Solar power installation on the winter garden roof

Posted on September 9, 2021 by jonas

I have had quite a bill from the local energy supplier for many years. Admittedly due to some extensive usage of electrical equipment such as computers in various forms. The AC is also quite power hungry but the days when its service is needed is limited to around 25 days (I did not count, but could serve as a ballpark figure in Canton Zurich…) a typical year.

Pay and forget would kind of solve the problem I guess but with the increased solar panel efficiency this is an option for us who has some roof/balcony or similar to host some panels.

I obviously did a bit of reading and feeding back to the grid would obviously be quite interesting to reduce the electricity bill but it has two drawbacks. More than 600 W requires some bureaucracy which I would be happy to live without and it does not give the same sense of independence/backup compared to the island approach since it requires the grid to be online (which it typically does but nevertheless).

So I settled for the hybrid island approach meaning the panels charge batteries via an intelligent hybrid inverter which also serves as the AC power source for the devices that should be at least partially solar powered. If the panels don’t deliver enough of energy to maintain a certain battery capacity, the batteries are charged via the AC grid.

Regarding my actual solution… I currently have 4 monocrystalline panels (Penta+ ASM6610M-series) with a theoretical capacity of 305 W each, in series-parallel (meaning two pairs of serially connected panels which are connected in parallel). (If you slept during those lessons in school and don’t work in that area, let’s say serial increases the voltage and parallel the current.) These panels are located on our winter garden roof and the hybrid converter is in a room in the cellar. Since the hybrid converter is kind of loud, imagine a medium noisy vacuum cleaner, it should really be in a room where you don’t need to conduct a lot of serious business on a regular basis.

My hybrid converter is a very common 24 V model from Voltronic Power (ODM, sold under a number of brands) rated for 2.4 kW which offers a USB interface (I use a simple client from https://github.com/nrm21/skymax to poll the device for values). It should be possible also to set values (e.g. change from PV charging to bypass mode) but I currently only use it to get values and expose them on a website for my personal pleasure. (I did play with a container feeding a MQTT message broker to expose the current state in a dashboard but my raw output in a table with some homegrown graphs turned out even more useful at the moment. I might revisit that later.)

Battery wise I was choosing among AGM, Gel or Lithium. I settled for the middle road, 4 times 12 V 140 Ah Gel batteries connected in a matching series-parallel connection, which are supposed to be good for 5-7 years. Hopefully we have cheaper Lithium batteries or some other great option when it is time to replace them.

To help the batteries to keep healthy I am using an equalizer to balance the battery load depending on its current state and a battery pulser desulfator to extend the lifetime.

On top of this I have a DC switch (40 A) for the panels, a DC fuse for the batteries (100 A), 16 A AC switch and a Residual current circuit breaker (30 mA) in case some connected AC device (or human) misbehaves.

In theory this system should be able to deliver up to 6 kWh per day but what I have seen during the short time I have had it connected is more like 3 kWh per day. Since a kilowatt hour costs 15.8 rappen on average (considering the “hoch- and niedertarif” hours and rates) I would not consider my setup very cost effective. In about 26 years we should have the costs back (assuming my time is free…) but the batteries won’t last that long.

Financially I think we will have to let the “backup feature” bear some of the costs, redundancy and safety comes at a cost, but I have to admit that the driver for this project was not money but rather the fun of producing ones own electricity…

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Fixing the freezer remote

Posted on August 13, 2019 by jonas

I got a Dometic CFX 35W which boasts about a convenient wifi interface. The description was not a lie, it does indeed have a wireless network connection, just not implemented the way I would have preferred it. When reading about it, it is not clear exactly how that wifi connection works and I have to admit I was a bit disappointed when I unpacked and noticed that it exposes its own access point instead of the possibility to connect to an existing wireless network. If it would have been able to connect it to existing infrastructure it could have exposed itself for remote control over Internet.

Since it is not possible to connect to an existing internet connected network, it is obviously tricky to control the freezer over Internet out of the box. You are supposed to connect to the freezer’s own network via your mobile phone, so you and your mobile phone has to be physically close to the freezer and in addition loosing the Internet connection (since the phone is connected to a wifi network without Internet access) and on top of that only one client is allowed to connect at a time. I can imagine a use case when this makes sense but in general it is quite useless compared to be able to manage the freezer from anywhere over Internet. Imagine for example where you have the freezer off but you want to cool down some drinks an hour before coming home from work.

So, what to do…? Since the hardware is there and seemingly well working, the case is obviously not lost. Time to apply some basic hacking. Since I plan to typically have the freezer in the vicinity of the house, it will be within reach for my Raspberry Pi acting as server which anyway always is on. It uses the Ethernet interface for network connectivity and the wireless network interface was idle. By connecting it to the freezer’s network we have the network communication established.

The remaining part would be to make it speak the freezer’s protocol and to be able to control it over the web. Since the Android client is easily downloadable (the apk file that is) and not obfuscated, the protocol is basically open. With some basic understanding of Java, anyone is able to decompile and turn the Android app to a plain Java console app. I added a few command-line arguments for the things I wanted to control, like switching the freezer on/off and settings a certain temperature. On top of that I created a simple web page (PHP to the rescue) exposing that capability over the web so I don’t have to SSH onto the server.

Simple web UI for controlling the Dometic CFX 35W remotely.
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Hong Kong Trail

Posted on September 16, 2017 by jonas

I have spent the last week in Hong Kong and have had the opportunity to spend some of it on Hong Kong Trail.

In brief, it is a 50 km foot path through the five country parks on Hong Kong island. It is divided into 8 sections and is fairly well marked and documented. The trail has its finish at the beach Big Wave Bay, not too far from our hotel so it was pretty convenient to be able to walk to it and start walking backwards. On Tuesday I walked over there and did section 8-5 and the following day I did the first four sections which made me end up at the starting point of the trail, Victoria Peak.

After a more normal tourist day with Tanya and her class mates and monkeys on Kowloon on Thursday, my legs and feet were fit for fight. On Friday, i.e. yesterday, I decided to try to do the whole trail in one day. 50 km is obviously not a long distance for one day but the elevation profile is almost “Swiss style”. I would not say that it is demanding but the heat and humidity adds an exotic touch and the main issue is to avoid getting some blisters or sprain that prevents you from continuing without severe pain.

I had my watch tracking my steps and on the “race day” I reached 74974 steps (61.51 km) which is a new record and which can be compared to last year’s 66560 steps when I ran Adliswil-Zug back and forth.

I was on the trail from 10:40 to 19:10 so that’s 8 hours and 30 minutes. The official conservative estimates says the whole trail takes 15 hours but that is probably more for elderly and picnic excursions.

I walked most of the distance and I only did some slow pace running on flat stretches like section 7 in order to not risk anything. I brought fresh water but refilled with “mountain water” at two places. Halfway through the distance I had a Corny Big 50 gram peanut bar (240 kcal).

For those that think it sounds easy peasy, maybe Hong Kong 4in4 Challenge could be something? At least day 4 and The MacLehose Trail sounds like a challenge.

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July wrap up

Posted on August 8, 2016 by jonas

I did not sum up the “get in shape” exercise when it reached its official end on 1st of July so I better do it now meanwhile I still remember…

The target was to reach 70 kg by first of July without loosing too much muscle tissue and I reached that by cutting back on the carbs in the end of June. The scales showed 68.7 kg but in fairness a part of that was due to the depletion of the glycogen depots (and more significantly the water that it binds) in muscles and liver that happens when you cut back on carbs. Anyway, I considered the target as reached and moved on to a more relaxed diet to compensate for a somewhat ascetic lifestyle.

What is more interesting in the long run is of course if the weight jumped back severely afterwards. Naturally some weight was added when the carbs were re-introduced and now, 5 weeks after, the weight is at around 72 kg. If one looks at the weight from the beginning of the exercise in February, it means a loss of 10 kg of which it should be mostly fat since I did not get weaker in the major lifts. I aim to keep running and biking during the autumn, knowing that I won’t have as much time as I have had lately, and then it should be possible to stay around 70 kg going forward. That seems to be a healthy weight and if I could switch a few kilos of fat to muscles, that would be great.

Talking of running, yesterday I did a trip to Zug which ended up being 59 km. The weather was perfect and it felt great. I had to walk a bit in the end but in general it worked out well. The pace was nothing to brag about, 5:59 per km, but the goal was to make it home and the time was not of significance. My smart watch reported a new record regarding the number of steps, 66560 and 68 km in total for the day which included some walking in Uster with Andrzej in the evening. I think it will take some time until I beat that record.

Lately I have also re-discovered my Cyclo-cross bicycle. I bought it five years ago but have not used it much. It is great fun though and I have perfect tracks along the river so I look forward to more of that in the future. I probably also need a bike for the road as well but I think that has to wait until I have a bigger garage…

Since I wrote last time I have been to Malta for a week. I was combining work, holiday and a bubb.la meetup. I enjoyed the reliable weather, 30 degrees Celsius every day, and got to swim a bit in the Mediterranean sea. Malta is indeed a very interesting place and the living costs are indeed attractive compared to Zurich. I did a lot of “sightseeing by running” and stayed in a room in Sliema which I rented via airbnb. My host had his peculiarities but it worked out reasonably well. Especially taken into account the modest fee I paid.

Before Malta I also spent a week in Wroclaw, where I always have a great time. Obviously it was a lot of work during the days but I also had a chance to meet with the guys in a more relaxed environment during the evenings. Except for Lufthansa letting me down and stranding me in Frankfurt for a night on the way to Poland, it all worked out fine.

On a final note, I should also mention a great weekend with Rasmus and Veronica in mid-July. Among other things, we went for a very nice hike at Fürenalp in the vicinity of Engelberg.

Now I have one final work week in front of me before the trip to Siberia. (Thieves don’t need to worry, I have a guy staying in the apartment meanwhile who can take care of them.)

Posted in bil, båt, tåg och flyg, cykel, hälsa, löpning, motion, resor, semester, sport, utflykter | Leave a comment

June milestone

Posted on June 1, 2016 by jonas

The final milestone before the final target was reached this morning. The target was 72 kg and I ended up with 70.7 kg this morning since I did not want to take any chances and fail by 0.1 kg or so 🙂

The idea was to get rid of fat, not muscle tissue, and that seems to have succeeded. The weight loss so far is about 11 kg and it seems to be mostly fat if I should believe the scales and the dead lift results.

The strategy in May was very basic, i.e. trying to get as many days as possible with a negative calorie balance by getting the cardio done in the morning (usually on a crosstrainer) and the resistance training during lunch meanwhile eating as before. The resistance training was a basic half-split with either upper or lower body exercises. I tried to do at least one of the major basic exercises (in my case; dead lifts, squats, bench press, military press) on a daily basis.

May was a month with a quite a lot of cheating with too many tempting hotel breakfasts and restaurant visits in Barcelona and Venice. Anyway, some progress was made and the body definitely got some days of extensive energy input as well which potentially could have helped to keep the BMR reasonable. The strategy regarding the food is also simple in theory, go high on protein and low on carbs and don’t over eat too often. Research is pretty clear that it is easier that way, especially when it comes to keeping the weight under control in the long term, due to a number of factors.

June will hopefully be a month with some further moderate progress. Nothing radical, just some slow steady steps towards the previously defined target of 70 kg.

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May milestone

Posted on May 2, 2016 by jonas

I did study the scales with some interest on Sunday morning to see if I had met the target of the 1st-of-May-milestone. To improve my chances and have some margins, I did not eat an awful lot the day before.

The goal was to weigh less than 74 kg and the scales did show 72.5 kg so I can tick that one off.

The milestone for 1st of June is still 72 kg. I am aware that the weight is currently varying between 72.5 and 74 kg so getting it stabilized below 72 is still a valid target for the next milestone and it would put me in a good position for the 1st of July final.

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Milestone 1 and 2

Posted on April 5, 2016 by jonas

The first milestone is now in the past and the scales did show 76.3 kg on 1st of April which is 5.6 kg less since the start 6 weeks ago. Next milestone is 1st of May and I have approximately 6 kg and 3 months left until the target, i.e. 70 kg on 1st of July. That means 2 kg per month if I aim for “linear progression”. To make it easy I’ll go for that and aim for 74 kg on 1st of May. I can see a challenge on the horizon since I have a visit to Barcelona planned for the second half of April…

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One month later – reality check

Posted on March 20, 2016 by jonas

It is about a month after announcing the get-in-shape challenge and it is time to check the progress. I am approaching the first milestone which is in 10 days and the plan says I should be at 77 kg by then. The scales did show 78.4 this morning so with a good finish it should be possible. If we would trust the scales, which one could of course argue against but this is not a scientific study by any means, I would be minus 3.5 kilos of fat since a month back. It’s alright, not great and not bad.

The past week had its own set of challenges and temptations since I spent it on a business trip with hotel breakfasts and daily social dinners in restaurants. Fortunately I did not get totally carried away and seems to have neither gained or lost any weight in Poland. I did squeeze in one or two exercise sessions per day so I guess that helped.

Well, that’s enough as a status check for now. I’ll write again after the upcoming milestone to keep up the motivational pressure.

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Get in shape challenge

Posted on February 18, 2016 by jonas

After a long break, the blog is resurrected and returns with a classic “get-in-shape-saga”. Facebook is clearly not the right forum for that, so the blog will do in order to up the ante and add some peer pressure.
 
I have to admit that since the move to Switzerland, my physical shape has degraded substantially and some people need to hit the bottom in order to get one’s act together. Some clothes don’t fit at all or much worse than before and this got to stop before overweight turns obese. Now is the time.
 
Tanya is on-board with her set of goals but here I will focus on my own targets and (hopefully) achievements.
 
To help to achieve ambitious goals we don’t only need a stoic mindset – technology to the rescue! In this spirit we have therefore invested 50 hard earned francs in scales worthy of the 20th century, i.e. with Bluetooth and apps.
 
After the initial set up of the new technological wonder, the scales are able to understand if it is Tanya or myself who is staring at the display and the scales present all measurement values (BMI, body fat percentage, and – wait and behold – the weight), on her or my mobile together with graphs and indicators.
 
It should be noted that the method used by these cheap scales to measure fat, water and muscles, bioelectrical impedance analysis, is not always 100% accurate but if measured in the same way at the same point in time of the day with the same device, the figures can be used to observe trends.
 
So, now to the hard figures… I start off at an not so impressing 81.9 heavy kilograms which is way too many taken into account my 175 centimeters and my current body fat and muscle percentages. Just the weight alone would of course not say much since in theory I could have much more muscles and much less fat than what is the actual case (and muscles obviously weigh more than fat).
 
To have a simple goal which is “easy” to work towards, I have stipulated that on 1st of July (this year, I am closing down that loophole…) the weight is no more than 70 kg and the muscle percentage (41.3) not lower than today. That should protect against the sloppy solution of just getting rid of muscles and preserving the hefty body fat level of 20.5.
 
So, what is the strategy? It is possible to theorize about energy balance, calorie deficit, the thermic effect of carbs vs protein and so on but it can also be put quite simple: eat well and do more work-out. “Eat well” in this case means for me to skip the sugar (and other food with excessive GI load) and up the protein on the expense of carbs. When it comes to the training, I aim for more and heavier power training and some cardio to be able to eat enough to keep the protein synthesis level reasonable. The lunch gym sessions that I already do needs to be more serious and be allowed to get longer. It goes without saying that alcohol will be kept to a minimum.
 
The almost 20 weeks are split in three blocks. The first block, which started yesterday is about shocking the body and making some progress which is good for motivation. There will be a noticeable calorie deficit and by 1st of April  we have the first milestone, the scales should show no more than 77 kg. The would mean almost 5 kg in 5 weeks which is challenging but realistic.
 
It is not possible to keep a hefty calorie deficit for long, the body adapts and lowers the basic metabolic rate and it might start to use muscle tissue as an energy source. In the second block I will keep only moderate calorie deficit and increase the workout intensity. Heavy load is the only way to show the body it needs to keep, and add, muscles meanwhile continuing to loose body fat due to still being on a calorie deficit. I expect a weight around 75 kg on 15th of May.
 
In the third phase it is time to get in shape for the grand finale which means back to fewer calories again and sufficient training to reach 70 kg on 1st of July.
 
Sounds easy. I hope I will have good news to report along the way instead of some miserable excuses.

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Fishing expedition

Posted on August 26, 2015 by jonas

Sasha and I joined a few guys and went for a three day trip to a remote location far from cellular network and electronic grid along river Terensug which joins with river Tom which flows through Novokuznetsk in south-west Siberia.

To get there we took a taxi to Mezhdurechensk on Friday morning, then a train to Balyksu and from there jeep and Russian 4×4 all-road (off road) military truck (GAZ-66) to the end of the “road”. The road was not suitable for normal cars since it crossed multiple small rivers without bridges and sometimes was more terrain than actual road. Since we sat on the truck bed we clearly noticed where and how we were going. To go by car to Balyksu is also a challenge for normal cars and the train is preferable.

The next day we went up early and walked a few kilometers to some spots along the river which were suitable for fishing Thymallus. Unfortunately we did not have much luck and our small company (Andryosha, Sasha and I) only got two during the whole day. Anyway, it was a great place and I got a chance to improve my fishing technique. The weather was perfect, at least in general (maybe not in terms of the fish catching suitability), but the water was cold so it was good to have warm socks under the waders. In the evening it was obviously time for banya and dinner. The place, owned by one of the guys, offered simplistic facilities but everything that was needed (including 57 bee houses) was in place.

On Sunday we went back to civilization the same way and also transported about one hundred kilograms of honey from the honey factory in the forest to Mezhdurechensk.

All in all a memorable experience which gives some more understanding of the background of the movie Peculiarities of the National Fishing.

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