Tag: Zero Net Energy Homes

Report and Insights From The Passive House Conference – Part 1

A school in Reidberg, Germany, built using the passive house approach
A school in Reidberg, Germany, built using the passive house approach

I got back yesterday from the 13th Annual Passive House Conference in Frankfurt, Germany. My biggest takeaways from the conference are:

  • While the growth of passive houses in Europe is impressive, even in Europe there are still marketing challenges
  • The opportunity to use energy efficient buildings as a hedge against climate change is immense
  • We are way behind on energy efficient building here in the U.S. – in fact, essentially no one in the U.S. is doing this kind of building.

Over the next few days I’ll be posting about things I learned at the conference, and also about the implications of what I saw for building – and for climate change mitigation – in the U.S.

Not only are there more than 30,000 certified Passive House buildings in Europe, representing a lot of tons of CO2 averted, their level of building science and technology is very advanced. The exhibitors showed a number of innovative insulation materials (most of which are not available in the U.S.), many different very highly efficient window and door options (most of which are not available in the U.S.), highly efficient heat recovery ventilation systems (most of which are not available in the U.S.), and several innovative building technologies (available in the U.S.? I don’t think so). Even so, I thought the exhibition was remarkably small, with about 70 vendors, indicating that even in Europe, there’s a huge amount of growth potential.

Several of the presentation sessions reported on studies comparing the performance of buildings constructed or renovated using the [intlink id=”368″ type=”post” target=”_blank”]passive house approach[/intlink] – super-insulated, super-airtight, with heat recovery ventilation – to buildings using other energy efficiency approaches such as the European “low energy house” standard (which is more similar to U.S. energy efficiency codes). They found, as expected, that energy use in the passive house buildings, as well as comfort levels and measured air quality levels, were significantly improved. One study compared to identical apartment buildings, next to one another on the same street, one of which was renovated as a passive house, the other as a low energy house. Both buildings were instrumented with a variety of sensors, and then tracked over a two year period. The energy bills for tenants in the passive house were 1/3 those for the low energy house.

Obviously, these results reflect not only a savings for the tenants, but also a significant reduction in greenhouse gas emissions, at a relatively low additional cost for the building.

Some future post topics:

  • What do you do if you want to build a highly efficient house, using the passive house approach, in the U.S.?
  • How does the passive house approach compare to other energy efficiency and “green” standards like California’s Title 24, LEED, Green Point Rating, and HERS?
  • How does the passive house approach work for buildings other than single-family residences?
  • If passive houses are so great, how can we get more of them in the U.S., and what will it take to make a significant dent in the U.S.’s greenhouse gas emissions via energy efficient buildings?
  • How do passive houses and  “zero net energy” interact?
  • How about passive houses in temperate and semi-tropical climates like California and Florida, where it’s not heating, but cooling, that takes the most energy?

If you have other questions about the passive house approach or the conference, let me know in the comments and I’ll tell you what I know or find some answers for you.

Introducing New Silicon Valley Passive Homes Website

Silicon Valley From Space
Silicon Valley From Space

Over the weekend I put up what I hope will be an important resource in the goal of achieving 100% zero-net energy homes in California by 2018 – a new website for the Silicon Valley Passive House Coalition.

From the site:

SVPH is helping local municipalities to set challenging but practical goals for maximizing energy efficiency and carbon emission reduction in the local communities of the San Francisco Bay Area and Northern California.

In particular, many communities are creating “climate action plans” which include incentives for the use of design options that promote energy efficiency and carbon savings. SVPH promotes including an incentive related to the use of extremely energy-efficient design and building approaches such as super insulation, zero-net energy, and the “Passive House” concept.

Please take a quick look and let me know via the comments what you think about the new baby (both the site and the organization)!

Menlo Park Climate Action Plan Research

Menlo Park Train Station
Menlo Park Train Station

Just about two weeks ago, my friend Matt Harris, an architect with a green building practice, sent me an email:

The City of Menlo Park has this Climate Action plan and they are looking for community input. Would you be interested in formulating some kind of response that would of course include our plug for passive house initiatives. Maybe we can get them to include some passive home or even passive building information or plans or guidelines in the Climate action plan. They have already cited “commercial buildings” as a target energy hog in the city for action in the action plan.

So we’ve been working on this. We got together last weekend to come up with a strategy, then Matt wrote the first draft while I was in Finland last week. I did some editing this weekend, and now he’s got it again.

I wanted to share some of the information I discovered while researching our recommendations for the plan.

Here’s the first set – an annotated list of sites from which I got a lot of great information and inspiration both for this project as well as my high-level goal of having all homes built in California be zero-net energy by 2018.

Aggressive Home Efficiency

  • Architecture 2030 – The Architecture 2030 challenge includes the following goal for 2010: “All new buildings, developments and major renovations shall be designed to meet a fossil fuel, GHG-emitting, energy consumption performance standard of 50% of the regional (or country) average for that building type.”
  • California Public Utility Commission Long Term Energy Efficiency Strategic Plan – The CPUC plan includes four “Big Bold strategies” strategies for significant energy-savings, two of which are: 1) all new residential construction in California will be zero net energy by 2020, and 2) all new commercial construction in California will be zero net energy by 2030.
  • Passive House Institute (Germany) – Already familiar to regular readers, the Passive House Institute, Darmstadt, Germany, a research institute dedicated to residential energy efficiency and systems, has shown that actual built structures can achieve 80-90% heating and cooling energy reduction based on their design guidelines. Over 9,000 “passive house” structures, including single family, multi-family, and apartment buildings, have been built in Europe that perform at or near energy goal
  • Passive House Institute (U.S.) () – The U.S. affiliate of the German Passive House Institute
  • Many green building standards have set zero (or near zero) net energy use for residential buildings as a progressive goal for structures and building codes in the near future, including the Leadership in Environmental and Energy-Efficient Design (LEED) standard’s residential rating system, Architecture 2030, and Build It Green’s GreenPoint Rated Checklist residential rating system / Green Building Guidelines for New Home Construction. Several California municipalities have adopted local building codes inspired by Architecture 2030 that exceed the 2005 California Building Energy Efficiency Standards:

I’ll keep you updated on our progress on getting these changes into the Menlo Park Climate Action Plan. It’s exciting to consider that Menlo Park could be on the forefront of the effort to get to zero net energy in ten years!

Old Favorites

Chocolate-covered Oreo Cake
Cake for our six month anniversary (image by ginnerobot, CC 2.0 license)

In honor of this blog’s six month anniversary, I’m going to relink to some of my favorite posts from the past:

  • [intlink id=”5″ type=”post”]My first post, on fuel cell and battery innovations[/intlink]
  • [intlink id=”119″ type=”post”]Why I am optimistic about our energy and climate future[/intlink]
  • [intlink id=”126″ type=”post”]Some reasons my optimism is tempered (a follow up to the post above)[/intlink]
  • [intlink id=”329″ type=”post”]My predictions for 2018 (ten years in the future)[/intlink]

Also, as regular readers know, I’ve been presenting a series of posts on zero net energy homes. I’ve recently added a new plug-in for the blog that makes it easy for you to find these series, and I’ve put the link to the series over on the right hand column (and right here).

Fuel Cell Innovation Update

The week I started this blog in August 2008, there were [intlink id=”5″ type=”post” target=”_blank”]three major fuel-cell related discoveries[/intlink] making the rounds in the science magazines. Since then, there have been [intlink id=”7″ type=”post” target=”_blank”]new announcements every week[/intlink] of an [intlink id=”229″ type=”post” target=”_blank”]improved catalyst or membrane or electrolyte[/intlink]. As these discoveries mature into real products and enter the market, the option of using fuel cells for energy storage, both for homes as well as vehicles, will become more and more cost-effective.

Energy storage is potentially a big part of the zero-net energy house picture, and is certainly critical for the hydrogen automobile transition. I thought I’d highlight a few recent discoveries and advances in the world of fuel cells, the “energy storage of the future.”

  • Cheaper Fuel Cells with nanotubes instead of platinum:

    “Fuel cells haven’t been commercialized for larger-scale applications because platinum is too expensive,” says Liming Dai, a materials-engineering professor at the University of Dayton, in Ohio, who led the work. “For electrodes, you need a cheaper material that still has a high performance.”

  • A new catalyst could make ethanol fuel cells practical for portable gadgets

    The new catalyst, developed by researchers at Brookhaven National Laboratory, breaks the carbon bonds without high voltages, efficiently releasing enough electrons to produce electrical currents 100 times higher than those produced with other catalysts.

  • A new fuel cell uses a cheap nickel catalyst

    Now researchers in China have developed a fuel cell that uses a new membrane material to operate in alkaline conditions, eliminating the need for an expensive catalyst. The power output of the new prototype, which uses nickel as a catalyst, is still relatively low, but it provides a first demonstration of a potentially much less expensive fuel cell.

  • A novel low-temperature electrolyte could make solid-oxide fuel cells more practical –

    Solid-oxide fuel cells are promising for next-generation power plants because they are more efficient than conventional generators, such as steam turbines, and they can use a greater variety of fuels than other fuel cells. They can generate electricity with gasoline, diesel, natural gas, and hydrogen, among other fuels. But the high temperatures required for efficient operation make solid-oxide fuel cells expensive and limit their applications.

Home-generated energy is sustainable, non-polluting, and carbon-free. As the price of energy generation continues to drop, it’s possible to imagine [intlink id=”329″ type=”post” target=”_blank”]the nation’s homes becoming the nation’s power plant[/intlink]. But that can’t happen until we have effective home-based energy storage.

High Tech Innovations Vs. Low Tech

Bamboo thicket
Bamboo - Fast Growing CO2 Sequestration (Image by Joi, CC 2.0 licensed)

I read Technology Review for the latest innovations and breakthroughs in fuel cell technology, transparent solar cells, exotic new batteries and things like that. But there are tons of much lower tech innovations happening all the time. I happened to meet a guy the other night who’s working on a new startup related to building construction.

They’ve developed a new structural component – basically a really strong sheet of plywood – and some connectors, and they think based on their current testing results that they can build houses for 70% of the cost of regular 2×4 stud construction, much faster. They have almost no waste on the job site, and the waste in their factory is all reused. The system is fairly green as well – the feedstock for their plywood is bamboo, one of the best plants for taking up CO2 – and they use non-toxic glues and finishes. And their construction method will work very well for [intlink id=”393″ type=”post”]passive houses[/intlink] as [intlink id=”368″ type=”post” target=”_blank”]discussed elsewhere[/intlink] on “Keeping The Lights On”.

But just like the fuel cell breakthroughs, these low-tech innovations have a tough road to travel to success. For a new building process, you have to convince builders that it’s a better alternative, and that they’ll make more money faster. You also have to certify that the houses will stand up in an earthquake, weather a big storm (or ten of them, over the years), and do all the normal things that houses do in their lifetime. You can be sure that other innovators are coming up with competitive building technologies, all trying to accomplish the same thing as you – displace the old way. So not only do you have to deal with differentiation and other competitive marketing activities, but this also means the air around the head of your prospects is blue with pitches from every direction about “revolutionizing the industry” and “lower cost, faster” and “extremely green.”

If you accomplish all those things, and get a good competitive position, then you have to actually make the new materials and all the fittings, making sure you can address the trickier needs of real houses – which are not just square walls and right angle corners.

I think the new plywood-based approach I saw can address all these issues, but my point is that just because it’s good, it’s still going to be a difficult journey. That’s true of any new innovation.

I hope to do an interview in March with the “plywood people” and put it up on the blog, and I’ll be asking them how they plan to address all these issues as they ramp up. It should be interesting to watch them and other innovations in the building trades, especially in this time of massive investment in green building and energy efficiency.

Zero Net Energy Homes Part 5 – Passive Houses

The Smith House - A passive house in Urbana, IL
The Smith House - A passive house in Urbana, IL

What if you didn’t have to heat your house at all, no matter the climate? Or at least, never turn on the furnace? Well, that’s practically what life is like in one of the “passive houses” designed with the principles of the PassivHaus Institut in Darmstadt, Germany. Recently featured in an article in The New York Times, No Furnaces but Heat Aplenty in ‘Passive Houses’

… these houses are part of a revolution in building design: There are no drafts, no cold tile floors, no snuggling under blankets until the furnace kicks in. There is, in fact, no furnace.

The idea of keeping all the heat inside a house and all the cold outside has been around for decades, but it took a number of technological innovations to do so while preventing stagnant air and mold. Passive houses are characterized by extreme levels of insulation (R-40 or more) and extremely air-tight construction to prevent drafts and heat leakage, coupled with sophisticated mechanicals – called air-to-air heat exchangers or heat recovery ventilators (HRVs) – that constantly refresh the inside air with outside air, while making sure the heat stays in.

Because they use 80% less energy for heating and cooling, passive houses are going to be a critical part of the goal of zero net energy homes. The less energy that’s needed to operate the house – and heating and cooling typically is 40% or more of the energy use in a house – the less energy has to be generated with solar panels or a wind turbine, lowering the cost of energy generation and improving the payback period.

And the cost of building a passive house, at least in Germany, is typically only a few percent higher than building a regular house of the same size, and the energy payback and the savings versus installling a traditional central system – not to mention the improved indoor air quality – makes the payback quite fast.

Over 6,000 passive houses have been built in Germany, but their take off has been slower here in the States. There are about a dozen “official” passive houses – sanctioned by the Passive House Institute US, the U.S. arm of the PassivHaus Institut –  in the U.S., although there are a number of unofficial ones as well, including quite a few mentioned on their forums.

The take off in the US has been slower for a variety of reasons – the different climates across the country, the fact that the expertise is primarily in Germany, and that much of the mechanicals – like the HRVs – need to be imported from Germany.

I bet you’ll be seeing passive houses going up on your street any day now, as the concepts are propagated into practice. The PassivHaus Institut website even features a section on renovating existing houses to passive house standards.

Zero Net Energy Homes Part 4 – Honda Accord Versus Solar Panels

El �ºltimo de los mohicanos
Money ('El Altimo de los Mohicanos' - photo by wakalani, CC 2.0 licensed)

One of the biggest problems for residential solar electricity generation is that it just costs too darn much to install those panels on your roof. Over the next five and ten years this will change significantly as new developments from the labs make it into large-scale production. Eventually houses will be generating all their own electricity using photovoltaics as a matter of course.

But is there a way to think about the cost today that makes the cost even seem reasonable?

Well, if you’re thinking about buying a new car, you should read on. Each year you don’t buy a new car and continue to drive the one that you’ve already paid for, you pays for another year of your solar panels. At the end of the loan period (seven years in my example below), you’re getting free electricity from a system that increases the value of your home and has another 20 years of life at the minimum. If you’d bought a car, in seven years you’d be driving a rapidly depreciating vehicle that you’d probably have to replace soon.

For my house, after rebates, putting up solar panels today would cost about $22,000. This would be a 4kw system, offsetting about 92% of my electric bill, according to the solar power calculator at Clean Power Estimator. With a $3,000 down payment, and using SunPower’s “Smart Financing” with a seven year term, my monthly net cost would be about $250, after subtracting out my electric bill.

So, $22,000 total cost, $3,000 down payment, $250 monthly – that sounds just about exactly like buying a new car, doesn’t it? In fact, if I go to carsdirect.com and price out a new Honda Accord EX, that comes out to $22,372. My current car, a 2000 Honda Accord, is worth $4,000. So I need to finance $18,000. With a four year loan, I’ll be paying about $420 per month.

Netting it out, for each year that I make the decision to buy solar panels versus a new car, I actually save about $170 per month. At the same time, according to the solar power calculator, I eliminate almost four tons of CO2 (worth an additional $320 at the currently accepted value of $80/ton). After seven years, all that electricity will be free to me, for at least the rated life of the panels. And I’ll get most or all of the cost of the panels back when I sell my house. When I sell the new Honda, I’ll get a lot less than I paid for it.

As an additional note, if you’re thinking about buying a new BMW, such as an M3. If you chose a BMW 335i with Sport Package instead, you could put up the solar panels with the difference in cost: 1 BMW M3 = 1 BMW 330i + Sport Package + solar panels. You’d get nearly the same performance – much more than you can effectively use anywhere in the U.S. except on a race track – and you’d offset all the CO2 you’d be generating with your new car.

Definitely let me know if I’ve convinced you to put up solar panels instead of buying a car this year! Or if you have any other comments on this topic – I’d love to hear from you.

Zero Net Energy Homes Part 3 – The Federal R&D Agenda

A House
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.

Zero Net Energy Homes Part 2: Some Beautiful Examples

Cannon Beach zero-net energy house
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: