The Solar Self-Building Movement

Every year the International Energy Agency publishes a detailed report on worldwide usage of solar thermal energy. The last one from 2019 is based on data from 2017. Countries are ranked by their installed capacity: Collectors' thermal heating power under standard operating conditions is linked to their area: 0.7 kWth (kilo Watt thermal) per square … Continue reading The Solar Self-Building Movement

Can the Efficiency Be Greater Than One?

This is one of the perennial top search terms for this blog. Anticlimactic answer: Yes, because input and output are determined also by economics, not only by physics. Often readers search for the efficiency of a refrigerator. Its efficiency, the ratio of output and input energies, is greater than 1 because the ambient energy is … Continue reading Can the Efficiency Be Greater Than One?

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. Today this simulation tool comprises e.g. a model of our control system, real-live weather data, … Continue reading Ice Storage Hierarchy of Needs

On Photovoltaic Generators and Scattering Cross Sections

Subtitle: Dimensional Analysis again. Our photovoltaic generator has about 5 kW rated 'peak' power - 18 panels with 265W each. Peak output power is obtained under so-called standard testing condition - 1 kWp (kilo Watt peak) is equivalent to: a panel temperature of 25°C (as efficiency depends on temperature) an incident angle of sunlight relative to … Continue reading On Photovoltaic Generators and Scattering Cross Sections

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

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. Last year I blogged in detail about economics of solar power and batteries and on … Continue reading Photovoltaic Generator and Heat Pump: Daily Power Generation and Consumption

Alien Energy

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 months and we have encountered one alien attack, albeit by beneficial aliens. The Sunny Baseline … Continue reading Alien Energy

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 air is influenced by the forces caused by the earth's rotation, but by temperature gradients … Continue reading Temperature Waves and Geothermal Energy

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