Real Life Review: Purple Air PA-II Air Quality Sensor

Living in the high desert of Southern California and within distant sight of Cajon Pass,there have been many days when I can see the wall of haze / smog / general yuck in the air rising up the pass from the LA basin and Inland Empire and overflowing the pass, spreading out in the Victor Valley. It is not unusual for days to start out clear and the San Gabriel Mountains are clearly visible, yet by mid-evening the pollution has obscured them entirely.   When I turn and look the other way, however, the air is usually perfectly clear.  It’s prompted me to wonder how much of the pollution I see actually makes it to my location, and if there are elements I can’t see which are making it up here.

The local air quality district does have monitoring stations, but they are few and far between and do not have nearly the spatial resolution to be of use at an individual level. I looked into renting a similar sensor for a few weeks, but the cost far outweighed my curiosity.  I basically gave up on being able to lean more about the air in my specific environment.

A week or so ago I found out about a novel, web enabled, air quality sensor for measuring particulates that was starting to gain a following in the “citizen science” community which is being produced and distributed by “Purple Air”, which also hosts a real-time map of the installed sensors which have had data sharing activated.   It uses the same type of laser particle detection and quantifying system as some of the higher end (and much higher cost) certified systems, but instead of being aimed at the regulatory and compliance side of the spectrum it is targeted more at regular people.  Rather then being a calibrated and NIST traceable instrument the approach of the organization involved seems to be to go for sensor-to-sensor consistency rather than absolute accuracy, however they have had the sensors evaluated by the Air Quality Sensor Performance Evaluation Center, a branch of California’s South Coast Air Quality Management District, and a technical result of that evaluation is available on their website.   At slightly over $200 it seemed a reasonable way to satisfy my curiosity, if still a bit on the expensive side, so I ordered it.

Delivery was faster than I expected, which was a good thing as in the period between ordering and receiving I began looking for additional information about installation, setup, and use, and found basically nothing, which launched off a major research activity that could well have spun on for weeks.  When I did receive it, it was deceptively easy to get going – plug it in, connect to it’s standalone wifi network in order to configure it to your wifi network, and then go on the PurpleAir website to register it as a monitoring station.  All told it took under 10 minutes from pulling it out of the box to streaming data. I was interested in making sure it worked prior to doing the final install, so for that initial test I simply hung it on an existing nail on the front porch and let it run for a few hours while I looked into other installation options.

I ended up deciding that the front porch was probably the best spot overall as it offered a good combination of protection from the elements, separation from “domestic” pollution (e.g. my smoker and grill on the back porch) and good access to ambient air.  I had no objection to where I had first put it, but it comes with a 33 foot power cord and that location was only a few feet from the plug and left a mess of extra cable, so I basically neatly ran the cable up and around the porch structure and located the sensor at the point where I ran out of power cable.  The sensor itself is basically the size of a 3″ PVC pipe cap (which is what the outer cover actually is) and has an aluminum mounting strip attached to it.

The initial data showed what I had been suspecting – my local air quality was much better both on a relative and absolute scale than the official data, which was basically an extrapolation of the reading from one site about 15 miles away from me.  Areas “down the hill” in the Ontario / San Bernardino area were showing air quality index values of low 60’s, whereas I was in the low 20’s (on the AQI scale 0 is best).  A few hours later though I had a test case in the other direction – the smoke plume from a distant forest fire settled over my location for a few hours, moved elsewhere, then came back, …  which resulted in the PM2.5 values shown below.  At the peak of the smoke, my local AQI value was up to 130.  By sheer coincidence, I had data for both high and low ranges within my first 24 hours of usage, which has increaed my initial confidence in the values the unit is putting out.

In summary, so far I really like my PA-II air quality sensor, and it is nice to have data to back up the observation that the air quality where I am is as good as I think it is.  There are a few issues with some details of their site registration process when you want to share data with other sites such as Weather Underground and link it to an existing weather station, but I’m certain that will get smoothed out over the next few months if not days.  At the moment it appears that slightly over 500 of these sensors are installed worldwide, so time will tell how they do in terms of drift and longevity… but assuming that remains good, at under $250 including shipping and no direct operating costs, I can easily see a day when every public building and many private ones incorporate something like this.  That would allow a huge improvement in our ability to monitor and mitigate particulate pollution, and is something I would much rather see my tax dollars flow into than building a wall across a desert.

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Random Food of the Day

Grilled ponzu and chili oil marinated tuna steak with salad

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Going Solar – Part 9: Joining the Smartgrid

A few days ago a postcard showed up in my mailbox advising me of an impending deadline for an energy storage incentive for households with installed solar arrays. Interested, but assuming it was a scam of some nature, I did some research and found that it was a real program.  Put simply, the state and local utilities have decided that the model of distributed solar generation and storage, already widely used in Europe and Asia, is indeed something worth looking into.  This was something I had wanted to incorporate into my system from the start, but when I decided to install the solar array there was no incentive program and costs were excessive, the optimized hardware had not yet been certified, and the utility was, quite frankly, dead set against the idea.

The buzzword at the moment surrounding this approach is “Smartgrid” and there are numerous ways it is being considered and implemented.  At it’s most basic in this context, the idea is that the rapidly increasing availability of the “Internet of Things” (IoT) can be used to improve the efficiency and effectiveness of the electricity network. Using my solar installation as an example of a typical grid-tied, net metering system, the system works in a basic mode.  Assuming that all is normal with the grid, when the sun is shining my panels generate as much electricity as they can.  This electricity is then basically dumped into the power grid between my house and the utility meter. If my house needs all of that electricity at that moment it goes into the house; if not any excess goes into the grid.  Likewise, if my house needs more electricity than the panels are producing, the excess is supplied by the grid.  Per the terms of my net metering agreement (and indeed, what should be the terms for all end-user interconnect agreements) it is a 1 for 1 trade: for every kilowatt hour I give to the grid, I can pull one at a later time at no net cost.  This can easily be seen as using the grid as a “battery” backup for the nominal cost of the minimum monthly fee charged by the utility to help offset the cost of the distribution network, and at the top level it works well.

The challenge in this system is that as more solar generation is added to network as a whole a cyclical generation cycle develops – all the solar rolls in during the day and out in the evening.  The grid has to anticipate and react to this effect in order to maintain a steady supply to all users, and becomes yet more complicated as wind energy is included into the mixture.  This drives a very different operating mode relative to the traditional structure of large base load generators (e.g. huge nuclear or coal fired steam turbine stations) with a very narrow band of peak operating efficiency and relatively slow response to changes and smaller peaking stations (e.g. diesel or gas turbine stations) which are capable of fast response to the changes in demand.

One approach to help balance this dynamic is the implementation of “Time of Use” energy tariffs.  This breaks the day up into periods of high and low use, and the price of a kilowatt hour of electricity varies in relation to what time block the energy is used in.  The underlying principle behind this is that in a traditional, non-solar, network there is a significant overcapacity through the night while most people are sleeping if the system was sized to accommodate the peak daytime demand.  The idea is not new – when I was living in Germany in the early 1990’s this was already an established structure, and most large household appliances which did not need to run continuously (dishwashers, laundry machines, …) incorporated timers so they could be set to run overnight when electricity was less expensive, and electric water heaters had programmable cycles to optimize on energy price.  The coin-op laundry in my apartment building charged different rates depending on the time of day, leading to the busiest time being 3 AM on Sunday morning because it cost about half the price to wash and dry a load at that time compared to washing only at a more normal time.

Unfortunately, time of use charges combined with a solar supply cycle on the grid don’t necessarily work as they do in a non-solar grid.  To make most effective use of the solar supply, energy prices would need to peak at night when the solar supply is offline and then drop in the middle of the day when supply was highest.  Given the relative percentages of solar vs non-solar supply, the overlapping model becomes quite a complicated system, particularly when one looks at the regulatory environment that this occurs in.

Here is where the Smartgrid concept comes into play.  By using a network of interconnected sensors to actively monitor the systems involved, the overall grid can be continuously optimized and near-term predications made based on real-time data.  As the technology grows and becomes more prevalent, the granularity of the involved systems improves – where once this was used to help determine when to bring peaking stations online, now it can be used both to do that as well as to throttle back demand by reducing discretionary loads at the end user level.  This can take many forms, such as utilities providing discounts to residential customers who allow the utility to install remote disconnects for high load devices such as air conditioners or swimming pool pumps or commercial customers who enable the utility to manage their building thermostats within a given range.

This all applies to production and usage, but there is another large area still to be integrated: storage.  Various forms of energy storage have been available for decades at both large and small scales, however they were generally quite expensive, limited in scope, and relatively inefficient.  One example of a large scale system is a hydroelectric peaking plant: when electric demand is low excess production is used to drive pumps that send water uphill into a reservoir, but when extra power is needed to cover peak loads the water is routed back down through turbines.  Variations of this have been demonstrated using air in abandoned salt mines and with giant mechanical flywheels turning in a vacuum chamber.  At a smaller level some commercial users have either battery or capacitive storage capability, mainly intended as an independent system backup rather than a grid level storage, but the end effect is that depending on how these systems ae set to charge it can have a positive effect on stabilizing the grid.

What has been missing from the US grid is a homeowner level grid storage capability of sufficient capacity to aid in stabilizing the grid as a whole.  Again, this technology has been on the market in other regions for years, but the US utilities have until recently been strongly opposed to the concept. What is currently happening, though, is that as homeowner scale installations of solar and / or wind energy increases, utilities in certain areas such as Southern California are finally coming around to see homeowner generators as a potential source of the overall solution rather than a problem to be excluded from consideration.  By offering suitable incentives to bring the homeowner’s cost of the necessary infrastructure down to a reasonable level, the utilities hope to create enough capacity to be an effective overall tool in better managing the grid.

Which brings me back to the postcard I received.  The sender turned out to be a consulting firm that represents several of the “home battery” manufacturers and performs system design activities on behalf of independent system installation contractors.  After doing a bit of research to get an idea of what was available and typical pricing, I called the number on the postcard and spent a bit over an hour having a detailed technical discussion with a system designer, and we ended up deciding that a Tesla PowerWall 2 would be the most cost effective solution for my installation within the incentive program.  When I initially purchased my solar array I selected a SolarEdge inverter in order to be upgrade ready for when they came out with the StorEdeg system in the US market, and while there was a LG battery which potentially could have worked with the StorEdge DC-DC coupled approach, by the time the cost of upgrading my inverter and the battery were combined the Tesla with the built in inverter made more sense even with the added efficiency hit of having to go DC-AC-DC. In addition, although currently not set up to do so, the DC-AC-DC option provides an ability to eventually use grid charging capabilities at a future point.

So what does adding a battery to my system bring me?  At the moment I have to admit not a whole lot.  My current system is pretty close to a net zero system, e.g. I produce basically what I use, so I don’t have much in the way of excess capacity to store.  My local grid has been very reliable, and there are relatively few cloudy days or even periods within a day due to my high desert location.  If anything, I actually stand to lose from both a cost and production basis, as despite the incentives the battery system will still run me about $5000 installed and whatever electricity goes through the battery is subject to around a 10% loss due to storage and transformer losses.. and I’ll still be paying the monthly minimum utility fee for being grid tied.  In the event that I was living in one of the backward utility regions where they use a producer / consumer accounting system (whereby any excess energy production to your own needs is “sold” to the utility as a low rate and then any additional consumption is “bought” from the utility at a higher rate, even if the net energy comes out to be zero) instead of net metering, the situation would be different as there is a direct cost advantage to storing and using your own production.

So what do I stand to gain? In large part it’s simply the feeling of doing what’s right for the greater good.  More expansively, it’s taking one of the steps within my power to actively demonstrate my opposition to Mr. Trump’s misguided and disastrous energy and environmental policies. More concretely, I do gain slightly stronger self-generation capabilities in the event of a grid outage.  Without a battery system, a grid tie solar installation is required to be turned off whenever there is a grid outage in order to prevent current flowing from the solar array back through the grid to the point where it is being worked on and potentially injuring a utility worker or others who may come in contact.  With a battery system part of the control circuitry will isolate the grid side as before, but will still allow the panels and battery to supply the household needs.  In this case the panels will only be shut down in the event that the battery is fully charged and there is no household draw.

How does this help the utility?  Quite simply, it helps them to shave off the peaks and troughs of solar production going into the grid.  If every solar installation had a battery and was properly configured, the excess energy produced during the day would be stored locally and then available for overnight use.  This helps to shave the peaks and troughs of solar supply and night demand at an individual site, and by extension to the rest of the grid.  When these individual storage capabilities are then integrated into the Smartgrid as part of a distributed generation and storage network, it provides a dynamic energy reserve for the system to be able to draw on in.  Likewise, in the event that there is a grid outage, even a few residential batteries in the affected region could be used to help buffer the step load to the remainder of the local grid as power is restored to the affected region.

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The Art of BEEing: Yes, my bees sting

I got the bright idea relatively late this morning (after the day started to heat up) to go out and remove the bee feeder so I could clean it. After I had opened the hive up and pulled the top feeder I figured I’d go ahead and swap out some of the now-drawn honey super frames as well so that hopefully the bees would start drawing comb on the new frames and I could use the full frames to feed through the winter and then have empty comb ready in case we get a decent spring flow next year. I left the hive open, headed into the garage and got some blank frames, and went back over to the hive and started to pull a frame.

And I was met with a wave of bees. Not just the usual one or two that do their due diligence in buzzing around and making sure you know they are unhappy with you taking apart their house, but hundreds. And they were not happy. Despite the bees bouncing off my lightweight (and untucked) bee jacket like hailstones, I remained relatively calm, decided it had been a bad idea to go after the frames, and started to close the hive back up… Then I realized I had a bee on the inside of the jacket and it was bouncing off my glasses. All caution thrown to the wind, I swatted it against my face along the idea of at that point the odds were better of not being stung in the eye by trying to kill it before it could sting than of leaving it alone. I was successful on that one, but the arm movement to swat at it seemed to trigger the others to start stinging.

At least 7 stings later I made it back to the relative safety of the back porch which, being out of sight of the hive, usually gets all but the most adamant of defensive bees to turn around and give up the chase. In this case that still worked, but then I realized there were still several bees inside the bee jacket. I didn’t want to bring them in the house, so in a wild bout of unattractive strip-tease I managed to yank off the bee jacket, brush a few straggler bees off my shirt and jeans, open the back door, get inside and slam it shut.

Moral of the story – when you decide to be stupid around bees they are not afraid to remind you of the consequences of your stupidity. In this case I had been lulled into complacency by my habit of feeding them early in the morning when the air is still cool, and most of the time my doing so barely elicits a change in tone from the colony.  That is a relatively quick and non-invasive activity, which was my intent when I went out this morning. Had I taken the smoker and worn my heavier suit, or potentially even just had take the step to tuck in the bee jacket, I could well have done what I decided to do at the last minute today without any stings…  But I didn’t, and I my tuition for the lesson are a few stingers in me, a few dead bees, and a backyard colony that’s gong to need a few hours to settle back down (so I’ll probably use the clothes dryer for laundry today instead of the clothesline).

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Democratic Legitimacy and the lessons of an illegitimate, incompetent, and incapable presidency

It’s been 6 months since Mr. Trump ursuped the office of the US presidency following one of the most bizarre election cycles in US history. Even before the foreign involvement elements of the election which are currently monopolizing press coverage, the very nature of the primaries gave a foreshadowing of what was to come – open lies, disregard for the legitimate press, incomprehensible actions, vindictive tendencies, and a complete and utter lack of regard and respect for the basic tenets of a democratic system and those living within it. While other candidates detailed how they would go about achieving their platforms (with various degrees of believability), Trump simply kept adding elements to his based on whatever direction the populist trends of were pointing and never bothered to address how they could be achieved or what the impacts would be.

There is a concept known as Democratic Legitimacy which in large part explains the mess the US finds itself in at the moment. The Trump regime has had to fight against it from the start – it didn’t so much win the Republican nomination as inherited it from the abdication of real candidates. A fair number of the votes it did get in the presidential election were not actually for Trump but against Clinton, as well as from partisan voters who voted Republican despite misgivings over the individual. By gaining the presidency not by the real election of the popular vote but through the arcane (and inherently undemocratic) institution of the electrical college, the regime already started off on a poor footing relative to legitimacy – when you only win by virtue of non-representative vote counting and the majority of people did not vote for you it’s hard to consider it a legitimate victory.

Mr. Trump aside, the current government, being controlled by one party as a result of an inherently flawed winner take all system, has an obligation under the tenants of Democratic Legitimacy to take extra steps to avoid even the impression of laws being passed or considered based on partisan principles. The idea of Democratic Legitimacy is that actions speak louder than words when it comes to being a legitimate democratic government – there are numerous examples of regimes calling themselves democracies without actually being one. Key elements of this are actually embracing and following the underlying guidelines of democracy such as honesty, integrity, open access to information, consideration of the views of all stakeholders, merit based appointments, respecting the rule of just laws, and acting in the best interest of the population regardless of individual viewpoint. The Trump regime has failed in these areas to a tragically humorous level.

Whereas past administrations of both parties have had occasional blunders in these areas, the Trump regime distinguishes itself as only having the occasional observance. Policy decisions are arbitrary and inconsistent. Appointees with grievous conflicts of interest are routine. The legitimate press is excluded from access in favor of known dubious outlets. Decades of successful policies are arbitrarily reversed. Groups of men claiming to act against “big government” sit in closed sessions to determine the legality of what women can do with their own bodies. People who have the best health coverage in the country, paid for fully by taxpayers, work to find ways of removing what little coverage is available to everyone. The confirmation hearing for an existing Supreme Court Justice nominee is blocked for over a year by a Republican congress, and then that nominee is replaced without ever having a hearing by a new one and the rules are changed to fast-track him through. Longstanding regulations protecting the health of entire communities and regions are repealed in the interest of a handful of temporary jobs. Longstanding traditions of the president divesting from personal business interests and openly revealing their dealings are simply ignored despite calls from all sectors of society for that transparency. These are not the actions of a legitimate leader or government.

Trump’s background should have been a warning to those of his supporters who believed he could deliver what he was promising. His background experience as a real estate developer was based on a history of failed promises and rule bending. Real estate “development” is one of the most artificial businesses there is, and in general is based on finding ways around the regulations intended to protect those who are already there or, if that can’t be obtained in the required timeframes, simply ignore rules and use massive financial backing to lock things up in litigation so long that the impact of going back to the original state is no longer an option.

The end goal of a developer is not to create a longstanding and positive part of the organic local community, but to take profit, move on, and leave the fallout to those left holding the actual property – regardless of impact to those who were there to start with. A great example of this is what happened where I used to live in Indiana. It was a mainly rural county with low population density, and the county had a zoning regulation requiring minimum lot sizes and certain spacing between new houses, ostensibly to protect the character of the area for those living there. When challenged by a consortium of well-funded external developers, the resources of individual landowners to defend this regulation were soon expended and, without a public vote, the zoning board (with developers as members) decided to allow developers with plans to build at multiple locations to take an average of all their planned projects in the county. This resulted in what had been a relatively open market with organic growth mainly by independent homeowner / builder combinations buying lots of 1-10 acres for individual properties being overrun by groups that had the external funding to buy land by the thousands of acres for speculative building at a greatly reduced price per acre. To comply with the revised zoning, the developer would then break ground for a “luxury” community with significantly larger lots than required and maybe build a model home, then stop work on it, focus on building several higher density “basic” communities on much smaller lots which, at an individual basis, would not have met the zoning requirements, and eventually claim the market no longer supported the “luxury” community and either sell it to another developer or apply for a zoning exemption to turn it into a “basic” one. For over 5 years I watched new “basic” developments popping up in contravention of the actual zoning while the offsetting “luxury” one sat idle and was sold multiple times. The quality of life for those originally living in the area decreased dramatically with increased noise, traffic, and pollution as well as increased taxes to pay for the infrastructure changes needed to keep up with the external growth, and the profits of the development went out of the county.  The point of this example – someone whose background is the large real estate development industry is coming from an area where regulations and restrictions are seen as nothing more than things which can be bought off or worked around with no significant individual impact to themselves.

This is the general background Trump came from – one where rules do not apply, individual accountability is zero, and if by some stretch of fortune something does come back at you, you throw enough money at it and it goes away. In addition, Trump lived in a virtual bubble where people were paid to cater to his every whim. The end result – a dangerous person who has no knowledge of the realities that exist outside his own ego nor any sense of consequence for his actions.

In a healthy democracy a person like Trump would have never made it to the level of a national primary candidate much less receive a party nomination – he would have been called to account numerous times for lack of relevant experience, understanding, and accountability. This is a key reason why the German system has the 5% hurdle – painfully learned by the experiences of the Weimar Republic. But the US system is not a healthy democracy, nor has it been one for many years. A healthy democracy puts the best interests of the whole over that of the individual or party, but what was seen in the 2016 election was a triumph of partisanship over democracy. It’s now up to the population to ensure that the government is held accountable for their actions and to continue to live up to the democratic principles of openness, transparency, and working for the common good.

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Book Review: Goodbye to Berlin

Goodbye to Berlin
Isherwood, Christopher
Vintage, 1998 ed, of 1939 original

Per the author’s introduction, this collection of loosely connected sketches featuring a first person narrative from a character sharing his name, his background, and many of his experiences is fiction and was intended to be something larger than it came out to be. It is a convenient, and perhaps accurate, approach to classify the gray area between autobiography, fiction, and reflection. It also makes it possible to write the stories an author anticipates for themselves but which may never have had a factual base.

The beauty of this book lies not so much in this format, nor it’s direct timeframe, but in the detailed and generally factual description of life as an English writer in Berlin as the Nazis came to power. With contacts ranging from a wealthy Jewish family where he works as a private english tutor, through the English ex-pat community with all it’s variations, the matron of his middle-class boarding house through to the working class family whose son invites him to move in with them when his finances take a turn for the worse, the fictional Mr. Isherwood sees a broad swath of humanity in one of the leading cities of Europe just as it’s light is about to be extinguished. From neighborhood dives filled with pick-pockets and prostitutes winding down their day to high end nightclubs, tenements to mansions, rural holidays to urban centers, the book slices a cross section of the society just as it is about to change in a way that would make these scenes unrecognizable for decades.

The book ends as the author leaves to return to England, having decided that it is too dangerous for him to stay in Germany any longer. The timeframe is approximately 1933, and while war is still a few years away the daily decline has already begun.

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Book Review: Black Wings Has My Angel

Black Wings Has My Angel
Chaze, Elliott
New York Review Books, 2016 ed of 1953 original

Basically a pulp fiction novella with a bit more depth, this is a good period piece of mid-1950’s America. The story revolves around an escaped convict’s obsession for carrying out the perfect heist which he and one of the other prisoners developed while in prison. His partner was killed in the escape, but after a fling with a hotel prostitute in a backwater town leads to an unlikely affair he finds in her a perfect and willing accomplice. The plan takes time to develop, and as they travel the country in search of the perfect place the tone shifts from pulp crime to road novel to social observations of time and place.


Eventually, however, the book shifts back away from descriptions of how neighbors water their lawns or the dangers of being on the backside of office politics in a pre-OSHA factory, and the long planned heist takes place, but despite the apparent success of their plan the couple find themselves caught in the uncertainty of their relationship with one another and the various worlds they have created around themselves. The book ends as any good 1950’s story must – but it leaves a reader pondering how it would have ended had it been written in a later period.

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