What About Net-Negative?

By George Harvey

Many people question whether a zero-energy building is really possible. In fact, it is not really hard to imagine, if you think about it. And it is not all that hard to do – lots of people do it.

To achieve zero-energy does not really mean using no power and putting out no carbon emissions. It means producing at least as much power as you use and emitting no more greenhouse gasses than are sequestered by your activity. Burning firewood is considered by some people to be carbon-neutral, apart from the carbon emissions from equipment to cut and move it. And carbon emissions from burning fossil fuels can be offset by activities that sequester carbon.

We might reflect that most farmhouses were carbon-neutral in the not-so-distant past. A country house that was heated by hand-cut firewood and lighted by homemade candles could easily have been carbon-neutral. For some folks a carbon emitting lifestyle was ordinary living, until their houses got electricity. Today, many people choose to life off the grid and achieve carbon neutrality.

For our planet to continue as we know it, carbon neutrality by a few off-grid exemplars will not suffice. We will all have to move in that direction. Some of us will have to go farther, just to make up for those who do not make it. Some of us must have net-negative consumption.

Net-negative energy consumption means producing more energy than you consume. If you have a solar or wind system and are grid-tied, it is easy to understand putting more energy on the grid than you consume. In many places, you get a statement with a check instead of a bill, when you do this. It is common for this to happen in Europe.

There are good points about this aside from making money. One thing it means is that when the power on the grid goes down, if you are set up to detach your power from the grid, you will go on producing electricity you can use.

Another good thing is that you wind up offsetting your neighbors’ energy consumption and carbon emissions. Financially, this is to your benefit and at their expense.

In fact, we can extend the idea of net-zero carbon emissions into areas of life that are not exclusively associated with electrical power or heat. Any act that sequesters carbon is net-negative in carbon emissions. For example, if you use a woodstove and put your fire out, you can grind or smash the charcoal and bury it in the ground. Done with a little knowledge and care, the charcoal, called biochar, is a permanently fertilizing soil amendment. It is also profoundly net-negative in carbon emissions.

Understanding that some people will be net-negative energy consumers and net-negative carbon emitters, we can see that at some point in the not-so-distant future our entire society can achieve a net-zero status, or possibly even net-negative. When that happens, we will be able to emit less carbon dioxide than we remove from the atmosphere.

We might add that there are well-informed and intelligent people who believe not only that this is possible, but also that it will happen at some point in the not-so-distant future.