Mountain Solar Electricity

Case in point: the Desert View Tower proposal along I-8 in California

Underlying engineering

Renewable energy is one of the driving issues of our time. We’re looking for a progressive university that wants to be ahead of the curve on climate change.

Mountain chimneys possess a number of inherent advantages over every other electrical generation method:

• We can generate electricity from the smokestack exhaust from other power plants, because we can operate with lower temperature hot air than anyone else.
• We can create a heat sink in the ground at the low end of the chimney. We can generate electricity from this heat sink at night, and then send the waste steam and waste heat up the chimney at night to generate more electricity from the remainder of the same heat.
• The critical parts of our technology were already tested. The Manzanares prototype ran faithfully for seven years. For the most part the prototype had only one moving part. We have added a number of our own improvements that, so far, look like pretty low-grade engineering problems. Our biggest remaining problem is containment of pressurized air in our tube. Our second problem is extracting maximum power from a much higher head air pressure drop, on the order of 0.3 pounds per square inch of head.
• Using a mountain can give us a factor of ten better power conversion than using a vertical chimney, and the mountain will never fall down.
• Our air channels are designed to store and release heat. Heat storage solves the intermittency problem that plagues most other solar and wind generating projects.
• We can generate our own low-temperature solar heat at a surprisingly low cost per therm of heat.
• Our chimney is a good neighbor. Wind turbines produce flicker, noise and bird strikes, but our air turbine is fully enclosed and can be soundproofed. We can hide our chimney under ivy vines or camouflage it.
• We plan for far better durability and for far lower lifetime maintenance than most power companies are accustomed to seeing. Small hydropower dams can eventually flood out, photovoltaic panels degrade in twenty years and we just keep running.
• Our single large turbine needs a single power line. We don’t have a photovoltaic farm’s electrical spaghetti problem.

Our ultimate goal is on-demand thermal electricity at a cost of two or three cents per kilowatt-hour, when we start to build solar chimneys in the 500 megawatt range. Early prototypes should at least be competitive with other after-dark renewable energy sources.

Shown in the picture below is a view of Charleston Peak in southern Nevada, west of Las Vegas, looking northeast from a spot near the town of Pahrump, Nevada, with a solar chimney sketched onto the mountain's slope. Charleston Peak has nearly an 8,000 foot rise from Pahrump to the mountain's peak. Many lesser western mountains are available.

Our chimney should be reasonably compatibile with local activities such as hiking and hunting on the mountain. We assume that we wouldn't have access to the mountain's peak itself, which has notable natural beauty, but that we would be allowed to use a lesser promontory for solar energy generation. Our air chimney is able to traverse gullies and leap over highways, leaving migration channels for wildlife and paths for hikers. If the chimney is shot up with several hunters' bullets, it should continue generating electricity with 99.9% of its original power output. We might camoflauge the chimney so that it looks nearly invisible as seen from a nearby town. The chimney's fully enclosed air turbine or turbines should be approximately noiseless to hikers on the chimney's outside. The solar chimney should create little or no additional fire danger to the area, except where fallen electric power lines might create sparks in tinder brush.

Our inspiration was the world’s first solar chimney, which started producing electricity in 1982 in Manzanares, Spain.  The chimney stood 600 feet high.  It was powered by 11 acres of plastic that heated air.  The air, as it rose up the chimney, created a draft.  A wind turbine in the chimney generated 50 kilowatts every sunny day at a price of about 25 cents per kilowatt-hour. The picture below shows the 600 foot tall chimney and the many plastic sheets mounted ten feet above ground level . The wind turbine is inside the base of the chimney.

Klinkman Solar Design’s mountain solar chimney, U.S. patent #8,823,197, was granted on September 2, 2014. We're looking for a path to develop and deploy the invention. The system is designed to generate large-scale thermal on-demand solar electricity day and night. It gets use out of even marginal heat sources. Organizations dedicated to sustainability and to renewable energy are invited to contact us to explore development options.

Our chimney solves a number of engineering problems inherent in the Manzanares design. 

• A 600 foot tall chimney is an aviation hazard.  Our chimney curves diagonally up the side of a mountain.
• Wikipedia lists gathering heat as the chimney's major cost. We spread an amazingly inexpensive solar air collection surface over the ground for our initial air warming task.
• Because the cost of the tower is much of the installation’s remaining cost, using a mountain dramatically lowers the installation's cost per kilowatt-hour. The taller the mountain, the greater the percentage of power that we move from our gathered solar heat into electricity.
• Our design generates a flow of hot air far more cost-efficiently than the Manzanares design.  The Manzanares single layer of plastic sheeting is designed to minimize air friction under the plastic, but they didn't think out their heating system. The hotter the air, the more power is generated.
• Our design utilizes heat storage for electric generation on demand and after sundown.  Some power towers use molten salt for heat storage, which sounds to us like an engineering problem waiting to happen. Our mountain solar system uses rocks and air. Our storage system has nothing to fail, to melt, to boil or to overheat and rocks are affordable. Our entire system is long-lasting and sustainable.
• Current solar power towers can cook birds in flight, but we're careful with our well-distributed solar concentration system. Our goal is to be a good neighbor to the local ecology.
• Our design thrives on sources of waste heat from other solar installations. No exhaust heat source is ever a waste to us.
• Our design will siphon much of an inverted layer smoggy air out of an enclosed, hot inland valley. This cools the valley, saving on everyone's air conditioning costs, creating free negawatts.
• One notable benefit of storing heat in the desert is that temperatures can drop by 20 degrees Celsius from day to night. This means that we accrue 20 degrees Celsius of free power when we send heat collected in the daytime up the chimney at night, when the cold night air is relatively heavier than the daytime air.
• Around fifty separate innovations went into this patent, far more than I can discuss here. When many separate innovations each improve the chimney by 10% or by 20%, one or two of the innovations can be left behind on implementation but the system will still be quite profitable. The concept of a massive wave of innovations, each innovation backstopping the other innovations, insures that investors will make money in the end.

The net result is sustainable electric power on demand.  Our somewhat overly-optimistic estimate of cost per kilowatt-hour, on a large scale, is well below an incredible 1 cent per kilowatt-hour.  We’ll be happy if we can hit a conservative target of 2 to 3 cents per kilowatt-hour.  Natural gas can’t compete with such a low price target. Photovoltaic panels can't compete, and they especially can't compete after sunset. Solar power towers can't compete on price because molten salt is difficult to re-liquefy once it cools into a solid mass of rock salt. Air doesn't freeze.

  A cross-section of a diagonal chimney -- different roof layers serve different purposes. A rubber chimney section may be under considerable positive or negative air pressure, which creates bulges in its pressure layer, but a fairing layer on the chimney's inside can insure smooth air flow. By way of contrast, the Manzanares experimental chimney was a simple uninsulated metal cylinder.

We can use passive heat banks such as parking lots, smog inversions and geothermal springs. We can use smokestack heat. Our design then moves to high heat.

Some possible sources of heat:

Solar chimneys can simultaneously remove nitrous oxide from the atmosphere. See https://ec.europa.eu/environment/integration/research/newsalert/pdf/nitrous_oxide_removed_atmosphere_generation_renewable_energy_476na3_en.pdf