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 […]Read More First Year of Rooftop Solar Power and Heat Pump: Re-Visiting Economics
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 […]Read More Half a Year of Solar Power and Smart Metering
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 […]Read More Economics of the Solar Air Collector
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 […]Read More Heat Pump System Data: Three Seasons 2012 – 2015
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 […]Read More Having Survived the Hottest July Ever (Thanks, Natural Cooling!)
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 […]Read More An Efficiency Greater Than 1?
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 […]Read More How to Evaluate a Heat Pump’s Performance?