Last night (actually Tuesday morning, December 8 ) it got down to 4° F – three degrees colder than ever recorded here at the farm since we arrived in 1994 and began keeping records, and five degrees colder than the 9° F low of the previous night.

How did the passive solar greenhouse cope with record frigid temperatures? At eight in the morning, I found the door frozen shut and had to first break the ice seal with a small sledge and block. Inside, it was a relatively balmy 34° F – cold, but safely above freezing. All plants and seedlings had survived.

Ice patterns on greenhouse door. I was going to clip a panel of insulation to the inside for the winter, but haven't yet done so.

At 4:00 on Monday afternoon, the temperature inside the greenhouse had reached 56° F. I’ll update this post with today’s high temperature this afternoon. If we can figure out how to get the camera to communicate with the laptop, we’ll post a photo (Irina’s computer is on the fritz).

Note to self: get high/low thermometer for greenhouse.

Update 9/12: Yesterday’s high: 36°
Last night’s low: 3° (!)
Greenhouse high: 54°
Greenhouse low: 32° (whew – that was close!)

Not bad. I don’t expect we’ll ever see weather conditions like this again here, at least in my lifetime.

You can see from the satellite image below why it’s so cold here – frigid air is pouring straight from the Arctic Ocean, down across Canada to the U.S., including the west coast.

Odd – in this WordPress program, if I type the number “8″ and then “close parenthesis” without a space, it shows up as a smiley face with sunglasses, like this 8).

The DOE has released a series of reports on the future of the US electric grid. The overall evaluation is that the government needs to make a significant intervention in the power market; it has completely failed to do so for the past eight years (and longer); and conservation needs to be part of anything we do.

Gail “the Actuary” Tverberg at The Oil Drum has a “letter to Obama” post pointing out that our buildings are the first place we should look to cut our energy consumption. The “why?” is obvious from this graph:

That’s right – running our buildings takes almost half of all the energy we use. And our buildings are terribly inefficient.

We know how to build really efficient buildings. It’s already being done in Britain.

And then there’s the Passive House architectural movement that originated in Germany.

The biggest new energy source available is saving energy in our buildings by retrofitting existing buildings and ensuring that all new buildings approach zero net energy use. Tverberg has a list of specific recommendations for getting there that deserve a look.

The DOE’s FINAL Report on Electricity Supply Adequacy says that energy availability, climate, and other problems could be lessened by  “demand-side resources” – that is, efficiency measures that reduce the generating and transmission needs – but “current energy efficiency and demand response / load management programs are barely scratching the surface of what is achievable.”

And that’s without reducing demand by increasing building efficiency, which was beyond the scope of the DOE’s studies.

The U.S. Department of Transportation reports that people continued to drive less through November even as gasoline prices plummeted:

Travel on all roads and streets changed by -5.3% (-12.9 billion vehicle miles) for November 2008 as compared with November 2007. Travel for the month is estimated to be 230.4 billion vehicle miles.

Cumulative Travel for 2008 changed by -3.7% (-102.1 billion vehicle miles). The Cumulative estimate for the year is 2,656.2 billion vehicle miles of travel.

Calculated Risk has a great graph showing that the decrease in driving is even greater than during the two oil shocks of ’73-’75 and ’79-’80. Unfortunately it cannot be reproduced and shared.

Calculated Risk also has a great chart showing that housing starts are at the lowest levels since the Census Bureau began tracking housing starts in 1959. The Census Bureau reports that single-family completions are significantly higher than single-family starts, suggesting completions will probably continue to decline.

A new SMR study finds changes in household size and bigger houses have been the main causes of over-consumption of energy by American consumers. Conservation efforts such as minimum auto fuel efficiency standards and increased home insulation have failed to prevent massive energy waste because they have been overwhelmed by these two counter-trends.

The study concludes:

• The size of a home mainly determines energy usage. The average square footage of newly constructed homes continues to rise.
• Energy spending and usage rises – both per-household and per-capita – along with incomes and levels of education.
• The notion that high-income or highly educated people are more likely to be environmentally sensitive is disproved by usage data.
• Energy usage per capita is lowest among young adults, Hispanic households, and those living in the least expensive homes.

From 1960 to 2007, the average number of people per household in the USA declined from 3.33 to a record low of 2.56. The main cause: Single-person households grew by 350%. Meanwhile, over just 25 recent years, the average size of newly built homes increased by 34.2%.

These two events – by themselves – ruined other progress made in energy conservation. Yet, in the debate over global warming and energy independence, these two events are almost never mentioned.

James Kunstler is scathing in his evaluation of the results of decades of “progress”:

We’ve constructed a daily living arrangement that is depressing, demoralizing, unrewarding, unfair to children and old people, grossly wasteful, ecologically unsound to-the-max, and profoundly unhealthy. It is a bad human habitat. It’s toxic in every sense. It punishes us intensely, despite the number of bathrooms per inhabitant and the air conditioning. And for most people in the USA, it is absolutely normal – it’s all they know.

For the first time in at least a decade, the size of new houses is shrinking.

According to the National Association of Home Builders, the average size of new single-family homes grew from 1,750 square feet in 1978 to 2,479 in 2007. But homes started in the third quarter of 2008 averaged 2,438 square feet, down from 2,629 square feet in the second quarter. There have been other slight dips since the compilation of quarterly data began in 1999, but the latest drop was much steeper.

The American Institute of Architects (AIA) also reports a shift toward smaller houses. In a survey last April, the AIA found twice as many architects reporting a size decline rather than an increase. In 2006, the reverse was true.

The collapsing economy and high energy costs are contributing to big homes losing their status and investment value. With shrinking household sizes, people don’t really need all that space – and it’s expensive to build, power, maintain, and clean.

Nate Hagens at The Oil Drum has a good introductory post about simple solar design. Hagens provides this slick diagram that shows the basic concept at work.

This basic design isn’t nearly as efficient as the Passivhaus – but it’s simple, and can be done cheaply.

This is the concept Irina and I followed when we first renovated our house, which was nothing more than a pole-barn sheepshed converted (badly) into a dwelling, back in 1994.  Fortunately the building was oriented to face the south (which is one of the reasons we purchased the property).  We closed up most of the east- and west-facing windows and enlarged and added windows on the south side, with double-glazed glass. We laid black tile over the concrete slab floor to absorb heat (too bad we couldn’t insulate under concrete, which could easily be done with new construction). Wall insulation was R-19, ceiling R-30. All this was done for a few thousand dollars – cheap (we later replaced the roof with a white steel roof, which added considerably to the cost, and summer performance).

And the house has performed well.  Without any heating or cooling other than a small wood stove, it’s warm and cozy in winter, and cool in summer except for a couple of hours in the late afternoon/early evening on the few very hottest days which a small fan makes tolerable. A couple of cords of wood gets us through the winter.

Starting from scratch would have made it possible to increase performance by better sealing, insulating the floor, and controlling thermal mass more precisely. But then consider all the energy saved by recycling an existing structure. We’re happy with the results.

One approach to energy efficiency in buildings is to apply new energy efficiency standards like the Leadership in Environmental and Energy Design (LEED) standard to design homes with better insulation and high-efficiency appliances and to use alternative sources of power, like solar panels and wind turbines.

The Passivhaus Institut in Darmstadt, Germany is taking a different approach: build a house that can provide all the heat and hot water needed from the amount of energy required to run a hair dryer. Using ultrathick insulation and complex doors and windows, homes are encased in an airtight shell so that barely any heat escapes and barely any cold seeps in. That allows a passive house to be warmed not only by the sun, but also by the heat from appliances and even from occupants’ bodies. The goal is to create a warm house without energy demand. That goal is being achieved, and cheaply – a passive house costs only 5-7% more than a conventional house.

Site selection is important because a successful passive house relies on the sun for solar gain. If passive houses were to spread to the U.S., we would have to rethink our relationship to space – passive-house mansions may be oxymoronic. Compact shapes are simpler to seal, while sprawling homes are difficult to insulate and heat. Most passive houses allow about 500 square feet per person, a comfortable though not expansive living space. People who want thousands of square feet per person should look for another design.

Earlier attempts at creating sealed solar-heated homes ran into problems with stagnant air and mold. But new passive houses solve those problems with a heat-exchanging ventilation system. The warm air going out passes side by side with clean, cold air coming in, exchanging heat with 90% efficiency.

The NY Times reports that there are now an estimated 15,000 passive houses around the world, the vast majority built in the past few years in German-speaking countries or Scandinavia. The industry is thriving in Germany, where components are now being mass-produced and even schools are being built using the techniques.

The European Commission is promoting passive-house building, and the European Parliament has proposed that new buildings meet passive-house standards by 2011.

Achieving massive energy efficiency improvements in the US building infrastructure is key to cutting energy use enough to make coal-fired electricity plants unnecessary and to the feasibility of meeting U.S. electricity needs entirely from renewable sources. Architecture 2030 has put forth a stimulus plan that would jump-start a U.S. energy-efficiency renovation industry while saving money and slashing greenhouse gas emissions.

It’s not at all clear from the briefing material that less overall energy use is the primary objective. Hitting efficiency targets and using “green” energy are the metrics, which doesn’t really get directly at the Passivhaus objective of slashing overall energy needs. The tool to encourage residential buildings is a requirement that to get a GSE mortgage homeowners would have to renovate to meet energy efficiency standards. The amount of the mortgage is increased to cover the cost of the renovations, and Interest rates are subsidized – the greater the efficiency achieved, the greater the interest rate subsidy (new homes get similar subsidies). The lever for commercial buildings is vastly accelerated depreciation.

Can either of these stimuli actually work in the present economic environment, where both the residential and commercial real estate markets are glutted and moribund and neither homeowners nor businesses have the resources or the incentive to invest more money in buildings?

There’s a really great post at newworldeconomics.com pointing out the obvious: life used to be without cars – and was pretty swell. Most of the cities and civilizations of the world were developed without cars. In fact, there really hasn’t been much in the way of cities and civilizations built since cars became common.

Even many Americans have experienced life without cars.

Life Without Cars (I’ve done it) is actually a lot of fun. There is no hardship or privation involved. It’s cheaper, too, which means everyone can play. Probably the closest many Americans have come to a Life Without Cars is the time they may have spent at a residential university. The university campus is about the best example of a no-car-needed environment you’ll find in the U.S. these days. And wasn’t it fun?

There are lots of great photos, of beautifully dressed people in beautiful places. Unfortunately the site isn’t friendly to their reproduction. But this shot from our travels in Prague will give you some idea of the flavor:

Prague, city square

Once you get the cars out of the picture, architecture – and life – tends to be a lot more interesting.

The passive house could play a major role in cutting energy consumption and stopping global warming. All it would take is radically altering our building practices.

A Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply. The result is an impressive system that not only saves up to 90% of space heating costs while also providing excellent indoor air quality.

To be called a “passive house,” a building must meet the passive house performance standards which are set by the Passive House Institute in Germany. The basic standard is that a building must consume no more than 15 kilowatt-hours per square meter in heating energy per year (equivalent to 4746 BTU per square foot per year). This is achieved by constructing a building envelope, (floors, walls, ceilings, and a roof) that is extremely well insulated and air tight. This means R40 in the walls and R60 in the roof and floor. The building must not leak more air than 0.6 times the house volume per hour at 50 pascals of pressure. The result is a building that uses 90% less heating and air conditioning energy than a typical building according to the Passive House Institute US.

If all new houses were to be passive and existing homes were fully retrofitted to the passive house standards, we would be far along the road to stabilizing our climate.

Buildings are responsible for almost half of U.S. energy consumption.

Here’s a major way that the way we develop and use land has contributed to global warming.

click to view image

This graphic is from a post by Nate Hagens at The Oil Drum titled “A Long Term Solution to Our Financial Crisis: The Other Forms of Capital.”