Rebekah Hren stands over the small desk in the bedroom she and her husband Stephen share in Durham, North Carolina, and powers up their Mac mini. She clicks straight to the local television station’s weather site and opens its up-to-the-minute DUALDoppler 5000 radar feature.
Rebekah isn’t concerned with whether she’ll want to carry an umbrella today. Instead, she’s deciding which appliances the couple wants to avoid, which windows and blinds to open and close at what times and how long a dish will take to cook in their solar oven. "Every morning we take stock of the weather and then do the windows and shades," she says. "It doesn’t take long. You get used to it."
Although the Hrens (pronounced "Rens") live in the city, their 1,400-square-foot home isn’t connected to the power grid for now. Their energy comes instead from six 200-volt solar panels on the roof, generating 1.2 kilowatts of power. That’s not an awful lot of electricity, but then, the couple doesn’t need all that much.
Since Rebekah, 33, and Stephen, 34, moved to their Durham house two years ago, they’ve been on a mission to live free of fossil fuels, a goal that by their accounts they’ve come pretty close to achieving. "I think we’ve done a pretty good job," Stephen says. "We cut about 95 percent of our non-renewable energy use."
They didn’t reach that low level of consumption by buying a spiffy new high-tech "green" home, but by retrofitting an older house. "There’s almost no such thing as a new green home," Stephen notes. "New homes require not only new materials, all of which are heavily energy intensive, but often new land and roads."
The Hrens are part of what Stephen calls "a quiet revolution" in microgeneration, in which consumers produce their own renewable electricity. This change is fuelled not by off-grid homeowners but by those connecting to local utilities. The vast majority of solar installations in the U.S. tie into the conventional electricity grid, as the Hrens plan to do, so that any extra energy generated can be sent back to the grid and used by someone else.
It is the first time I have ever been excited by a Table of Contents. Most books just list the chapters and the page number; in Stephen and Rebeka Hren's The Carbon Free Home they list their thirty-six projects, but also on that one page list the time it will take, the cost, the energy saved whether it is renter-friendly and the skills you need. Whew.
The whole book is like that; a well-thought out explanation about how to make your house carbon free from people who have walked the walk and really done it.
The Hrens have learned the hard way, and pass on their experiences, from their first attempt in a cob house they built thirty miles out of town, from their realization that driving that distance negated all the carbon savings and that they were not competent farmers, and then the move back into town.
They then take us through what they did to their house, doing the math and showing us how, all with links, references and cute little drawings.
Some of the projects are easy, that anyone could do; others are a lot more complicated, like this extraordinary solar wall oven.
Looking at Windows
I am preoccupied by windows, and use them as my test to judge what the writers' values are. Here the Hrens are music to my ears:
In our opinion, replacing a functioning window that could potentially last many decades if not several centuries with a window that will be defunct in twenty years is planned obsolescence designed to sell as much product as possible. It is inherently energy inefficient and not viable in the long run.
They also do a very sensible bang-for-the-buck analysis of solar power comparing photovoltaics to solar hot water, and a wonderful comparison of biofuels to bicycles, noting that 41 pounds of soybeans made into biodiesel will push a car 30 miles, but if fed to a cyclist, the same number of calories would push that bike 3,332 miles.
It is sometimes a bit intimidating, but then Stephen is a master carpenter and Rebeka installs solar panels for a living; they have the skills to do just about anything. But they express themselves clearly, lay out the science and the math, and describe from their own experience how they did what they did, and there is much in this book that anyone can do.
When the book was written, the big front-of-mind issue was climate and energy; now it is money and the economy. Yet every trick that Stephen and Rebekah teach us will save money in heating, cooling, transportation and food, from their freedom from utility bills to their rooftop vegetable garden. Whatever your reasons for going carbon free, this book is the operating manual.
By James Murray-White
April 15, 2009
Carbon emissions from the building environment are globally one of the major contributors to climate change. On average up to 50% of all carbon emissions are related to domestic use of energy – our household consumption.
How then will our personal conduct have any influence on the global climate?
The answer to that is it all adds up. As is the case in the current global economic crisis, the “butterfly effect” also works on carbon emissions, hence accumulations of local reductions will have a positive global impact. So we are not alone in reducing our carbon-footprint as you will be able to read in this book: ‘The Carbon-Free Home’ by Stephen and Rebekah Hren.
The authors have gone through several phases in their attempt to live in a carbon-free home and have gained many valuable insights they share from their experience.
Many of the eleven chapters not only include the technical nitty gritty but also personal stories which make reading this book more enjoyable. Some insights are quite remarkable and the authors also bravely admit their mistakes. One was moving out of the city only to find that their daily commuting cancelled out any carbon reductions they may have made in their green country house. They realized that ultimately moving back to the city and retrofitting existing houses is the preferable solution.
The book includes a very good overview in the form of a table of projects, 36 in total, as well as a useful index. The table provides estimated costs for each measure and an indication to their effectiveness in saving energy and CO2 emissions as well as time and skills required.
Many proposals are quite practical providing diverse solutions such as various alternative energy sources, alternative cooking methods an so on. Each chapter has also useful and hand-on advice, various references as well as black and white illustrations.
Unfortunately some of the technical information provided is not in metric units; perhaps in a future edition this can be put right.
All in all the book is recommended both for professionals as well as ordinary house holders as it provides enjoyable reading combined with practical advice which can be implemented, at large or in phases, in most homes. Their widespread implementation contributing to a more energy efficient and carbon-free home for our own benefit as well as for the benefit of the global environment.
The Carbon-Free Home – Stephen and Rebekah Hren, Chelsea Green Publishing, 2008, 260 pages www.chelseagreen.com
This book is reviewed by Gil Peled, a Jerusalem-based green architect, whose practise is called ‘Eco Challenges’, and he is the co-ordinator of Jerusalem’s Eco-Housing Pilot Project, in the Rehavia neighbourhood. And he is a great friend of Green Prophet to boot.
The Valley News
By Warren Johnston
December 5, 2008
This book is designed for those motivated to reduce and eventually eliminate the use of nonrenewable fossil fuels in their existing homes.
In addition to chapters detailing simple to complex projects that save or eliminate energy use, the book also provides a basic understanding of energy consumption. It's a guide that can be used to trim fuel bills or to help move you completely off the grid.
The projects, which range in scope from growing mushrooms to building a closed-loop solar hot-water heater, are outlined at the beginning with the time it takes to build, the skill level needed, materials, costs and energy savings.
There is a long section of the book on food and landscaping as well as chapters on cooking, refrigeration, appliances and lighting, heating and hot water and waste disposal among others. The authors make it clear that inexpensive projects that take little time can have large return in savings.
Stephen and Rebekah Hren live in Durham, N.C., where she is a solar designer and photovoltaic and hot water system installer. He is a carpenter specializing on restoring antebellum houses.
September 21, 2008
I found a great new book at the library last week - The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil-Fuel Habit by Stephen & Rebekah Hren.
I’m not all the way through this book yet, but already I can tell you it’s worth far more than the $23 it’ll cost you. (Awesome price!). Of course you can always be like me and get this book at the library, but if you own your house, it’d be a good bookshelf book.
This book covers 36 remodeling projects that can help you go greener at home (as if you didn’t guess that from the title). The huge benefit of this book is how super user friendly it is. Here are some main points…
- Handy chart at the start which shows general costs and time involved in said project, the skills you need to pull the project off, energy saved if you do the project, and the chart even points out if the project is renter friendly (rare in green project books).
- In the actual project guides throughout the book, all the background is explained (i.e. why you should consider the project), and there’s a more in-depth discussion of tools, time, and skills needed.
- Great how-to diagrams, photos, and illustrations. Even if you don’t consider yourself particularly handy or crafty, there are projects you can do in this book.
- Plenty of listed resources for other green building books, websites, and DVDs.
Examples of projects included:
- Batch solar water heater
- Outdoor cob oven
- Install a 5-V metal roof
- Storm windows
- Insulation of existing fridge
- Simple box cooker
- And of course many more
I really like this book so far and think it’s a great green home manual no matter your building or green skill level.
Carbon-Free Home Book Review and Giveaway!
June 25, 2008
So Chelsea Green was kind enough to pass along a copy of Stephen and Rebekah Hren's new book officially titled The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil Fuel Habit. As always, I've handled the book with care and will give it away to one lucky, random commenter below.* To give you an idea of the quality material contained in the book, here's a review comment from the green guru Bill McKibben: "It's hard to imagine a more comprehensive, and comprehensible, guide to making your home work for you and for the planet, inside and out. It's frugal, it's sensible, and it will help!" I'd like to echo the comments of Bill McKibben myself, because this book is completely legit.
I've found this book to be incredibly resourceful -- it's thorough, practical, and authentic. Plus, the authors know what they're talking about.
The Carbon-Free Home is meant to be a guide for the owner or renter of an existing home who is motivated to reduce and eliminate his/her use of nonrenewable fossil fuel energy and the emissions associated with such energy usage. To do that, the authors created a neat Table of Projects explaining each of 36 green remodeling projects, including the time it takes to do any given project, the cost of the project, the energy saved by the project, whether the project is renter-friendly, and the skills required to complete the project.
For instance, let's say you're thinking of installing a rain barrel. The Table of Projects says installing a rain barrel will take an afternoon, cost anywhere from $20-$100, result in little energy saved, and can be installed with basic carpentry and plumbing skills. The table also tells you where to find more information on the project in the book.
The Carbon-Free Home goes into detail explaining several helpful home renovation tips, such as building a horizontal trellis for shading, installing a closed-loop pressurized solar water heater, insulating a hot-water tank and hot-water pipes, and sealing drafts and unused windows, etc. Lots of good information in here so make sure you go pick up a copy.
*[The contest applied to the original post only and is now closed.]
The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil-Fuel Habit
Stephen and Rebekah Hren. Chelsea Green, $35 (280p) ISBN 978-1-933392-62-2
With an endearing mix of down-to-earth practical solutions and funky DIY projects, this book provides readers with much-needed information on how to renovate habits and home to move closer to a zero-carbon existence. The Hrens, respectively a carpenter and a photovoltaic installer living in Durham, N.C., give specific and technical advice, based on their own experience, on how to lower energy use within and outside the house, with 36 projects ranging from simple and inexpensive activities like sealing drafts, resetting the water heater thermostat and planting potatoes in a barrel to more heavy-duty and costly tasks such as installing a green roof or a solar hot-water heater and replacing a lawn with a permaculture garden. Some projects, such as building an outdoor cob oven—which the authors themselves describe as time-consuming with low energy savings—will be of little interest to any but devoted backyard hobbyists. Converting from a flush toilet to humanure, which involves lugging five-gallon buckets of human waste to a compost pile on a weekly basis, is even less likely to be adopted by the urban dwellers the Hrens hope to influence. But just about anyone will find something useful to do in this book, and the detailed, clear and enlightening chapter on understanding home energy use is, alone, almost worth the purchase price. (June)