I blog about anything heat-pump-related, in particular about our system. In addition, I am interested in thermodynamics, heat pumps and heating systems in general - and their integration with the smart grid and related security concerns. These are my postings about our 'ice-storage-/solar-' powered system specifically and postings on closely related subjects like the power grid, renewable energy and sustainable living.
My lecture slides on PKI and security are a bit dated already, I add them for completeness though.
Articles on my blog are targeted to a broader audience - perhaps they are too 'philosophical' for security experts. See the complete list of postings below, after the image.
- Between 2007 and 2010 I gave a lecture called Authentication, Authorization and PKIs in a master's degree programme at University of Applied Sciences FH Joanneum, then called Advanced Security Engineering (ASE).
- Public Key Infrastructures - Vision, Trends and Real-World Implementation - talk I gave in April 2007 at the opening event of that degree program.
- German lecture Verschlüsselungs- und Signaturtechnologien - von den theoretischen Grundlagen bis zur praktischen Umsetzung, given 2006 at ditact, on IT summer school for female students.
- German talk at .NET Conference in Vienna 2002 - PKI Implementierung. Effectively introducing new features of the Windows 2003 PKI.
This is my list of Links to white papers and the like that I have found useful (restarted 2014). It is not an attempt to create a balanced or educational list. I am adding what I need right now!
Comprehensive reviews of PKI issues
Analysis by Peter Gutmann who likes to throw rocks at PKI according to his bio:
- Everything you Never Wanted to Know about PKI but were Forced to Find Out
- Book Draft, see chapter on PKI: Engineering Security
- X.509 Certificates - part of the crypto tutorial.
- The legendary X.509 Style Guide
- PKI: Lemon Markets and Lemonade: Incl. many examples of certificates invalid in different respects but yet recognized by PKI applications.
Request for Comments:
- RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile. Including an algorithm for X.509 certification path validation.
- RFC 4158: Internet X.509 Public Key Infrastructure: Certification Path Building. In an alternate universe in which Richard Feynman had become a computer scientist, he would have written such RFCs instead of inventing his Feynman diagrams.
- Strict RFC compliance re validation of Certificate Policies OIDs enforced in Windows 2008 R2.
In Windows systems:
- Certificate Revocation Checking in Windows Vista and Windows Server 2008 - interesting: pre-fetching or CRLs and support for OCSP signing certificates signed by another CA.
- Troubleshooting Certificate Status and Revocation: explaining in detail how Windows clients build certificate chains, such as matching names based on a binary comparison or doing a name match only when AKI is not populated - which does not match my experience for Windows 2008 - I seen it agressively doing name matching despite non-matching AKI/SKI and this resulting in a alleged 'corrupt signatures'. But don't take my word on this - I might habe messed something up on testing. Anyway, this paper also demonstrates how awfully complicated it is to check certificate paths. Windows 2000 and XP did it differently (see at the middle of the document) - so this has probably changed again.
- Troubleshooting PKI Problems on Windows Vista
- How Certificate Revocation Works
- Windows XP: Certificate Status and Revocation Checking
Cross-certification and hierachies
- Planning and Implementing Cross-Certification and Qualified Subordination Using Windows Server 2003: On cross-certificates and constraints.
- Microsoft's own showcase. They went from a 3-tier internal PKI to a simple 2-tier infrastructure.
Cross-certification of inhouse CAs by Verizon (former
Cybertrust), solution name formerly known as 'Omniroot'.
This case study still shows this name):
More case studies:
Links for Microsoft's autoenrollment are provided in more MS-related sections
- Simple Certificate Enrollment Protocol: The eternal draft (?) of a protocol originally developed by CISCO.
Weird, hacked, forged certificates
- Legendary X.509 certificate by Markku-Juhani Saarinen with: invalid dates, a public key exponent of 1, a huge RSA modulus whose BASE64 version includes a funny message (I found this gem quoted in Peter Gutmann's various PKI slides, e.g. these ones). Validated correctly on Windows systems in 2000 - just tested: as per 2014 it stil does.
- MD5 considered harmful today - Creating a rogue CA certificate: Epic and educational hack, based on a combination of the algorithm's weakness and out-of-the-box thinking / social engineering. A rogue CA cert., hash-colliding with a legitimate cert. issued by a SSL CA that was not very creative in creating serial numbers and validity dates.
- Null Prefix Attacks Against SSL/TLS Certificates by Moxie Marlinspike. How inserting NULL characters into the subject name and adding some domain you own after this character will result in great certificates for phishing purposes.
- Active Directory Certificate Services Step-by-Step Guide
- Best Practices for Implementing a Microsoft Windows Server 2003 Public Key Infrastructure: Old but still good.
- Securing Wireless LANs with Certificate Services: Again old but good. Comparing this to Securing Wireless LANs with PEAP and Passwords shows that PKI is by far the most time-consuming part of the infrastructure
- Active Directory Certificate Services Migration Guide: The CA is migrated by moving key, database, and conifguration over to a machine - which probably runs on a different operating system. The guide is for software-based key stores. With an HSM the migration is essentially the same once the HSM crypto provider has been configured and the HSM connected to the new machine.
- Windows CA Performance Numbers and Evaluating CA Capacity, Performance, and Scalability
Windows PKI: Features and management
After I started compiling my own list, I found this - I will keep picking some of the microsoft.com links and publish them to this page though:
- Windows PKI Documentation Reference and Library: Comprehensive overview of all MS resources related to the Windows CA ('Active Directory Certificate Services').
Some of the features required to run a Microsoft PKI in a larger, corporate environment:
- Windows Server 2012: Certificate Templates and Options - templates are classified in a new way, by the combination of the OSs of CA and certificate subscriber. The schema version is derived from these OS versions and the intended cryptographic providers.
- Note that version 3 templates are not available via the web enrollment (ASP) pages.
- Implementing and Administering Certificate Templates - for CAs <= 2008 R2
- Certificate Enrollment Web Services in Windows Server 2008 R2: This is to solve the issue with (not) allowing clients to use RPC/DCOM for certificate enrollment. These PKI roles allow for HTTPs-based enrollment via a 'proxy' instead. The HTML version of the paper. Starting with Windows 2012 key based renewal is supported - so non-domain joined machines only need to enroll for the intial certifiate manually.
- Active Directory Certificate Services PKI - Key Archival and Management: Storing private keys to the CA database, using split administration.
- Credential Roaming: Using Active Directory for roaming and backing up users's keys and certificates.
- Certificate Autoenrollment in Windows Server 2003: Especially the section on troubleshooting is interesting.
- Online Responder Installation, Configuration, and Troubleshooting Guide: Most interesting is how long response live: They are generated from CRLs and live as long this CRL or the OCSP signing certificate whatever is more short-lived. In addition, the cache time for responses served can be configured. How to make OCSP responders high-available.
- Network Device Enrollment Service - Microsoft's implementation of SCEP, Simple Enrollment Protocol. Starting with Windows Server 2012 R2 a custom policy module can be used with NDES.
- Failover Clustering and Active Directory Certificate Services: Clustering is supported if an HSM is used as a keystore. Then, actually, the HSM should be clustered as well.
- Evaluating CA Capacity, Performance, and Scalability: Performance of the Windows 2003 CA in terms of certificates issued per time and database size. Database performance in terms of creating views is not given.
Windows PKI 2008 R2 versus 2012 R2 and upgrade of hash algorithms
New features in 2012! Note I started added some the detailed articles about specific features - NDES, templates - also to other sections. This section is for overviews covering many new features or cryptograpy / algorithms in particular.
- What's New in Certificate Services in Windows Server 2012
- Windows Server 2012: Certificate Template Versions and Options - probably the change the PKI admin notices first.
New ways to leverage a TPM chip - key attestation by validation of an endorsement key. You could have used a TPM chip as a custom key store for the machine / SYSTEM in earlier versions of Windows (basically like a 'smartcard for machines) in case the vendor of the TPM chip or a vendor of crypto software provided a suitable CSP / CNG provider. Starting with Windows 8.1 as the end-entity's OS the CA (2012 R2) is able to check if the private key had really been stored to a TPM chip.
- Changing public key algorithm of a CA certificate - only the hash algorithm can be changed (for CNG providers), not the provider itself.
Upgrade Certification Authority to SHA256
- after the change of a registry key the CA signs anything with the new
algorithm, including CRLs and its own CA certificate when renewed (Step-by-step-instructions).
Attention - according to my experiences with 2008 R2 the registry value for hash values is case-sensitive. Good: The change of the hash algorithm can be reverted easily. Bad: This is a per-CA settings, so once the algorithm has been changed all certificates and CRLs issued by that CA are signed using the new algorithm.
Certificate and key stores
Windows client-side stores:
- Migrating a Certification Authority Key from a Cryptographic Service Provider (CSP) to a Key Storage Provider (KSP)
- Key Storage and Retrieval: CNG architecture and location of keys in the file system.
- Windows Data Protection: Private key files are encrypted using a master key generated from a user's or machine's SID and password. DPAPI security explains why users don't lose access to their EFS private keys if their passwords are reset by a domain admin.
- The key associated with a self-signed certificate in the computer store is used in the Microsoft implementation of DNSSEC.
- Advanced Certificate Enrollment and Management: White Paper incl. sample commands for the Windows tool certreq and a summary on BASE64 and ASN.1
- BASE64 explained
- The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
- dumpasn1.c: Peter Gutmann's tool for checking ASN.1 encoding of any file.
- DER Encoding of ASN.1 Types - introduction to ASN.1 by Microsoft.
- Syntax of Windows' tool certutil that can (among many other things) show ASN.1 or encode/decode/encode hex files.
Using certificates for authentication
Native Active Directory logon:
- How to use certificates to integrate with the Kerberos protocol: RFC 4556 - Public Key Cryptography for Initial Authentication in Kerberos (PKINIT).
- Certificate Processing Logic, Figure 21 in Windows Vista Smart Card Infrastructure. Essential: String-based mapping of UPN in SAN onto UPN in AD. Secure though because the issuing CA's certificate need to be present in the NTAuth object.
- IIS configuration details of Active Directory Certificate Mapping: Client Certificate Mapping Authentication.
- Security advice by Microsoft - use this feature with caution and don't allow 'PKI admins' to control both a CA and the details of requests: Because user input can be abused by persons with malicious intent, precautions should be taken to mitigate the risks associated with the use of user-defined SANs.
- Specification of the Remote Certificate Mapping Protocol. An example of how the protocol is used in the communication between domain controllers and web servers.
Webserver-based mapping (no directory)
Apple iDevices, SAP, and other non-MS clients
- In contrast to Windows'/AD's native logon via UPN string mapping
SAP uses a 1:1 mapping of binary certificates to users:
Single Sign-on mit SAP (part of a German book, assignment of the certificate is explained on pp.33)
- Apple iPhones, 802.1x authentication against Active Directory using Windows
RADIUS server (NPS)
(promoted to blog post, summary kept here for traceability).
- Properties of the certificate
Subject CN: host/machine.domain.com
Subject Alternative Name machine.domain.com
Certificate Template (Windows Enterprise PKI): Copy the default template Workstation Authentication, Subject Name: Name as submitted with the Request.
- Create the key, request and certificate on a dedicated enrollment machine and export key and certificates as PKCS#12 (PFX) file.
- Create a shadow account in Active Directory
- According to my tests, the creation of an additional name mapping (as recommended here) is not required - SAN-DNS gets mapped onto dnsHostName in AD.
- Properties of the certificate
Network authentication of devices
- Overview: Certificates for different services / protocols, like 802.1x or IPsec
Started in 2014-10. Usual suspects as SMIME, EFS, 802.1x to be added as needed over time. See also the list of Technet Postings and the PKI FAQ.
- DNSSEC: Secure DNS Deployment Guide, Step-by-Step: Demonstrate DNSSEC in a Test Lab.
- Remote Desktop Services: Certificate requirements for RDP.
- Domain Controllers: Certificate requirements when using a third-party CA. These are the same requirements as with an inhouse CA - an external CA chain needs to be manually imported in addition (Trusted Roots, NTAuth).
Useful commands (in the Windows world)
- Some interesting flags for locking down access to a Windows CA. See section on Config_CA_Interface in this Configuration List.
- Windows Certificate Services Tools and Settings: Describing the CA's registry keys.
Emergency processes, for Windows.
- Delete cached CRLs:
certutil -setreg chain\ChainCacheResyncFiletime @now
(Weitere Optionen siehe diesen MS-PKI-Team-Blogeintrag)
- Start a CA even if the revocation check on its own certificate has
failed - set this flag:
certutil –setreg ca\CRLFlags +CRLF_REVCHECK_IGNORE_OFFLINE
- Key Recovery:
- Search for the archived keys of a specific user and create a batach
script (CA admin permissions required)
certutil –getkey domain\username >recovery-username.bat
This script also contains the password of the p12 key file that will be created.
- Run this batch file. This creates a single p12 file including all keys for this user. Pre-requisites: The user executing the script needs to have one Key Recovery Agent's certificates associated with each of the keys to be recovered in his/her store. In addition CA Admin permissions are required and this needs to be an admin cmd session.
- Search for the archived keys of a specific user and create a batach script (CA admin permissions required)
- The batch file does the following for every key found:
certutil -getkey [SerialNumber] [encrypted blob]
certutil -recoverykey [encrypted blob]
A temporary p12 file is created from every blob; then all p12 files are merged using certutil -mergepfx and all temporary files are deleted.
PKI and smart metering
Requirements for a smart meter PKI in Germany:
Sicherheitsinfrastruktur für „smarte“ Versorgungsnetze
An example: Smart Meter mit PKI Sicherheit
Here I maintain a list of physics books, documents, blogs, and lectures I read / watch or that I have put on the (virtual) bedside table.
The collection is not some carefully crafted, balanced list - I am not searching for resources to add them here but I add what is interesting to me as a professional or a dilettante science blogger. I apologize for the mixture of German and English resources, and the structure is always work in progress.
This list had been formerly curated on my blog, on a page called Physics Books on the Bedside Table. I decided to migrate these links over here as in 2014 I had started to curate all my tech / science links on radices.net.
Popular Science Books 'enthusiastic'
- The Particle at the End of the Universe by Sean Carroll
- Knocking On Heaven's Door: How Physics and Scientific Thinking Illuminate our Universe by Lisa Randall
- Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions by Lisa Randall
- The Universe in a Nutshell by Stephen Hawking
Popular Science Books 'critical' (Note: This is not 'Alternative science')
- The Trouble with Physics by Lee Smolin.
- Farewell to Reality: How Fairytale Physics Betrays the Search for Scientific Truth by Jim Baggott. See a review on wavewatching.net here.
History of Science and Biographies of Physicists
- The Strangest Man, a biography of Paul Dirac by Graham Farmelo. See also the review by Peter Coles.
- carnotcycle – the classical blog on thermodynamics, by Peter Mander.
- Physics on the Fringe by Margaret Wertheim. I blogged about his book here.
- Genius: The Life and Science of Richard Feynman by James Gleick.
- Isaac Newton by James Gleick
- Einstein: A Biography by Jürgen Neffe
- Inside The Centre: The Life of J. Robert Oppenheimer by Ray Monk
Quantum Physics, Quantum (Field) Theory
Oersted Medal Lecture 2002: Reforming the Mathematical Language of Physics, as recommended here. Actually, this is about all of physics and how more powerful, concise, and elegant Geometrical Algebra would do away with concepts that just appear tacked on – as there is an underlying hidden structure. It is useful in classical physics but especially to understand the seemingly weird world of the complex wave function.
- Lectures on Quantum Field Theory by David Tong. Videos of his lectures delivered at Perimeter Institute can be found here (different formats available). These lectures were my starting point for (re-)learning QFT having been exposed to mainly condensed-matter-related and non-relativistic quantum statistics and 'second quantization' 20 years ago.
- Quantum Field Theory in a Nutshell, a concise textbook by Anthony Zee. David Tong highly recommends this book, saying tongue-in-cheek: He lies to you all the time, but in a good way. It is not an easy read because the presentation of the material is quite condensed. You have to fill a lot of intermediate steps in derivations. On the other hand this makes it a great book for serious self-study. It shows that Zee is a gifted writer of popular science books as well as his conceptual overviews are spot-on and very helpful for tackling the hard stuff.
- I trust Graham Farmelo on this and put Stephen Weinberg's book on my To-read-list.
- Student Friendly Quantum Fielf Theory by Robert D. Klauber. Klauber describes and writes out details in derivations, avoids all references to so-called trivial, obvious and easy steps, and he refers to his own learning QFT often. The book seems to have been written from the learner's perspective – he often anticipates those typical baffled student's questions and answers them before you dared to ask it. More praise in this post of mine.
- A lecture on Quantum Field Theory in German, by Gerhard Soff. I like these lecture notes because topics are reviewed from different angles (such as: canonical quantization versus path integrals) and the derivations are done in detail for all the different options.
- The Fun is Real. Blog author Warren Huelsnitz definitely meets his goal: to sort through the myths and misconceptions, and the excessive and misleading hype, associated with quantum physics.
- An Island In Theoryspace – an awesome blog by Jaques Pienaar on physics (mainly of the quantum variety) and sometimes also on its interface with philosophy.
Quantum Computing and Quantum Cryptography
The first field that rekindled by excitement for physics in about 2003, having worked in IT already for some years.
- wavewatching.net. A blog written by a physicist and IT consultant who tries to separate fact from VC fiction and to predict what impact quantum computing will have on corporate IT.
- Lecture notes on General Relativity by Sean Carroll plus his No-nonsense summary on GRT.
- Special and General Relativity – a German textbook by N. Dragon that covers it all. Amazing what kind of material is available for free! Using an unsual way to present Special Relativity (German) – I learned from physicspages.com that this is called k calculus.
Thermodynamics and statistical mechanics
Fascinating water, water vapor, and ice
- Mpemba effect from a viewpoint of an experimental physical chemist, the winning paper in this contest.
- Lecture on the 2nd law and thermodynamics – a summary of what has happened since Boltzmann.
- A lecture on Thermodynamics and Statistical Mechanics in German, by Michael Potthoff. I searched for lecture slides rather than notes in order to use them as quick “refresher” on the subject. These slides are excellent because very concise but still complete.
Classics: Basics and fundamentals – books and blogs that cover all of physics
- The Feynman Lectures on Physics. Vol. 1 is available online since September 2013!
- The 6 volumes my former professor in Theoretical Physics has written: Wilhelm Macke, who was Heisenberg's PhD student: Ein Lehrbuch der Theoretischen Physik: Teilchen – Felder – Wellen – Quanten – Thermodynamik und statistische Mechanik – Quanten und Relativität (Basically: Mechanics – electrodynamics – fields – thermodynamics and QFT). I was more than happy to discover that so many second book shops are now selling used books over the internet – and that Prof. Macke's books are still available as they have been out of stock when I was a student.
- The German physics text books I used in high school (last 4 years) by Josef Schreiner. I am still in awe of the way Schreiner was capable of tailoring all of classical and modern physics to high school students – incl. quantum mechanics and relativity at a rather advanced, but still accessible level.
It is very interesting to compare Feynman's and Macke's books – they have been published at about the same time and might serve as good examples for both excellent, but different ways to describe physics from scratch – 'American' versus 'German'.
- A very detailed blog – physicspages.com – Physics Tutorials with lots of examples, introductions and the author's solutions to text book problems.
- Scientific Finger Food: Sebastian Templ achieves his goal – quote from his About page: “I give my best to break it down into simple language. In doing so, I hope that I can serve you some pieces of physics, which I like to think of as being clear to me, in 'delicious and manageable bites' “.
- motionmountain.net: Six volumes on physics, written by a physicist who works as an innovation manager. Probably the most professional hobby / moonlighting physics project I have come across.
Classical (point particle) mechanics
- The physics of rotation by Cleon Teunissen. Classical mechanics at its best, see for example: Gyroscope Physics.
Tinkering, Science, and (Not) Sharing It
I stumbled upon this research paper called PVC polyhedra: We describe how to construct a dodecahedron, tetrahedron, cube, and octahedron out of pvc pipes using standard fittings. … In particular, if we take a connector that takes three pipes each …
Simulations: Levels of Consciousness
In a recent post I showed these results of simulations for our heat pump system: I focused on the technical details – this post will be more philosophical. What is a ‘simulation’ – opposed to simplified calculations of monthly or …
Heat Transport: What I Wrote So Far.
Don’t worry, The Subversive Elkement will publish the usual silly summer posting soon! Now am just tying up loose ends. In the next months I will keep writing about heat transport: Detailed simulations versus maverick’s rules of thumb, numerical solutions …
Simulating Peak Ice
This year ice in the tank was finally melted between March 5 to March 10 – as ‘visual inspection’ showed. Level sensor Mr. Bubble was confused during the melting phase; thus it was an interesting exercise to compare simulations to …
Mr. Bubble Was Confused. A Cliffhanger.
This year we experienced a record-breaking January in Austria – the coldest since 30 years. Our heat pump system produced 14m3 of ice in the underground tank. The volume of ice is measured by Mr. Bubble, the winner of The …
Where to Find What?
I have confessed on this blog that I have Mr. Monk DVDs for a reason. We like to categorize, tag, painstakingly re-organize, and re-use. This is reflected in our Innovations in Agriculture … … as well as in my periodical …
Ice Storage Hierarchy of Needs
Data Kraken – the tentacled tangled pieces of software for data analysis – has a secret theoretical sibling, an older one: Before we built our heat source from a cellar, I developed numerical simulations of the future heat pump system. …
Earth, Air, Water, and Ice.
In my attempts at Ice Storage Heat Source popularization I have been facing one big challenge: How can you – succinctly, using pictures – answer questions like: How much energy does the collector harvest? or What’s the contribution of ground? …
Frozen Herbs and Latent Energy Storage
… having studied one subject, we immediately have a great deal of direct and precise knowledge … of another. —Richard Feynman Feynman referred to different phenomena that can be described by equations of the same appearance: Learning how to calculate …
My Data Kraken – a Shapeshifter
I wonder if Data Kraken is only used by German speakers who translate our hackneyed Datenkrake – is it a word like eigenvector? Anyway, I need this animal metaphor, despite this post is not about facebook or Google. It’s about …
And Now for Something Completely Different: Rotation Heat Pump!
Heat pumps for space heating are all very similar: Refrigerant evaporates, pressure is increased by a scroll compressor, refrigerant condenses, pressure is reduced in an expansion value. *yawn* The question is: Can a compression heat pump be built in a …
Same Procedure as Every Autumn: New Data for the Heat Pump System
October – time for updating documentation of the heat pump system again! Consolidated data are available in this PDF document. In the last season there were no special experiments – like last year’s Ice Storage Challenge or using the wood …
Re-Visiting Carnot’s Theorem
The proof by contradiction used in physics textbooks is one of those arguments that appear surprising, then self-evident, then deceptive in its simplicity. You – or maybe only: I – cannot resist turning it over and over in your head …
Hacking My Heat Pump – Part 2: Logging Energy Values
In the last post, I showed how to use Raspberry Pi as CAN bus logger – using a test bus connected to control unit UVR1611. Now I have connected it to my heat pump’s bus. Credits for software and instructions: …
Hacking My Heat Pump – Part 1: CAN Bus Testing with UVR1611
In the old times, measuring data manually sometimes meant braving the elements: Now, nearly all measurements are automated: In order to calculate the seasonal performance factor of the heat pump system we have still used the ‘official’ energy reading provided …
Photovoltaic Generator and Heat Pump: Daily Power Generation and Consumption
You can generate electrical power at home but you cannot manufacture your own natural gas, oil, or wood. (I exempt the minority of people owning forestry). This is often an argument for the combination of heat pump and photovoltaic generator. …
Everything as a Service
Three years ago I found a research paper that proposed a combination of distributed computing and heating as a service: A cloud provider company like Google or Amazon would install computers in users’ homes – as black-boxes providing heat to …
I am sure it protects us not only from lightning but also from alien attacks and EMP guns … So I wrote about our lightning protection, installed together with our photovoltaic generator. Now our PV generator is operational for 11 …
No, You Cannot ‘Power Your Home’ by One Hour of Cycling Daily
In the past days different versions of an article had popped up in my social media streams again and again – claiming that you could power your home for 24 hours by cycling for one hour. Regular readers know that …
Temperature Waves and Geothermal Energy
Nearly all of renewable energy exploited today is, in a sense, solar energy. Photovoltaic cells convert solar radiation into electricity, solar thermal collectors heat hot water. Plants need solar power for photosynthesis, for ‘creating biomass’. The motion of water and …
How Does It Work? (The Heat Pump System, That Is)
Over the holidays I stayed away from social media, read quantum physics textbooks instead, and The Chief Engineer and I mulled over the fundamental questions of life, the universe and everything. Such as: How to explain our heat pump system? …
Half a Year of Solar Power and Smart Metering
Our PV generator and new metering setup is now operational for half a year; this is my next wall of figures. For the first time I am combining data from all our loggers (PV inverter, smart meter for consumption, and …
Peter von Rittinger’s Steam Pump (AKA: The First Heat Pump)
Peter von Rittinger’s biography reads like a success story created by a Victorian novelist, and his invention was a text-book example of innovation triggered by scarcity ( Bio DE / EN). Born 1811, he was poor and became an orphan …
The Impact of Ambient Temperature on the Output Power of Solar Panels
I have noticed the impact of traversing clouds on solar power output: Immediately after a cloud has passed, power surges to a record value. This can be attributed to the focusing effect of the surrounding clouds and/or cooling of the …
Economics of the Solar Air Collector
In the previous post I gave an overview of our recently compiled data for the heat pump system. The figure below, showing the seasonal performance factor and daily energy balances, gave rise to an interesting question: In February the solar …
Heat Pump System Data: Three Seasons 2012 – 2015
We have updated the documentation of monthly and seasonal measurement data – now including also the full season September 2014 to August 2015. The overall Seasonal Performance Factor was 4,4 – despite the slightly lower numbers in February and March, …
Having Survived the Hottest July Ever (Thanks, Natural Cooling!)
July 2015 was the hottest July ever since meteorological data had been recorded in Austria (since 248 years). We had more than 38°C ambient air temperature at some days; so finally a chance to stress-test our heat pump system’s cooling …
Solar Energy, Batteries, and Autonomy
This is the third post in my series on our photovoltaic generator. It had been a part of previous post with the data for the first month, but I cut and saved it as the other post was so long …
Solar Power: Some Data for the First Month.
On May 4, 2015, we started up our photovoltaic generator. Here are some numbers and plots for the first month – and what I plan to do next. Our generator has a rated power of 4,77 kWp (kilowatt peak), one …
An Efficiency Greater Than 1?
No, my next project is not building a Perpetuum Mobile. Sometimes I mull upon definitions of performance indicators. It seems straight-forward that the efficiency of a wood log or oil burner is smaller than 1 – if combustion is not …
Two Weeks After Lift-Off
After a little delay our photovoltaic generator went online – we had been waiting for the delivery of this sophisticated addition to our office decoration: People on G+ had very cool suggestions, such as a rotating alien-fighting device throwing darts. …
How to Evaluate a Heat Pump’s Performance?
The straight-forward way is to read off two energy values at the end of a period – day, month, or season: The electrical energy used by the heat pump and the heating energy delivered. The Seasonal Performance Factor (SPF) is …
Ice Storage Challenge: High Score!
Released from ice are brook and river By the quickening glance of the gracious Spring; The colors of hope to the valley cling, And weak old Winter himself must shiver, Withdrawn to the mountains, a crownless king. These are the …
We Have Come a Long Way: Rooftop Solar Power Now!
We had considered it already a few years ago – when we decided to live and work in the middle of a dusty and noisy construction site for a few months: The upper part of the roof is inclined by …
Data Logging with UVR1611 – FAQ
I have received several questions related to my article on data logging on this blog, or to my postings on monitoring and control on our German blog. Thus I have decided to write the article I would have wanted to read …
The Ice Storage Challenge
The more we enjoyed our spring-like winter, the more we were worried if we will ever see much ice in our underground water tank this heating season. So we did what I had announced – we switched off the solar …
“An Unprecedented Test for Europe’s Electricity System”
And we will not be able to contribute – by a hair. We have just ordered our photovoltaic generator, and installation is planned for April. It is the (partial) Solar Eclipse on March 20 that made Europe’s Transmission System Operators …
A Sublime Transition
Don’t expect anything philosophical or career-change-related. I am talking about water and its phase transition to ice because … …the fact that a process so common and important as water freezing is not fully resolved and understood, is astonishing. (Source) …
More Ice? Exploring Spacetime of Climate and Weather.
I have become obsessed with comparing climate data for different regions in the world and in different years (space + time). Finally I have found the tool I was looking for; now I can compare average Ice Days quickly – days …
Personal Risk Assessment
We all do risk management intuitively – when we decide on uploading our data to the cloud where the NSA may spy on us. Or when we install heating systems that depend on electrical energy. The previous post triggered an …
We Want Ice!
We haven’t seen much of it this winter yet. I am talking both about the ice you would expect in winter and about the one created from extracting heat from a water tank – our heat pump system‘s heat source. …
Cistern-Based Heat Pump – Research Done in 1993
One of the most recent search terms on this blog was: ‘cistern for water source heat pump’. I wanted to double-check and searched for this phrase myself. This was the first Google Search result: Cistern-Based Water-Source Heat Pump System Design …
“Being Creative with What Is Available”
This is a quote from Simon Dale’s website who has built several eco-friendly ‘Hobbit’ houses. It reminded me of the cave house built into lava bubbles by Lanzarote’s most famous artist César Manrique: Being creative with what is available has …
Google and Heating Systems (2)
I googled our company name. Then I found this: Auftrag means order and the obfuscated parts contain our full company name, the Chief Engineer’s name, the URL of a vendor we ordered material from recently, invoice total, and a comment …
A 1970s Pioneer in Self-Sufficient Living
Living in southern France, Jean Pain developed a self-sustaining ecosystem in the 1970s that supplied his home with 100% of the energy needed. He built a 50 tons compost mound from chipped wood – brushwood that had to be cleaned out to lower the …
Pumped Heat from the Tunnel
The idea to use a reservoir of water as a heat pump’s heat source is not new. But now and then somebody dares to do it again in a more spectacular way. Provided governmental agencies give you permit, lakes or …
Biology / Chemistry Challenge or: Should We Really Blame the Dead Frog?
We often say we operate in Leonardo da Vinci Renaissance Mode – given our odd ‘portfolio of diverse services’. But as much as the Chief Engineer does not like to work with mortar, cement, or any other slimy substances I …
Big Data, Big Plastic Worms, and How to Utilize Your Cellar
Our heat pump system will soon commence its third heating season. The amount of measurement data collected so far has exceeded the capabilities of the software I had once developed; so I crafted a new application based on a real database server. Now you …
What Learning about Feynman’s Path Integrals Was Good for
I have gone to great lengths on this blog in order to explain how and why a degree in physics prepares you for seemingly different careers, or at least does not hurt. But it would have been so simple. I …
Art from Plastic and Wood
After the musings on Life, the Universe and Everything you deserve a break – and a post with not too much verbiage. I am borrowing some images from a series of posts the Chief Engineer is currently running on our …
Measurement Data for Our Heat Pump System – Finally Translated Documentation
In an earlier post I said Although we have very innovative, and if I may say so, geeky / nerdy customers it is rather unlikely that we will plan heat pump systems in Australia via sending checklists or doing ‘remote …
Lost in Translation – an Overdue Update
In this post I try something new: I will keep it short. This is actually an update long overdue. Months ago I have written a post on how to control the four elements that is how to harvest energy from …
Greatest Innovation Ever
I like Top Something Lists, in particular the hilarious variety. In a more serious state of mind I wondered what a list of the top inventions or top innovations of humankind might comprise. (Nitpickers, I don’t care about distinguishing ‘innovation’ …
Welcome to the Real World!
Warning: This is a disturbing post – despite the allusion to The Matrix in the title it is – really – about the real world only. Hardly any geekiness included. In order to compensate for that I will craft a …
Controlling the Four Elements. Or: Why Heat Pumps Are Cool.
Despite my attempts to post mainly geeky and weird stuff peppered with (very often not down-to-earth) physics, I got involved in some serious discussions on renewable energy, sustainability, heat pumps, and the pleasures of Building Your Own Stuff. So I …
Trading in IT Security for Heat Pumps? Seriously?
Astute analysts of science, technology and the world at large noticed that my resume reads like a character from The Big Bang Theory. After all, an important tag used with this blog is cliché, and I am dead serious about theory and …
The First Heat Pump Ever Was Built in Austria
I have confessed recently that I am from Austria. So the patriot in me wants to entertain her readers with the story of a milestone in the history of engineering thermodynamics – set by an Austrian! The development of the …
Why Do Heat Pumps Pump Energy so Easily?
I know my posts are usually walls of text, but I am trying to improve! In his landmark physics course, the Feynman Lectures on Physics, Richard Feynman tries to explain what an explanation in physics actually is. You can always understand …