for people in small, rented apartments to make their homes more energy efficient?

That's a good question. Sabotaging that ancient fridge might be a great first step so you're landlord has to buy a new, much more efficient one. Most walk-ups are already very efficient, in fact, city living uses just half the energy (and hence fossil fuels and carbon pollution) that suburban living uses. Having just one or two exterior walls in multi-family dwellings is a fantastic way to save energy, so most folks get props for just being urban. There are simple things to do that we go through in our book, notably sealing cracks on exterior walls with caulk and making drafty windows less so through rope caulk or temporary storm windows, which can be made out of simple clear plastic.

Tell me a little about researching your book The Carbon-Free Home. What surprised you and what was the most difficult topic to master?

What surprised us the most was how easy it was to make huge leaps and bounds and dramatically reduce our energy consumption from that of a typical household, often with very little or no inconvenience and often with substantial money savings. This was really a wonderful thing to figure out. On many levels, the problem of global climate disruption and our destructive addiciton to fossil-fuels can be solved by simple habit changes: regulation of our homes and appliances; walking, biking and taking public transit; and eating local foods. Amazingly, these things help solve other problems, especially health-related ones like obesity. Many New Yorkers already know these things of course.

The most difficult two things were cooking and trying to not use fossil fuels for transportation. Cooking doesn't use that much energy in a typical household, so transition to renewable fuels wasn't exceedingly urgent. Yet we wanted to have a home that didn't require any fossil fuels. Creating the high temperatures when you want them, where you want them turns out to be tricky, but not impossible. Ultimately we ended with a lot of options: our solar oven, which we love, and basically is a crockpot for cooking super delicious stews, meats, soups, veggies, etc; an ethanol cookstove; an induction cooktop; our woodstove; and a rocket stove developed by Aprovecho and Stovetec. Transit-wise we're good about biking and walking, that was a big motivation for moving into the city from the solar country pad we'd built (much more about this in our book). But kicking the automobile altogether proved difficult. We spent a year without one, had a diesel we converted to run on used veggie oil, and now we're stuck with an efficient hatchback. Of course, if we sell enough books we'll get one the new electric cars coming on line and be able to do our motoring off renewable juice we make on our rooftop. Two things stuck out as particularly difficult.

How can the government encourage people to make energy-efficient renovations in their homes?

The government is picking up on the need to do this, and there is a fabulous website that details all the federal and state incentives for both renewable energy and energy efficiency. Check it out at

How efficient is your home in Durham, NC? Do you actually produce energy, and if so, what happens to it?

It's good but it still could be better. We don't use any fossil fuels in the day to day operation of our home. So when we turn on a light, use hot water, or cook food, it's coming from renewable energy. There's different types of energy, of course. The most efficient way to use solar energy is to produce heat, for hot water for example. But we also have photovoltaic panels that produce electricity that then feeds out to the grid when the sun is shining. And when it's not (at night for instance), we pull electricity from the grid to run our appliances. Electricity-wise, we produce roughly as much as we use over the course of the year, although individual months might swing either way.

You two have a beautiful edible garden in front of your house, but lots of neighborhoods have pretty strict neighborhood associations that only want people to have standard grass lawns for property value reasons. Any suggestions for getting around this problem?

We suggest the sneak attack. Win them over with beauty. Plant a bed that has lots of flowers and a few veggies. Sneak in a plum or peach tree. Start a new bed the next year, until your yard is overflowing with food. And if you feel like you're getting dirty stares from a neighbor, make sure to bring them a bag of fresh tomatoes, and watch their resistance melt in the summer sun.

With the BP oil spill, a lot of anger has (rightly so) been pointed towards BP and the MMS. Ultimately, however, they were just feeding our incredible thirst for oil. How do we convince people to take ownership of this current disaster and wean themselves off oil?

Ultimately, you have to make the alternative sustainable way of life more attractive than the fossilized polluting one. The power of example is truly amazing. People often don't realize they can grow lots of food in a small space, along with plenty of flowers. We have fruit trees out front, and perennial veggies like artichokes, and a solar hot water heater and PV panels on our roof, just a half mile from downtown Durham, NC, and people come by and lots of times they're blown away. What is that thing on your roof? It heats our water with the sun. No way! Is that an orchard in your front yard? Yes it is. I had no idea you could grow fruit in the city! Actually it's much easier, there's no deer here. And so on. Each crisis is an opportunity for creating awakening and the best way to do this is to lead by example.