This weblog post is written to celebrate the upcoming 10th anniversary of Vortex Bladeless, as a concept, and the 81st anniversary of the collapse of the Tacoma Narrows Bridge on 1940-11-07. I have watched videos documenting the bridge collapse many times, and shown these to students in science classes over the years. Unfortunately, I lacked the insight of David Yáñez who was able to see the potential of oscillations in the generation of electricity.

David Yáñez and the Vortex Bladeless Tacoma at Avila, Spain in 2019. Photo: Vortex Bladeless.

Preliminary considerations

Living on a cliff-face, the residents at Cliff Cottage experience some wind, but less than many people might expect. The one-word reason is updraughts. That is, when the wind hits the cliff, it is deflected upwards, and then over the house. While the residents have considered installing horizontal bladed wind turbines at the cliff-face to provide electrical power, that take advantage of these updraughts, there is probably too little energy to make any investment economically worthwhile.

For example, a product was being offered on Kickstarter. On 2020-09-29, Nick Hodges, founder of Halcium, in Salt Lake City, UT, launched a funding round for (yet another device referred to as) a Powerpod, which was described as the “safest, most powerful wind turbine in the world”. He set US$ 200 000 as a minimum goal. When the fundraising period ended at the end of 2020-10, the goal was not met.

The product offered by Hodges, was not ideal for Cliff Cottage. The wind we are interested in using comes from one direction only, so being able to take advantage of wind coming from anywhere does not offer any advantages.

A major problem with the Kickstarter launch was an amateur approach to the electrical technology. After reading a description of the project, one was left with more questions than answers. Hodges apparently has a degree in small business management and an MBA with a finance emphasis from Arizona State University.

As another resident pointed out to me, entrepreneurship requires three competencies, finance (and related areas of business management), marketing and technical competence. From the material presented, it was obvious that Hodges had marketing competence, but lacked science and engineering skills.

For example, he claimed that Powerpods are “cheaper than solar panels and more efficient in places that get fewer than 300 days of sun a year.” When examining this statement, it is difficult to understand the specific apples and oranges being compared and contrasted. The number of square meters of solar panels is unspecified. Wind speed is an unknown factor, and there didn’t seem to be any documentation that related wind speed to power produced, only an attractive graph comparing power from a Powerpod with power from a normal wind turbine, whatever that is.

The number of days of sun is an unusual metric. Sunshine duration in hours per year is more common, something that can be determined using a World Meteorological Organization (WMO) standardized Campbell-Stokes recorder, which has been in common use since 1962. In 2003, the sunshine duration was finally defined as the period during which direct solar irradiance exceeds a threshold value of 120 W/m2.

There are claims that each 1kW in the Powerpod wind turbine creates up to three times more power than a regular, mounted turbine. The extra power comes from the blade system in the pod. While there is a graph showing this magic, there appear to be no supporting documents. There are no wind speed or power measurements, In fact, the graph incorrectly expresses power in volts, rather than correctly in watts.

The Powerpod system uses 12 Volt components. These are typically used on recreational vehicles to be compatible with vehicle electrical power systems. While they are used in residential systems, 48 V is quickly becoming the new standard. In part, this is because of the high amperage involved with 12 or 24 V. Transmitting 960 W of power with a 12 V system involves wiring capable of transmitting 80 A. With 48 V this is reduced to 20 A. Of course, if this power has to be transported any distance, it will have to be even thicker. Thick wiring is expensive and difficult to obtain.

Hodges goes on to compare wind and solar energy. In Norway it costs from NOK 30 000 to NOK 120 000 to have solar cell panels installed on an average single-family dwelling. This is typically financed by re-negotiating an existing mortgage. On average, the payback time for such an investment is about 17 years. The life-expectancy of the solar cell panels is from 25 to 50 years, and manufacturers offer a 25 year product guarantee on the solar cell panels, so that house owners do not face additional risks. Inverters may have a shorter life-span, and are not usually covered by the guarantee.

Unfortunately, the climatic situation in Norway means that solar panels can only produce substantial quantities of electricity during the summer. It is not that the equipment doesn’t work in the winter. Rather, the sun is close to the horizon, and not visible for many hours. On the date of publication, sunrise was at 08:16, sunset will be at 15:41. This gives 7h24m 43s of daylight. At the winter solstice (2021-12-21) daylight hours will be reduced to 4h17m21s. At the next summer solstice (2021-06-21) there will be 20h53m32s of daylight. Selling power usually requires one to participate in a spot-market, where prices are usually low in the summer, but high in the winter. Despite this, most people who install solar panels in one form or another want to connect to the mains in order to to sell excess electricity, or to access electricity when there is a production deficit. Batteries could be used, but new batteries are expensive. Some people will decide to buy discarded batteries from electric vehicles and store electricity with these. This is a more common model for cabin/ vacation cottage solar panels, less common for primary residences, because the cost is too large in relation to potential savings. Once again, people have risk aversion.

Another approach is to produce electricity in the summer and store it until it is needed in the winter. While the return-on-investment calculation for this looks good, mainly because of the high price for electricity in the winter, a large battery capacity is necessary.

Hodges’ main goal is admirable. He wants to reduce dependence on fossil fuel. He wanted to use the $200 000 funding to mass-produce Powerpods. The money sought would cover the cost of having the product tested, the raw materials for products being sold as part of the kickstarter project, as well as factory tooling.

After reading the project description, I was not totally convinced that Hodges had a viable product, or the necessary skills to make one. Hodges should partner with someone who has the necessary electrical engineering skills. This would allow for the development of the entire infrastructure needed for off-grid power production. These will have to meet agreed standards. At a minimum this consists of battery storage, a suitable inverter and a net metering system to allow produced energy to be used in the residence, or fed to the grid (especially at peak times). The equipment must be able to handle abnormal situations, such as power surges and power failures. The system should also prohibit sending power onto the grid, when it is down, as this could be potentially dangerous for crew members working to restore power.

There are also a number of legal issues that have to be negotiated, including energy purchase and sales agreements, and liability (including liability insurance). The specifics vary from jurisdiction to jurisdiction. Thus, it might be appropriate for Hodges to restrict his sales to Utah, and to find other people to cooperate with in other states, provinces and countries.

At Cliff Cottage we probably won’t participate in such a project. Instead, we will work slowly and methodically to find solutions that meet our specific energy needs. As a first step this will involve measuring wind speeds at the cliff face, to determine if wind energy is viable. If it is, then this process will slowly intensify as we select a more viable solution.

A More Viable Answer

The Vortex Bladeless turbine, popularly referred to as the Skybrator, has its origins in 2012 after David Yáñez watched a video of the Tacoma Narrow’s bridge oscillating in the wind. Since then, Vortex Bladeless, a Spanish tech startup, has been working to produce electricity from oscillations induced by wind.

Vortex Bladeless is a vibration resonant wind generator: It does not rotate, and is not a turbine, in contrast to the common horizontal-axis wind turbines (HAWT) and less common vertical axis wind turbines (VAWT) that work by rotation. Instead, it harnesses energy by allowing a fibreglass and carbon fibre reinforced polymer mast to oscillate in the wind, taking advantage of von Kármán vortices that form when a moving fluid (air) passes over a slender structure (the mast). At the bottom of the mast, a carbon fibre rod moves an alternator to generates electricity.

Wind turbines have issues, including maintenance costs, amortization rates, noise levels, bird deaths and other environmental impacts. Remote locations can have logistics challenges, while their visual and aural impact on a location is not always appreciated. The mass (and dimension) of vortex generators, indicate that they will use less raw materials in their construction compared to rotary wind turbines of the same power. They have a low centre of gravity that allows for a smaller foundation and less wake turbulence. Thus, they can produce more power (greater energy density) per unit of land area.

However, the market Vortex Bladeless envisions if for a small wind-turbine alternative for the end-consumer market and for low-power systems. These are markets that are served poorly (or not at all) by larger-scale wind turbine manufacturers.

  • Vortex Nano – 1 m high and 3 W nominal power output. For off-grid, low-power systems, especially with solar panels.
  • Vortex Tacoma – 2.75 m high and 100 W nominal power output. For small-scale residential/ rural autonomous operation, with solar panels.
  • Vortex Atlantis/Grand – 9–13 m high and around 1 kW nominal power output. For residential/ rural autonomous operation, with solar panels.

All of these are slender, vertical, cylindrical devices, composed of two main parts: a fixed base where the device is attached to an anchor, and a flexible mast which, acting as a cantilever, that interacts more freely with moving fluid (air) in an oscillating movement. The oscillator has no gears or moving parts in contact with each other, so there is no need for lubricants.

A linear alternator, with neodymium magnets and its stator is located inside the moving part of the device, converts mechanical to electrical (chemical) energy. During this process the alternator damps/ cushions the induced oscillation movements. These devices operate with minimal maintenance and operating costs.

Tacoma Narrows Bridge

With newspaper editor Leonard Coatsworth’s car still on the deck, vertical and torsional motion was recorded on the Tacoma Narrows Bridge, 1940-11-07. Oscillations eventually destroyed the bridge. Credit: Library of Congress Prints and Photographs Division.

There is 1.4 km of Puget Sound separating Tacoma from Gig Harbor. Yet, before the construction of the Tacoma Narrows Bridge, one had to drive 172 km between them. With the bridge in place, this was reduced to 13 km. The bridge also linked McChord Air Field near Tacoma with the Navy shipyard in Bremerton, both important elements of the American military’s infrastructure, and probably the most critical one that allowed the funding of the bridge. Washington States bridge engineer, Clark Eldridge, had proposed a conventional design for the state highway department and Toll Bridge Authority. However, the federal Public Works Administration, insisted that bridge engineer Leon Moisseiff, designer of the Manhattan and Golden Gate bridges, be hired as the lead consultant and designer, and to use deflection theory as the basis of the design, producing a lighter, narrower, more flexible and cheaper structure.

Construction of the bridge started in 1938 and took 19 months. When finished, the Tacoma Narrows Bridge had an 853-meter-long centre span, almost half its total length. It was the third longest suspension bridge in the world, behind the Golden Gate and George Washington bridges. It also had the smallest ever width-to-length ratio: 1 to 72. Even before the bridge was completed the bridge deck shook in a wave-like vertical motion. This earned the bridge its nickname, Galloping Gertie. The bridge opened on 1940-07-01.

On 1940-11-07/ November 7th, 1940/ 7 November 1940, south-westerly winds, with gusts up to 68 km/h began to buffet the bridge. The deck began its customary rippling, bouncing up and down with more than a meter of displacement from its normal position at times. Shortly after 10:00 traffic was halted because of bridge deck oscillations. Soon after the bridge’s vertical movement was supplemented by a twisting motion that whipped the deck up and down to either side of the centre of the roadway. The twisting grew increasingly severe, with one sidewalk up to 8.5 meters higher than the other.

At 11:02., a 180-meter portion of the centre span gave way, crashing into the water below. Additional sections followed. The last major section fell at 11:10. With most of the centre span gone, all that was left were dangling suspension cables, a hole between the two towers and remnants of sagging side spans at either end of the bridge.

Earth magazine has an article that provides further information about this bridge failure.

Foiling Moth

A moth (International Moth Class) “flying” over the water in the port of Kiel in 2008. Photo: VollwertBIT

Wikipedia comments on the Moth class, “Originally a small, fast home-built sailing boat designed to plane, since 2000 it has become an expensive and largely commercially-produced boat designed to hydroplane on foils. The pre-hydrofoil design Moths are still sailed and raced, but are far slower than their foiled counterparts.”

There have been many iterations of the Moss dinghy, with the exact number dependent on how they are counted. First, it began life in Australia in 1928 when Len Morris built a cat rigged = single sail, wooden scow = a flat-bottomed boat with a horizontal rather than a more common vertical bow. It was hard chined = with a sharp change in angle in the cross section of a hull, 3.4 m long, with a single 7.4 m2 mainsail. A second iteration emerged in North Carolina in 1929, with a 6.7 m2 sail, on a somewhat shorter mast. In 1933, The Rudder, an American boating magazine, published an article about the American Moths. A third iteration came about in 1932, when a British Moth class was started. This was a one-design, which meant that there could be very little variation between the boats. One designs are used in competitions so that winners can be distinguished on the basis of sailing ability, rather than in boat characteristics.

The fourth iteration was initiated with the Restricted Moth of the 1960s and 1970s. With few design restrictions, individuals were allowed to modify their boats. This allowed the class to develop and adjust to new technology and materials. An International Moth arose in Australia and New Zealand.

The Europa Moth, which became the Olympic Europe dinghy, can be regarded as a fifth iteration. This was followed by a sixth iteration, in the form of a New Zealand Mark 2 Scow Moth, in the 1970s. Finally, a seventh iteration emerged with the International Moth, a fast sailing hydrofoil dinghy with few design restrictions.

Most people who choose a Moth do so because it is a development class. In much the same way that there are two types of motorsport enthusiasts, those who want to keep their vehicles stock, and those who want to modify it. The Moth appeals to those who want to modify their boat. There are plenty of other one-design classes, some designed for racing, others more suitable for cruising, for sailors without genes that demand they experiment, and take risks.

The Moth of the 1930s was a heavy, narrow scow that weighed about 50 kg. Today’s foiling moth has a hull weight of under 10 kg. During some periods wider skows without wings have been popular. Now, hulls are narrow and wedge-shaped, but with hiking wings stretching to the maximum permitted beam. Sail plans have evolved from cotton sails on wooden spars, through the fully battened Dacron sails on aluminum spars, to today’s sleeved film sails on carbon spars.

While foiling moths are mainly used in protected areas, they can also be used offshore. On 2017-01-21 Andy Budgen sailed Mach 2 a foiling International Moth Nano Project to complete the 60 nautical mile (nm) = ca. 111 km (1 nm = 1852 m) Mount Gay Round Barbados Race at a record pace of 4 hours, 23 minutes, 18 seconds, to established the Absolute Foiling Monohull record.

In 2021, the much larger 75 feet = 23.86 m foiling AC75 monohulls were competing. First, the Prada Cup series was held to determine who would challenge New Zealand in the America’s Cup. It ended with Luna Rossa Prada Pirelli/ Circolo della Vela Sicilia’s Luna Rossa defeating American Magic/ New York Yacht Club’s Patriot and Ineos Team UK/ Royal Yacht Squadron’s Britannia. Speeds were regularly over 50 knots = 92.6 km/h = 25.7 m/s = 57.5 mph. In the subsequent America’s Cup, Emirates Team New Zealand/ Royal New Zealand Yacht Squadron’s Te Rehutai defeated Luna Rossa, to retain the cup. Here is a 10 minute summary of the last race. This video will also show the massive size and speed of these vessels.

Readers may, at this point, wonder why this weblog post is being written, especially when this writer has no interest in sailing such a vessel. He would only be interested in helping to make one for others to use and enjoy. The typical person who could be interested in this, is an inmate at a Norwegian prison, perhaps this unidentified person who drove at 288 km/h = 179 mph, through a tunnel, and bragged about it on social media. Working with cutting edge technology, and sailing at the limits this technology allows, should be a perfect combination of activities for such a risk-oriented person. The advantage of sailing is that it doesn’t put other people in danger, although I would want to have a high-powered rigid inflatable boat (RIB) available during test runs, to rescue this person when (rather than if) he capsizes.

Unfortunately, I don’t expect the prison system to welcome this suggestion. They seem to think that having inmates make pallets will in some way create law-abiding citizens. It won’t. A previous weblog has discussed Flow as a means of motivating inmates.

Further information: International Moth Class Association, Mach 2 Boats, Mothmart (the International Moth marketplace).

Wind turbines in cold weather

The two major and three minor North American Electric Reliability Corporation (NERC) interconnections, and the nine NERC Regional Reliability Councils. The Regional Reliability Councils are: Eastern Interconnection with Florida Reliability Coordinating Council (FRCC); Midwest Reliability Organization (MRO); Northeast Power Coordinating Council (NPCC); ReliabilityFirst Corporation (RFC); SERC Reliability Corporation (SERC); and Southwest Power Pool (SPP). Western Interconnection with Western Electricity Coordinating Council (WECC). Texas Interconnection with Electric Reliability Council of Texas (ERCOT). Mapwork: Claude Boucher (1964-)

This weblog post started off as a response to several fake news posts in various media, alleging that the recent power outages in Texas were due to wind turbine issues. While some wind turbines have failed, there are other, more important reasons for electrical power supply failures, resulting in the inability of Texas to provide water, food and energy to state residents, during – and after – winter storm Uri. Many of these are related to a toxic political environment, where the standard answer to any political question is privatization, where many other jurisdictions have found more nuanced solutions, often involving government participation.

In addition, the post has expanded into new areas, including the use of electric vehicle batteries and household power-walls to provide emergency power. If power utilities (corporations) cannot provide inexpensive and reliable supplies of energy, people will have to take energy production and storage into their own hands. It is noted, but not further discussed, that spot pricing of electrical power in Texas, has not led to a more equitable distribution, but to price gouging, despite this being illegal during an emergency.

Wikipedia states: “The electrical power grid that powers Northern America is not a single grid, but is instead divided into multiple wide area synchronous grids. The Eastern Interconnection and the Western Interconnection are the largest. Three other regions include the Texas Interconnection, the Quebec Interconnection, and the Alaska Interconnection. Each region delivers power at a nominal 60 Hz frequency. The regions are not usually directly connected or synchronized to each other, but there are some high voltage direct current] HVDC Interconnectors.” Direct current is used to avoid any synchronizing issues between interconnections.

The American federal government regulated electrical power in the Federal Water Power Act of 1920-06-10. Its name was changed to the Federal Power Act in 1935. The content of the act has been changed at irregular intervals over the past century. Expressed less than rigorously, there are three electrical grids in the United States of America: The eastern grid, the western grid and the Texas grid, established so that the Lone-Star state/ Republic of Texas, could avoid regulation by the American federal government.

North American electrical energy production is coordinated by Regional Reliability Councils. These are: Eastern Interconnection with Florida Reliability Coordinating Council (FRCC); Midwest Reliability Organization (MRO); Northeast Power Coordinating Council (NPCC); ReliabilityFirst Corporation (RFC); SERC Reliability Corporation (SERC); and Southwest Power Pool (SPP). Western Interconnection with Western Electricity Coordinating Council (WECC). Texas Interconnection with Electric Reliability Council of Texas (ERCOT).

Winter Storm Uri, has an official starting date of 2021-02-13, caused temperatures in Texas to drop to -20 C, in some locations. This caused serious water, energy and hunger problems, and a significant loss of human life. Accessing adequate supplies of water, food and gasoline has been difficult/ impossible for many/ some.

In Texas, wrath was initially directed at wind turbines. Many of the people criticising them are staunch members of the Republican party, and fossil fuel supporters. Fortunately, as will be shown below, many of these criticisms were regarded as fake news, resulting in a significant backlash.

Sid Miller, Texas Commissioner of Agriculture, stated in a Facebook post 2021-02-16: “We should never build another wind turbine in Texas. The experiment failed big time. Governor Abbott’s Public Utility Commission appointees need to be fired and more gas, coal and oil infrastructure built.”

The same day Governor Greg Abbott told  Fox News’ Sean Hannity: “This shows how the Green New Deal would be a deadly deal for the United States of America. Our wind and our solar got shut down, and they were collectively more than 10% of our power grid, and that thrust Texas into a situation where it was lacking power on a statewide basis.”

Fortunately, there are wiser voices. Princeton engineering professor Jesse Jenkins tweeted: “Those of you who have heard that frozen wind turbines are to blame for this, think again. The extreme demand and thermal power plant outages are the principle cause.” PolitiFact reported: “Of the power shortfall that hit Texas, over 80% was due to problems at coal- and gas-fired plants.” Daniel Cohan, associate professor of environmental engineering at Rice University in Houston, Texas stated: “By far the biggest outages have come from our natural gas plants, a portion were down for scheduled maintenance. Others weren’t designed to operate reliably in extreme cold weather and others haven’t been able to get enough natural gas supply.” Even rapper Bun B (Bernard James Freeman) criticized Texas Governor Greg Abbott for falsely blaming blackouts on renewable energy.

Benjamin Sovacool, University of Sussex, professor of energy policy, stated: “In Northern Europe, wind power operates very reliably in even colder temperatures, including the upper Arctic regions of Finland, Norway, and Sweden. As long as wind turbines are properly maintained and serviced, they can operate reliably in temperatures well below zero [0 F = ca. -18 C]. Humans, to carry out servicing and maintenance and operation, are the most important factor, not the weather.”

Various sources state that the operating temperature range of a wind turbine is between -20 C and +40 C. Admittedly steel alloys suitable for cold-temperature environments are typically used in wind turbines located in colder climates. Lubricants are used that retain appropriate viscosity for the climate where they are operating. Wind turbines are equipped with cold-weather packages that ensure cold-weather operation.

Active anti-icing systems are installed on most Nordic wind turbines. These can fail during a power outage on the grid, because they are dependent on external power sources. In a worst case scenario, cold, ice and older technology could result in a 10 percent reduction in annual energy production. With newer and larger turbines equipped with appropriate anti icing systems this loss would be significantly lower.

Blades without an ice-prevention system installed may need to be stopped temporarily in cold weather because falling ice could present a hazard. However, icing can be managed. Current anti-icing options allow wind turbines to be effective sources of power in cold climates.

It is interesting to see that in Texas, thermal energy sources, including natural gas, coal and nuclear energy did not receive the same criticism. Excuses were made that thermal energy failings were due to frozen instruments. The main culprit had nothing to do with instrumentation, but freeze-off, a situation where liquids inside wells, pipes and valves freeze, forming ice that blocks gas flow, clogging pipes. It disrupts gas production across the US every winter.

Another challenge, not generally cited, was that cold weather increased demand for natural gas for residential heating. There simply wasn’t enough fuel available to power the state’s electricity needs. Natural gas production was halved at the Texas Permian Basin during the storm. It fell from 635 million cubic meters of gas produced per day in 2020-12 to about 300 million cubic meters of gas per day during the storm period. This means that gas production was at a four-year low. It could take several weeks to restore supplies fully, due to equipment damage.

There are pragmatic reasons why a reduction in natural-gas supply could result in a reduction of gas to electrical power plants. Texas Gas Services, a public utility, explained it when requesting help from the public to reduce the number of people who could potentially lose the delivery of gas to residences during these extremely cold conditions. They said that conservation (whatever that is, in this context) is critical to avoid widespread outages. If an outage occurs, it will take time and effort to restore service. In part, because each residence will have to be checked for leaks before gas service can be re-established. If only electricity is lost, gas-furnaces should be turned off. When electrical power is restored, consumers are advised to wait 10 minutes before restarting gas furnaces to allow the natural gas system to adjust to increased demand and to avoid further disruptions. In other words, a residential gas outage could result in weeks of delay in getting service restored, while a residential electrical outage would allow an immediate restoration of power.

Many Texans have expressed relief that their state has few electric vehicles. Plugin Texas states that there were 8 397 EVs registered in the state in 2016. Statista estimates that in 2016, there were a total of 8.3 million registered vehicles in the state, indicating that about 0.1% of vehicles in the state are EVs. About 13 million people live in Texas.

Vehicle-to-grid (V2G) power flows, enhanced with two-way advanced meters, would give power utilities an ability to flexibly manage charging. The combined capacity of EV batteries could dampen demand responses and prevent brownouts = an intentional or unintentional drop in voltage in the grid, or worse, blackouts = a loss of the electrical power network supply.

Normally, there should be limitations placed on the use of smart technologies to manage power consumption. Power utilities are keen to flatten electrical consumption throughout the day, so they want consumers to heat their water, wash their dishes and their clothes at night. Yet, insurance companies are concerned the use of dishwashers, washing machines and other appliances at night may increase the number of residential fires.

A more appropriate response may be to charge EV batteries during off-peak periods, then to use them during peak periods. This may be managed on a household basis, or involve large parts of a grid. This is one way to reduce the need for supplementary power stations. In one study, using power in this way may actually increase the life-span of EV battery packs.

In Europe, the ISO 15118-20 standard, comes into effect this year (2021). The standard covers everything from electric bikes, cars, buses and trucks to ships and airplanes. It can control AC and DC changing, as well as wireless power transfer (WPT) and bi-directional power transfer (BPT).

During exceptional times, such as winter storm Uri, electric vehicle batteries, with appropriate charging technology, can function as emergency power sources. They would turn the energy in their battery packs into alternating current (AC) power to provide emergency backup power.

Most EV manufacturers are now recycling used battery packs into second-life storage devices. One of these is Tesla’s Power Wall, but many others are coming onto the market. Power transistors are becoming much more efficient and compact, which has resulted in more efficient and compact domestic power inverters.

Micro power generation in the form of photovoltaic cells, miniature wind turbines or even concentrated solar (thermal) power units will also help make electrical supply more robust.

Some solutions encourage the prepper in everyone, including do-it-yourself (DIY) manufacturing of powerwalls, suitable for talented amateurs.

An Aside: At Cliff Cottage, we removed our main living room wood-burning stove. At one point we had intended on replacing it with a more modern stove, but this has met with opposition/ procrastination from all of the residents. They comment that every time a new log is put on a fire, smoke/ toxins enter the room. Thus, what we are considering now is a battery pack that will provide electricity when there is a blackout. In addition, it should be able to provide extra power during peak periods, and charge itself off-peak. A related project (Turtle Power) is to build a 1 kW miniature wind turbine, with no visible, unintentionally accessible moving parts, and occupying a volume of less than 1 m3. Anyone wanting further information, or an opportunity to participate, is invited to take contact.

Fossil fuels cause significant environmental and health problems. They are also a non-renewable resource. Relying on them is not a wise long-term energy strategy. Texans, and almost everyone else, will have to learn to do wind energy better, to install micro power generation equipment, and to use battery power at home and on the road.