First Year of Rooftop Solar Power and Heat Pump: Re-Visiting Economics

After I presented details for selected days, I am going to review overall performance in the first year. From June 2015 to May 2016 ... … we needed 6.600 kWh of electrical energy in total. The heat pump consumed about 3.600 kWh of that ... … in order to 'pump it up to' 16.800 kWh … Continue reading First Year of Rooftop Solar Power and Heat Pump: Re-Visiting Economics

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 heat pump system's monitoring), and I give a summary on our scrutinizing the building's electrical … Continue reading Half a Year of Solar Power and Smart Metering

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 collector was off for research purposes, and the performance factor was just a bit lower … Continue reading Economics of the Solar Air Collector

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, when was the solar collector was off during the Ice Storage Challenge. Edit: I have … Continue reading Heat Pump System Data: Three Seasons 2012 – 2015

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 option. Heating versus cooling mode In space heating 'winter' mode, the heat pump extracts heat … Continue reading Having Survived the Hottest July Ever (Thanks, Natural Cooling!)

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 perfect you will never be able to turn the caloric value into heat, due to … Continue reading An Efficiency Greater Than 1?

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 the ratio of these - the factor the input electrical energy is 'multiplied with' to … Continue reading How to Evaluate a Heat Pump’s Performance?

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 first lines of the English version of a famous German poem on spring, from the … Continue reading Ice Storage Challenge: High Score!

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 30° - which is the optimum angle for photovoltaic panels - whereas the windows in … Continue reading We Have Come a Long Way: Rooftop Solar Power Now!

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 when I once made myself familiar with this. The target audience for this article are … Continue reading Data Logging with UVR1611 – FAQ

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 collector completely: Since February 1st our heat pump has been extracting heat energy from the tank … Continue reading The Ice Storage Challenge

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 with a maximum temperature < 0°C. In the first quarter of 2014 there were: 5 … Continue reading More Ice? Exploring Spacetime of Climate and Weather.

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 interesting discussion about the risk of a power outage. Is it more risky to pick … Continue reading Personal Risk Assessment

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 ... a research paper that had been available for download at the website of Iowa … Continue reading Cistern-Based Heat Pump – Research Done in 1993

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 an appeal beyond economical necessities. As a teenage hobby astronomer I built a mounting for … Continue reading Being Creative with What Is Available

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 like The client said we should... The now inaccessible URL had pointed to a comma-separated … Continue reading Google and Heating Systems (2)

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 underground aquifers could be used. Today a (German) press release about a European research project called Sinfonia … Continue reading Pumped Heat from the Tunnel

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 tried to avoid pondering about the intricacies of living beings and chemicals so far. But … Continue reading Biology / Chemistry Challenge or: Should We Really Blame the Dead Frog?

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 know why I was not very active on social media recently. I have an excuse … Continue reading Big Data, Big Plastic Worms, and How to Utilize Your Cellar

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 German blog. (My job title is Science Officer, but we don't have a Captain). This … Continue reading Art from Plastic and Wood

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 support’ in the same way we work in IT projects. OK - now we really … Continue reading Measurement Data for Our Heat Pump System – Finally Translated Documentation

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 ambient air, solar radiation, the freezing of water, and ground here. A loyal reader told … Continue reading Lost in Translation – an Overdue Update

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 short search term poem - this time exclusively from yesterday's search terms: the universe is … Continue reading Welcome to the Real World!

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 will describe what I am actually working on / playing with when I am not … Continue reading Controlling the Four Elements. Or: Why Heat Pumps Are Cool.

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 practice of combining literally anything. [Edit in 2016: At the time of writing this post, … Continue reading Trading in IT Security for Heat Pumps? Seriously?

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 first heat pump is attributed to Peter von Rittinger [1]. (Note that [1] is by a Swiss author, … Continue reading The First Heat Pump Ever Was Built in Austria

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 "the math" and follow a proof step-by-step. But deep, yet intuitive, understanding becomes harder and … Continue reading Why Do Heat Pumps Pump Energy so Easily?