Sunday, September 30, 2012

V3Solar puts a new spin on PV efficiency

V3Solar puts a new spin on PV efficiency

V3Solar has developed a cone-shaped solar energy harvester that is claimed to generate over 20 percent more electricity than a flat panel thanks to a combination of concentrating lenses, dynamic spin, conical shape, and advanced electronics
Image Gallery (5 images)
For the vast majority of those looking to harvest energy from the sun to satisfy domestic or business electricity needs, the photovoltaic world is a static and flat one. Even many large scale solar farms feature row upon row of rigid panels, although there may at least be some movement as the panels follow the path of the sun as it moves across the sky. V3Solar's Spin Cell is a little different. It's claimed to be capable of generating over 20 times more electricity than a flat panel with the same area of PV cells thanks to a combination of concentrating lenses, dynamic spin, conical shape, and advanced electronics.
The V3 Spin Cell actually features two cones, one made up of hundreds of triangular PV cells and a static hermetically-sealed outer lens concentrator comprising a series of interlocking rings and a number of tubular lenses

IPS – Action Needed Now to Prepare for Severe Drought | Inter Press Service

Advancing Deserts, Environment, Food & Agriculture

Action Needed Now to Prepare for Severe Drought

Eroded soils in the municipality of San Cristóbal de las Casas, Chiapas, Mexico. Credit: Mauricio Ramos/IPS.
Eroded soils in the municipality of San Cristóbal de las Casas, Chiapas, Mexico. Credit: Mauricio Ramos/IPS.
UXBRIDGE, May 22 2012 (IPS) - Mexico and Central America look like they are covered in dried blood on maps projecting future soil moisture conditions.

The areas colored dark red-brown will suffer severe and permanent drought conditions if the average global temperature rises 2.5 degrees this century. Credit: Michael Wehner
The results from 19 different state-of-the-art climate models project extreme and persistent drought conditions (colored dark red-brown on the maps) for almost all of Mexico, the midwestern United States and most of Central America.
If climate change pushes the global average temperature to 2.5 degrees Celsius above pre-industrial era levels, as many experts now expect, these regions will be under severe and permanent drought conditions.
Future conditions are projected to be worse than Mexico’s current drought or the U.S. Dust Bowl era of the 1930s that forced hundreds of thousands of people to migrate.
These are some of the conclusions of the study “Projections of Future Drought in the Continental United States and Mexico”, which was published in the December 2011 issue of the American Meteorological Society’s Journal of Hydrometeorology and has gone largely unnoticed.
“Drought conditions will prevail no matter what precipitation rates are in the future,” said co-author Michael Wehner, a climate scientist at the Lawrence Berkeley National Laboratory, a U.S. government research centre in California.
“Even in regions where rainfall increases, the soils will get drier. This is a very robust finding,” Wehner told Tierramérica.
Without major reductions in carbon emissions from the burning of fossil fuels, global temperatures will increase to at least 2.5 degrees of warming between 2050 and 2090, depending on rates of emissions of greenhouse gases, climate sensitivity and feedbacks.
The 19 models used in the study show that the increased heat will dry soils more than any additional rain can replenish soil moisture levels. Ever warmer air temperatures will cause greater evaporation, drying out soils.
Climate change is also altering precipitation patterns, so that more and more precipitation occurs in winter months. And it is more likely to occur in the form of very heavy rainfalls over short periods of time, Wehner said.
Once the ground is dry, the sun’s energy goes into baking the soil, leading to a further increase in air temperature, as Beverly Law, a global climate change researcher at Oregon State University, told Tierramerica at the 16th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change, held in 2010 in Cancún.
Large areas of the Southern hemisphere, including major portions of Australia, Africa and South America, have been drying up in the past decade, according to a study by Law and colleagues, “Climate Change: Water Cycle Dries Out”, published in the journal Nature in 2010.
Another 2010 study in Nature, “Drought Under Global Warming: A Review”, examined future climate projections and also found severe drying of soils over much of the central United States, Mexico and Central America by 2060, but beginning well before then.
This study by Aiguo Dai, a scientist at the National Centre for Atmospheric Research (NCAR) in the U.S. state of Colorado, also projected that northeastern South America will experience similar drought conditions.
“If the projections in this study come even close to being realised, the consequences for society worldwide will be enormous,” Dai said in 2010.
According to Wehner, the very latest projections from the newest computer models that have not yet been published also show very similar results. “At the very least we are looking at severe drought conditions in future.”
Wehner said he was surprised the study received very little media attention, given the serious implications for the future.
What this means for future generations is “a very difficult issue for me to talk about” at a personal level, Wehner admitted.
At the same time, there is little research on how these much drier conditions will affect agriculture, water availability and human settlement.
“I’ve been trying to work with agricultural and other experts to find out, but am having trouble getting funding,” he said.
“It is hard to imagine the consequences under those future conditions,” says Lester Brown, an international agriculture expert, author and founder of the Earth Policy Institute in Washington, D.C. “We’re already on the edge,” Brown told Tierramérica.
Mexico’s current drought is the worst in 70 years. Last year, the southern U.S. state of Texas suffered its worst ever drought, and this year, 56 percent of the United States was in drought conditions as of May 8, almost twice the area compared to last year at this time, according to data from the U.S. Drought Monitor.
“Farmers around the world are struggling to keep up with demand for food,” stressed Brown.
World grain consumption has more than doubled, as have prices. Water shortages, extreme weather and higher temperatures are all having impacts right now, he said.
“Our entire agricultural system is geared to the stable climate conditions we’ve enjoyed for the last few thousand years. And that’s changing,” he added. “Agriculture and climate are getting out of sync.”
The situation has led to intense competition for land and water. But land grabbing is the worst kind of response to these challenges, he said.
Speculators, investment banks, pension funds and state corporations have taken control of perhaps 200 million hectares of land from poor farmers in Africa, Latin America and Asia in recent years. As local people lose access to land and water, they become more desperate and it leads to violent reactions, warned Brown.
“We need to work together. We cannot meet these future challenges with every country only looking out for itself.”
*The writer is an IPS correspondent. This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Programme and the World Bank.

Tuesday, September 18, 2012

Tesla Founder Marc Tarpenning: How to Start a Car Company : Greentech Media

Tesla Founder Marc Tarpenning: How to Start a Car Company : Greentech Media

In any case, Tarpenning is a founder of Tesla along with Martin Eberhard, Elon Musk, Ian Wright and maybe Tom Gage and JB Straubel. Strong feelings still run high amongst that group. The history of the company includes boardroom drama and power grabs that are typical of VC-funded startups with megalomaniacal founders and investors. This is one founder's perspective on the firm.
A decade ago, Tarpenning and co-founder Martin Eberhard studied the transportation industry and came to the conclusion that "[e]lectric cars are by far the best choice."
After studying and analyzing the costs and benefits of hydrogen fuel cells, ethanol, and cellulosic ethanol, the two engineers were "convinced that electric was going to be the winner." Tarpenning noted that with close to a billion cars on the road and 2 billion on the road in the near future, "Even the head of OPEC says we can't power all of these with oil."
They ruled out fuel cells ("Hydrogen is an energy carrier, not a primary fuel. And unfortunately, it's not a good energy carrier."). Turning biomass to ethanol was inefficient ("You'd do better by just burning it."). And the jury seems to be out on the efficiency of cellulosic ethanol and the practice of devoting arable land to transportation fuels.
The two engineers also calculated that electric vehicles (EVs) are more efficient than internal combustion engines, even if the electricity source is from coal. Things look even better if the electricity comes from a combined cycle gas turbine, according to Tarpenning.
Tarpenning said, "All the supercars ten years from now will be electric or electric-assisted."
The duo funded a study with EV pioneer AC Propulsion about the feasibility of using lithium-ion cells. "Originally, all we wanted to do was the drivetrain," according to Tarpenning. However, the horizontally integrated aspect of the nature of the auto industry, with everything outsourced, convinced the duo to build the entire vehicle.

Here's the timeline, according to Tarpenning:
April 2004: The firm had five employees and closed a Series A led by Elon Musk. SDL Ventures was also an investor in that round, which Tarpenning said was $7 million on a $7 million pre-money valuation. The founders estimated it would take $70 million to get the roadster into production.

Jan 2005: The company now had eighteen employees and the mule ("a car that doesn't reproduce") went for its first drive. Another venture round was closed, led by Musk along with Compass Technology and Valor Equity Partners. Gliders (a car without a drivetrain) were being provided by Lotus.
March 2005: Twenty-four employees
April 2005:  Full-scale clay model completed
July 2005: Aerodynamic tuning underway; 38 employees
Aug 2005: 41 employees
Jan 2006: Driveable Mule #2 completed. Engineering prototype EP1 being assembled.
May 2006: Series C led by Vantage Point and Elon Musk along with DFJ and JP Morgan -- "A great round";  92 employees
July 2006: "Public launch" with EP1 and EP2. Crash testing on EP3.  
Aug 2006: 100 employees
January 2007: Cold weather drivetrain testing at the Arctic Circle in Arvidsjaur, Sweden. ABS and traction control tuning.
Feb 2007:  First transmission design underway; 205 employees; VPs (validation prototypes)
March 2007: 230 employees
April 2007: $45 million funding round led by Technology Partners and Musk along with Capricorn Investment Group, Vantage Point Venture Partners, Draper Fisher Jurvetson, JP Morgan Bay Area Equity Fund, Valor Equity Partners and Compass Venture Partners
June 2007: New two-speed transmission running on dyno

Sept 2007: Roadster clocks 0-60 MPH in 3.86 seconds
Oct 2007: Delays in production due to failure of two-speed production transmission. According to Tarpenning, the transmissions all broke in different ways and wouldn't work past the 3,000-mile mark.
Jan 2008: 260 employees
April 2008: Bridge financing led by Elon Musk and Valor Equity
May 2008: New drivetrain being tested. In Tarpenning's words, they were "rescued by Moore's Law." Improved IGBT technology in turn improved inverter performance and allowed Tesla to meet production targets with a one-speed transmission. Retail store opens in Los Angeles, Ca.
June 2008: Tarpenning left the firm. He said that he owned as much stock "as he was ever going to own." First customer deliveries. Retail store opened in Menlo Park, Ca.
Oct 2008: Elon Musk becomes CEO. "I wish he had done that earlier," said Tarpenning. "Elon was the perfect CEO -- it was bold and out-there."
March 2009: Hundreds of Roadsters are on the road; Model S sedan announced with a projected 300-mile range. "We knew we had to get into the sedan market to get the price down."

June 2009: 600 Roadsters delivered. U.S. federal government delivers $500 million loan guarantee.
June 2010: Tesla went public soon after "the gift" of the NUMMI plant. "All the investors did well."
June 2012: 2,000 employees

EV technology is still in its in infancy, and not every EV will be a success. But every car company is launching an EV.

A Few Words on Batteries
Tarpenning confronted some battery myths. He dispelled the idea that batteries lack energy relative to an ICE, although one gallon of gasoline can provide 34 kilowatt-hours (an ICE is inherently inefficient, while an EV drivetrain is small and compact). He said, "The energy density of batteries at the moment is OK. It would be great if it was higher. Higher energy densities would yield more interesting cars."

As far as battery life is concerned and the issue of the slow fade of battery performance, Tarpenning reiterated that the current battery is "OK." Batteries can endure 500 cycles, and that's over 100,000 miles, according to the Tesla founder.  He noted that partial cycles are better than full cycles and cells should last the life of the car. Cells still dominate the car's bill-of-materials, but "prices are dropping in a slow Moore's Law."

He noted that the Tesla motor design did not use rare earth elements such as neodymium. He suggested that lithium faces no materials shortage and that large reserves exist, but simply have not been tapped yet because we are in the early stage of demand for the element.

Tarpenning said he is aware of new battery technologies such as lithium air, but added, "Unless they reduce their price, they're not that interesting."

Tarpenning's conclusion was that "EVs are here to stay because they are so much more efficient than everything else."
Tesla has a $3.2 billion market cap and has already made its early investors a considerable return. The firm has proven that there is demand for a well-designed electric vehicle. And as Tarpenning has said, battery technology could stand improvement, but it's really battery pricing that needs to be improved.
Tesla's ultimate chapter as a mainstream automotive supplier is an act yet be written. Potential glory rests on the company's ability to scale to production volumes of the Model S Sedan in the coming quarter and in 2013. That will determine if Tesla and Musk become the next GM or the next Tucker.

Climate Code Red: Arctic warning: As the system changes, we must adjust our science

Climate Code Red: Arctic warning: As the system changes, we must adjust our science

Update 17 September:

EXTENT: Satellite data shows Arctic melt sea-ice extent yesterday at less than 3.5 million square kilometres, previous record in 2007 was 4.2 m.sq.kms. The JAXA daily raw data is here and the NSIDC date is here. This extent is now well less than half of the average extent of the 1980s.

VOLUME: The sea-ice volume is now down to just one-fifth of what it was in 1979. Latest PIOMAS volume from September 3, 2012 is 3407 cubic kilometers of ice remaining in the Arctic. Contrasted with the 16,855 of 1979, that is just about 20 per cent. Extent has dropped further since 3 September , so volume is still going down this melt season.

Northern Polar Institute Research Director Kim Holmen, left,
with UN Foundation Board Chairman Ted Turner and
President Timothy Wirth in the Arctic
Posted 13 September:
The Arctic sea-ice big melt of 2012 “has taken us by surprise and we must adjust our understanding of the system and we must adjust our science and we must adjust our feelings for the nature around us”, according to Kim Holmen, Norwegian Polar Institute (NPI) international director.
     From Svalbard (halfway between mainland Norway and Greenland), the BBC’s David Shukman reported on 7 September that Holmen had described the current melt rate “a greater change than we could even imagine 20 years ago, even 10 years ago”.
     As detailed last week, the thin crust of sea-ice which floats on the north polar sea is now only half of the average minimum summer extent of the 1980, and just one-quarter of the volume twenty years ago.
     Yet the IPCC 2007 report suggested sea-ice would last all, if not most, of this century: “in some projections using SRES scenarios, Arctic late-summer sea ice disappears almost entirely by the latter part of the 21st century”. One modelling image in the IPCC report (below)shows sea-ice still existent in period 2080-2100. This has proven to be dramatically conservative.

"As a scientist, I know that this is unprecedented in at least as much as 1,500 years. It is truly amazing – it is a huge dramatic change in the system”, says the NPI’s Dr Edmond Hansen. It is “not some short-lived phenomenon – this is an ongoing trend. You lose more and more ice and it is accelerating – you can just look at the graphs, the observations, and you can see what's happening."
And the trend is clear. Cambridge Professor and Arctic expert Peter Wadhams predicts Arctic summer sea ice “all gone by 2015”, except perhaps for a small multi-year remnant. Other Arctic specialists are now saying we will see an ice-free Arctic in summer within a decade or so.
Clearly the IPPC 2007 report is no longer scientifically adequate on the Arctic – and much else – and Holmen’s call to “adjust our understanding of the system and… adjust our science” is timely. The nub of the problem is that climate policy-making in Australia, and internationally, is stuck in the IPCC 2007 frame and is thereby disconnected from what is occurring on the ground, in the seas and at the poles. For that reason it can only fail.
The IPCC 2007 report dramatically underestimated sea-level rises to 2100, as being in the range of 0.18–0.59 metre this century, “excluding future rapid dynamical changes in ice flow”. Because ice sheet melting and carbon-cycle feedbacks such as permafrost are non-linear or difficult to model, the IPCC report projections “do not include uncertainties in climate-carbon cycle feedbacks nor the full effects of changes in ice sheet flow, therefore the upper values of the ranges are not to be considered upper bounds for sea level rise.” The use of paleo-climate (climate history) data as a guide to future sea levels, as advocated by researchers such as James Hansen of NASA, was excluded.
Four of six emissions IPCC scenarios found the “best estimate” of warming to 2100 to be at or below 2.8°C, whilst the trigger for substantial Greenland ice mass loss was put at at 2.7°C with a range of 1.9-4.6°C, “if global average warming were sustained for millennia” (my emphasis).
Put this IPCC 2007 picture together, and the science frame we get is:

Arctic sea-ice unlikely to be lost until the end of the century, or later.
No clear evidence as to whether polar ice sheet melting would accelerate, and in any case the trigger point for Greenland was close to 3°C (implicitly perhaps a century away).
Hence low estimates given for sea-level rises, based on a linear pattern of polar melt. Dynamic and accelerating melting was noted as a possibility but not quantified, effectively rendering it as a footnote.
The language of “tipping points” was not deployed, and the strong implicit message – for the Arctic, Greenland and sea-levels – was that tipping points were not likely in next few decades, and some would play out on millennia time scales.
With the world aspiring to hold warming to 2°C, there is time enough to stop really bad things happening.
So even for the developed, high-polluting (Annex 1) countries, warming could be held to 2°C so long as they reduced emissions by 80 per cent by 2050; for other countries the target was as vague as “substantial deviation from baseline”. Still polluting in 2050 was OK, because the very bad things weren’t going to happen till well after that.

Contrast this to what we now know and observe, and “adjust our science” – as Holmen put it – to a post-IPCC-2007 science frame:

Climate changes and impacts happening more quickly and at lower temperatures than expected, such as Arctic sea-ice which is in a “death spiral” and likely to be gone in summer within a few years.
The tipping point for Greenland has been revised down to 1.6ºC (uncertainty range of 0.8-3.2ºC) above pre-industrial, just as regional temperatures are increasing up to four times faster than the global average, and the increased heat trapped in the Arctic by the loss of reflective sea-ice ensures an acceleration in Greenland melt rate.
Significant tipping points have been already crossed and others are imminent, with particular concern for coral reef systems and the West Antarctic Ice Sheet, to name but two.
The revision of sea-level rise of up to 2 metres by 2100; but the Australian government is stuck on 1.1 metre and state governments are back-pedalling on an 0.8 metre standard because of effect on some coastal property values. IMHO even 2 metres is too conservative, for the reasons articulated by James Hansen.
Establishment of “safe boundaries” approach to the planetary system at less than 350 parts per million (ppm) atmospheric carbon dioxide, compared to today’s level which is nudging 400 ppm.
Advocacy of the 350 target, but even this is too high since 350 ppm at equilibrium is warming of 1°C, and we can now observe at just 0.8°C warming that significant tipping points have been crossed or are at hand.
Carbon cycle feedbacks now being unleashed. In a paper just published, Vonk et al show activation of old carbon by erosion of coastal and sub-sea permafrost in Arctic Siberia is ten times larger than previously estimated. Another research paper published last Sunday by MacDougall et al. shows a “significant contribution to climate warming from the permafrost carbon feedback”. Co-author Andrew Weaver explains in the Huffington Post:

“Instrumental records have clearly revealed that the world is about 0.8°C warmer than it was during pre-industrial times. Numerous studies have also indicated that as a consequence of existing levels of greenhouse gases, we have a commitment to an additional future global warming of between 0.6 and 0.7°C. Our analysis points out that the permafrost carbon feedback adds to this another 0.4 to 0.8°C warming. Taken together, the planet is committed to between 1.8 and 2.3°C of future global warming -- even if emissions reductions programs start to get implemented.’

The application of carbon budget approach developed by Potsdam Institute shows that even for a 2°C target a delay in reaching peak emissions till 2020 then requires a maximum emissions reduction rate of nine per cent per year.
But establishment of the 350 benchmark shows a need for emission levels to fall of a cliff and establishes need for large-scale drawdown of atmospheric carbon.

Are some in our science community concerned that educating politicians and the public about this post-IPCC-2007 frame is politically counter-productive because it paints the current climate legislation as puny and largely irrelevant to the urgency of the problem at hand? A forthcoming Climate Commission statement on the latest Arctic developments is expected to present the full range of peer-reviewed research and expert elicitations. It is hoped that the wider implications for policy-makers of an ice-free Arctic in a decade will be explored.
This is essential because there is no indication that either of the major parties have a clue about this post-IPCC science frame. Nor are there many signs of the major environment and climate advocacy groups incorporating this understanding into their public communications. Most of their campaigning is stuck in the IPCC 2007 frame.
Is this another form of climate science denial? Not the denial of the Murdoch press and the Moncktons and Plimers, but the denial of those who for the sake of political convenience live in a bubble of outmoded policy frames that have been superseded by the pace of events in the real, physical world.

Monday, September 17, 2012

Floating passive house close to mass production - Renewable Energy Magazine, at the heart of clean energy journalism

Floating passive house close to mass production - Renewable Energy Magazine, at the heart of clean energy journalism

“The AUT-ARK Home is a perfect example of how the homes of the future will look,” claims Peter Meijers, Managing Director of IBC Solar B.V. in the Netherlands enthusiastically. Once it has been anchored at its mooring, the passive house does not need to be connected to a waterside power supply – electricity and water are produced and treated by the home itself.
“This is of particular interest in those areas where there is an abundance of rivers and lakes and only limited housing space. This problem could be solved with the passive house, which offers a new, self-sufficient living space,” explains Meijers. Thanks to its innovative construction and self-sufficiency concept, the floating passive home is ten times more energy-friendly than a conventional home of a comparable size.
Peter Meijers was immediately convinced of the idea of the self-sufficient home and offered his advice in designing the power supply from the very beginning. The planning stage of the project was quite complicated. For example, the construction plans for the passive home were altered several times. IBC Solar B.V. adapted the energy concept for each draft accordingly. IBC Solar B.V. took on the costs of the entire planning process and design of the photovoltaic system.
After the planning phase was completed, IBC Solar B.V. supplied a total of 24 Yingli Panda YL265 WP photovoltaic modules and a SMC 6000A type inverter for the prototype of the AUT-ARK home. A solar energy storage unit system consisting of 24 batteries stores the generated solar power, thereby guaranteeing an energy supply that will last for a total of four days. The necessary 230 V grid voltage is generated by means of the bi-directional stand-alone inverter Sunny Island 5048. The residents can use the IBC SolGuard Monitoring System in their living room so that they are always able to keep an eye on the current output of the photovoltaic system. In adverse weather conditions, a bio-diesel generator supplies the home with additional power.
The solid EPS exterior makes the 130-ton-heavy floating home more buoyant. The water needed for drinking, washing-up and washing is extracted from the bilge water by osmosis. Waste water is purified in a cellar tank and returned to the surface water in a 90% purified form. The various on-board water tanks increase the stability of the home. Warm water is generated by six heat collectors installed on the roof and heats the entire living space above the integrated floor heating. In the summer months, cold water from the tanks also runs through this system to keep the AUT-ARK home cool.
For additional information:
AUT-ARK home

fin and tube heat baseboard units now absorb heat. | Flickr - Photo Sharing!

fin and tube heat baseboard units now absorb heat. | Flickr - Photo Sharinges,

Changed out the car radiator, had nothing but air pocket troubles, instead installed sealed copper pipe fin and  tube old baseboard radiators, solved the airlock problems!
Well, almost eliminated it, the pump ran so quietly, cool, but then in the late afternoon, it came back, air in the pump!
so back to pushing in more cold water, draining the lines and pushing out air, a labo
rious process that invovles, a lot of running here and there, opening and closing valves, with water pouring and spraying, very stressful!

warm water storage | Flickr - Photo Sharing!

warm water storage | Flickr - Photo Sharing!
 Warm water is stored in two 55gallon plastic barrels, cold water feed of the DHW tank runs through 30' copper coils inside top of each barrel, thus pre-heating the DHW and saving power, another step to zero carbon comfort!

Saturday, September 15, 2012

Solarsphere – Hybrid PV/CSP Capturing 72% of the Sun`s Energy? - Solar Feeds

Solarsphere – Hybrid PV/CSP Capturing 72% of the Sun`s Energy? - Solar Feeds

The fact that their “sphere” is made up cheap materials – half of it comes from post-consumer recycled plastic – makes the new invention cost-effective with traditional PV systems. And on top of this, it could also capture the solar thermal energy that is generated within the device.
The system consists of a reflector that is based on traditional telescope designs. By using a parabolic dish reflecting sunlight onto a smaller dish, energy concentrated in a single beam can be captured by a triple junction PV chip.
“With that much concentration we can generate energy in two ways. First, we produce electricity with 40 percent efficiency, as high as the most efficient units commercially available today. But that’s just the photovoltaics part. With a 1,000 times concentration there’s a lot of heat generated. So we capture that thermal energy in a liquid.” Says the founders Corbyn Jahn, COO, and Adam Burwell, CEO, both students of Renewable Energy Engineering at Oregon Tech, in an interview with GeekWire.
The team is currently early in the process of designing their system. They are contemplating to run the hot liquid through a Rankine cycle or Stirling engine in order to elimante the intermittence of standard solar power. They are also open for capturing the heat energy in other ways.
Jahn and Burwell are currently in the process of finding an investor for seed capital and take their prototype to a pilot system.

In Focus: Solar Housing - Solar Feeds

In Focus: Solar Housing - Solar Feeds

Solar architecture is pretty much a distinctive type of construction. There are some main peculiarities adhered during projecting and erection periods. First of all, soon-to-be housing must be located in an area that is open to the sun and is well protected from the wind. Secondly, solar houses have embedded windproof walls, solar collectors and thermal devices, aimed to accumulate and preserve the sunlight in a best way. Thirdly, solar houses are marked with special finishing materials and shape. It is important that an inner surface of the walls could provide adequate concentration of the rays and their absorption in order to heat the thermal arrays. A windward side of the roof and walls can be transformed into a beautiful green hill. This ensures not only excellent protection against cold northern winds, but additional conservation of accumulated heat.
There are also some nice examples, which demonstrate a perfect implementation of solar house technologies and, by the way, contribute to modern urban landscape. Barcelona, a city of old-fashioned architecture, tremendous art masterpieces and incredible culture, can boast of solar houses too, which point out Spanish appreciation of green technologies.  In fact, the Solar House 2.0 was constructed on quay of Barcelona. Its facade is made of extruded polystyrene panels, each containing a solar cell (battery). The key thing is that every panel is set at different angle to collect maximum solar radiation. It is impossible not to mention that the project of Barcelona solar house was much facilitated by digital technologies, which figured the best angles to collect sunlight, enabled computer-aided manufacturing of standard and non-standard (resembling architect’s ideas) details, and allowed their scaling due to project’s requirements. Rodrigo Rubio, chief architect of Solar House 2.0, compared its construction to completing a puzzle.
Since 2003 the solar house has been operated in Northern Hesse (Germany). It uses solar power solely, generated by solar collector (45 square meters), which heats hydraulic accumulator (its volume is 12 square meters). In contrast, the house is located in east-west direction in order to fit local residential area. Therefore, windows facing south are suitable for passive accumulation of solar energy, while solar battery roofing for a solar house collects the biggest share of sunlight. Berthelsdorf solar house (Free State of Saxony, Germany), does not use any advantages of passive solar houses, but totally depends on thermal accumulator, which is mounted in the central part of the building. The entire house is divided into zones, instead of rooms (residency, kitchen, and dining-room). The architect project of the solar house is designed considering a big size of thermal accumulator that is bigger than in any other solar house ever constructed.
Maria Kruk, an author for
The Environmental Impacts of 9/11

Wednesday, September 5, 2012

LogTemp software for charting temperatures using 1 wire


'via Blog this'


LogTemp program can be used for viewing and saving of several 1-Wire temperature sensors measurements. The interval of the measurements can be adjusted.
Measurements will be shown in day/week/month graphics. These pictures can be saved automatically using defined intervals. Last measurement values can also be saved to html-file. MySQL™ database could also be used for saving the measurements.
LogTemp program can be localized to other languages very easily. All program captions, messages etc. are read from the external lng-file. Default installation installs english.lng and finnish.lng files to the program directory. Other translations can be done by using the english.lng as a reference file.
If you want to log temperatures with Windows native service, see DS18x Service.
More LogTemp pictures:

LogTemp requirements

  • Operating system Windows 95 / 98 / ME / NT / 2000 / XP / Vista / 7
    • Only x86 systems, although x64 with 32-bit 1-Wire drivers has been reported to work
  • MicroLAN (1-Wire) adapter connected to the computer
  • TMEX drivers, i.e. TMEX runtime environment or new 1-wire drivers
    • Works only with 32-bit drivers
  • Supported 1-wire sensors

1-wire sensors / chips supported by LogTemp

  • DS1820 temperature sensors
    • Measuring -50°C - +70°C
    • Resolution 0,1°C, accuracy in practice ±0,5°C
    • Better accuracy if calibration is used
  • DS18B20, DS1822 and DS1920 temperature sensors
  • DS2438
  • DS2423 Counter
  • DS2405 and DS2406 Switch
    • Alarm event can e.g. control relay board
    • DS2406 has one (TO92 package) or two (TSOC package) channels to be used and in general it's more reliable than DS2405
  • DS2409
  • DS2760
    • Temperature measurements using type E, J, K, R, S or T thermocouples
  • UV Index Meter
    • Hobby Boards special UV Index Meter with 1-Wire interface
    • Not recommended due to serious design failures of the meter. Poor temperature compensation and missing CRC protection. Not usable below +10°C temperatures


If you like see new versions of the LogTemp software, you may  assist this by making a voluntary donation via Paypal. Button below will guide you to secure PayPal site for making donation. Thank you for your invaluable support.


Version history

  • Version  21 Aug 2011
    • xAP messages withdrawn
    • Corrected Min/Max values when Fahrenheit is set
    • Corrected settings for counter (DS2423) properties
    • Corrected DS276x reading in Windows 7 environment
    • Corrected DS2438 reading for combined sensors (e.g. Hum+Sun) when another sensor fails
    • Corrected CSV-file columns compared to header line
    • Setup form redesigned
    • Changed  FTP timer to compatible with other timers (x times measuring interval)
      • Check your FTP timer now
    • Added timer for MySQL. If used, measurements will cached until timer event, then sent all
    • Added TIMEZONE_BIAS_UTC to XML-file, difference between UTC and Local time
    • Added TemperatureGroups (three) for temperature measurements. Each group has own graphs
    • Minor adjustments
  • Earlier version history see this

Software for monitoring 8 digital inputs with Dallas 1-Wire DS2408 on MicroLan- ssds041

Software for monitoring 8 digital inputs with Dallas 1-Wire DS2408 on MicroLan- ssds041:

'via Blog this'

If you have a MicroLan adapter, a DS2408, and digital inputs wired to the DS2408, then this page is for you! (If you don't have those things, you may want to learn a bit about MicroLans!) 

If connecting up hardware "isn't your thing", you can buy a nice 8 channel I/O board with all sorts of worthwhile features from the long established HobbyBoards. 

This page describes and gives you access to a program to monitor the inputs connected to the DS2408. The program draws a graph showing their state, and records the data in a log file.New features have been added to the program since the version shown in the screen shot. 

Screenshot of DS041 

You don't have to pay anything to try the program. However, if you want it to work fully, or if you have been using it long enough to see what it does, then you have to buy a license to continue using it. 

To try the program, download the zip file. Unzip it. You will get several files.... the .exe file (application), a help file, an ini file and a readme text file which mostly only repeats things already on this page. 

You do not have to "install" the program. 
The program will not "do things" to your computer, the registry, etc. 
The program is fully self contained.... you don't need arcane .DLLs, etc, to run it. you do, as with any 1-Wire work, have to have a working 1-Wire environment, hardware and software. 

Click here to download the zip. 

The rest of this page tells you more about the program, in case you weren't willing to download it to see how good it is. 

Not shown in the screenshot: An additional panel where you can have a graph of the values in the two counters of a DS2423 chip, and of temperatures (2) from DS1820 or DS18B20 chips. (Or from one of each.) 

Look again at the screenshot, showing a similar program in action.... 

Don't worry too much about all the options... Concentrate on the graph. 

"Now" is always at the right hand edge. As time passes, the display scrolls to the left. (The green line is gradually lost.) 

The rows can be re-labeled just by editing the ini file (and re-running the program.) The screenshot you see is real data taken from a home heating system. Blue regions represent the heat being off; red shows the heat on. The heat has not been on in the office; in "KBD" it has been switching on briefly about twice an hour. The vertical blue bar marks midnight; the vertical green bars mark 2am, 4am, 6am, etc. The program was started at about 11am the day before the plot shown, and the screenshot was saved at about 7am. 

Note that in almost every case, the red bars do not extend across the whole vertical width of the bar they are part of. When the red bar extends half way across the bar, it is saying that the heat was on for about half the time represented by that narrow sliver of the bar. Only in the Kitchen and Living Room was the heat on for almost all of any measuring period, for any time covering the whole of a column of a bar. 

DS041 records the data as it is read. If the program is stopped, and later restarted, old data is re-plotted on the graph. The program which generated the screenshot is not capable of recording or re-plotting the data. The diagonal green line shows the portion of the graph which represents time before the program was started. If the screenshot were taken of DS041, and if the program had been running for about 36 hours, the full width of the graph would show blue bars with red bits in them. If the program had been started, say, 18 hours ago, the green diagonal line would still be present, behind the bars, and ending about half way across the graph. 

You can change, independently, how often the inputs are tested, and how often the graph scrolls. Thus a variety of requirements can be served. 

I'm afraid the program is not "hub friendly"... it will not "see" chips downstream of a hub unless you close the relevant switch "by hand". 

You can usually see the output from a DS041 in operation by visiting one of my FarWatch installations, a system letting users monitor premises from afar. 

Be sure to check other pages of this site for things which might have appeared on this page, but were either mis-sited or had a more general relevance.
To search THIS site....
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Ad from page's editor: Yes.. I do enjoy compiling these things for you... I hope they are helpful. However.. this doesn't pay my bills!!! If you find this stuff useful, (and you run an MS-DOS or Windows PC) please visit my freeware and shareware page, download something, and circulate it for me? Links on your page to this page would also be appreciated!
--Click here to visit editor's freeware, shareware page.--

By the way.... I am interested in buying any second hand Dallas Rain Gauge or Wind sensor (any version). It must be in reasonable condition mechanically- no cracks or broken bits, but I'm hoping you have one with "dead" electronics, which you are willing to sell for a price that reflects the fact. The "no broken bits" requirement doesn't extend to the electronics. Shipping: It can be to the US or the UK. If you have something for me, please click here for my eddress?

Other projects

This is part of just one of my web sites. Please visit any of the following.... 

Delphi Tutorials
Pascal programming tutorials
Electronics for hobbyists and schools
Main Home Page... various topics, not all computery. 

You can email this page's editor, Tom Boyd. Click here for details. 

Index of sensing and control pages (From there you can also go to other help from the editor of this page.)

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Arduino playground - OneWire

Arduino playground - OneWire:

'via Blog this'

Dallas Semiconductor (now Maxim) produces a family of devices  that are controlled through a proprietary 1-wire  protocol. There are no fees for programmers using the Dallas 1-Wire (trademark) drivers.
On a 1-Wire network, which Dallas has dubbed a "MicroLan" (trademark), a single "master" device communicates with one or more 1-Wire "slave" devices over a single data line, which can also be used to provide power to the slave devices. (Devices drawing power from the 1-wire bus are said to be operating inparasitic power mode.) Tom Boyd's guide to 1-Wire  may tell you more than you want to know... but it may also answer questions and inspire interest.
The 1-wire temperature sensors  have become particularly popular, because they're inexpensive and easy to use, providing calibrated digital temperature readings directly. They are more tolerant of long wires between sensor and Arduino. The sample code below demonstrates how to interface with a 1-wire device using Jim Studt's OneWire Arduino library, with the DS18S20 digital thermometer as an example. Many 1-Wire chips can operate in both parasitic and normal power modes .
MicroLans can be accessed directly by an Arduino, using the mature Arduino OneWire library . Alternatively, they can be accessed through an interface which costs a little money, but reduces the workload inside the Arduino. The interface cost $8 in kit form at 2/2010. There is a guide to using it  from an independent source.

Powering OneWire devices

The chip can be powered two ways. One (the "parasitic" option) means that only two wires need go to the chip. The other may, in some cases, give more reliable operation (parasitic often works well), as an extra wire carrying the power for the chip is involved. For getting started, especially if your chip is within 20 feet of your Arduino, the parasitic option is probably fine. The code below works for either option, anyway.
Parasite power mode
When operating in parasite power mode, only two wires are required: one data wire, and ground. At the master, a 4.7k pull-up resistor must be connected to the 1-wire bus. When the line is in a "high" state, the device pulls current to charge an internal capacitor.
This current is usually very small, but may go as high as 1.5 mA when doing a temperature conversion or writing EEPROM. When a slave device is performing one these operations, the bus master must keep the bus pulled high to provide power until the operation completes; a delay of 750ms is required for a DS18S20 temperature conversion. The master can't do anything during this time, like issuing commands to other devices, or polling for the slave's operation to be completed. To support this, the OneWire library makes it possible to have the bus held high after the data is written.
Normal (external supply) mode
With an external supply, three wires are required: the bus wire, ground, and power. The 4.7k pull-up resistor is still required on the bus wire. As the bus is free for data transfer, the microcontroller can continually poll the state of a device doing a conversion. This way, a conversion request can finish as soon as the device reports being done, as opposed to having to wait 750ms in "parasite" power mode.
Note on resistors:
For larger networks, you can try smaller resistors.
The ATmega328/168 datasheet indicates starting at 1k6 and a number of users have found smaller to work better on larger networks.

Addressing a OneWire device

Each 1-Wire device contains a unique 64-bit 'rom' code, consisting of an 8-bit family code, a 48-bit serial number, and an 8-bit CRC. The CRC is used to verify the integrity of the data. For example, the sample code, below, checks if the device being addressed is a DS18S20 temperature sensor by checking for its family code, 0x10. To use the sample code with the newer DS18B20 sensor, you'd check for a family code of 0x28, instead, and for the DS1822 you'd check for 0x22.
Before sending a command to a slave device, the master must first select that device using its rom code. Alternatively, you can address a command to allslave devices by issuing a 'skip rom' command (0x, instead. This is only safe if you are sure there is only one slave device on the MicroLAN. for commands that don't elicit a response from the slave devices - data collision will occur if data is requested from more than one slave.
Please see the DS18S20  or DS18B20  datasheets for more detailed information.


In 2007, Jim Studt created the original OneWire library that makes it easy to work with 1-Wire devices. The forum thread describes the evolution. Jim's original version only worked with arduino-007 and required a large (256-byte) lookup table to perform CRC calculations. This was later updated  to work with arduino-0008 and later releases. The most recent version  (unavailable at this moment?) eliminates the CRC lookup table; it has been tested under arduino-0010.
The OneWire library has a bug causing an infinite loop when using the search function. Fixes to this can be found in this Arduino thread, see posts #3#17,#24#27 for a variety of fixes.
Version 2.0  merges Robin James's improved search function and includes Paul Stoffregen's improved I/O routines (fixes occasional communication errors), and also has several small optimizations.
Version 2.1 adds compatibility with Arduino 1.0-beta and an improved temperature example (Paul Stoffregen), DS250x PROM example (Guillermo Lovato), chipKit compatibility (Jason Dangel), CRC16, convenience functions and DS2408 example (Glenn Trewitt).
Miles Burton derived its Dallas Temperature Control Library  from it as well.

Example code

#include <OneWire.h>

// DS18S20 Temperature chip i/o
OneWire ds(10);  // on pin 10

void setup(void) {
  // initialize inputs/outputs
  // start serial port

void loop(void) {
  byte i;
  byte present = 0;
  byte data[12];
  byte addr[8];

  if ( ! {
      Serial.print("No more addresses.\n");

  for( i = 0; i < 8; i++) {
    Serial.print(addr[i], HEX);
    Serial.print(" ");

  if ( OneWire::crc8( addr, 7) != addr[7]) {
      Serial.print("CRC is not valid!\n");

  if ( addr[0] == 0x10) {
      Serial.print("Device is a DS18S20 family device.\n");
  else if ( addr[0] == 0x28) {
      Serial.print("Device is a DS18B20 family device.\n");
  else {
      Serial.print("Device family is not recognized: 0x");

  ds.write(0x44,1);         // start conversion, with parasite power on at the end

  delay(1000);     // maybe 750ms is enough, maybe not
  // we might do a ds.depower() here, but the reset will take care of it.

  present = ds.reset();;  
  ds.write(0xBE);         // Read Scratchpad

  Serial.print(" ");
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] =;
    Serial.print(data[i], HEX);
    Serial.print(" ");
  Serial.print(" CRC=");
  Serial.print( OneWire::crc8( data, 8), HEX);
For more compact version of the code above, as well as for description of sensor's command interface look here .

Converting HEX to something meaningful (Temperature)

In order to convert the HEX code to a temperature value, first you need to identify if you are using a DS18S20, or DS18B20 series sensor. The code to read the temperature needs to be slightly different for the DS18B20 (andDS1822), because it returns a 12-bit temperature value (0.0625 deg precision), while the DS18S20 and DS1820 return 9-bit values (0.5 deg precision).
First off, you need to define some variables, (put right under loop() above)
int HighByte, LowByte, TReading, SignBit, Tc_100, Whole, Fract;
Then for a DS18B20 series you will add the following code below theSerial.println(); above
LowByte = data[0];
  HighByte = data[1];
  TReading = (HighByte << 8) + LowByte;
  SignBit = TReading & 0x8000;  // test most sig bit
  if (SignBit) // negative
    TReading = (TReading ^ 0xffff) + 1; // 2's comp
  Tc_100 = (6 * TReading) + TReading / 4;    // multiply by (100 * 0.0625) or 6.25

  Whole = Tc_100 / 100;  // separate off the whole and fractional portions
  Fract = Tc_100 % 100;

  if (SignBit) // If its negative
  if (Fract < 10)

This block of code converts the temperature to deg C and prints it to the Serial output.

A Code Snippet for the DS 1820 with 0.5 Degree Resolution

Above example works only for the B-type of the DS1820. Here is a code example that works with the lower resolution DS1820 and with multiple sensors diplaying their values on a LCD. Example is working with Arduino pin 9. Feel free to change that to an appropriate pin for your use. Pin 1 and 3 of theDS1820 has to be put to ground! In the example a 5k resistor is put from pin 2 of DS1820 to Vcc (+5V). See LiquidCrystal documentation for connecting the LCD to the Arduino.
#include <OneWire.h>
#include <LiquidCrystal.h>
// LCD=======================================================
//initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
#define LCD_WIDTH 20
#define LCD_HEIGHT 2

/* DS18S20 Temperature chip i/o */

OneWire  ds(9);  // on pin 9
#define MAX_DS1820_SENSORS 2
byte addr[MAX_DS1820_SENSORS][8];
void setup(void)
  lcd.begin(LCD_WIDTH, LCD_HEIGHT,1);
  lcd.print("DS1820 Test");
  if (![0]))
    lcd.print("No more addresses.");
  if ( ![1]))
    lcd.print("No more addresses.");
int HighByte, LowByte, TReading, SignBit, Tc_100, Whole, Fract;
char buf[20];

void loop(void)
  byte i, sensor;
  byte present = 0;
  byte data[12];

  for (sensor=0;sensor<MAX_DS1820_SENSORS;sensor++)
    if ( OneWire::crc8( addr[sensor], 7) != addr[sensor][7])
      lcd.print("CRC is not valid");

    if ( addr[sensor][0] != 0x10)
      lcd.print("Device is not a DS18S20 family device.");

    ds.write(0x44,1);         // start conversion, with parasite power on at the end

    delay(1000);     // maybe 750ms is enough, maybe not
    // we might do a ds.depower() here, but the reset will take care of it.

    present = ds.reset();[sensor]);  
    ds.write(0xBE);         // Read Scratchpad

    for ( i = 0; i < 9; i++)
    {           // we need 9 bytes
      data[i] =;

    LowByte = data[0];
    HighByte = data[1];
    TReading = (HighByte << 8) + LowByte;
    SignBit = TReading & 0x8000;  // test most sig bit
    if (SignBit) // negative
      TReading = (TReading ^ 0xffff) + 1; // 2's comp
    Tc_100 = (TReading*100/2);  

    Whole = Tc_100 / 100;  // separate off the whole and fractional portions
    Fract = Tc_100 % 100;

    sprintf(buf, "%d:%c%d.%d\337C     ",sensor,SignBit ? '-' : '+',Whole, Fract < 10 ? 0 : Fract);