Pasive Energy Products and Heliostats. A leader in the development and manufacture of passive energy products since 1969.
Nick Pine emailed me a copy of something Steve Baer wrote. I have reprinted them here.
Heliostats--Sameshine vs Sunshine
A heliostat reflects light onto a target. The sun may be at its original strength (less losses on reflection) or it may be concentrated or dispersed. The amount of sun a heliostat is able to reflect to an ideal target over a day is greater than the amount of sun striking any fixed surface of the same area but not quite as great as the best tracking surface, for the heliostat turns only halfway into the sun.
Think about the thousands of ways the sun could be used if it did not move in the sky. We cannot prevent the sun going off and on, for the earth still spins and clouds come and go, but we can easily and eventually inexpensively have the sun stand still. Today no one craves the sun to stand still. If we suddenly could produce inexpensive, reliable heliostats, there would not likely be an immediate large demand for them. It will take time for people to discover that sunlight passing through space always in the same direction has a multitude of uses that turning sunlight cannot have. Such sunlight will indeed need a new name, samelight, and sameshine.
A square foot beam of sunlight can replace 200 watts of electric lights but sunlight moves and is soon shining in the wrong place.
( I have calculated that a 4" square mirror will deliver the equivelant of about 250 watts of incandescent light. redrok )
Samelight can be distributed directly by beam or fiber optics. Samelight can be dispersed inexpensively; 20 square feet of samelight can light a 2000 square foot building. To light, samelight needs electricity as a partner for the predictable and unpredictable periods of unlight (when there is no direct beam radiation.)
In the Southwest, over a year, a thousand watts of samelight could replace 2000 kWh of electricity. This saves $200/year yet the capital costs of transforming sunlight into samelight should be no more than $500/kW ($2500 for a 5 m^2 heliostat--8'x8') and yearly costs should not exceed $40/kW of samelight, $50/5m^2 heliostat maintenance, and $150/5m^2 set aside for replacement.
Samelight can be directed at a protected target that never freezes. Samelight can be concentrated. Samelight, unlike sunlight can easily be converted to extremely high temperatures, heat storage can be accomplished in smaller volumes than has been traditional in solar energy systems. For instance, with samelight we can cycle a cubic foot of rocks through 500 F which gives an energy storage of:
500x200Btu/F = 10,000 Btu/ft^3 or 3 kWh/ft^3 vs 1/5 this with sunlight.
Note that samelight can take on several entirely different tasks--as providing light when light is needed (light stands first in line since we cannot store light as we can store heat) and if light is not needed, a heliostat can be directed to a different target where samelight is converted to heat, electricity, cold, or mechanical power.
Samelight can be converted to electricity with concentrating Fresnel lenses using PV cells. These same cells can be cooled convectively with water or other liquid and the energy used as both electricity and light. No inconvenient outside, flexible coupling needed. Samelight can power Stirling engines to produce electricity. During unlight, gas or other fuel can kick in.
This is the perfect task for samelight. Samelight can operate existing absorption refrigeration equipment. Samelight is most abundant during times when refrigeration equipment is most needed and extra samelight can produce ice to store cool during times of unlight.
The same heliostats can be used for all the above tasks. A heliostat can be moved from one building to another or one task to another. The heliostat, once many uses have become established is a commodity which will be manufactured, after a time, by several large and efficient manufacturers.
Ten heliostats might be used one decade to pump ground water and then during the next decade (after the well was pumped dry) the same heliostats could be used to refrigerate a motel.
Heliostats and samelight can be used extensively in space and on other planets as we colonize them. Indeed, samelight and the uses we discover for it here on earth may be the crucial boost to give us confidence to get off our asses and out into space. Some planets have no clouds and therefore abundant samelight. In space, samelight is as easy to have as sunlight.
The great problem I see with samelight is fire hazard. It will be tempting to make concentrating heliostats that throw a beam of concentrated, lethally hot sunlight, rather than reflecting one sun to fixed concentrating targets. Concentrating targets are inherently safe; no hot spot wanders about, but concentrating heliostats can easily wander and start fires. This hazard may be so great that even if a safe business is started using flat heliostats and concentrating targets the devices will soon be misused and the entire business brought into jeopardy and perhaps finally failure.
Trivial uses may lead the way. The first heliostats may shine on north facing billboards.
Civil engineering is much simplified by having gravity always work in the same direction. How could we construct buildings and canals and bridges if gravity changed its direction during the day? Furniture toppling from one side of the room to another each day, objects sliding north and south with the seasons. Naval and aeronautical engineers must face the problems the civil engineer avoids, for boats and planes pitch and roll. In solar engineering, no one has the luxury of the civil engineer. The sun never stands still; it moves all day and each day is different than the last. The solar engineer accepts these impossible circumstances because he knows nothing else. Once the widespread introduction of heliostats produces a new branch of engineering of sameshine and samelight, these new engineers will marvel at how their predecessors grappled with the constantly turning sun. A race of sailors that never touched land would not even know to identify seasickness. Sameshine engineers will understand and forgive the previous problems of solar engineers--after all they had to deal with unceasing sun-sickness and did not even know it.
Some of the symptoms of engineering sun-sickness have been low temperatures, low efficiency, and high prices.
Pasive Energy Products and Heliostats. A leader in the development and manufacture of passive energy products since 1969.
Skylights: The Flourescent Conspiracy
by Steve Baer, Zomeworks Corporation
This article originally appeared in "Solar Mind," Issue 15--1993.
New discoveries in photovoltaic cells and solar thermal power plants are announced every few months, but unfortunately we are forgetting old uses of the sun faster than we are discovering new ones.
Why do new stores have no skylights? A few weeks ago I visited an enormous new single story toy store. Shelves of plastic toys reached up towards a heaven of rows of flourescent lights. The huge store was using 50 to 100 horsepower of electricity to light unpleasantly what a few percent of the roof in skylights would light pleasantly. (At 1 watt per square foot the same power running electric motors could lift cars parked bumper-to-bumper over the same enormous floor about 1 foot a minute.) At least 100 acres of these toy stores, grocery stores, fabric stores, dime stores, drug stores and auto supply stores have been put up in the last few years in Albuquerque. They gave forgotten how to use natural lighting. Ten megawatts of electricity need never have been generated if the architects could remember how single story buildings were made 75 or 100 years ago.
Why have we forgotten how to use the sun? If you shine enough flourescent light on me, I also forget. I come under a spell, a new outline to my personality appears under the strong electric lights, like a picture revealed under UV lights. Struggling with my flourescent form in the huge new stores, I notice strange people in the aisles, the flourescent gang, figures you don't see elsewhere--a deeply tanned 60-year-old blonde with a low-cut blouse, a man dressed as if he were an assistant cowboy. I am not myself. I simply don't form the sentence for the store manager, "I wish you would put in skylights or clerestories and turn off these unpleasant electric lights."
Today if you read the press you find our hope for solar energy is placed on new photovoltaic panels, not on old-fashioned skylights, but if you take a typical photovoltaic panel and pull the expensive silicon crystals away from the front glass and use the plain glass in a skylight, it will admit not twice as much, but at least ten times a much light as could be produced by the photovoltaic cells powering electric lights--and most of us prefer the quality of natural light.
Is there a force weaning us from mother nature's free and natural sun so we will grow up to purchase an electric substitute? If you discuss the matter of lighting with a store manager while 100 kilowatts of electricity glow around him, you suspect that your protests about electricity and desire for the sun suggest the tiresome whining of a child being weaned.
God gave us the sun long ago. It is no use questioning whether the sun is a good energy source or whether it would have been better if he'd used flourescent bulbs. I felt the question was out of reach until a conversation with a man who works for astronomers and materials scientists setting up heliostats which reflect sun onto targets and solar furnaces. I was unsettled by his offhand answer that it would be impossible to use a giant heliostat to light and thaw a north entrance of a shopping center:
He: It's too bright.
Me: But with reflective losses the reflected sun is less bright than the real sun.
He: Yeah, you got a good point, but I tell you it's just too bright.
Me: Maybe, if you have both the real and the reflected sun shining, but this spot is otherwise in shadow.
He: Well, you'll see.
This was the first man I'd ever met competent to discuss the sun as if it were simply a fixture, a huge incandescent bulb. He only dealt with it because his job required it. I was able to look at the sun through his eyes. I saw that except for habit the sun would never be accepted today. Sure there would be a few fans, but not enough to even test-market it--think of the glare, the sun burn, its unpredictable appearance. How many people die every day from accident because the sun gets in their eyes? Mother nature would be swamped with lawsuits.
Is the unnecessary use of electricity in endless rows of flourescent lights like the self-imposed exercise of someone doing calisthenics? Are we training for an adventure to come, where there will be no sun? Will we move underground into enormous clammy galleries or set off in space through the dark on the way to a new star?
Is our society more interested in expensive photovoltaic power plants than cheap skylights because solar power plants could be switched to nuclear power without the public knowing?
I found in investigating these stores with their endless flourescent ceilings I began to invest in the problem, savoring the insult of each new flourescent bulb glowing during the bright day. When finally, on my third visit, I overcame the flourescent spell and protested to a store manager, something in me was delighted at his guarded hostility. For a moment I thought he might throw me out of Walmart for my impertinence in questioning their judgement bathing their customers in the 60 cycle electric illumination and refusing the sun. The tense moment passed like a huge ocean swell that you anticipate breaking in a wave, but merely lifts you up and lets you down. As we sank in a trough the manager confided that, although helpless to use the sun here, he had added skylights to his own house and that he had suspected I was snooping for their competitor K-Mart.
Further upsetting in my quest to corner the flourescent conspirators in their acres of chain stores was a visit to the Price Club. The Albuquerque Price Club has 3 per cent of the roof in skylights. That should be light enough on this sunny day, but here all the lights were on anyway. I found the manager and more-or-less demanded that he turn the lights off. No, he wouldn't. He pointed to the new addition where he had been able to double the skylights (but the electric lights were on there too) and explained that all the new stores were like this new addition. Phoenix, L. A., Denver--all skylights, no need for daytime electric lights. But did they leave their electric lights on anyway, as he did?
There must be a flourescent conspiracy, but as I discovered when I thought I had trapped a conspirator by the coffee shop at Walmart, the conspiracy's energy and information are in waves, not objects. When you counter a conspirator, you catch nothing, since the problem is the wave, caused by a distant economic storm, not the store manager who merely rides the wave. Everything is still a mystery. Why would the Price Club manager pay $10 per hour to keep a light switch on, even though the store is flooded with sunlight?