The Cannon Beach house, built by Nathan Good, architect, and Rich Elstrom Construction. I saw this house first in Fine Homebuilding special edition on green housing. Fine Homebuilding, and the Taunton site in general, has a huge amount of information on green building.
This is the first post in a series on zero-net energy homes. Over the course of the series I will be covering all aspects of this topic, from the technology and knowledge available today, to the changes needed in technology, building codes, trade skills, design approaches, and will to achieve the goal of all new homes eventually being zero net energy.
Definitions and feasibility
What is a “zero-net energy home?” Zero net energy homes generate as much energy as they use. Energy used = Energy Generated. The experience of thousands of “off the grid” home owners and those bleeding edge homeowners with big solar panel installations on their roofs show that zero-net energy homes are technically feasible today. For example, see this article on Amory Lovins’ home and office in Snowmass, CO.
We know how to build them. Unfortunately, for most homeowners, they are too expensive, because the energy generation side of the equation is too costly. There are three ways to address this problem.
Reduce the cost of home-based energy generation, typically either solar or wind. That depends on technological improvements and manufacturing efficiencies by the solar panel companies, and they are busily doing their best to address this situation.
Change the cost basis for comparison – energy generation is expensive compared to the cost of electricity from coal-fired plants, but a carbon tax on those plants would automatically make solar more competitive (and raise the cost of energy for all of us).
Make the demand side of the equation – energy used – smaller. Reducing the energy used by half cuts the energy required by half, which cuts the cost by half. And typically reducing energy use has numerous other cost benefits, and often performance benefits as well.
Over the course of this series of articles, I’ll be looking at how both sides of the equation can be reduced, but the particular focus will be on getting the demand side down.
Privation is not the solution
One way to reduce the energy use of the home is simply to do less – for example, you can save a lot of hot water if you simply stop showering every other day. Other techniques are leave the heater off when it’s cold, or the AC off when it’s hot. There’s also sitting in the dark – lighting accounts for about 15% of home energy use. Strangely, most homeowners in the U.S. are unwilling to reduce their energy demand by cutting “services” in this way.
Therefore, we have to find ways to reduce energy usage while not cutting the “services” the home provides. We all need our showers, our lights, and our comfortable temperatures. The good news is that by making small changes in how homes are designed and built, typically at a very small increment to the cost of the home overall, we can build houses that use one half the energy or less, and often at a higher level of comfort and “service” than standard-built homes.
As we will see over the next few articles, we already have all the technology, and some people have the experience, to build “zero-net energy ready” houses cost effectively.
On the energy generation side, although there’s currently a premium to get to zero-net energy, over the next ten years this premium will go to zero. In fact, looking farther ahead, it may become cost-effective to get to positive-net energy – where the house is generating more energy than it needs! Such a change has world-changing implications – but we’ll cover that later in the series.
Zero-net energy homes is a huge topic, and some of the areas we’ll be covering in future posts are:
Home energy storage
Zero-net energy for existing homes
Zero-net energy and LEED
Practical steps for finding a zero-net energy home builder
Examples of zero-net energy homes
Achieving a zero-net energy home cost-effectively
How the cost-benefit equation on zero-net energy homes is likely to change over the next five and ten years
As I get started on this series, I’d love to hear your comments and thoughts on what I’ve presented here, as well as other topics I should cover in future posts.
On December 30 of last year (six days ago), my wife and I were in Pasadena, CA visiting the Greene and Greene exhibit at the Huntington Library. It was one of those glorious and rare smog-free days in the LA basin. The air sparkled, you could see for miles in every direction, and mountain range after mountain range was visible – all the way out to the snow-covered San Gabriels. Nowadays, the air is only ever this clear around the Christmas holiday, when the freeway traffic is substantially reduced and a lot of factories shut down for the week. It got me thinking about how the future – say ten to twenty years hence – may be unrecognizable in both dramatic and mundane ways. For example, smog-free days may no longer be rare in LA, once the economy has shifted off fossil fuels. (I suspect the traffic will remain, unfortunately!)
Like LA’s typical skies, the energy future is murky in the short term – this year and 2010 – and I’ll leave those predictions to others. But the big trends – sustainability, carbon fighting, and technological breakthroughs – enable us to make better sense of the mid- and long-term. Therefore, In the spirit of the New Year, the incoming administration, and the tipping point that the world has come to about climate change and sustainability, here are ten things I believe are very likely to happen in the next ten years.
Residential solar PV will be cost effective in most U.S. locations (via a combination of price reduction, new design thinking, much more efficient homes, and a carbon tax on fossil fuels).
Home energy storage – via batteries, hydrogen reforming, fuel cells, or other technology – will be available and installed in 10% of new homes in California, for when the sun don’t shine.
More than 10% of new homes in California will be zero-net energy.
50% of new residential construction in California will be zero-net energy “ready.”
The current LEED standards will be considered obsolete.
More than 20% of peak grid electricity will come from excess capacity from residential solar PV.
There will be general consensus that efficiency and frugality alone will not provide enough CO2 mitigation to prevent major climate change – we will need a technological solution to actually reducing atmospheric CO2 or artificially cooling the earth.
There will be a mid-priced carbon fiber, plugin hybrid passenger car in production that gets more than 75 miles per gallon. The company making it will be the “next GM.”
10% of the cars on the road will be powered by 100% renewable energy and will be essentially non-polluting.
New technologies for capturing carbon from the atmosphere will be available, powered by excess solar capacity.
What do you think? Am I off base here? Too optimistic? Too pessimistic? Let me know in the comments. I’d love to hear your thoughts, challenges, and predictions for 2018.
Zero-net Energy Series Coming Up
Over the next few weeks, I will be publishing a series on “zero-net energy” residences (related to predictions 1-6 above). This area is about to explode. We already have all the technology, and some people have the experience, to build “zero-net energy ready” houses cost effectively. And although there’s currently a premium to get to zero-net energy, over the next ten years this premium will go to zero, and probably it will be cost-effective to get to positive-net energy – where the house is generating more energy than it needs! Talk about a world-changing situation – it really is possible to have energy too cheap to meter, but it’s going to come off our roofs, not from a nuclear plant or one of those imaginary fusion reactors.