We're leaving money on the table by not improving energy efficiency (image by pfala, CC 2.5 licensed)

Would you spend $520 to save $1,200? That's the choice McKinsey & Co is offering to the U.S. about energy efficiency. In their new report on energy efficiency, released last week, McKinsey shows how the U.S. can reduce its non-transportation energy use by 23%, eliminate the emissions of 1.1 billion tons of greenhouse gases annually, and save $1,200 billion, for a cost of about $520 billion.

They do recognize that achieving these results requires some new thinking on our parts:

Such energy savings will be possible, however, only if the United States can overcome significant sets of barriers. These barriers are widespread and persistent, and will require an integrated set of solutions to overcome them – including information and education, incentives and financing, codes and standards, and deployment resources well beyond current levels.

The report not only provides the conclusions, but also the steps we can take to address barriers and achieve the desired results. They suggest an overarching strategy, including the key point that "energy efficiency is an important energy resource to help meet future energy needs..." and the need for an integrated portfolio of different approaches to unlock the full potential of energy efficiency.

Link

Nabih Tahan's passive house remodel in Berkeley

Last night BuildItGreen's South Bay Professional Guild hosted Nabih Tahan, a Berkeley-based architect who was recently featured in a New York Times article on passive houses. Nabih discussed the passive house concept and how it is being applied in Germany and the rest of Europe, as well as his experience building Low Energy Houses (Niedrigenergiehaus - the generation of homes before the passive houses) in Austria and remodeling his conventional house in the Berkeley flatlands into a passive house.

The term "passive house" reflects the concept that these houses do not have heaters to provide warmth. Instead, they  "passively" recover heat from all the other activities in the home - such as cooking, lighting, and even human activity. To enable this, a passive house is highly insulated, with an airtight building envelope, so that no heat can escape. To keep the air quality high, passive houses use "heat recovery ventilators" or "energy recovery ventilators" with air-to-air heat exchangers to constantly replace the old inside air with new outside air, while keeping the heat from the old air inside.

Passive houses typically use about 80% less energy for heating and cooling than conventionally-built houses.

(See more about passive houses in this post on my blog, and the Passive House Insitute U.S.'s web site.)

Tahan's talk covered a huge amount of ground. Some of the high points included:

• A description, with a number of photos and a video, of the current German and Austrian technologies for building houses and multi-family residences. These homes are built in factories, by automated, computer-controlled machines, and assembled in a few days on site. Because all the pieces are designed to high tolerances, the building sites are very quiet - if you hear a power saw on one of these sites, you know someone made a mistake.
• He showed a picture of "model home mall" in Austria (here's something similar in Germany - in German), where more than 40 of these pre-built home builders have built 80 model homes that you can tour. The homes range in size and style from modest single family houses to large mini-mansions, to apartment buildings.
• I asked what one change in the U.S. would make it easier to build passive houses here. He said better windows and doors. Insulated and well-sealed windows and doors, often with triple-glazing and special coatings on the glass, comprise a key component of passive houses in terms of keeping the building envelope airtight. There are many manufacturers of these components in Germany and the rest of Europe, but none to very few in the States. In fact, Tahan is currently in discussions with investors on starting a factory to build these components, in partnership with an Austrian company.
• For his Berkeley house, he decided to work with a U.S. supplier, Sierra Pacific, to demonstrate that the passive house standard is possible in the California climate with local products. In any case, buying the windows in Austria would have cost less than buying them here, but the cost of shipping would have made the Austrian windows more expensive.
• In building a passive house, airtightness is as important as the insulation - they work hand in hand. And it's the most difficult part, especially in the United States where buildings are not constructed by computer-controlled machines.
• In Europe, building a passive house costs 4-5% more than conventional construction, but it saves 80% of the energy. Currently it's a somewhat bigger premium to build a passive house in the States, due to lack of suppliers and know-how.

The passive house concept and approach is clearly a component of a zero-net energy home program. Reducing the amount of energy a home uses means it's a lot easier and cheaper to generate that energy onsite. Architects like Tahan will be a key enabler of getting to the 2018 goal of 100% zero net energy homes in California.

This was an excellent talk, and I'm looking forward to hearing more from Nabih Tahan, and attending more BuildItGreen functions. If they're all at this level, they'll be a great resource for getting California to the goal of 100% zero net energy new houses by 2018.

Update (2/13/09): Nabih tells me that the Passive House California Group has just set up their website, where you can read about their next group meeting and other topics.

House, ready to become zero net energy (Image by Panoramas, CC 2.0 licensed)

In October 2008, a number of federal government departments and research organizations collaborated to produce the Federal R&D Agenda for Net Zero Energy High Performance Green Buildings (PDF). It's a fascinating document, its origins driven primarily in response to two energy policy laws passed in 2005 and 2007 (during the Bush administration). In particular, the Energy Independence and Security Act of 2007 (EISA 2007) created an Office of Commercial High Performance Green Buildings and a consortium on a Zero Net Energy Commercial Buildings Initiative. This consortium produced the R&D agenda.

The EISA 2007 act also includes a $250 million program that the DOE and other agencies are administering with the goal of “all new commercial buildings to be so efficient in energy consumption and in on-site renewable energy generation that they offset any energy use from the grid,” part of the Energy Independence & Security Act (EISA) of 2007 passed by Congress and signed by President Bush last year.

Noting that buildings represent about 40% of U.S. energy use, and 40% of our greenhouse gas emissions, the report says:

Buildings present one of the best opportunities to economically reduce energy consumption and limit greenhouse gases.

And we already have in hand technology and techniques to get a good start on this:

From an energy perspective along, high performance building technologies can already reduce building net energy consumption on average by 30-50%. New technologies to achieve net-zero energy - buildings that over a period of time produce as much energy as they consume - must be developed and integrated holistically into building design to make buildings more self-sufficient.

For the remaining 50% of the job, the report defines six areas of research and development that are needed:

• Improving our ability to measure the performance of buildings, and design integration
  

  Credible performance measures, combined with tools, performance data, and design guidelines, will create market demand for emerging building energy technologies, economies of scale, and reduced capital costs.Designing for effective daylighting, ventilation, and passive solar energy management, for example, could yield energy savings approaching 40%, without advances in individual technology efficiencies.

• Developing building technologies and strategies to achieve net-zero energy
  

  Energy-efficient and direct-use renewable energy technologies - in the forms of cost-effective materials, components, subsystems, and construction techniques - still have enormous potential for energy savings at costs lower than acquiring supplies from traditional or renewable power sources. At the same time, renewable power and other supply technologies also have enormous advancement potential.

• Improving water use and water retention
• Improving the energy footprint of building materials and building activities
• Improve occupant health, safety, and productivity
• Enable these new technologies to be put into use in practice
  

  Adequate information and communication flows are critical to achieving energy and resource goals. Substantial technology transfer efforts will be required to penetrate all facets of the building and construction sectors.To enable a future where truly integrated design is the rule, rather than the exception, the process by which buildings are planned, designed, constructed, operated, and demolished requires a radical cultural change.

I recommend taking a look at this report - it's quite interesting reading. As a government-sponsored work, it is naturally somewhat conservative, but even so it holds out a lot of hope - and suggests numerous avenues to pursue - for significantly reducing the energy demand of our commercial and residential buildings in the U.S.

Cannon Beach zero-net energy house

In lieu of a longer post today, I thought I'd provide links to examples of some of the amazing homes people are building today to achieve zero net energy:

• The Truro house, designed by ZeroEnergy Design in New England and built by Silvio and Silvio. Hat tip to commenter Adam Prince for this link.
• 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.
• Amory Lovins' house and office.
• Vermont's "Most Efficient House" also from Fine Homebuilding.
• These German houses, using passive heating, are not quite zero energy, but they definitely reduce the "Energy Demand" side of the equation significantly

Snow on the San Gabriel Mountains (photo by Jerry Thompson1, CC 2.0 license)

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.

1. 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).
2. 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.
3. More than 10% of new homes in California will be zero-net energy.
4. 50% of new residential construction in California will be zero-net energy "ready."
5. The current LEED standards will be considered obsolete.
6. More than 20% of peak grid electricity will come from excess capacity from residential solar PV.
7. 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.
8. 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."
9. 10% of the cars on the road will be powered by 100% renewable energy and will be essentially non-polluting.
10. 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.

Amory Lovins

Amory Lovins is one of my true heros, and I'm thrilled to hear that U.S New has named him one of World's Best Leaders in their report this week. Lovins has inspired multitudes (and this blog) with his vision of "getting off oil at a profit" and "drilling for negabarrels under Detroit." The Rocky Mountain Institute, a "think and do" tank that he founded 26 years ago, takes this vision and makes it happen for Fortune 1000 companies, the military, and governments around the world (including Portola Valley, just up the street from me, where he spoke a few weeks ago).

Lovins argues that, contrary to the common belief, efficiency is much cheaper than energy use. Especially when pursued with a technique he calls "integrative design,' doing efficiency right results in lower energy use, lower costs in the first place, and better productivity. The last point is critical - efficiency improves not only the bottom line by reducing costs, it also improves the top line by increasing productivity and profits.

So why aren't we pursuing energy efficency faster, if it has so many benefits? Many companies are doing so, getting benefits that go directly to their bottom line and give them a competitive advantage, like Dupont. And Intel. And Wal-Mart.

In 2006, for example, RMI partnered with Wal-Mart to boost the fuel efficiency of the retailer's truck fleet. "When Wal-Mart came to us," he says, "we had a lot of internal discussion, because they have big issues," notably the company's history of labor problems. "But we decided if we worked only with perfect companies, we wouldn't get anything done." The collaboration has proved fruitful. Wal-Mart is now working to retrofit its 6,800 trucks with designs developed by RMI that should allow its fleet to go from getting 6 miles a gallon to between 16 and 18 miles a gallon by 2015, saving about $500 million annually.

These companies, and many more, are enjoying an "unfair advantage" due to their pursuit of efficiency. But for many companies, there are mixed up incentives, such as between commercial landlords and their tenants. The landlord has to pay for the efficiency, but the tenant reaps the benefits - their interests are not aligned, and so "business is usual." In his books and talks, Lovins provides techniques, guidelines, and policy suggestions to help align these incentives.

For more on Lovins, I can recommend his books, Winning The Oil Endgame and Climate: Making Sense and Making Money (both available free for download) and Natural Capitalism, written with Hunter Lovins and Paul Hawken.

You can hear Lovins in numerous talks and interviews available as podcasts, including this outstanding series of five talks at Stanford University in 2007. Download those to your iPod or mp3 player and prepare to be amazed by the possibilities.

Congratulations Amory!

Spider silk has desirable technical properties that manmade materials cannot replicate yet

I just visited AskNature.org, [url corrected] a new resource and social site for people interested in understanding how nature has solved various design problems - such as energy conservation, water collection, and energy generation - and how we can use those solutions as inspiration for our own technology.

AskNature is a bio-inspiration website where innovators can learn from nature's solutions, biologists can find a whole new audience for their research, students can be inspired through science, and collaborators from different disciplines can work together to create innovative, sustainable, bio-inspired designs.

Currently on their home page they link to articles on the three topics I mentioned above - conservation, water, and energy generation. The articles feature an overview of the topic and how nature has addressed it, an example organism that's solved the problem in an interesting way, and then one or more technology solutions that are based on nature's approach - often contrasted with technologies for the same problem that are not inspired by nature.

Nature solves problems for organisms using evolution, using millions of experiments over tremendous time to optimize the solution under the constraints of very low energy inputs, ability to build the solution from basic materials using a digital program (genes), and only generating waste that can be used by other organisms. When nature's solutions can be repurposed to solve technological problems, those same constraints are additional benefits - reducing the energy required for the solution, making the process digital, and eliminating waste.

The site is a project of Janine Benyus' Biomimicry Institute, a not-for-profit whose mission is to nurture and grow a global community of people who are learning from, emulating, and conserving life's genius to create a healthier, more sustainable planet.

The Sahara Forest project will use seawater and solar power to grow food in greenhouses across the desert. Photograph: Exploration Architecture

The Sahara Forest project represents integrative design at a huge scale. (Integrative design combines multiple design improvements to get an overall improvement that's bigger than the sum of its components.) As it says on the the Sahara Forest project home page:

The project combines two proven technologies in a new way to create multiple benefits: producing large amounts of renewable energy, food and water as well as reversing desertification.

The two technologies are the Seawater Greenhouse, invented by Charlie Paton, and a concentrating solar energy generation capability. The synergies arise in several ways - the energy generation provides the power to run fans to work the greenhouse, while the greenhouse creates excess fresh water for cleaning the mirrors of the generator, for example. The team that's come together to create the project also represents some interesting synergies:

An inventor - Charlie Paton, creator of the Seawater Greenhouse; an architect - Michael Pawlyn of Exploration Architecture, previously of Grimshaw and the lead architect on the iconic Eden Project; an engineer - Bill Watts of Max Fordham & Partners, an engineering firm that focuses on energy efficient systems for the built environment.

The Sahara Forest post at Treehugger features a long interesting response in the comments by Pawlyn in response to questions raised by other commenters.

This is one of several projects I've read about recently that combine energy generation via visible light with use of the excess heat to achieve much higher solar energy conversion efficiencies. For example, this report in Science Daily last year about a prototype PV/Thermal system that was projected to capture 80% of the energy. While it complicates the mechanicals of the system, it certainly seems to make sense to take advantage of the heat created as a side effect of PV energy collection, especially since the PV cells work better - are more efficient - at lower temperatures. The heat needs to be removed anyway!

So far neither the project's website or news reports about the project have many details about its progress or funding, but it's definitely something to keep an eye on.

Solar power systems covering the areas defined by the dark disks could provide more than the world total primary energy demand in 2006 (assuming a conversion efficiency of 8%). Image from Wikipedia.

I recently asked physicist Richard Muller whether he thought the price-performance of solar electricity generation would follow a Moore's Law-type curve. He said that this would not occur due to improving the efficiency of solar collection, as the current levels of efficiency - 20-40% - are reasonably high. However, he added

"I do expect the price to drop by a factor of 10, so we will have lots of solar."

Well, in the nature of things, there's definitely a limit to how much energy a solar PV collector can get from a square meter of sunlight. (There's about 1kw of energy in a square meter - as I learned in Physics For Future Presidents, by Professor Muller - so we can expect to get 400 watts or less.) The amount of this energy per square meter we can collect will go up, but asymptotically approach (at best) the physical limits.

On the other hand, I'd argue that the cost of collecting it can go down a nearly unlimited amount - certainly multiple orders of magnitude. So what will solar PV look like in 2018 - ten years from now?

There's no physical reason that a solar collector roof would cost more than an increment above a conventional roof - the increment having to do with interconnecting the roof to the house's power system. That is, if the conventional roofing material includes solar collection capabilities. (For example, check out Solar Century's C21 solar PV roofing tiles.)

Just to run the numbers out:

• One square (100 sq feet, or ~9 sq meters) of metal roofing costs about $2,000 installed ($1,110 for the material, $750 for the installation). Metal roofing is not the cheapest type, but it's convenient for these calculations.
• One square (or 9 square meters) represents about two kilowatts of solar PV at 20% efficiency. This is about the electricity used by a normal single family household.
• Today 2kw of PV costs at least $12,000 installed, or six times as much as the regular roof. The payback for installing 2kw at that cost is typically 8-10 years.
• Assuming one quarter of the solar PV cost is installation (this is a high estimate), then a factor of ten reduction in the cost/kw for the collector takes the cost for this 2kw system down to $3,900.
• If the solar PV panels are structural roofing as well, then I'm paying a $1,900 premium for each 2kw of solar PV. That premium represents just about a one year payback.
• In fact, it's so cost effective, I would probably choose to put 4kw on my roof - twice what I need. The excess can be used to fill my not-very-efficient storage devices such as a fuel cell or batteries for my plug-in hybrid SUV.
• By using integrative design to solve two problems at once with my solar PV collector system - energy and roofing (and I could also include insulation and possibly other benefits depending on the design) - and projecting the factor of 10 reduction in price/kw, it becomes cost effective to over-generate, meaning I can then also replace my trips to the gas or hydrogen station

So, when I talk about solar PV having a Moore's Law-like improvement in price-performance, this type of integrative design is what I mean. Technology improvements in the collection itself (efficiency and manufacturing of the collectors) get us the first factor of ten price reduction. Then other types of innovations - such as roofing materials becoming solar collectors - get us another factor of two-to-five.

Moore's Law about the price-performance of silicon chips was and is based on a constant reduction in feature size. Smaller feature size drives price-performance of chips because of several factors, but primarily due to the fact that electrons have to travel around, and the shorter the distance they have to travel, the faster they get there. A similar "feature size"-based price-performance reduction is happening in hard disks as well; the engineers keep making the magnetic domains smaller and closer together, so the heads have less distance to travel to get to data and more data can be packed into the same space.

However, in contrast, the price-performance revolutions in solar PV are not going to be based on feature size - the feature size is already fixed at 1kw per square meter. And in fact feature size, especially for residential solar PV, is not a big problem - most of our roofs have much more space than needed for our energy needs. Instead the revolution is going to come about on the cost side, via a combination of:

• More efficient and cheaper manufacturing approaches, ranging all the way down to nano-assembly eventually
• New PV materials (e.g., CIGS and organic PVs) and improvements in existing materials
• New form factors, such as integrating PV into roofing, windows, and siding, that embed the cost of the PV incrementally into existing costs
  • Note that because roofs and other housing surfaces are so large, PV cell efficiency is much less important than cost per KW, as long as the cost is incremental to the existing material
• Other new approaches we can't even think of right now

Just as the semiconductor and disk drive industries have had to come up with innovation upon innovation to maintain the pace of Moore's Law, so will the solar industry - and it will.