I'm giving an "environmental sermon" at 10 AM this Sunday at
the Pottstown UU Fellowship about 25 miles west of Philadelphia.
I'll append a preview.
The US has 5% of the world's population and we use 25% of the world's energy,
but most people find energy boring, intangible, and hard to understand.
1.0 Why should we care about energy?
1.1 Global warming
I've been reading about global warming lately. I've seen Al Gore's movie.
I was surprised to see from the graphs in our program that the earth has had
lots of periodic warmings and coolings, and it has been warmer than it is now,
and it would be very hot like Venus if there were no life on earth. Wetlands
play a large part in this. Humans haven't been around very long in earth's
history, so they haven't had much to do with controlling the earth's climate
in the past, although we might do that in the future. Our fossil fuel use
might be delaying a global cooling cyyle now. Perhaps we should burn more
fossil fuels in a few thousand years from now, in order to stabilize earth's
temperature. Then again, our actions may be unimportant in the big picture,
or maybe not.
We may have to stop burning fossil fuels before they become too expensive,
because of air pollution. Coal and wood burning cause asthma. The Exxon
Valdiz caused serious water pollution and environimental degradation.
Global warming affects other species. Warm-weather is moving north and south
from the equator at 35 miles per decade, but warm-weather animals are only
moving north and south at 4 miles per decade, squeezing polar bears off
the planet. Some now have to swim more than 60 miles to find ice. Some drown.
Glaciers are shrinking. Ski seasons are shorter. Forest fire seasons are
longer. Storms are stronger. Deserts are drier. Floods are more frequent.
Nairobi residents moved uphill to escape mosquito diseases, but now
the mosquitoes are moving uphill. If we don't change, Mount Kilimanjaro
will have no snow, we will lose 40% of the dry land in Florida, and
all of Bangladesh may be underwater by 2020, only 14 years from now.
Energy is cheap, but if we count Gulf wars and acid rain and the health
effects of air pollution, the real cost of a gallon of gasoline is about $5.
We don't pay that at the pump, which confuses consumers. We pay some at
the pump and the rest as higher income taxes and health care costs and so on.
We are seeing higher gas prices. What will we do if it hits $ a gallon?
Transportation accounts for 68% of our oil addiction. In France, Thomson
Microelectronics provides free buses to pick up employees every day within
a few blocks of their houses, so few drive to work. Telecommuting saves
energy, but employers are reluctant to trust employees to work unsupervised,
so that may not help much. Only 6% of us use public transportation. Battery
vehicles are promising. GM's EV1 was a fine electric car, but oil companies
badly want some kind of fuel to pump in all their gas stations. Electric
bicycles are improving, with an energy cost of less than a penny a mile.
Energy conservation saves money. Compact fluorescents use 3 or 4 times
less energy than incandescent bulbs. I can demonstrate this later in
the social room.
For a rational person, solar electricity might be the last step, at a cost
of 100 times more than solar house heat, per peak watt, but photovoltaics
are a major focus for government subsidies. Why? Some economists say they
will get a lot cheaper as people buy more, like integrated circuits, based
on some learning curve, but making photovoltaics cheap is a difficult
problem. Lots of people have been trying hard to make them cheap since
1934, so it won't happen soon, in my opinion.
Our priorities are backwards, from an economic point of view. Photovoltaics
are hideously expensive and most houses need several times more heat than
electrical energy, and we can reduce the electrical slice of the pie with
more efficient appliances. People say "solar is uneconomical," as if
electricity were the only form of solar energy.
Solar water heating costs more than space heating, but it's economical now.
People add attic insulation to save money, but fewer people zone houses,
which is cheaper and can save more. And air leaks waste 50% of the fuel in a
typical US house, but very few people airseal houses and confirm the houses'
performance with blower door tests. It's required in all new low-income
Philadelphia homes, but it's unknown to most people.
Popular forms of solar heating seem uneconomical these days, with high costs
and low solar fractions (20% for some water heaters), so they only appeal to
to customers who are concerned about climate change and other environmental
issues. If more people knew that solar house heating can be cheaper than
other forms of heating, more people might use it.
1.3 World peace
[Choir begins to sing "Onward Christian Soldiers"--dahdah dahdah dah,
dahdahdhadha, dha dha dha, dhadha dha... ]
Our energy use causes wars in Iraq, Afghanistan, Iran, and Israel.
For years, Afghans refused to let us build an oil pipeline through
their country, until we invaded it and replaced the government.
The pipeline just started working. People said George the First
would not have invaded Iraq if they'd only grown broccoli there :-)
Renewable energy can be fun, with a sense of personal competence and
independence. Someday, solar house heating may be a competitive hobby, like
sailing. We might proudly compare low fuel bills, saying "I only spent
$05 to heat my house last year."
My friend Bill Freeborn only spent $2/year to heat his solar house
I used to rent 12' Amphi-Cats at the Jersey shore. Cougar used to own one.
There's a large Styrofoam ball on top of the mast designed to keep them
from capsizing more than halfway. The rental people were always surprised
when I came back with mud on the ball. I would tuck the end of the leeward
hull into the water and flip the catamaran end-for-end diagonally,
completely upside down in the water! That was fun. I like getting something
for nothing, compared to a power boat. Solar house heating can be like that,
with powerful natural forces and smart low-power controls...
By 1980 I had a serious interest in solar heating. That summer I sailed
up the Atlantic coast with a friend. It was my first time sailing at night,
with one of us sleeping and the other watching for tankers. At one point
we were 60 miles offshore. In Newport, we watched a team practice for
the America's Cup, tacking over and over in little fast triangles. I asked
one member if he had a day job. He said, "I guess so. I'm an accountant.
I took a leave of absence 12 years ago..."
America's Cup boats do not have outboard motors. They are well-engineered!
Saint Exupery said "If you want to build a ship, don't herd people together
to collect wood and don't assign them tasks... teach them to long for the
endless immensity of the sea." But this year, each boat in the America's
Cup has a budget of about $0 million, with 15 thousand person-hours of
development and 25 thousand person-hours of full-scale construction and
testing. What kind of solar house performance could we achieve with those
2.0 Solar house heating history
Solar heating is nothing new.
2.1 Greeks and Romans
The Greeks heated houses with wood until they ran out of trees in 500 BC and
started building solar houses. We didn't have glass until Roman times, but
Greek solar houses worked well. A naked person sitting in a Greek solar room
would have been comfortable 67% of the time in the winter. Romans heated
houses with wood fires under hollow floors called hypocausts, burning up to
2 cords per day until they ran out of trees in 100 AD. Pliny the Younger
built 2 solar villas around 200 AD to save money on firewood. He called his
favorite room a _heliocaminus_, which means "solar furnace."
2.2 US Amnesia
Time passed. During the dark ages, houses had few windows. Around 1000 AD,
American Indians in the Southwest built solar houses with no glass, and
700 years later, New England colonials built salt box houses with south-
facing glass. By 1860, solar building was a lost art in the US. Millions
of immigrants came to cities like Philadelphia and lived in houses with
random orientations. In 1912, architect William Atkinson built a "sun house"
near Boston. It worked fine and reached 100 degrees indoors on freezing days.
He wrote a book about it, and his work was forgotten, in a kind of solar
Twenty years later, in 1932, the American Society of Heating and Ventilating
Engineers built a test structure with a south window. The president of the
Society was amazed that it was easy to heat. In January, architect Fred Keck
visited his own "House of Tomorrow," with plate glass walls designed for the
Chicago World's Fair. The sun was shining, it was below zero outdoors, and
Keck was amazed to see workmen in shirtsleeves. He went on to build what
became known as "solar houses" with popular picture windows. One developer
built thousands of fake solar houses with picture windows in every direction.
People built real solar houses all over the US in the 1940s, but mechanical
heating systems and falling fuel prices led to a complete lack of interest
in solar architecture by the late 1950s.
2.3 Modern systems (see easel)
system type: direct gain indirect gain ceiling mass
-------- sun -------- --------
| |/ |m <-- | sun |mmmmmm| | sun
| | |m | |/ | <-- |/
| /| |m |/| | |/|
| / | |m | | | | |
| / | |m | | | | |
|mmmmmmmm| |m --> | | --> |
attribute: -------- -------- --------
complexity 1 2 3
night heat loss high low low
room temp control poor poor good
night setbacks poss? no no yes
heat storage easy harder harder
mass temp swing low low high
# days storage 1 2 5
solar heat fraction ~30% ~60% >90%
I used to design integrated circuits and radar and communications systems.
Solar house heating is much simpler! Simpler than TVs or cellphones or cars.
It's been misunderstood for years, but after I learned to ignore the experts,
I realized that doing it well is mostly just high-school physics:
Houses need heat. That's about 4% of our US oil consumption, and 15% of our
national energy budget, but unlike Congress, we can control it directly :-)
First, insulate, airseal, and collect enough solar heat for a house on
an average winter day. Then store it: if cloudy days are like coin flips and
a house can store heat for 1 day, it can be 50% solar-heated at best; 2 days
of storage make 75% possible, and so on. We still need a little fuel. No
matter how fine the design, nature can supply enough cold cloudy days in
a row to exhaust any thermal store, but there's a nice compromise between
tiny fuel bills and the cost of a house. More than 5 days with 97% solar
heating turns out to be uneconomical.
But most of today's "solar houses" are less than 50% solar-heated, with
old-fashioned direct-gain low-performance "mass and glass" technology.
Sun shines through south windows onto masonry floors in living spaces.
The windows lose lots of heat at night, and the occupants "live inside
the heat battery," which limits the temperature to about 80 degrees, so
we can't store much heat. If we add windows to collect more heat, we lose
more heat at night, so we can't increase the solar heating fraction much.
To collect more sun, we can add windows on a separate sunspace and circulate
warm air between the sunspace and the living space during the day and
let the sunspace get cold at night while the living space stays warm.
Very few solar houses have this kind of "indirect gain," although it's
the best of both worlds, as windows go, collecting more heat during the day
and losing less at night. But it's harder to store solar heat this way.
We can store overnight heat with overhead mass in a concrete ceiling or
sewer pipes under a ceiling. Harold Hay and Norman Saunders and Steve Baer
have done this in the US, but their work is mostly unknown. Italian
architect Orazio Barra built hundreds of successful houses like this
in Europe and Africa, but his work is mostly unknown in the US. Hot
ceiling mass can store more heat than floor mass, and we can use a slow
ceiling fan and a thermostat and an occupancy sensor to keep the room
temperature constant and save money with night setbacks.
So now we have two ways of heating a house: we can circulate air between
a sunspace and a living space during the day, and we can bring down warm air
from ceiling mass at night. The next step is to store heat for several
cloudy days in a row in something like an insulated circular swimming pool
in the basement. Because long strings of cloudy days are unlikely, we can
keep the pool hot with a very small solar collector. And if we put that
collector inside a warm sunspace instead of outdoors, it will be more
efficient, and its heat loss will warm air which heats the house, in
a kind of thermal cogeneration.
After a house is close to 100% solar-heated (which very few are--maybe a
dozen, outside of the Southwest), the next big need is water heating. An
efficient greywater heat exchanger can warm 60 degree fresh water to 95
using 100 degree shower drain water. If building codes permitted single-
wall heat exchangers, we could easily warm water from 95 to 105 degrees
with a cloudy-day store to get close to 100% solar hot water.
3.0 Change isn't easy
If solar house heating is simple, why doesn't everyone do it? This confused
me a lot, but looking back, in 1980 I was naive. Professional Engineer Howard
Reichmuth says "To do good solar work, you have to understand the large scale
lows of money as well as the small scale flows of heat."
3.1 "No need for change"
Builders and architects obfuscate, and solar homeowners think wishfully.
There's lots of hand-waving. Most US Department of Energy "zero energy
houses" use fossil fuels. "Zero energy" just means they generate as much
solar electricity as they use, or even less. The latest ones only generate
a fraction of their electrical use. The Rocky Mountain Institute in Colorado
claims to be solar heated, but there's a huge propane tank behind a snow
fence. Nobody mentions it during the eco-tour.
A popular book by Dan Chiras repeats the mistakes of others, who make many
more mistakes. Kachadorian overestimates the need for fresh air and ignores
the effects of radiation and evaporation and the fact that warm air rises,
and he confuses power and energy. I couldn't find any new solar heating
books at Borders recently, but I counted 12 new paperbacks on feng shui.
Some people want new houses to look like they were built 200 years ago, and
we ask architects to design energy-efficient homes, but most of them act
more like artists than engineers. Professional Engineer Norman Saunders has
been designing houses with high solar fractions in New England since 1946.
He tells clients to buy an electric space heater for backup, but some never
do that. He estimates how often they will have to wear sweaters or "purchase
heat" like other engineers predict floods. Once every 35 years, for example.
Houses are big investments, and people worry that they may never be able to
sell a solar house. Sailors have more courage. Storms called "howlers and
screamers" circle the southern part of the world with no land to interrupt
them. One man sailed around the world into a storm near Tasmania that
flipped his 60' steel boat end-for-end, lengthwise, leaving it with the mast
sticking straight down into the water. Afterwards, he said nonchalantly,
"She was well buttoned-up. After a few minutes, she righted herself."
Sailors go for performance, not looks, but sailboats are beautiful.
These days, people sail because they want to, not because they have to.
They prefer harnessing natural forces to using more convenient fossil fuels.
3.2 Industry pressures
MIT physicist Charlie Wing's Cornerstones owner-builder school taught solar
heating so well that Exxon bought him out after two years and closed the
school. He is now sailing around the world on a nice yacht. In the 80s,
scientists in white coats surrounded by lush green plants made TV commercials
saying carbon dioxide is good for the earth. We haven't heard from them lately.
The Passive Solar Industry Council Guidelines are heavily influenced by
the brick and masonry industries.
People with axes to grind write building codes. MIT lighting professor
Bill Lam says:
To increase the "demand" for more power plants, the power and lighting
industries were very effective in promoting ever-increasing illumination
levels and incorporating them into codes. In some cases "required" light
levels were so high that artificial lights had to be used all the time,
regardless of the external climate and availability of natural light.
Such lights often heated buildings to the extent that air conditioning
was needed year-round.
Pennsylvania's new ICC residential code no longer requires houses to have
8% of the floorspace as windows, which is good :-)
3.3 Government help...
After spending so much tax money on "solar research" in our national labs
for so many years, where are all the houses that heat and cool themselves?
Solar pioneer Harold Hay puts full-page ads in Solar Today magazine asking
when we will stop wasting money and employing all the unemployable
scientists doing "solar research" at our national labs. If they ever
succeed, they might find themselves without jobs :-)
After several speakers got up at a 1980 conference and said at great length
that solar energy was promising, but a lot more research was needed and it
was very expensive now, Steve Baer got up and put both hands on the podium
and looked at the audience and said "Bullshit!" and sat down. Some projects
act as "solar insecticide," like releasing large numbers of sterile male
insects who mate and leave females infertile. After a few generations,
the problem insects disappear.
Solar subsidies are back, but many feel they have done more harm than good.
Tax credits tend to reward expenditures rather than performance. They delay
shakeups and competitive markets that would sort out which systems work and
which ones are economical.
The Canadian government worried so much about losing political power as
a result of individual energy independence that they ordered Brace Research
Institute to stop printing their popular Solarium Design Manual and destroy
all existing copies in English and French. I got one rescued from a car
trunkful just before they went to the incinerator.
So let's focus on what we can do today, vs. what we might get
"the government" to do tomorrow...